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missing panel/dsi/gpu/mdss in mainlined yoshino device tree #2

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rhjdvsgsgks opened this issue Aug 21, 2022 · 4 comments
Closed

missing panel/dsi/gpu/mdss in mainlined yoshino device tree #2

rhjdvsgsgks opened this issue Aug 21, 2022 · 4 comments

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@rhjdvsgsgks
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sorry for the stupid question.

im trying to run pmos on my maple. but seems like panel/dsi/gpu/mdss part of dt is just disappeared in mainline code. even they already finished (or actually not?) in some branch of this repo, such as 3ae7ae0 . is there any reason that prevented display part of dt merged into upstream (such as they are still WIP)?

i noticed that there is another project on gitlab (https://gitlab.com/msm8998-mainline/linux) trying to run mainline linux on msm8998. and they have some newer commit for yoshino (such as audio) which authored by member of somainline. but i didn't find where these commit came from. are they come from some private repo that include WIP commits? or that's the new place you contribute to?

i tried 5.18.y branch and some other older branch of msm8998-mainline because they are the branch conntains dt of display and have a .config that able to compile without too much edit. but none of them can make the screen/gpu works. /sys/kernel/debug/devices_deferred and dmesg showed there is a dependencies cycle (mdss c900000 -> mnoc 1744000 -> mmcc c8c0000 -> dsi0_phy 994400 -> mmcc c8c0000). i spent few month on figure out how to resolve this. unfortunately, i still didn't figure it out until now. can i get some help here? thanks

konradybcio pushed a commit that referenced this issue Sep 22, 2022
Petr Machata says:

====================
mlxsw: Adjust QOS tests for Spectrum-4 testing

Amit writes:

Quality Of Service tests create congestion and verify the switch behavior.
To create congestion, they need to have more traffic than the port can
handle, so some of them force 1Gbps speed.

The tests assume that 1Gbps speed is supported. Spectrum-4 ASIC will not
support this speed in all ports, so to be able to run QOS tests there,
some adjustments are required.

Patch set overview:
Patch #1 adjusts qos_ets_strict, qos_mc_aware and sch_ets tests.
Patch #2 adjusts RED tests.
Patch #3 extends devlink_lib to support querying maximum pool size.
Patch #4 adds a test which can be used instead of qos_burst and do not
assume that 1Gbps speed is supported.
Patch #5 removes qos_burst test.
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
konradybcio pushed a commit that referenced this issue Sep 22, 2022
…itical-section'

Ido Schimmel says:

====================
ipmr: Always call ip{,6}_mr_forward() from RCU read-side critical section

Patch #1 fixes a bug in ipmr code.

Patch #2 adds corresponding test cases.
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
konradybcio pushed a commit that referenced this issue Sep 22, 2022
…org/drm/drm-intel into drm-next

drm/i915 feature pull #2 for v6.1:

Features and functionality:
- More Meteorlake platform enabling (Radhakrishna, Imre, Madhumitha)
- Allow seamless M/N changes on eDP panels that support it (Ville)
- Switch DSC debugfs from output bpp to input bpc (Swati)

Refactoring and cleanups:
- Clocking and DPLL refactoring and cleanups to support seamless M/N (Ville)
- Plenty of VBT definition and parsing updates and cleanups (Ville)
- Extract SKL watermark code to a separate file, and clean up (Ville)
- Clean up IPC interfaces and debugfs (Jani)
- Continue moving display data under drm_i915_private display sub-struct (Jani)
- Display quirk handling refactoring and abstractions (Jani)
- Stop using implicit dev_priv in gmbus registers (Jani)
- BUG_ON() removals and conversions to drm_WARN_ON() and BUILD_BUG_ON() (Jani)
- Use drm_dp_phy_name() for logging (Jani)
- Use REG_BIT() macros for CDCLK registers (Stan)
- Move display and media IP versions to runtime info (Radhakrishna)

Fixes:
- Fix DP MST suspend to avoid use-after-free (Andrzej)
- Fix HPD suspend to avoid use-after-free for fbdev (Andrzej)
- Fix various PSR issues regarding selective update and damage clips (Jouni)
- Fix runtime pm wakerefs for driver remove and release (Mitul Golani)
- Fix conditions for filtering fixed modes for panels (Ville)
- Fix TV encoder clock computation (Ville)
- Fix dvo mode_valid hook return type (Nathan Huckleberry)

Merges:
- Backmerge drm-next to sync the DP MST atomic changes (Jani)

Signed-off-by: Dave Airlie <[email protected]>

From: Jani Nikula <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
@JamiKettunen
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JamiKettunen commented Oct 7, 2022

@rhjdvsgsgks May you try a current master branch checkout on msm8998-mainline/linux? It's been rebased on top of v6.0 and msm8998_defconfig should include the panel driver and (hopefully) other related things. Let me know how it goes!

konradybcio pushed a commit that referenced this issue Oct 26, 2022
With lockdeps enabled, we get the following warning:

======================================================
WARNING: possible circular locking dependency detected
------------------------------------------------------
kworker/u12:1/53 is trying to acquire lock:
ffff80000adce220 (coresight_mutex){+.+.}-{4:4}, at: coresight_set_assoc_ectdev_mutex+0x3c/0x5c
but task is already holding lock:
ffff80000add1f60 (ect_mutex){+.+.}-{4:4}, at: cti_probe+0x318/0x394

which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:

-> #1 (ect_mutex){+.+.}-{4:4}:
       __mutex_lock_common+0xd8/0xe60
       mutex_lock_nested+0x44/0x50
       cti_add_assoc_to_csdev+0x4c/0x184
       coresight_register+0x2f0/0x314
       tmc_probe+0x33c/0x414

-> #0 (coresight_mutex){+.+.}-{4:4}:
       __lock_acquire+0x1a20/0x32d0
       lock_acquire+0x160/0x308
       __mutex_lock_common+0xd8/0xe60
       mutex_lock_nested+0x44/0x50
       coresight_set_assoc_ectdev_mutex+0x3c/0x5c
       cti_update_conn_xrefs+0x6c/0xf8
       cti_probe+0x33c/0x394

other info that might help us debug this:
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(ect_mutex);
                               lock(coresight_mutex);
                               lock(ect_mutex);
  lock(coresight_mutex);
 *** DEADLOCK ***

4 locks held by kworker/u12:1/53:
 #0: ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1fc/0x63c
 #1: (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x228/0x63c
 #2: (&dev->mutex){....}-{4:4}, at: __device_attach+0x48/0x1a8
 #3: (ect_mutex){+.+.}-{4:4}, at: cti_probe+0x318/0x394

To fix the same, call cti_add_assoc_to_csdev without the holding
coresight_mutex and confine the locking while setting the associated
ect / cti device using coresight_set_assoc_ectdev_mutex().

Fixes: 177af82 ("coresight: cti: Enable CTI associated with devices")
Cc: Mathieu Poirier <[email protected]>
Cc: Suzuki K Poulose <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Leo Yan <[email protected]>
Signed-off-by: Sudeep Holla <[email protected]>
Reviewed-by: Mike Leach <[email protected]>
Signed-off-by: Suzuki K Poulose <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
konradybcio pushed a commit that referenced this issue Oct 26, 2022
…locator'

Hou Tao says:

====================

From: Hou Tao <[email protected]>

Hi,

The patchset aims to fix one problem of bpf memory allocator destruction
when there is PREEMPT_RT kernel or kernel with arch_irq_work_has_interrupt()
being false (e.g. 1-cpu arm32 host or mips). The root cause is that
there may be busy refill_work when the allocator is destroying and it
may incur oops or other problems as shown in patch #1. Patch #1 fixes
the problem by waiting for the completion of irq work during destroying
and patch #2 is just a clean-up patch based on patch #1. Please see
individual patches for more details.

Comments are always welcome.

Change Log:
v2:
  * patch 1: fix typos and add notes about the overhead of irq_work_sync()
  * patch 1 & 2: add Acked-by tags from [email protected]

v1: https://lore.kernel.org/bpf/[email protected]/T/#t
====================

Signed-off-by: Alexei Starovoitov <[email protected]>
konradybcio pushed a commit that referenced this issue Oct 26, 2022
…kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.1, take #2

- Fix a bug preventing restoring an ITS containing mappings
  for very large and very sparse device topology

- Work around a relocation handling error when compiling
  the nVHE object with profile optimisation
konradybcio pushed a commit that referenced this issue Oct 26, 2022
Merge series from Andy Shevchenko <[email protected]>:

Currently the SPI PXA2xx devices on Intel platforms can be instantiated
via the following paths:
 1) as ACPI LPSS device on Haswell, Bay Trail and Cherry Trail;
 2) as ACPI LPSS device on the Sky Lake and newer;
 3) as PCI LPSS device on Haswell, Bay Trail and Cherry Trail;
 4) as PCI LPSS device on the Sky Lake and newer;
 5) as PCI device via ID table.

Each of these cases provides some platform related data differently,
i.e.:
 1) via drivers/acpi/acpi_lpss.c and drivers/spi/spi-pxa2xx.c
 2) via drivers/mfd/intel-lpss-acpi.c
 3) via drivers/spi/spi-pxa2xx-pci.c
 4) via drivers/mfd/intel-lpss-pci.c and drivers/spi/spi-pxa2xx.c
 5) via drivers/spi/spi-pxa2xx-pci.c

This approach has two downsides:

a) there is no data propagated in the case #2 because we can't have
   two or more drivers to match the same ACPI ID and hence some cases
   are still not supported (Sky Lake and newer ACPI enabled LPSS);

b) the data is duplicated over two drivers in the cases #1 & #4 and,
   besides to be a bloatware, it is error prone (e.g. Lakefield has
   a wrong data right now due to missed PCI entry in the spi-pxa2xx.c).

This series fixes the downsides, and enables previously unsupported
cases.
Haxk20 pushed a commit that referenced this issue Nov 14, 2022
esw_attr is only allocated if namespace is fdb.

BUG: KASAN: slab-out-of-bounds in parse_tc_actions+0xdc6/0x10e0 [mlx5_core]
Write of size 4 at addr ffff88815f185b04 by task tc/2135

CPU: 5 PID: 2135 Comm: tc Not tainted 6.1.0-rc2+ #2
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x57/0x7d
 print_report+0x170/0x471
 ? parse_tc_actions+0xdc6/0x10e0 [mlx5_core]
 kasan_report+0xbc/0xf0
 ? parse_tc_actions+0xdc6/0x10e0 [mlx5_core]
 parse_tc_actions+0xdc6/0x10e0 [mlx5_core]

Fixes: 94d6517 ("net/mlx5e: TC, Fix cloned flow attr instance dests are not zeroed")
Signed-off-by: Roi Dayan <[email protected]>
Reviewed-by: Maor Dickman <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
Haxk20 pushed a commit that referenced this issue Nov 14, 2022
…e-during-reload'

Jiri Pirko says:

====================
net: devlink: move netdev notifier block to dest namespace during reload

Patch #1 is just a dependency of patch #2, which is the actual fix.
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Haxk20 pushed a commit that referenced this issue Nov 14, 2022
Resolve forward declarations that don't take part in type graphs
comparisons if declaration name is unambiguous. Example:

CU #1:

struct foo;              // standalone forward declaration
struct foo *some_global;

CU #2:

struct foo { int x; };
struct foo *another_global;

The `struct foo` from CU #1 is not a part of any definition that is
compared against another definition while `btf_dedup_struct_types`
processes structural types. The the BTF after `btf_dedup_struct_types`
the BTF looks as follows:

[1] STRUCT 'foo' size=4 vlen=1 ...
[2] INT 'int' size=4 ...
[3] PTR '(anon)' type_id=1
[4] FWD 'foo' fwd_kind=struct
[5] PTR '(anon)' type_id=4

This commit adds a new pass `btf_dedup_resolve_fwds`, that maps such
forward declarations to structs or unions with identical name in case
if the name is not ambiguous.

The pass is positioned before `btf_dedup_ref_types` so that types
[3] and [5] could be merged as a same type after [1] and [4] are merged.
The final result for the example above looks as follows:

[1] STRUCT 'foo' size=4 vlen=1
	'x' type_id=2 bits_offset=0
[2] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED
[3] PTR '(anon)' type_id=1

For defconfig kernel with BTF enabled this removes 63 forward
declarations. Examples of removed declarations: `pt_regs`, `in6_addr`.
The running time of `btf__dedup` function is increased by about 3%.

Signed-off-by: Eduard Zingerman <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Reviewed-by: Alan Maguire <[email protected]>
Acked-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Haxk20 pushed a commit that referenced this issue Nov 14, 2022
Eduard Zingerman says:

====================

The patch-set is consists of the following parts:
- An update for libbpf's hashmap interface from void* -> void* to a
  polymorphic one, allowing to use both long and void* keys and values
  w/o additional casts. Interface functions are hidden behind
  auxiliary macro that add casts as necessary.

  This simplifies many use cases in libbpf as hashmaps there are
  mostly integer to integer and required awkward looking incantations
  like `(void *)(long)off` previously. Also includes updates for perf
  as it copies map implementation from libbpf.

- A change to `lib/bpf/btf.c:btf__dedup` that adds a new pass named
  "Resolve unambiguous forward declaration". This pass builds a
  hashmap `name_off -> uniquely named struct or union` and uses it to
  replace FWD types by structs or unions. This is necessary for corner
  cases when FWD is not used as a part of some struct or union
  definition de-duplicated by `btf_dedup_struct_types`.

The goal of the patch-set is to resolve forward declarations that
don't take part in type graphs comparisons if declaration name is
unambiguous.

Example:

CU #1:

struct foo;              // standalone forward declaration
struct foo *some_global;

CU #2:

struct foo { int x; };
struct foo *another_global;

Currently the de-duplicated BTF for this example looks as follows:

[1] STRUCT 'foo' size=4 vlen=1 ...
[2] INT 'int' size=4 ...
[3] PTR '(anon)' type_id=1
[4] FWD 'foo' fwd_kind=struct
[5] PTR '(anon)' type_id=4

The goal of this patch-set is to simplify it as follows:

[1] STRUCT 'foo' size=4 vlen=1
	'x' type_id=2 bits_offset=0
[2] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED
[3] PTR '(anon)' type_id=1

For defconfig kernel with BTF enabled this removes 63 forward
declarations.

For allmodconfig kernel with BTF enabled this removes ~5K out of ~21K
forward declarations in ko objects. This unlocks some additional
de-duplication in ko objects, but impact is tiny: ~13K less BTF ids
out of ~2M.

Changelog:
 v3 -> v4
 Changes suggested by Andrii:
 - hashmap interface rework to allow use of integer and pointer keys
   an values w/o casts as suggested in [1].
 v2 -> v3
 Changes suggested by Andrii:
 - perf's util/hashtable.{c,h} are synchronized with libbpf
   implementation, perf's source code updated accordingly;
 - changes to libbpf, bpf selftests and perf are combined in a single
   patch to simplify bisecting;
 - hashtable interface updated to be long -> long instead of
   uintptr_t -> uintptr_t;
 - btf_dedup_resolve_fwds updated to correctly use IS_ERR / PTR_ERR
   macro;
 - test cases for btf_dedup_resolve_fwds are updated for better
   clarity.
 v1 -> v2
 - Style fixes in btf_dedup_resolve_fwd and btf_dedup_resolve_fwds as
   suggested by Alan.

[v1] https://lore.kernel.org/bpf/[email protected]/
[v2] https://lore.kernel.org/bpf/[email protected]/
[v3] https://lore.kernel.org/bpf/[email protected]/

[1] https://lore.kernel.org/bpf/CAEf4BzZ8KFneEJxFAaNCCFPGqp20hSpS2aCj76uRk3-qZUH5xg@mail.gmail.com/
====================

Signed-off-by: Andrii Nakryiko <[email protected]>
Haxk20 pushed a commit that referenced this issue Nov 14, 2022
Yang Yingliang says:

====================
stmmac: dwmac-loongson: fixes three leaks

patch #2 fixes missing pci_disable_device() in the error path in probe()
patch #1 and pach #3 fix missing pci_disable_msi() and of_node_put() in
error and remove() path.
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
Haxk20 pushed a commit that referenced this issue Nov 14, 2022
Syzbot reported the following lockdep splat

======================================================
WARNING: possible circular locking dependency detected
6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Not tainted
------------------------------------------------------
syz-executor307/3029 is trying to acquire lock:
ffff0000c02525d8 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x54/0xb4 mm/memory.c:5576

but task is already holding lock:
ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline]
ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline]
ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (btrfs-root-00){++++}-{3:3}:
       down_read_nested+0x64/0x84 kernel/locking/rwsem.c:1624
       __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline]
       btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline]
       btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279
       btrfs_search_slot_get_root+0x74/0x338 fs/btrfs/ctree.c:1637
       btrfs_search_slot+0x1b0/0xfd8 fs/btrfs/ctree.c:1944
       btrfs_update_root+0x6c/0x5a0 fs/btrfs/root-tree.c:132
       commit_fs_roots+0x1f0/0x33c fs/btrfs/transaction.c:1459
       btrfs_commit_transaction+0x89c/0x12d8 fs/btrfs/transaction.c:2343
       flush_space+0x66c/0x738 fs/btrfs/space-info.c:786
       btrfs_async_reclaim_metadata_space+0x43c/0x4e0 fs/btrfs/space-info.c:1059
       process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
       worker_thread+0x340/0x610 kernel/workqueue.c:2436
       kthread+0x12c/0x158 kernel/kthread.c:376
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

-> #2 (&fs_info->reloc_mutex){+.+.}-{3:3}:
       __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
       btrfs_record_root_in_trans fs/btrfs/transaction.c:516 [inline]
       start_transaction+0x248/0x944 fs/btrfs/transaction.c:752
       btrfs_start_transaction+0x34/0x44 fs/btrfs/transaction.c:781
       btrfs_create_common+0xf0/0x1b4 fs/btrfs/inode.c:6651
       btrfs_create+0x8c/0xb0 fs/btrfs/inode.c:6697
       lookup_open fs/namei.c:3413 [inline]
       open_last_lookups fs/namei.c:3481 [inline]
       path_openat+0x804/0x11c4 fs/namei.c:3688
       do_filp_open+0xdc/0x1b8 fs/namei.c:3718
       do_sys_openat2+0xb8/0x22c fs/open.c:1313
       do_sys_open fs/open.c:1329 [inline]
       __do_sys_openat fs/open.c:1345 [inline]
       __se_sys_openat fs/open.c:1340 [inline]
       __arm64_sys_openat+0xb0/0xe0 fs/open.c:1340
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
       el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #1 (sb_internal#2){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1826 [inline]
       sb_start_intwrite include/linux/fs.h:1948 [inline]
       start_transaction+0x360/0x944 fs/btrfs/transaction.c:683
       btrfs_join_transaction+0x30/0x40 fs/btrfs/transaction.c:795
       btrfs_dirty_inode+0x50/0x140 fs/btrfs/inode.c:6103
       btrfs_update_time+0x1c0/0x1e8 fs/btrfs/inode.c:6145
       inode_update_time fs/inode.c:1872 [inline]
       touch_atime+0x1f0/0x4a8 fs/inode.c:1945
       file_accessed include/linux/fs.h:2516 [inline]
       btrfs_file_mmap+0x50/0x88 fs/btrfs/file.c:2407
       call_mmap include/linux/fs.h:2192 [inline]
       mmap_region+0x7fc/0xc14 mm/mmap.c:1752
       do_mmap+0x644/0x97c mm/mmap.c:1540
       vm_mmap_pgoff+0xe8/0x1d0 mm/util.c:552
       ksys_mmap_pgoff+0x1cc/0x278 mm/mmap.c:1586
       __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline]
       __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline]
       __arm64_sys_mmap+0x58/0x6c arch/arm64/kernel/sys.c:21
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
       el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #0 (&mm->mmap_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3095 [inline]
       check_prevs_add kernel/locking/lockdep.c:3214 [inline]
       validate_chain kernel/locking/lockdep.c:3829 [inline]
       __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053
       lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666
       __might_fault+0x7c/0xb4 mm/memory.c:5577
       _copy_to_user include/linux/uaccess.h:134 [inline]
       copy_to_user include/linux/uaccess.h:160 [inline]
       btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203
       btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl fs/ioctl.c:856 [inline]
       __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
       el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

other info that might help us debug this:

Chain exists of:
  &mm->mmap_lock --> &fs_info->reloc_mutex --> btrfs-root-00

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(btrfs-root-00);
                               lock(&fs_info->reloc_mutex);
                               lock(btrfs-root-00);
  lock(&mm->mmap_lock);

 *** DEADLOCK ***

1 lock held by syz-executor307/3029:
 #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline]
 #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline]
 #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279

stack backtrace:
CPU: 0 PID: 3029 Comm: syz-executor307 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156
 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2053
 check_noncircular+0x14c/0x154 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3095 [inline]
 check_prevs_add kernel/locking/lockdep.c:3214 [inline]
 validate_chain kernel/locking/lockdep.c:3829 [inline]
 __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053
 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666
 __might_fault+0x7c/0xb4 mm/memory.c:5577
 _copy_to_user include/linux/uaccess.h:134 [inline]
 copy_to_user include/linux/uaccess.h:160 [inline]
 btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203
 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
 el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

We do generally the right thing here, copying the references into a
temporary buffer, however we are still holding the path when we do
copy_to_user from the temporary buffer.  Fix this by freeing the path
before we copy to user space.

Reported-by: [email protected]
CC: [email protected] # 4.19+
Reviewed-by: Anand Jain <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Haxk20 pushed a commit that referenced this issue Nov 14, 2022
Syzbot reported the following lockdep splat

======================================================
WARNING: possible circular locking dependency detected
6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Not tainted
------------------------------------------------------
syz-executor307/3029 is trying to acquire lock:
ffff0000c02525d8 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x54/0xb4 mm/memory.c:5576

but task is already holding lock:
ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline]
ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline]
ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (btrfs-root-00){++++}-{3:3}:
       down_read_nested+0x64/0x84 kernel/locking/rwsem.c:1624
       __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline]
       btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline]
       btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279
       btrfs_search_slot_get_root+0x74/0x338 fs/btrfs/ctree.c:1637
       btrfs_search_slot+0x1b0/0xfd8 fs/btrfs/ctree.c:1944
       btrfs_update_root+0x6c/0x5a0 fs/btrfs/root-tree.c:132
       commit_fs_roots+0x1f0/0x33c fs/btrfs/transaction.c:1459
       btrfs_commit_transaction+0x89c/0x12d8 fs/btrfs/transaction.c:2343
       flush_space+0x66c/0x738 fs/btrfs/space-info.c:786
       btrfs_async_reclaim_metadata_space+0x43c/0x4e0 fs/btrfs/space-info.c:1059
       process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
       worker_thread+0x340/0x610 kernel/workqueue.c:2436
       kthread+0x12c/0x158 kernel/kthread.c:376
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

-> #2 (&fs_info->reloc_mutex){+.+.}-{3:3}:
       __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
       btrfs_record_root_in_trans fs/btrfs/transaction.c:516 [inline]
       start_transaction+0x248/0x944 fs/btrfs/transaction.c:752
       btrfs_start_transaction+0x34/0x44 fs/btrfs/transaction.c:781
       btrfs_create_common+0xf0/0x1b4 fs/btrfs/inode.c:6651
       btrfs_create+0x8c/0xb0 fs/btrfs/inode.c:6697
       lookup_open fs/namei.c:3413 [inline]
       open_last_lookups fs/namei.c:3481 [inline]
       path_openat+0x804/0x11c4 fs/namei.c:3688
       do_filp_open+0xdc/0x1b8 fs/namei.c:3718
       do_sys_openat2+0xb8/0x22c fs/open.c:1313
       do_sys_open fs/open.c:1329 [inline]
       __do_sys_openat fs/open.c:1345 [inline]
       __se_sys_openat fs/open.c:1340 [inline]
       __arm64_sys_openat+0xb0/0xe0 fs/open.c:1340
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
       el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #1 (sb_internal#2){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1826 [inline]
       sb_start_intwrite include/linux/fs.h:1948 [inline]
       start_transaction+0x360/0x944 fs/btrfs/transaction.c:683
       btrfs_join_transaction+0x30/0x40 fs/btrfs/transaction.c:795
       btrfs_dirty_inode+0x50/0x140 fs/btrfs/inode.c:6103
       btrfs_update_time+0x1c0/0x1e8 fs/btrfs/inode.c:6145
       inode_update_time fs/inode.c:1872 [inline]
       touch_atime+0x1f0/0x4a8 fs/inode.c:1945
       file_accessed include/linux/fs.h:2516 [inline]
       btrfs_file_mmap+0x50/0x88 fs/btrfs/file.c:2407
       call_mmap include/linux/fs.h:2192 [inline]
       mmap_region+0x7fc/0xc14 mm/mmap.c:1752
       do_mmap+0x644/0x97c mm/mmap.c:1540
       vm_mmap_pgoff+0xe8/0x1d0 mm/util.c:552
       ksys_mmap_pgoff+0x1cc/0x278 mm/mmap.c:1586
       __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline]
       __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline]
       __arm64_sys_mmap+0x58/0x6c arch/arm64/kernel/sys.c:21
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
       el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #0 (&mm->mmap_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3095 [inline]
       check_prevs_add kernel/locking/lockdep.c:3214 [inline]
       validate_chain kernel/locking/lockdep.c:3829 [inline]
       __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053
       lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666
       __might_fault+0x7c/0xb4 mm/memory.c:5577
       _copy_to_user include/linux/uaccess.h:134 [inline]
       copy_to_user include/linux/uaccess.h:160 [inline]
       btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203
       btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl fs/ioctl.c:856 [inline]
       __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
       el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

other info that might help us debug this:

Chain exists of:
  &mm->mmap_lock --> &fs_info->reloc_mutex --> btrfs-root-00

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(btrfs-root-00);
                               lock(&fs_info->reloc_mutex);
                               lock(btrfs-root-00);
  lock(&mm->mmap_lock);

 *** DEADLOCK ***

1 lock held by syz-executor307/3029:
 #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline]
 #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline]
 #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279

stack backtrace:
CPU: 0 PID: 3029 Comm: syz-executor307 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156
 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2053
 check_noncircular+0x14c/0x154 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3095 [inline]
 check_prevs_add kernel/locking/lockdep.c:3214 [inline]
 validate_chain kernel/locking/lockdep.c:3829 [inline]
 __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053
 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666
 __might_fault+0x7c/0xb4 mm/memory.c:5577
 _copy_to_user include/linux/uaccess.h:134 [inline]
 copy_to_user include/linux/uaccess.h:160 [inline]
 btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203
 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
 el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

We do generally the right thing here, copying the references into a
temporary buffer, however we are still holding the path when we do
copy_to_user from the temporary buffer.  Fix this by freeing the path
before we copy to user space.

Reported-by: [email protected]
CC: [email protected] # 4.19+
Reviewed-by: Anand Jain <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
MarijnS95 pushed a commit that referenced this issue Nov 15, 2022
CQE compression feature improves performance by reducing PCI bandwidth
bottleneck on CQEs write.
Enhanced CQE compression introduced in ConnectX-6 and it aims to reduce
CPU utilization of SW side packets decompression by eliminating the
need to rewrite ownership bit, which is likely to cost a cache-miss, is
replaced by validity byte handled solely by HW.
Another advantage of the enhanced feature is that session packets are
available to SW as soon as a single CQE slot is filled, instead of
waiting for session to close, this improves packet latency from NIC to
host.

Performance:
Following are tested scenarios and reults comparing basic and enahnced
CQE compression.

setup: IXIA 100GbE connected directly to port 0 and port 1 of
ConnectX-6 Dx 100GbE dual port.

Case #1 RX only, single flow goes to single queue:
IRQ rate reduced by ~ 30%, CPU utilization improved by 2%.

Case #2 IP forwarding from port 1 to port 0 single flow goes to
single queue:
Avg latency improved from 60us to 21us, frame loss improved from 0.5% to 0.0%.

Case #3 IP forwarding from port 1 to port 0 Max Throughput IXIA sends
100%, 8192 UDP flows, goes to 24 queues:
Enhanced is equal or slightly better than basic.

Testing the basic compression feature with this patch shows there is
no perfrormance degradation of the basic compression feature.

Signed-off-by: Ofer Levi <[email protected]>
Reviewed-by: Tariq Toukan <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
MarijnS95 pushed a commit that referenced this issue Nov 15, 2022
Patch series "rapidio: fix three possible memory leaks".

This patchset fixes three name leaks in error handling.
 - patch #1 fixes two name leaks while rio_add_device() fails.
 - patch #2 fixes a name leak while  rio_register_mport() fails.


This patch (of 2):

If rio_add_device() returns error, the name allocated by dev_set_name()
need be freed.  It should use put_device() to give up the reference in the
error path, so that the name can be freed in kobject_cleanup(), and the
'rdev' can be freed in rio_release_dev().

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: e8de370 ("rapidio: add mport char device driver")
Fixes: 1fa5ae8 ("driver core: get rid of struct device's bus_id string array")
Signed-off-by: Yang Yingliang <[email protected]>
Cc: Alexandre Bounine <[email protected]>
Cc: Matt Porter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
konradybcio pushed a commit that referenced this issue Nov 18, 2022
Syzbot reported the following lockdep splat

======================================================
WARNING: possible circular locking dependency detected
6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Not tainted
------------------------------------------------------
syz-executor307/3029 is trying to acquire lock:
ffff0000c02525d8 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x54/0xb4 mm/memory.c:5576

but task is already holding lock:
ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline]
ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline]
ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (btrfs-root-00){++++}-{3:3}:
       down_read_nested+0x64/0x84 kernel/locking/rwsem.c:1624
       __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline]
       btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline]
       btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279
       btrfs_search_slot_get_root+0x74/0x338 fs/btrfs/ctree.c:1637
       btrfs_search_slot+0x1b0/0xfd8 fs/btrfs/ctree.c:1944
       btrfs_update_root+0x6c/0x5a0 fs/btrfs/root-tree.c:132
       commit_fs_roots+0x1f0/0x33c fs/btrfs/transaction.c:1459
       btrfs_commit_transaction+0x89c/0x12d8 fs/btrfs/transaction.c:2343
       flush_space+0x66c/0x738 fs/btrfs/space-info.c:786
       btrfs_async_reclaim_metadata_space+0x43c/0x4e0 fs/btrfs/space-info.c:1059
       process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
       worker_thread+0x340/0x610 kernel/workqueue.c:2436
       kthread+0x12c/0x158 kernel/kthread.c:376
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

-> #2 (&fs_info->reloc_mutex){+.+.}-{3:3}:
       __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
       btrfs_record_root_in_trans fs/btrfs/transaction.c:516 [inline]
       start_transaction+0x248/0x944 fs/btrfs/transaction.c:752
       btrfs_start_transaction+0x34/0x44 fs/btrfs/transaction.c:781
       btrfs_create_common+0xf0/0x1b4 fs/btrfs/inode.c:6651
       btrfs_create+0x8c/0xb0 fs/btrfs/inode.c:6697
       lookup_open fs/namei.c:3413 [inline]
       open_last_lookups fs/namei.c:3481 [inline]
       path_openat+0x804/0x11c4 fs/namei.c:3688
       do_filp_open+0xdc/0x1b8 fs/namei.c:3718
       do_sys_openat2+0xb8/0x22c fs/open.c:1313
       do_sys_open fs/open.c:1329 [inline]
       __do_sys_openat fs/open.c:1345 [inline]
       __se_sys_openat fs/open.c:1340 [inline]
       __arm64_sys_openat+0xb0/0xe0 fs/open.c:1340
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
       el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #1 (sb_internal#2){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1826 [inline]
       sb_start_intwrite include/linux/fs.h:1948 [inline]
       start_transaction+0x360/0x944 fs/btrfs/transaction.c:683
       btrfs_join_transaction+0x30/0x40 fs/btrfs/transaction.c:795
       btrfs_dirty_inode+0x50/0x140 fs/btrfs/inode.c:6103
       btrfs_update_time+0x1c0/0x1e8 fs/btrfs/inode.c:6145
       inode_update_time fs/inode.c:1872 [inline]
       touch_atime+0x1f0/0x4a8 fs/inode.c:1945
       file_accessed include/linux/fs.h:2516 [inline]
       btrfs_file_mmap+0x50/0x88 fs/btrfs/file.c:2407
       call_mmap include/linux/fs.h:2192 [inline]
       mmap_region+0x7fc/0xc14 mm/mmap.c:1752
       do_mmap+0x644/0x97c mm/mmap.c:1540
       vm_mmap_pgoff+0xe8/0x1d0 mm/util.c:552
       ksys_mmap_pgoff+0x1cc/0x278 mm/mmap.c:1586
       __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline]
       __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline]
       __arm64_sys_mmap+0x58/0x6c arch/arm64/kernel/sys.c:21
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
       el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #0 (&mm->mmap_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3095 [inline]
       check_prevs_add kernel/locking/lockdep.c:3214 [inline]
       validate_chain kernel/locking/lockdep.c:3829 [inline]
       __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053
       lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666
       __might_fault+0x7c/0xb4 mm/memory.c:5577
       _copy_to_user include/linux/uaccess.h:134 [inline]
       copy_to_user include/linux/uaccess.h:160 [inline]
       btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203
       btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl fs/ioctl.c:856 [inline]
       __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
       el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

other info that might help us debug this:

Chain exists of:
  &mm->mmap_lock --> &fs_info->reloc_mutex --> btrfs-root-00

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(btrfs-root-00);
                               lock(&fs_info->reloc_mutex);
                               lock(btrfs-root-00);
  lock(&mm->mmap_lock);

 *** DEADLOCK ***

1 lock held by syz-executor307/3029:
 #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline]
 #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline]
 #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279

stack backtrace:
CPU: 0 PID: 3029 Comm: syz-executor307 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156
 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2053
 check_noncircular+0x14c/0x154 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3095 [inline]
 check_prevs_add kernel/locking/lockdep.c:3214 [inline]
 validate_chain kernel/locking/lockdep.c:3829 [inline]
 __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053
 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666
 __might_fault+0x7c/0xb4 mm/memory.c:5577
 _copy_to_user include/linux/uaccess.h:134 [inline]
 copy_to_user include/linux/uaccess.h:160 [inline]
 btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203
 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
 el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

We do generally the right thing here, copying the references into a
temporary buffer, however we are still holding the path when we do
copy_to_user from the temporary buffer.  Fix this by freeing the path
before we copy to user space.

Reported-by: [email protected]
CC: [email protected] # 4.19+
Reviewed-by: Anand Jain <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
konradybcio pushed a commit that referenced this issue Nov 18, 2022
netfslib has a number of places in which it performs iteration of an xarray
whilst being under the RCU read lock.  It *should* call xas_retry() as the
first thing inside of the loop and do "continue" if it returns true in case
the xarray walker passed out a special value indicating that the walk needs
to be redone from the root[*].

Fix this by adding the missing retry checks.

[*] I wonder if this should be done inside xas_find(), xas_next_node() and
    suchlike, but I'm told that's not an simple change to effect.

This can cause an oops like that below.  Note the faulting address - this
is an internal value (|0x2) returned from xarray.

BUG: kernel NULL pointer dereference, address: 0000000000000402
...
RIP: 0010:netfs_rreq_unlock+0xef/0x380 [netfs]
...
Call Trace:
 netfs_rreq_assess+0xa6/0x240 [netfs]
 netfs_readpage+0x173/0x3b0 [netfs]
 ? init_wait_var_entry+0x50/0x50
 filemap_read_page+0x33/0xf0
 filemap_get_pages+0x2f2/0x3f0
 filemap_read+0xaa/0x320
 ? do_filp_open+0xb2/0x150
 ? rmqueue+0x3be/0xe10
 ceph_read_iter+0x1fe/0x680 [ceph]
 ? new_sync_read+0x115/0x1a0
 new_sync_read+0x115/0x1a0
 vfs_read+0xf3/0x180
 ksys_read+0x5f/0xe0
 do_syscall_64+0x38/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Changes:
========
ver #2)
 - Changed an unsigned int to a size_t to reduce the likelihood of an
   overflow as per Willy's suggestion.
 - Added an additional patch to fix the maths.

Fixes: 3d3c950 ("netfs: Provide readahead and readpage netfs helpers")
Reported-by: George Law <[email protected]>
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Reviewed-by: Jingbo Xu <[email protected]>
cc: Matthew Wilcox <[email protected]>
cc: [email protected]
cc: [email protected]
Link: https://lore.kernel.org/r/166749229733.107206.17482609105741691452.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/166757987929.950645.12595273010425381286.stgit@warthog.procyon.org.uk/ # v2
konradybcio pushed a commit that referenced this issue Nov 18, 2022
Patch series "rapidio: fix three possible memory leaks".

This patchset fixes three name leaks in error handling.
 - patch #1 fixes two name leaks while rio_add_device() fails.
 - patch #2 fixes a name leak while  rio_register_mport() fails.


This patch (of 2):

If rio_add_device() returns error, the name allocated by dev_set_name()
need be freed.  It should use put_device() to give up the reference in the
error path, so that the name can be freed in kobject_cleanup(), and the
'rdev' can be freed in rio_release_dev().

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: e8de370 ("rapidio: add mport char device driver")
Fixes: 1fa5ae8 ("driver core: get rid of struct device's bus_id string array")
Signed-off-by: Yang Yingliang <[email protected]>
Cc: Alexandre Bounine <[email protected]>
Cc: Matt Porter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
konradybcio pushed a commit that referenced this issue Nov 18, 2022
The "ib_port" structure must be set before adding the sysfs kobject,
and reset after removing it, otherwise it may crash when accessing
the sysfs node:
  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050
  Mem abort info:
    ESR = 0x96000006
    Exception class = DABT (current EL), IL = 32 bits
    SET = 0, FnV = 0
    EA = 0, S1PTW = 0
  Data abort info:
    ISV = 0, ISS = 0x00000006
    CM = 0, WnR = 0
  user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000e85f5ba5
  [0000000000000050] pgd=0000000848fd9003, pud=000000085b387003, pmd=0000000000000000
  Internal error: Oops: 96000006 [#2] PREEMPT SMP
  Modules linked in: ib_umad(O) mlx5_ib(O) nfnetlink_cttimeout(E) nfnetlink(E) act_gact(E) cls_flower(E) sch_ingress(E) openvswitch(E) nsh(E) nf_nat_ipv6(E) nf_nat_ipv4(E) nf_conncount(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) mst_pciconf(O) ipmi_devintf(E) ipmi_msghandler(E) ipmb_dev_int(OE) mlx5_core(O) mlxfw(O) mlxdevm(O) auxiliary(O) ib_uverbs(O) ib_core(O) mlx_compat(O) psample(E) sbsa_gwdt(E) uio_pdrv_genirq(E) uio(E) mlxbf_pmc(OE) mlxbf_gige(OE) mlxbf_tmfifo(OE) gpio_mlxbf2(OE) pwr_mlxbf(OE) mlx_trio(OE) i2c_mlxbf(OE) mlx_bootctl(OE) bluefield_edac(OE) knem(O) ip_tables(E) ipv6(E) crc_ccitt(E) [last unloaded: mst_pci]
  Process grep (pid: 3372, stack limit = 0x0000000022055c92)
  CPU: 5 PID: 3372 Comm: grep Tainted: G      D    OE     4.19.161-mlnx.47.gadcd9e3 #1
  Hardware name: https://www.mellanox.com BlueField SoC/BlueField SoC, BIOS BlueField:3.9.2-15-ga2403ab Sep  8 2022
  pstate: 40000005 (nZcv daif -PAN -UAO)
  pc : hw_stat_port_show+0x4c/0x80 [ib_core]
  lr : port_attr_show+0x40/0x58 [ib_core]
  sp : ffff000029f43b50
  x29: ffff000029f43b50 x28: 0000000019375000
  x27: ffff8007b821a540 x26: ffff000029f43e30
  x25: 0000000000008000 x24: ffff000000eaa958
  x23: 0000000000001000 x22: ffff8007a4ce3000
  x21: ffff8007baff8000 x20: ffff8007b9066ac0
  x19: ffff8007bae97578 x18: 0000000000000000
  x17: 0000000000000000 x16: 0000000000000000
  x15: 0000000000000000 x14: 0000000000000000
  x13: 0000000000000000 x12: 0000000000000000
  x11: 0000000000000000 x10: 0000000000000000
  x9 : 0000000000000000 x8 : ffff8007a4ce4000
  x7 : 0000000000000000 x6 : 000000000000003f
  x5 : ffff000000e6a280 x4 : ffff8007a4ce3000
  x3 : 0000000000000000 x2 : aaaaaaaaaaaaaaab
  x1 : ffff8007b9066a10 x0 : ffff8007baff8000
  Call trace:
   hw_stat_port_show+0x4c/0x80 [ib_core]
   port_attr_show+0x40/0x58 [ib_core]
   sysfs_kf_seq_show+0x8c/0x150
   kernfs_seq_show+0x44/0x50
   seq_read+0x1b4/0x45c
   kernfs_fop_read+0x148/0x1d8
   __vfs_read+0x58/0x180
   vfs_read+0x94/0x154
   ksys_read+0x68/0xd8
   __arm64_sys_read+0x28/0x34
   el0_svc_common+0x88/0x18c
   el0_svc_handler+0x78/0x94
   el0_svc+0x8/0xe8
  Code: f2955562 aa1603e4 aa1503e0 f9405683 (f9402861)

Fixes: d8a5883 ("RDMA/core: Replace the ib_port_data hw_stats pointers with a ib_port pointer")
Signed-off-by: Mark Zhang <[email protected]>
Reviewed-by: Michael Guralnik <[email protected]>
Link: https://lore.kernel.org/r/88867e705c42c1cd2011e45201c25eecdb9fef94.1667810736.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <[email protected]>
konradybcio pushed a commit that referenced this issue Nov 18, 2022
Patch series "rapidio: fix three possible memory leaks".

This patchset fixes three name leaks in error handling.
 - patch #1 fixes two name leaks while rio_add_device() fails.
 - patch #2 fixes a name leak while  rio_register_mport() fails.


This patch (of 2):

If rio_add_device() returns error, the name allocated by dev_set_name()
need be freed.  It should use put_device() to give up the reference in the
error path, so that the name can be freed in kobject_cleanup(), and the
'rdev' can be freed in rio_release_dev().

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: e8de370 ("rapidio: add mport char device driver")
Fixes: 1fa5ae8 ("driver core: get rid of struct device's bus_id string array")
Signed-off-by: Yang Yingliang <[email protected]>
Cc: Alexandre Bounine <[email protected]>
Cc: Matt Porter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Haxk20 pushed a commit that referenced this issue Nov 22, 2022
Sahid Orentino Ferdjaoui says:

====================

As part of commit 93b8952 ("libbpf: deprecate legacy BPF map
definitions") and commit bd05410 ("libbpf: enforce strict libbpf
1.0 behaviors") The --legacy option is not relevant anymore. #1 is
removing it. #4 is cleaning the code from using libbpf_get_error().

About patches #2 and #3 They are changes discovered while working on
this series (credits to Quentin Monnet). #2 is cleaning-up usage of an
unnecessary PTR_ERR(NULL), finally #3 is fixing an invalid value
passed to strerror().

v1 -> v2:
   - Addressed review comments from Yonghong Song on patch #4
   - Added a patch #5 that removes unwanted function noticed by
     Yonghong Song
v2 -> v3
   - Addressed review comments from Andrii Nakryiko on patch #2, #3, #4
     * clean-up usage of libbpf_get_error() (#2, #3)
     * fix possible return of an uninitialized local variable err
     * fix returned errors using errno
v3 -> v4
   - Addressed review comments from Quentin Monnet
     * fix line moved from patch #2 to patch #3
     * fix missing returned errors using errno
     * fix some returned values to errno instead of -1
====================

Reviewed-by: Quentin Monnet <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Haxk20 pushed a commit that referenced this issue Nov 22, 2022
…nel/git/at91/linux into soc/dt

AT91 DT for 6.2 #2

It contains:
- one typo fix for a SAMA7G5 pin; the pin is not used anywhere in the
  device trees.

* tag 'at91-dt-6.2-2' of https://git.kernel.org/pub/scm/linux/kernel/git/at91/linux:
  ARM: dts: at91: sama7g5: fix signal name of pin PD8

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
Haxk20 pushed a commit that referenced this issue Nov 22, 2022
…kernel/git/at91/linux into arm/fixes

AT91 fixes for 6.1 #2

It contains:
- fix UDC on at91sam9g20ek boards by adding vbus pin

* tag 'at91-fixes-6.1-2' of https://git.kernel.org/pub/scm/linux/kernel/git/at91/linux:
  ARM: dts: at91: sam9g20ek: enable udc vbus gpio pinctrl

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
Haxk20 pushed a commit that referenced this issue Nov 22, 2022
Patch series "rapidio: fix three possible memory leaks".

This patchset fixes three name leaks in error handling.
 - patch #1 fixes two name leaks while rio_add_device() fails.
 - patch #2 fixes a name leak while  rio_register_mport() fails.


This patch (of 2):

If rio_add_device() returns error, the name allocated by dev_set_name()
need be freed.  It should use put_device() to give up the reference in the
error path, so that the name can be freed in kobject_cleanup(), and the
'rdev' can be freed in rio_release_dev().

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: e8de370 ("rapidio: add mport char device driver")
Fixes: 1fa5ae8 ("driver core: get rid of struct device's bus_id string array")
Signed-off-by: Yang Yingliang <[email protected]>
Cc: Alexandre Bounine <[email protected]>
Cc: Matt Porter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
MarijnS95 pushed a commit that referenced this issue Dec 7, 2022
Matt reported a splat at msk close time:

    BUG: sleeping function called from invalid context at net/mptcp/protocol.c:2877
    in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 155, name: packetdrill
    preempt_count: 201, expected: 0
    RCU nest depth: 0, expected: 0
    4 locks held by packetdrill/155:
    #0: ffff888001536990 (&sb->s_type->i_mutex_key#6){+.+.}-{3:3}, at: __sock_release (net/socket.c:650)
    #1: ffff88800b498130 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close (net/mptcp/protocol.c:2973)
    #2: ffff88800b49a130 (sk_lock-AF_INET/1){+.+.}-{0:0}, at: __mptcp_close_ssk (net/mptcp/protocol.c:2363)
    #3: ffff88800b49a0b0 (slock-AF_INET){+...}-{2:2}, at: __lock_sock_fast (include/net/sock.h:1820)
    Preemption disabled at:
    0x0
    CPU: 1 PID: 155 Comm: packetdrill Not tainted 6.1.0-rc5 torvalds#365
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
    Call Trace:
    <TASK>
    dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4))
    __might_resched.cold (kernel/sched/core.c:9891)
    __mptcp_destroy_sock (include/linux/kernel.h:110)
    __mptcp_close (net/mptcp/protocol.c:2959)
    mptcp_subflow_queue_clean (include/net/sock.h:1777)
    __mptcp_close_ssk (net/mptcp/protocol.c:2363)
    mptcp_destroy_common (net/mptcp/protocol.c:3170)
    mptcp_destroy (include/net/sock.h:1495)
    __mptcp_destroy_sock (net/mptcp/protocol.c:2886)
    __mptcp_close (net/mptcp/protocol.c:2959)
    mptcp_close (net/mptcp/protocol.c:2974)
    inet_release (net/ipv4/af_inet.c:432)
    __sock_release (net/socket.c:651)
    sock_close (net/socket.c:1367)
    __fput (fs/file_table.c:320)
    task_work_run (kernel/task_work.c:181 (discriminator 1))
    exit_to_user_mode_prepare (include/linux/resume_user_mode.h:49)
    syscall_exit_to_user_mode (kernel/entry/common.c:130)
    do_syscall_64 (arch/x86/entry/common.c:87)
    entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)

We can't call mptcp_close under the 'fast' socket lock variant, replace
it with a sock_lock_nested() as the relevant code is already under the
listening msk socket lock protection.

Reported-by: Matthieu Baerts <[email protected]>
Closes: multipath-tcp/mptcp_net-next#316
Fixes: 30e51b9 ("mptcp: fix unreleased socket in accept queue")
Signed-off-by: Paolo Abeni <[email protected]>
Reviewed-by: Matthieu Baerts <[email protected]>
Signed-off-by: Matthieu Baerts <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
MarijnS95 pushed a commit that referenced this issue Dec 7, 2022
QAT devices on Intel Sapphire Rapids and Emerald Rapids have a defect in
address translation service (ATS). These devices may inadvertently issue
ATS invalidation completion before posted writes initiated with
translated address that utilized translations matching the invalidation
address range, violating the invalidation completion ordering.

This patch adds an extra device TLB invalidation for the affected devices,
it is needed to ensure no more posted writes with translated address
following the invalidation completion. Therefore, the ordering is
preserved and data-corruption is prevented.

Device TLBs are invalidated under the following six conditions:
1. Device driver does DMA API unmap IOVA
2. Device driver unbind a PASID from a process, sva_unbind_device()
3. PASID is torn down, after PASID cache is flushed. e.g. process
exit_mmap() due to crash
4. Under SVA usage, called by mmu_notifier.invalidate_range() where
VM has to free pages that were unmapped
5. userspace driver unmaps a DMA buffer
6. Cache invalidation in vSVA usage (upcoming)

For #1 and #2, device drivers are responsible for stopping DMA traffic
before unmap/unbind. For #3, iommu driver gets mmu_notifier to
invalidate TLB the same way as normal user unmap which will do an extra
invalidation. The dTLB invalidation after PASID cache flush does not
need an extra invalidation.

Therefore, we only need to deal with #4 and #5 in this patch. #1 is also
covered by this patch due to common code path with #5.

Tested-by: Yuzhang Luo <[email protected]>
Reviewed-by: Ashok Raj <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Signed-off-by: Jacob Pan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lu Baolu <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>
konradybcio pushed a commit that referenced this issue Dec 14, 2022
Fix some checker warnings in the trace code by adding __printf attributes
to a number of trace functions and their declarations.

Changes:
========
ver #2)
 - Dropped the fix for the unconditional tracing_max_lat_fops decl[1].

Link: https://lore.kernel.org/r/[email protected]/ [1]
Link: https://lore.kernel.org/r/166992525941.1716618.13740663757583361463.stgit@warthog.procyon.org.uk/ # v1
Link: https://lkml.kernel.org/r/167023571258.382307.15314866482834835192.stgit@warthog.procyon.org.uk

Signed-off-by: David Howells <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
konradybcio pushed a commit that referenced this issue Dec 14, 2022
…g the sock

There is a race condition in vxlan that when deleting a vxlan device
during receiving packets, there is a possibility that the sock is
released after getting vxlan_sock vs from sk_user_data. Then in
later vxlan_ecn_decapsulate(), vxlan_get_sk_family() we will got
NULL pointer dereference. e.g.

   #0 [ffffa25ec6978a38] machine_kexec at ffffffff8c669757
   #1 [ffffa25ec6978a90] __crash_kexec at ffffffff8c7c0a4d
   #2 [ffffa25ec6978b58] crash_kexec at ffffffff8c7c1c48
   #3 [ffffa25ec6978b60] oops_end at ffffffff8c627f2b
   #4 [ffffa25ec6978b80] page_fault_oops at ffffffff8c678fcb
   #5 [ffffa25ec6978bd8] exc_page_fault at ffffffff8d109542
   torvalds#6 [ffffa25ec6978c00] asm_exc_page_fault at ffffffff8d200b62
      [exception RIP: vxlan_ecn_decapsulate+0x3b]
      RIP: ffffffffc1014e7b  RSP: ffffa25ec6978cb0  RFLAGS: 00010246
      RAX: 0000000000000008  RBX: ffff8aa000888000  RCX: 0000000000000000
      RDX: 000000000000000e  RSI: ffff8a9fc7ab803e  RDI: ffff8a9fd1168700
      RBP: ffff8a9fc7ab803e   R8: 0000000000700000   R9: 00000000000010ae
      R10: ffff8a9fcb748980  R11: 0000000000000000  R12: ffff8a9fd1168700
      R13: ffff8aa000888000  R14: 00000000002a0000  R15: 00000000000010ae
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
   torvalds#7 [ffffa25ec6978ce8] vxlan_rcv at ffffffffc10189cd [vxlan]
   torvalds#8 [ffffa25ec6978d90] udp_queue_rcv_one_skb at ffffffff8cfb6507
   torvalds#9 [ffffa25ec6978dc0] udp_unicast_rcv_skb at ffffffff8cfb6e45
  torvalds#10 [ffffa25ec6978dc8] __udp4_lib_rcv at ffffffff8cfb8807
  torvalds#11 [ffffa25ec6978e20] ip_protocol_deliver_rcu at ffffffff8cf76951
  torvalds#12 [ffffa25ec6978e48] ip_local_deliver at ffffffff8cf76bde
  torvalds#13 [ffffa25ec6978ea0] __netif_receive_skb_one_core at ffffffff8cecde9b
  torvalds#14 [ffffa25ec6978ec8] process_backlog at ffffffff8cece139
  torvalds#15 [ffffa25ec6978f00] __napi_poll at ffffffff8ceced1a
  torvalds#16 [ffffa25ec6978f28] net_rx_action at ffffffff8cecf1f3
  torvalds#17 [ffffa25ec6978fa0] __softirqentry_text_start at ffffffff8d4000ca
  torvalds#18 [ffffa25ec6978ff0] do_softirq at ffffffff8c6fbdc3

Reproducer: https://github.com/Mellanox/ovs-tests/blob/master/test-ovs-vxlan-remove-tunnel-during-traffic.sh

Fix this by waiting for all sk_user_data reader to finish before
releasing the sock.

Reported-by: Jianlin Shi <[email protected]>
Suggested-by: Jakub Sitnicki <[email protected]>
Fixes: 6a93cc9 ("udp-tunnel: Add a few more UDP tunnel APIs")
Signed-off-by: Hangbin Liu <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
konradybcio pushed a commit that referenced this issue May 7, 2024
Merge series from Jerome Brunet <[email protected]>:

This patchset fixes 2 problems on TDM which both find a solution
by properly implementing the .trigger() callback for the TDM backend.

ATM, enabling the TDM formatters is done by the .prepare() callback
because handling the formatter is slow due to necessary calls to CCF.

The first problem affects the TDMIN. Because .prepare() is called on DPCM
backend first, the formatter are started before the FIFOs and this may
cause a random channel shifts if the TDMIN use multiple lanes with more
than 2 slots per lanes. Using trigger() allows to set the FE/BE order,
solving the problem.

There has already been an attempt to fix this 3y ago [1] and reverted [2]
It triggered a 'sleep in irq' error on the period IRQ. The solution is
to just use the bottom half of threaded IRQ. This is patch #1. Patch #2
and #3 remain mostly the same as 3y ago.

For TDMOUT, the problem is on pause. ATM pause only stops the FIFO and
the TDMOUT just starves. When it does, it will actually repeat the last
sample continuously. Depending on the platform, if there is no high-pass
filter on the analog path, this may translate to a constant position of
the speaker membrane. There is no audible glitch but it may damage the
speaker coil.

Properly stopping the TDMOUT in pause solves the problem. There is
behaviour change associated with that fix. Clocks used to be continuous
on pause because of the problem above. They will now be gated on pause by
default, as they should. The last change introduce the proper support for
continuous clocks, if needed.

[1]: https://lore.kernel.org/linux-amlogic/[email protected]
[2]: https://lore.kernel.org/linux-amlogic/[email protected]
konradybcio pushed a commit that referenced this issue May 10, 2024
ui_browser__show() is capturing the input title that is stack allocated
memory in hist_browser__run().

Avoid a use after return by strdup-ing the string.

Committer notes:

Further explanation from Ian Rogers:

My command line using tui is:
$ sudo bash -c 'rm /tmp/asan.log*; export
ASAN_OPTIONS="log_path=/tmp/asan.log"; /tmp/perf/perf mem record -a
sleep 1; /tmp/perf/perf mem report'
I then go to the perf annotate view and quit. This triggers the asan
error (from the log file):
```
==1254591==ERROR: AddressSanitizer: stack-use-after-return on address
0x7f2813331920 at pc 0x7f28180
65991 bp 0x7fff0a21c750 sp 0x7fff0a21bf10
READ of size 80 at 0x7f2813331920 thread T0
    #0 0x7f2818065990 in __interceptor_strlen
../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:461
    #1 0x7f2817698251 in SLsmg_write_wrapped_string
(/lib/x86_64-linux-gnu/libslang.so.2+0x98251)
    #2 0x7f28176984b9 in SLsmg_write_nstring
(/lib/x86_64-linux-gnu/libslang.so.2+0x984b9)
    #3 0x55c94045b365 in ui_browser__write_nstring ui/browser.c:60
    #4 0x55c94045c558 in __ui_browser__show_title ui/browser.c:266
    #5 0x55c94045c776 in ui_browser__show ui/browser.c:288
    torvalds#6 0x55c94045c06d in ui_browser__handle_resize ui/browser.c:206
    torvalds#7 0x55c94047979b in do_annotate ui/browsers/hists.c:2458
    torvalds#8 0x55c94047fb17 in evsel__hists_browse ui/browsers/hists.c:3412
    torvalds#9 0x55c940480a0c in perf_evsel_menu__run ui/browsers/hists.c:3527
    torvalds#10 0x55c940481108 in __evlist__tui_browse_hists ui/browsers/hists.c:3613
    torvalds#11 0x55c9404813f7 in evlist__tui_browse_hists ui/browsers/hists.c:3661
    torvalds#12 0x55c93ffa253f in report__browse_hists tools/perf/builtin-report.c:671
    torvalds#13 0x55c93ffa58ca in __cmd_report tools/perf/builtin-report.c:1141
    torvalds#14 0x55c93ffaf159 in cmd_report tools/perf/builtin-report.c:1805
    torvalds#15 0x55c94000c05c in report_events tools/perf/builtin-mem.c:374
    torvalds#16 0x55c94000d96d in cmd_mem tools/perf/builtin-mem.c:516
    torvalds#17 0x55c9400e44ee in run_builtin tools/perf/perf.c:350
    torvalds#18 0x55c9400e4a5a in handle_internal_command tools/perf/perf.c:403
    torvalds#19 0x55c9400e4e22 in run_argv tools/perf/perf.c:447
    torvalds#20 0x55c9400e53ad in main tools/perf/perf.c:561
    torvalds#21 0x7f28170456c9 in __libc_start_call_main
../sysdeps/nptl/libc_start_call_main.h:58
    torvalds#22 0x7f2817045784 in __libc_start_main_impl ../csu/libc-start.c:360
    torvalds#23 0x55c93ff544c0 in _start (/tmp/perf/perf+0x19a4c0) (BuildId:
84899b0e8c7d3a3eaa67b2eb35e3d8b2f8cd4c93)

Address 0x7f2813331920 is located in stack of thread T0 at offset 32 in frame
    #0 0x55c94046e85e in hist_browser__run ui/browsers/hists.c:746

  This frame has 1 object(s):
    [32, 192) 'title' (line 747) <== Memory access at offset 32 is
inside this variable
HINT: this may be a false positive if your program uses some custom
stack unwind mechanism, swapcontext or vfork
```
hist_browser__run isn't on the stack so the asan error looks legit.
There's no clean init/exit on struct ui_browser so I may be trading a
use-after-return for a memory leak, but that seems look a good trade
anyway.

Fixes: 05e8b08 ("perf ui browser: Stop using 'self'")
Signed-off-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Ben Gainey <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: K Prateek Nayak <[email protected]>
Cc: Li Dong <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Oliver Upton <[email protected]>
Cc: Paran Lee <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ravi Bangoria <[email protected]>
Cc: Sun Haiyong <[email protected]>
Cc: Tim Chen <[email protected]>
Cc: Yanteng Si <[email protected]>
Cc: Yicong Yang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
konradybcio pushed a commit that referenced this issue May 10, 2024
Patch series "Introduce mseal", v10.

This patchset proposes a new mseal() syscall for the Linux kernel.

In a nutshell, mseal() protects the VMAs of a given virtual memory range
against modifications, such as changes to their permission bits.

Modern CPUs support memory permissions, such as the read/write (RW) and
no-execute (NX) bits.  Linux has supported NX since the release of kernel
version 2.6.8 in August 2004 [1].  The memory permission feature improves
the security stance on memory corruption bugs, as an attacker cannot
simply write to arbitrary memory and point the code to it.  The memory
must be marked with the X bit, or else an exception will occur. 
Internally, the kernel maintains the memory permissions in a data
structure called VMA (vm_area_struct).  mseal() additionally protects the
VMA itself against modifications of the selected seal type.

Memory sealing is useful to mitigate memory corruption issues where a
corrupted pointer is passed to a memory management system.  For example,
such an attacker primitive can break control-flow integrity guarantees
since read-only memory that is supposed to be trusted can become writable
or .text pages can get remapped.  Memory sealing can automatically be
applied by the runtime loader to seal .text and .rodata pages and
applications can additionally seal security critical data at runtime.  A
similar feature already exists in the XNU kernel with the
VM_FLAGS_PERMANENT [3] flag and on OpenBSD with the mimmutable syscall
[4].  Also, Chrome wants to adopt this feature for their CFI work [2] and
this patchset has been designed to be compatible with the Chrome use case.

Two system calls are involved in sealing the map:  mmap() and mseal().

The new mseal() is an syscall on 64 bit CPU, and with following signature:

int mseal(void addr, size_t len, unsigned long flags)
addr/len: memory range.
flags: reserved.

mseal() blocks following operations for the given memory range.

1> Unmapping, moving to another location, and shrinking the size,
   via munmap() and mremap(), can leave an empty space, therefore can
   be replaced with a VMA with a new set of attributes.

2> Moving or expanding a different VMA into the current location,
   via mremap().

3> Modifying a VMA via mmap(MAP_FIXED).

4> Size expansion, via mremap(), does not appear to pose any specific
   risks to sealed VMAs. It is included anyway because the use case is
   unclear. In any case, users can rely on merging to expand a sealed VMA.

5> mprotect() and pkey_mprotect().

6> Some destructive madvice() behaviors (e.g. MADV_DONTNEED) for anonymous
   memory, when users don't have write permission to the memory. Those
   behaviors can alter region contents by discarding pages, effectively a
   memset(0) for anonymous memory.

The idea that inspired this patch comes from Stephen Röttger’s work in
V8 CFI [5].  Chrome browser in ChromeOS will be the first user of this
API.

Indeed, the Chrome browser has very specific requirements for sealing,
which are distinct from those of most applications.  For example, in the
case of libc, sealing is only applied to read-only (RO) or read-execute
(RX) memory segments (such as .text and .RELRO) to prevent them from
becoming writable, the lifetime of those mappings are tied to the lifetime
of the process.

Chrome wants to seal two large address space reservations that are managed
by different allocators.  The memory is mapped RW- and RWX respectively
but write access to it is restricted using pkeys (or in the future ARM
permission overlay extensions).  The lifetime of those mappings are not
tied to the lifetime of the process, therefore, while the memory is
sealed, the allocators still need to free or discard the unused memory. 
For example, with madvise(DONTNEED).

However, always allowing madvise(DONTNEED) on this range poses a security
risk.  For example if a jump instruction crosses a page boundary and the
second page gets discarded, it will overwrite the target bytes with zeros
and change the control flow.  Checking write-permission before the discard
operation allows us to control when the operation is valid.  In this case,
the madvise will only succeed if the executing thread has PKEY write
permissions and PKRU changes are protected in software by control-flow
integrity.

Although the initial version of this patch series is targeting the Chrome
browser as its first user, it became evident during upstream discussions
that we would also want to ensure that the patch set eventually is a
complete solution for memory sealing and compatible with other use cases. 
The specific scenario currently in mind is glibc's use case of loading and
sealing ELF executables.  To this end, Stephen is working on a change to
glibc to add sealing support to the dynamic linker, which will seal all
non-writable segments at startup.  Once this work is completed, all
applications will be able to automatically benefit from these new
protections.

In closing, I would like to formally acknowledge the valuable
contributions received during the RFC process, which were instrumental in
shaping this patch:

Jann Horn: raising awareness and providing valuable insights on the
  destructive madvise operations.
Liam R. Howlett: perf optimization.
Linus Torvalds: assisting in defining system call signature and scope.
Theo de Raadt: sharing the experiences and insight gained from
  implementing mimmutable() in OpenBSD.

MM perf benchmarks
==================
This patch adds a loop in the mprotect/munmap/madvise(DONTNEED) to
check the VMAs’ sealing flag, so that no partial update can be made,
when any segment within the given memory range is sealed.

To measure the performance impact of this loop, two tests are developed.
[8]

The first is measuring the time taken for a particular system call,
by using clock_gettime(CLOCK_MONOTONIC). The second is using
PERF_COUNT_HW_REF_CPU_CYCLES (exclude user space). Both tests have
similar results.

The tests have roughly below sequence:
for (i = 0; i < 1000, i++)
    create 1000 mappings (1 page per VMA)
    start the sampling
    for (j = 0; j < 1000, j++)
        mprotect one mapping
    stop and save the sample
    delete 1000 mappings
calculates all samples.

Below tests are performed on Intel(R) Pentium(R) Gold 7505 @ 2.00GHz,
4G memory, Chromebook.

Based on the latest upstream code:
The first test (measuring time)
syscall__	vmas	t	t_mseal	delta_ns	per_vma	%
munmap__  	1	909	944	35	35	104%
munmap__  	2	1398	1502	104	52	107%
munmap__  	4	2444	2594	149	37	106%
munmap__  	8	4029	4323	293	37	107%
munmap__  	16	6647	6935	288	18	104%
munmap__  	32	11811	12398	587	18	105%
mprotect	1	439	465	26	26	106%
mprotect	2	1659	1745	86	43	105%
mprotect	4	3747	3889	142	36	104%
mprotect	8	6755	6969	215	27	103%
mprotect	16	13748	14144	396	25	103%
mprotect	32	27827	28969	1142	36	104%
madvise_	1	240	262	22	22	109%
madvise_	2	366	442	76	38	121%
madvise_	4	623	751	128	32	121%
madvise_	8	1110	1324	215	27	119%
madvise_	16	2127	2451	324	20	115%
madvise_	32	4109	4642	534	17	113%

The second test (measuring cpu cycle)
syscall__	vmas	cpu	cmseal	delta_cpu	per_vma	%
munmap__	1	1790	1890	100	100	106%
munmap__	2	2819	3033	214	107	108%
munmap__	4	4959	5271	312	78	106%
munmap__	8	8262	8745	483	60	106%
munmap__	16	13099	14116	1017	64	108%
munmap__	32	23221	24785	1565	49	107%
mprotect	1	906	967	62	62	107%
mprotect	2	3019	3203	184	92	106%
mprotect	4	6149	6569	420	105	107%
mprotect	8	9978	10524	545	68	105%
mprotect	16	20448	21427	979	61	105%
mprotect	32	40972	42935	1963	61	105%
madvise_	1	434	497	63	63	115%
madvise_	2	752	899	147	74	120%
madvise_	4	1313	1513	200	50	115%
madvise_	8	2271	2627	356	44	116%
madvise_	16	4312	4883	571	36	113%
madvise_	32	8376	9319	943	29	111%

Based on the result, for 6.8 kernel, sealing check adds
20-40 nano seconds, or around 50-100 CPU cycles, per VMA.

In addition, I applied the sealing to 5.10 kernel:
The first test (measuring time)
syscall__	vmas	t	tmseal	delta_ns	per_vma	%
munmap__	1	357	390	33	33	109%
munmap__	2	442	463	21	11	105%
munmap__	4	614	634	20	5	103%
munmap__	8	1017	1137	120	15	112%
munmap__	16	1889	2153	263	16	114%
munmap__	32	4109	4088	-21	-1	99%
mprotect	1	235	227	-7	-7	97%
mprotect	2	495	464	-30	-15	94%
mprotect	4	741	764	24	6	103%
mprotect	8	1434	1437	2	0	100%
mprotect	16	2958	2991	33	2	101%
mprotect	32	6431	6608	177	6	103%
madvise_	1	191	208	16	16	109%
madvise_	2	300	324	24	12	108%
madvise_	4	450	473	23	6	105%
madvise_	8	753	806	53	7	107%
madvise_	16	1467	1592	125	8	108%
madvise_	32	2795	3405	610	19	122%
					
The second test (measuring cpu cycle)
syscall__	nbr_vma	cpu	cmseal	delta_cpu	per_vma	%
munmap__	1	684	715	31	31	105%
munmap__	2	861	898	38	19	104%
munmap__	4	1183	1235	51	13	104%
munmap__	8	1999	2045	46	6	102%
munmap__	16	3839	3816	-23	-1	99%
munmap__	32	7672	7887	216	7	103%
mprotect	1	397	443	46	46	112%
mprotect	2	738	788	50	25	107%
mprotect	4	1221	1256	35	9	103%
mprotect	8	2356	2429	72	9	103%
mprotect	16	4961	4935	-26	-2	99%
mprotect	32	9882	10172	291	9	103%
madvise_	1	351	380	29	29	108%
madvise_	2	565	615	49	25	109%
madvise_	4	872	933	61	15	107%
madvise_	8	1508	1640	132	16	109%
madvise_	16	3078	3323	245	15	108%
madvise_	32	5893	6704	811	25	114%

For 5.10 kernel, sealing check adds 0-15 ns in time, or 10-30
CPU cycles, there is even decrease in some cases.

It might be interesting to compare 5.10 and 6.8 kernel
The first test (measuring time)
syscall__	vmas	t_5_10	t_6_8	delta_ns	per_vma	%
munmap__	1	357	909	552	552	254%
munmap__	2	442	1398	956	478	316%
munmap__	4	614	2444	1830	458	398%
munmap__	8	1017	4029	3012	377	396%
munmap__	16	1889	6647	4758	297	352%
munmap__	32	4109	11811	7702	241	287%
mprotect	1	235	439	204	204	187%
mprotect	2	495	1659	1164	582	335%
mprotect	4	741	3747	3006	752	506%
mprotect	8	1434	6755	5320	665	471%
mprotect	16	2958	13748	10790	674	465%
mprotect	32	6431	27827	21397	669	433%
madvise_	1	191	240	49	49	125%
madvise_	2	300	366	67	33	122%
madvise_	4	450	623	173	43	138%
madvise_	8	753	1110	357	45	147%
madvise_	16	1467	2127	660	41	145%
madvise_	32	2795	4109	1314	41	147%

The second test (measuring cpu cycle)
syscall__	vmas	cpu_5_10	c_6_8	delta_cpu	per_vma	%
munmap__	1	684	1790	1106	1106	262%
munmap__	2	861	2819	1958	979	327%
munmap__	4	1183	4959	3776	944	419%
munmap__	8	1999	8262	6263	783	413%
munmap__	16	3839	13099	9260	579	341%
munmap__	32	7672	23221	15549	486	303%
mprotect	1	397	906	509	509	228%
mprotect	2	738	3019	2281	1140	409%
mprotect	4	1221	6149	4929	1232	504%
mprotect	8	2356	9978	7622	953	423%
mprotect	16	4961	20448	15487	968	412%
mprotect	32	9882	40972	31091	972	415%
madvise_	1	351	434	82	82	123%
madvise_	2	565	752	186	93	133%
madvise_	4	872	1313	442	110	151%
madvise_	8	1508	2271	763	95	151%
madvise_	16	3078	4312	1234	77	140%
madvise_	32	5893	8376	2483	78	142%

From 5.10 to 6.8
munmap: added 250-550 ns in time, or 500-1100 in cpu cycle, per vma.
mprotect: added 200-750 ns in time, or 500-1200 in cpu cycle, per vma.
madvise: added 33-50 ns in time, or 70-110 in cpu cycle, per vma.

In comparison to mseal, which adds 20-40 ns or 50-100 CPU cycles, the
increase from 5.10 to 6.8 is significantly larger, approximately ten times
greater for munmap and mprotect.

When I discuss the mm performance with Brian Makin, an engineer who worked
on performance, it was brought to my attention that such performance
benchmarks, which measuring millions of mm syscall in a tight loop, may
not accurately reflect real-world scenarios, such as that of a database
service.  Also this is tested using a single HW and ChromeOS, the data
from another HW or distribution might be different.  It might be best to
take this data with a grain of salt.


This patch (of 5):

Wire up mseal syscall for all architectures.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jeff Xu <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Jann Horn <[email protected]> [Bug #2]
Cc: Jeff Xu <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Jorge Lucangeli Obes <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Muhammad Usama Anjum <[email protected]>
Cc: Pedro Falcato <[email protected]>
Cc: Stephen Röttger <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Amer Al Shanawany <[email protected]>
Cc: Javier Carrasco <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
konradybcio pushed a commit that referenced this issue May 23, 2024
Patch series "Introduce mseal", v10.

This patchset proposes a new mseal() syscall for the Linux kernel.

In a nutshell, mseal() protects the VMAs of a given virtual memory range
against modifications, such as changes to their permission bits.

Modern CPUs support memory permissions, such as the read/write (RW) and
no-execute (NX) bits.  Linux has supported NX since the release of kernel
version 2.6.8 in August 2004 [1].  The memory permission feature improves
the security stance on memory corruption bugs, as an attacker cannot
simply write to arbitrary memory and point the code to it.  The memory
must be marked with the X bit, or else an exception will occur. 
Internally, the kernel maintains the memory permissions in a data
structure called VMA (vm_area_struct).  mseal() additionally protects the
VMA itself against modifications of the selected seal type.

Memory sealing is useful to mitigate memory corruption issues where a
corrupted pointer is passed to a memory management system.  For example,
such an attacker primitive can break control-flow integrity guarantees
since read-only memory that is supposed to be trusted can become writable
or .text pages can get remapped.  Memory sealing can automatically be
applied by the runtime loader to seal .text and .rodata pages and
applications can additionally seal security critical data at runtime.  A
similar feature already exists in the XNU kernel with the
VM_FLAGS_PERMANENT [3] flag and on OpenBSD with the mimmutable syscall
[4].  Also, Chrome wants to adopt this feature for their CFI work [2] and
this patchset has been designed to be compatible with the Chrome use case.

Two system calls are involved in sealing the map:  mmap() and mseal().

The new mseal() is an syscall on 64 bit CPU, and with following signature:

int mseal(void addr, size_t len, unsigned long flags)
addr/len: memory range.
flags: reserved.

mseal() blocks following operations for the given memory range.

1> Unmapping, moving to another location, and shrinking the size,
   via munmap() and mremap(), can leave an empty space, therefore can
   be replaced with a VMA with a new set of attributes.

2> Moving or expanding a different VMA into the current location,
   via mremap().

3> Modifying a VMA via mmap(MAP_FIXED).

4> Size expansion, via mremap(), does not appear to pose any specific
   risks to sealed VMAs. It is included anyway because the use case is
   unclear. In any case, users can rely on merging to expand a sealed VMA.

5> mprotect() and pkey_mprotect().

6> Some destructive madvice() behaviors (e.g. MADV_DONTNEED) for anonymous
   memory, when users don't have write permission to the memory. Those
   behaviors can alter region contents by discarding pages, effectively a
   memset(0) for anonymous memory.

The idea that inspired this patch comes from Stephen Röttger’s work in
V8 CFI [5].  Chrome browser in ChromeOS will be the first user of this
API.

Indeed, the Chrome browser has very specific requirements for sealing,
which are distinct from those of most applications.  For example, in the
case of libc, sealing is only applied to read-only (RO) or read-execute
(RX) memory segments (such as .text and .RELRO) to prevent them from
becoming writable, the lifetime of those mappings are tied to the lifetime
of the process.

Chrome wants to seal two large address space reservations that are managed
by different allocators.  The memory is mapped RW- and RWX respectively
but write access to it is restricted using pkeys (or in the future ARM
permission overlay extensions).  The lifetime of those mappings are not
tied to the lifetime of the process, therefore, while the memory is
sealed, the allocators still need to free or discard the unused memory. 
For example, with madvise(DONTNEED).

However, always allowing madvise(DONTNEED) on this range poses a security
risk.  For example if a jump instruction crosses a page boundary and the
second page gets discarded, it will overwrite the target bytes with zeros
and change the control flow.  Checking write-permission before the discard
operation allows us to control when the operation is valid.  In this case,
the madvise will only succeed if the executing thread has PKEY write
permissions and PKRU changes are protected in software by control-flow
integrity.

Although the initial version of this patch series is targeting the Chrome
browser as its first user, it became evident during upstream discussions
that we would also want to ensure that the patch set eventually is a
complete solution for memory sealing and compatible with other use cases. 
The specific scenario currently in mind is glibc's use case of loading and
sealing ELF executables.  To this end, Stephen is working on a change to
glibc to add sealing support to the dynamic linker, which will seal all
non-writable segments at startup.  Once this work is completed, all
applications will be able to automatically benefit from these new
protections.

In closing, I would like to formally acknowledge the valuable
contributions received during the RFC process, which were instrumental in
shaping this patch:

Jann Horn: raising awareness and providing valuable insights on the
  destructive madvise operations.
Liam R. Howlett: perf optimization.
Linus Torvalds: assisting in defining system call signature and scope.
Theo de Raadt: sharing the experiences and insight gained from
  implementing mimmutable() in OpenBSD.

MM perf benchmarks
==================
This patch adds a loop in the mprotect/munmap/madvise(DONTNEED) to
check the VMAs’ sealing flag, so that no partial update can be made,
when any segment within the given memory range is sealed.

To measure the performance impact of this loop, two tests are developed.
[8]

The first is measuring the time taken for a particular system call,
by using clock_gettime(CLOCK_MONOTONIC). The second is using
PERF_COUNT_HW_REF_CPU_CYCLES (exclude user space). Both tests have
similar results.

The tests have roughly below sequence:
for (i = 0; i < 1000, i++)
    create 1000 mappings (1 page per VMA)
    start the sampling
    for (j = 0; j < 1000, j++)
        mprotect one mapping
    stop and save the sample
    delete 1000 mappings
calculates all samples.

Below tests are performed on Intel(R) Pentium(R) Gold 7505 @ 2.00GHz,
4G memory, Chromebook.

Based on the latest upstream code:
The first test (measuring time)
syscall__	vmas	t	t_mseal	delta_ns	per_vma	%
munmap__  	1	909	944	35	35	104%
munmap__  	2	1398	1502	104	52	107%
munmap__  	4	2444	2594	149	37	106%
munmap__  	8	4029	4323	293	37	107%
munmap__  	16	6647	6935	288	18	104%
munmap__  	32	11811	12398	587	18	105%
mprotect	1	439	465	26	26	106%
mprotect	2	1659	1745	86	43	105%
mprotect	4	3747	3889	142	36	104%
mprotect	8	6755	6969	215	27	103%
mprotect	16	13748	14144	396	25	103%
mprotect	32	27827	28969	1142	36	104%
madvise_	1	240	262	22	22	109%
madvise_	2	366	442	76	38	121%
madvise_	4	623	751	128	32	121%
madvise_	8	1110	1324	215	27	119%
madvise_	16	2127	2451	324	20	115%
madvise_	32	4109	4642	534	17	113%

The second test (measuring cpu cycle)
syscall__	vmas	cpu	cmseal	delta_cpu	per_vma	%
munmap__	1	1790	1890	100	100	106%
munmap__	2	2819	3033	214	107	108%
munmap__	4	4959	5271	312	78	106%
munmap__	8	8262	8745	483	60	106%
munmap__	16	13099	14116	1017	64	108%
munmap__	32	23221	24785	1565	49	107%
mprotect	1	906	967	62	62	107%
mprotect	2	3019	3203	184	92	106%
mprotect	4	6149	6569	420	105	107%
mprotect	8	9978	10524	545	68	105%
mprotect	16	20448	21427	979	61	105%
mprotect	32	40972	42935	1963	61	105%
madvise_	1	434	497	63	63	115%
madvise_	2	752	899	147	74	120%
madvise_	4	1313	1513	200	50	115%
madvise_	8	2271	2627	356	44	116%
madvise_	16	4312	4883	571	36	113%
madvise_	32	8376	9319	943	29	111%

Based on the result, for 6.8 kernel, sealing check adds
20-40 nano seconds, or around 50-100 CPU cycles, per VMA.

In addition, I applied the sealing to 5.10 kernel:
The first test (measuring time)
syscall__	vmas	t	tmseal	delta_ns	per_vma	%
munmap__	1	357	390	33	33	109%
munmap__	2	442	463	21	11	105%
munmap__	4	614	634	20	5	103%
munmap__	8	1017	1137	120	15	112%
munmap__	16	1889	2153	263	16	114%
munmap__	32	4109	4088	-21	-1	99%
mprotect	1	235	227	-7	-7	97%
mprotect	2	495	464	-30	-15	94%
mprotect	4	741	764	24	6	103%
mprotect	8	1434	1437	2	0	100%
mprotect	16	2958	2991	33	2	101%
mprotect	32	6431	6608	177	6	103%
madvise_	1	191	208	16	16	109%
madvise_	2	300	324	24	12	108%
madvise_	4	450	473	23	6	105%
madvise_	8	753	806	53	7	107%
madvise_	16	1467	1592	125	8	108%
madvise_	32	2795	3405	610	19	122%
					
The second test (measuring cpu cycle)
syscall__	nbr_vma	cpu	cmseal	delta_cpu	per_vma	%
munmap__	1	684	715	31	31	105%
munmap__	2	861	898	38	19	104%
munmap__	4	1183	1235	51	13	104%
munmap__	8	1999	2045	46	6	102%
munmap__	16	3839	3816	-23	-1	99%
munmap__	32	7672	7887	216	7	103%
mprotect	1	397	443	46	46	112%
mprotect	2	738	788	50	25	107%
mprotect	4	1221	1256	35	9	103%
mprotect	8	2356	2429	72	9	103%
mprotect	16	4961	4935	-26	-2	99%
mprotect	32	9882	10172	291	9	103%
madvise_	1	351	380	29	29	108%
madvise_	2	565	615	49	25	109%
madvise_	4	872	933	61	15	107%
madvise_	8	1508	1640	132	16	109%
madvise_	16	3078	3323	245	15	108%
madvise_	32	5893	6704	811	25	114%

For 5.10 kernel, sealing check adds 0-15 ns in time, or 10-30
CPU cycles, there is even decrease in some cases.

It might be interesting to compare 5.10 and 6.8 kernel
The first test (measuring time)
syscall__	vmas	t_5_10	t_6_8	delta_ns	per_vma	%
munmap__	1	357	909	552	552	254%
munmap__	2	442	1398	956	478	316%
munmap__	4	614	2444	1830	458	398%
munmap__	8	1017	4029	3012	377	396%
munmap__	16	1889	6647	4758	297	352%
munmap__	32	4109	11811	7702	241	287%
mprotect	1	235	439	204	204	187%
mprotect	2	495	1659	1164	582	335%
mprotect	4	741	3747	3006	752	506%
mprotect	8	1434	6755	5320	665	471%
mprotect	16	2958	13748	10790	674	465%
mprotect	32	6431	27827	21397	669	433%
madvise_	1	191	240	49	49	125%
madvise_	2	300	366	67	33	122%
madvise_	4	450	623	173	43	138%
madvise_	8	753	1110	357	45	147%
madvise_	16	1467	2127	660	41	145%
madvise_	32	2795	4109	1314	41	147%

The second test (measuring cpu cycle)
syscall__	vmas	cpu_5_10	c_6_8	delta_cpu	per_vma	%
munmap__	1	684	1790	1106	1106	262%
munmap__	2	861	2819	1958	979	327%
munmap__	4	1183	4959	3776	944	419%
munmap__	8	1999	8262	6263	783	413%
munmap__	16	3839	13099	9260	579	341%
munmap__	32	7672	23221	15549	486	303%
mprotect	1	397	906	509	509	228%
mprotect	2	738	3019	2281	1140	409%
mprotect	4	1221	6149	4929	1232	504%
mprotect	8	2356	9978	7622	953	423%
mprotect	16	4961	20448	15487	968	412%
mprotect	32	9882	40972	31091	972	415%
madvise_	1	351	434	82	82	123%
madvise_	2	565	752	186	93	133%
madvise_	4	872	1313	442	110	151%
madvise_	8	1508	2271	763	95	151%
madvise_	16	3078	4312	1234	77	140%
madvise_	32	5893	8376	2483	78	142%

From 5.10 to 6.8
munmap: added 250-550 ns in time, or 500-1100 in cpu cycle, per vma.
mprotect: added 200-750 ns in time, or 500-1200 in cpu cycle, per vma.
madvise: added 33-50 ns in time, or 70-110 in cpu cycle, per vma.

In comparison to mseal, which adds 20-40 ns or 50-100 CPU cycles, the
increase from 5.10 to 6.8 is significantly larger, approximately ten times
greater for munmap and mprotect.

When I discuss the mm performance with Brian Makin, an engineer who worked
on performance, it was brought to my attention that such performance
benchmarks, which measuring millions of mm syscall in a tight loop, may
not accurately reflect real-world scenarios, such as that of a database
service.  Also this is tested using a single HW and ChromeOS, the data
from another HW or distribution might be different.  It might be best to
take this data with a grain of salt.


This patch (of 5):

Wire up mseal syscall for all architectures.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jeff Xu <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Jann Horn <[email protected]> [Bug #2]
Cc: Jeff Xu <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Jorge Lucangeli Obes <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Muhammad Usama Anjum <[email protected]>
Cc: Pedro Falcato <[email protected]>
Cc: Stephen Röttger <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Amer Al Shanawany <[email protected]>
Cc: Javier Carrasco <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
konradybcio pushed a commit that referenced this issue May 29, 2024
In dctcp_update_alpha(), we use a module parameter dctcp_shift_g
as follows:

  alpha -= min_not_zero(alpha, alpha >> dctcp_shift_g);
  ...
  delivered_ce <<= (10 - dctcp_shift_g);

It seems syzkaller started fuzzing module parameters and triggered
shift-out-of-bounds [0] by setting 100 to dctcp_shift_g:

  memcpy((void*)0x20000080,
         "/sys/module/tcp_dctcp/parameters/dctcp_shift_g\000", 47);
  res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x20000080ul,
                /*flags=*/2ul, /*mode=*/0ul);
  memcpy((void*)0x20000000, "100\000", 4);
  syscall(__NR_write, /*fd=*/r[0], /*val=*/0x20000000ul, /*len=*/4ul);

Let's limit the max value of dctcp_shift_g by param_set_uint_minmax().

With this patch:

  # echo 10 > /sys/module/tcp_dctcp/parameters/dctcp_shift_g
  # cat /sys/module/tcp_dctcp/parameters/dctcp_shift_g
  10
  # echo 11 > /sys/module/tcp_dctcp/parameters/dctcp_shift_g
  -bash: echo: write error: Invalid argument

[0]:
UBSAN: shift-out-of-bounds in net/ipv4/tcp_dctcp.c:143:12
shift exponent 100 is too large for 32-bit type 'u32' (aka 'unsigned int')
CPU: 0 PID: 8083 Comm: syz-executor345 Not tainted 6.9.0-05151-g1b294a1f3561 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x201/0x300 lib/dump_stack.c:114
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_shift_out_of_bounds+0x346/0x3a0 lib/ubsan.c:468
 dctcp_update_alpha+0x540/0x570 net/ipv4/tcp_dctcp.c:143
 tcp_in_ack_event net/ipv4/tcp_input.c:3802 [inline]
 tcp_ack+0x17b1/0x3bc0 net/ipv4/tcp_input.c:3948
 tcp_rcv_state_process+0x57a/0x2290 net/ipv4/tcp_input.c:6711
 tcp_v4_do_rcv+0x764/0xc40 net/ipv4/tcp_ipv4.c:1937
 sk_backlog_rcv include/net/sock.h:1106 [inline]
 __release_sock+0x20f/0x350 net/core/sock.c:2983
 release_sock+0x61/0x1f0 net/core/sock.c:3549
 mptcp_subflow_shutdown+0x3d0/0x620 net/mptcp/protocol.c:2907
 mptcp_check_send_data_fin+0x225/0x410 net/mptcp/protocol.c:2976
 __mptcp_close+0x238/0xad0 net/mptcp/protocol.c:3072
 mptcp_close+0x2a/0x1a0 net/mptcp/protocol.c:3127
 inet_release+0x190/0x1f0 net/ipv4/af_inet.c:437
 __sock_release net/socket.c:659 [inline]
 sock_close+0xc0/0x240 net/socket.c:1421
 __fput+0x41b/0x890 fs/file_table.c:422
 task_work_run+0x23b/0x300 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x9c8/0x2540 kernel/exit.c:878
 do_group_exit+0x201/0x2b0 kernel/exit.c:1027
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xe4/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x67/0x6f
RIP: 0033:0x7f6c2b5005b6
Code: Unable to access opcode bytes at 0x7f6c2b50058c.
RSP: 002b:00007ffe883eb948 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f6c2b5862f0 RCX: 00007f6c2b5005b6
RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001
RBP: 0000000000000001 R08: 00000000000000e7 R09: ffffffffffffffc0
R10: 0000000000000006 R11: 0000000000000246 R12: 00007f6c2b5862f0
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
 </TASK>

Reported-by: syzkaller <[email protected]>
Reported-by: Yue Sun <[email protected]>
Reported-by: xingwei lee <[email protected]>
Closes: https://lore.kernel.org/netdev/CAEkJfYNJM=cw-8x7_Vmj1J6uYVCWMbbvD=EFmDPVBGpTsqOxEA@mail.gmail.com/
Fixes: e3118e8 ("net: tcp: add DCTCP congestion control algorithm")
Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
konradybcio pushed a commit that referenced this issue Jul 9, 2024
This adds a check before freeing the rx->skb in flush and close
functions to handle the kernel crash seen while removing driver after FW
download fails or before FW download completes.

dmesg log:
[   54.634586] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000080
[   54.643398] Mem abort info:
[   54.646204]   ESR = 0x0000000096000004
[   54.649964]   EC = 0x25: DABT (current EL), IL = 32 bits
[   54.655286]   SET = 0, FnV = 0
[   54.658348]   EA = 0, S1PTW = 0
[   54.661498]   FSC = 0x04: level 0 translation fault
[   54.666391] Data abort info:
[   54.669273]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[   54.674768]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[   54.674771]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[   54.674775] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000048860000
[   54.674780] [0000000000000080] pgd=0000000000000000, p4d=0000000000000000
[   54.703880] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[   54.710152] Modules linked in: btnxpuart(-) overlay fsl_jr_uio caam_jr caamkeyblob_desc caamhash_desc caamalg_desc crypto_engine authenc libdes crct10dif_ce polyval_ce polyval_generic snd_soc_imx_spdif snd_soc_imx_card snd_soc_ak5558 snd_soc_ak4458 caam secvio error snd_soc_fsl_micfil snd_soc_fsl_spdif snd_soc_fsl_sai snd_soc_fsl_utils imx_pcm_dma gpio_ir_recv rc_core sch_fq_codel fuse
[   54.744357] CPU: 3 PID: 72 Comm: kworker/u9:0 Not tainted 6.6.3-otbr-g128004619037 #2
[   54.744364] Hardware name: FSL i.MX8MM EVK board (DT)
[   54.744368] Workqueue: hci0 hci_power_on
[   54.757244] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   54.757249] pc : kfree_skb_reason+0x18/0xb0
[   54.772299] lr : btnxpuart_flush+0x40/0x58 [btnxpuart]
[   54.782921] sp : ffff8000805ebca0
[   54.782923] x29: ffff8000805ebca0 x28: ffffa5c6cf1869c0 x27: ffffa5c6cf186000
[   54.782931] x26: ffff377b84852400 x25: ffff377b848523c0 x24: ffff377b845e7230
[   54.782938] x23: ffffa5c6ce8dbe08 x22: ffffa5c6ceb65410 x21: 00000000ffffff92
[   54.782945] x20: ffffa5c6ce8dbe98 x19: ffffffffffffffac x18: ffffffffffffffff
[   54.807651] x17: 0000000000000000 x16: ffffa5c6ce2824ec x15: ffff8001005eb857
[   54.821917] x14: 0000000000000000 x13: ffffa5c6cf1a02e0 x12: 0000000000000642
[   54.821924] x11: 0000000000000040 x10: ffffa5c6cf19d690 x9 : ffffa5c6cf19d688
[   54.821931] x8 : ffff377b86000028 x7 : 0000000000000000 x6 : 0000000000000000
[   54.821938] x5 : ffff377b86000000 x4 : 0000000000000000 x3 : 0000000000000000
[   54.843331] x2 : 0000000000000000 x1 : 0000000000000002 x0 : ffffffffffffffac
[   54.857599] Call trace:
[   54.857601]  kfree_skb_reason+0x18/0xb0
[   54.863878]  btnxpuart_flush+0x40/0x58 [btnxpuart]
[   54.863888]  hci_dev_open_sync+0x3a8/0xa04
[   54.872773]  hci_power_on+0x54/0x2e4
[   54.881832]  process_one_work+0x138/0x260
[   54.881842]  worker_thread+0x32c/0x438
[   54.881847]  kthread+0x118/0x11c
[   54.881853]  ret_from_fork+0x10/0x20
[   54.896406] Code: a9be7bfd 910003fd f9000bf3 aa0003f3 (b940d400)
[   54.896410] ---[ end trace 0000000000000000 ]---

Signed-off-by: Neeraj Sanjay Kale <[email protected]>
Tested-by: Guillaume Legoupil <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
konradybcio pushed a commit that referenced this issue Jul 19, 2024
Add a set of tests to validate that stack traces captured from or in the
presence of active uprobes and uretprobes are valid and complete.

For this we use BPF program that are installed either on entry or exit
of user function, plus deep-nested USDT. One of target funtions
(target_1) is recursive to generate two different entries in the stack
trace for the same uprobe/uretprobe, testing potential edge conditions.

If there is no fixes, we get something like this for one of the scenarios:

 caller: 0x758fff - 0x7595ab
 target_1: 0x758fd5 - 0x758fff
 target_2: 0x758fca - 0x758fd5
 target_3: 0x758fbf - 0x758fca
 target_4: 0x758fb3 - 0x758fbf
 ENTRY #0: 0x758fb3 (in target_4)
 ENTRY #1: 0x758fd3 (in target_2)
 ENTRY #2: 0x758ffd (in target_1)
 ENTRY #3: 0x7fffffffe000
 ENTRY #4: 0x7fffffffe000
 ENTRY #5: 0x6f8f39
 ENTRY torvalds#6: 0x6fa6f0
 ENTRY torvalds#7: 0x7f403f229590

Entry #3 and #4 (0x7fffffffe000) are uretprobe trampoline addresses
which obscure actual target_1 and another target_1 invocations. Also
note that between entry #0 and entry #1 we are missing an entry for
target_3.

With fixes, we get desired full stack traces:

 caller: 0x758fff - 0x7595ab
 target_1: 0x758fd5 - 0x758fff
 target_2: 0x758fca - 0x758fd5
 target_3: 0x758fbf - 0x758fca
 target_4: 0x758fb3 - 0x758fbf
 ENTRY #0: 0x758fb7 (in target_4)
 ENTRY #1: 0x758fc8 (in target_3)
 ENTRY #2: 0x758fd3 (in target_2)
 ENTRY #3: 0x758ffd (in target_1)
 ENTRY #4: 0x758ff3 (in target_1)
 ENTRY #5: 0x75922c (in caller)
 ENTRY torvalds#6: 0x6f8f39
 ENTRY torvalds#7: 0x6fa6f0
 ENTRY torvalds#8: 0x7f986adc4cd0

Now there is a logical and complete sequence of function calls.

Link: https://lore.kernel.org/all/[email protected]/

Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
konradybcio pushed a commit that referenced this issue Jul 19, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following batch contains Netfilter fixes for net:

Patch #1 fixes a bogus WARN_ON splat in nfnetlink_queue.

Patch #2 fixes a crash due to stack overflow in chain loop detection
	 by using the existing chain validation routines

Both patches from Florian Westphal.

netfilter pull request 24-07-11

* tag 'nf-24-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables: prefer nft_chain_validate
  netfilter: nfnetlink_queue: drop bogus WARN_ON
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
konradybcio pushed a commit that referenced this issue Jul 19, 2024
When putting an inode during extent map shrinking we're doing a standard
iput() but that may take a long time in case the inode is dirty and we are
doing the final iput that triggers eviction - the VFS will have to wait
for writeback before calling the btrfs evict callback (see
fs/inode.c:evict()).

This slows down the task running the shrinker which may have been
triggered while updating some tree for example, meaning locks are held
as well as an open transaction handle.

Also if the iput() ends up triggering eviction and the inode has no links
anymore, then we trigger item truncation which requires flushing delayed
items, space reservation to start a transaction and that may trigger the
space reclaim task and wait for it, resulting in deadlocks in case the
reclaim task needs for example to commit a transaction and the shrinker
is being triggered from a path holding a transaction handle.

Syzbot reported such a case with the following stack traces:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.10.0-rc2-syzkaller-00010-g2ab795141095 #0 Not tainted
   ------------------------------------------------------
   kswapd0/111 is trying to acquire lock:
   ffff88801eae4610 (sb_internal#3){.+.+}-{0:0}, at: btrfs_commit_inode_delayed_inode+0x110/0x330 fs/btrfs/delayed-inode.c:1275

   but task is already holding lock:
   ffffffff8dd3a9a0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0xa88/0x1970 mm/vmscan.c:6924

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> #3 (fs_reclaim){+.+.}-{0:0}:
          __fs_reclaim_acquire mm/page_alloc.c:3783 [inline]
          fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3797
          might_alloc include/linux/sched/mm.h:334 [inline]
          slab_pre_alloc_hook mm/slub.c:3890 [inline]
          slab_alloc_node mm/slub.c:3980 [inline]
          kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4019
          btrfs_alloc_inode+0x118/0xb20 fs/btrfs/inode.c:8411
          alloc_inode+0x5d/0x230 fs/inode.c:261
          iget5_locked fs/inode.c:1235 [inline]
          iget5_locked+0x1c9/0x2c0 fs/inode.c:1228
          btrfs_iget_locked fs/btrfs/inode.c:5590 [inline]
          btrfs_iget_path fs/btrfs/inode.c:5607 [inline]
          btrfs_iget+0xfb/0x230 fs/btrfs/inode.c:5636
          create_reloc_inode+0x403/0x820 fs/btrfs/relocation.c:3911
          btrfs_relocate_block_group+0x471/0xe60 fs/btrfs/relocation.c:4114
          btrfs_relocate_chunk+0x143/0x450 fs/btrfs/volumes.c:3373
          __btrfs_balance fs/btrfs/volumes.c:4157 [inline]
          btrfs_balance+0x211a/0x3f00 fs/btrfs/volumes.c:4534
          btrfs_ioctl_balance fs/btrfs/ioctl.c:3675 [inline]
          btrfs_ioctl+0x12ed/0x8290 fs/btrfs/ioctl.c:4742
          __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1007
          do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
          __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
          do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
          entry_SYSENTER_compat_after_hwframe+0x84/0x8e

   -> #2 (btrfs_trans_num_extwriters){++++}-{0:0}:
          join_transaction+0x164/0xf40 fs/btrfs/transaction.c:315
          start_transaction+0x427/0x1a70 fs/btrfs/transaction.c:700
          btrfs_rebuild_free_space_tree+0xaa/0x480 fs/btrfs/free-space-tree.c:1323
          btrfs_start_pre_rw_mount+0x218/0xf60 fs/btrfs/disk-io.c:2999
          open_ctree+0x41ab/0x52e0 fs/btrfs/disk-io.c:3554
          btrfs_fill_super fs/btrfs/super.c:946 [inline]
          btrfs_get_tree_super fs/btrfs/super.c:1863 [inline]
          btrfs_get_tree+0x11e9/0x1b90 fs/btrfs/super.c:2089
          vfs_get_tree+0x8f/0x380 fs/super.c:1780
          fc_mount+0x16/0xc0 fs/namespace.c:1125
          btrfs_get_tree_subvol fs/btrfs/super.c:2052 [inline]
          btrfs_get_tree+0xa53/0x1b90 fs/btrfs/super.c:2090
          vfs_get_tree+0x8f/0x380 fs/super.c:1780
          do_new_mount fs/namespace.c:3352 [inline]
          path_mount+0x6e1/0x1f10 fs/namespace.c:3679
          do_mount fs/namespace.c:3692 [inline]
          __do_sys_mount fs/namespace.c:3898 [inline]
          __se_sys_mount fs/namespace.c:3875 [inline]
          __ia32_sys_mount+0x295/0x320 fs/namespace.c:3875
          do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
          __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
          do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
          entry_SYSENTER_compat_after_hwframe+0x84/0x8e

   -> #1 (btrfs_trans_num_writers){++++}-{0:0}:
          join_transaction+0x148/0xf40 fs/btrfs/transaction.c:314
          start_transaction+0x427/0x1a70 fs/btrfs/transaction.c:700
          btrfs_rebuild_free_space_tree+0xaa/0x480 fs/btrfs/free-space-tree.c:1323
          btrfs_start_pre_rw_mount+0x218/0xf60 fs/btrfs/disk-io.c:2999
          open_ctree+0x41ab/0x52e0 fs/btrfs/disk-io.c:3554
          btrfs_fill_super fs/btrfs/super.c:946 [inline]
          btrfs_get_tree_super fs/btrfs/super.c:1863 [inline]
          btrfs_get_tree+0x11e9/0x1b90 fs/btrfs/super.c:2089
          vfs_get_tree+0x8f/0x380 fs/super.c:1780
          fc_mount+0x16/0xc0 fs/namespace.c:1125
          btrfs_get_tree_subvol fs/btrfs/super.c:2052 [inline]
          btrfs_get_tree+0xa53/0x1b90 fs/btrfs/super.c:2090
          vfs_get_tree+0x8f/0x380 fs/super.c:1780
          do_new_mount fs/namespace.c:3352 [inline]
          path_mount+0x6e1/0x1f10 fs/namespace.c:3679
          do_mount fs/namespace.c:3692 [inline]
          __do_sys_mount fs/namespace.c:3898 [inline]
          __se_sys_mount fs/namespace.c:3875 [inline]
          __ia32_sys_mount+0x295/0x320 fs/namespace.c:3875
          do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
          __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
          do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
          entry_SYSENTER_compat_after_hwframe+0x84/0x8e

   -> #0 (sb_internal#3){.+.+}-{0:0}:
          check_prev_add kernel/locking/lockdep.c:3134 [inline]
          check_prevs_add kernel/locking/lockdep.c:3253 [inline]
          validate_chain kernel/locking/lockdep.c:3869 [inline]
          __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
          lock_acquire kernel/locking/lockdep.c:5754 [inline]
          lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
          percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
          __sb_start_write include/linux/fs.h:1655 [inline]
          sb_start_intwrite include/linux/fs.h:1838 [inline]
          start_transaction+0xbc1/0x1a70 fs/btrfs/transaction.c:694
          btrfs_commit_inode_delayed_inode+0x110/0x330 fs/btrfs/delayed-inode.c:1275
          btrfs_evict_inode+0x960/0xe80 fs/btrfs/inode.c:5291
          evict+0x2ed/0x6c0 fs/inode.c:667
          iput_final fs/inode.c:1741 [inline]
          iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
          iput+0x5c/0x80 fs/inode.c:1757
          btrfs_scan_root fs/btrfs/extent_map.c:1118 [inline]
          btrfs_free_extent_maps+0xbd3/0x1320 fs/btrfs/extent_map.c:1189
          super_cache_scan+0x409/0x550 fs/super.c:227
          do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435
          shrink_slab+0x18a/0x1310 mm/shrinker.c:662
          shrink_one+0x493/0x7c0 mm/vmscan.c:4790
          shrink_many mm/vmscan.c:4851 [inline]
          lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
          shrink_node mm/vmscan.c:5910 [inline]
          kswapd_shrink_node mm/vmscan.c:6720 [inline]
          balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
          kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
          kthread+0x2c1/0x3a0 kernel/kthread.c:389
          ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
          ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

   other info that might help us debug this:

   Chain exists of:
     sb_internal#3 --> btrfs_trans_num_extwriters --> fs_reclaim

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(fs_reclaim);
                                  lock(btrfs_trans_num_extwriters);
                                  lock(fs_reclaim);
     rlock(sb_internal#3);

    *** DEADLOCK ***

   2 locks held by kswapd0/111:
    #0: ffffffff8dd3a9a0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0xa88/0x1970 mm/vmscan.c:6924
    #1: ffff88801eae40e0 (&type->s_umount_key#62){++++}-{3:3}, at: super_trylock_shared fs/super.c:562 [inline]
    #1: ffff88801eae40e0 (&type->s_umount_key#62){++++}-{3:3}, at: super_cache_scan+0x96/0x550 fs/super.c:196

   stack backtrace:
   CPU: 0 PID: 111 Comm: kswapd0 Not tainted 6.10.0-rc2-syzkaller-00010-g2ab795141095 #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
   Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:88 [inline]
    dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
    check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187
    check_prev_add kernel/locking/lockdep.c:3134 [inline]
    check_prevs_add kernel/locking/lockdep.c:3253 [inline]
    validate_chain kernel/locking/lockdep.c:3869 [inline]
    __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
    lock_acquire kernel/locking/lockdep.c:5754 [inline]
    lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
    percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
    __sb_start_write include/linux/fs.h:1655 [inline]
    sb_start_intwrite include/linux/fs.h:1838 [inline]
    start_transaction+0xbc1/0x1a70 fs/btrfs/transaction.c:694
    btrfs_commit_inode_delayed_inode+0x110/0x330 fs/btrfs/delayed-inode.c:1275
    btrfs_evict_inode+0x960/0xe80 fs/btrfs/inode.c:5291
    evict+0x2ed/0x6c0 fs/inode.c:667
    iput_final fs/inode.c:1741 [inline]
    iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
    iput+0x5c/0x80 fs/inode.c:1757
    btrfs_scan_root fs/btrfs/extent_map.c:1118 [inline]
    btrfs_free_extent_maps+0xbd3/0x1320 fs/btrfs/extent_map.c:1189
    super_cache_scan+0x409/0x550 fs/super.c:227
    do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435
    shrink_slab+0x18a/0x1310 mm/shrinker.c:662
    shrink_one+0x493/0x7c0 mm/vmscan.c:4790
    shrink_many mm/vmscan.c:4851 [inline]
    lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
    shrink_node mm/vmscan.c:5910 [inline]
    kswapd_shrink_node mm/vmscan.c:6720 [inline]
    balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
    kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
    kthread+0x2c1/0x3a0 kernel/kthread.c:389
    ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
    </TASK>

So fix this by using btrfs_add_delayed_iput() so that the final iput is
delegated to the cleaner kthread.

Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Reported-by: [email protected]
Fixes: 956a17d ("btrfs: add a shrinker for extent maps")
Reviewed-by: Josef Bacik <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
konradybcio pushed a commit that referenced this issue Jul 19, 2024
Patch series "ioctl()-based API to query VMAs from /proc/<pid>/maps", v6.

Implement binary ioctl()-based interface to /proc/<pid>/maps file to allow
applications to query VMA information more efficiently than reading *all*
VMAs nonselectively through text-based interface of /proc/<pid>/maps file.

Patch #2 goes into a lot of details and background on some common patterns
of using /proc/<pid>/maps in the area of performance profiling and
subsequent symbolization of captured stack traces.  As mentioned in that
patch, patterns of VMA querying can differ depending on specific use case,
but can generally be grouped into two main categories: the need to query a
small subset of VMAs covering a given batch of addresses, or
reading/storing/caching all (typically, executable) VMAs upfront for later
processing.

The new PROCMAP_QUERY ioctl() API added in this patch set was motivated by
the former pattern of usage.  Earlier revisions had a patch adding a tool
that faithfully reproduces an efficient VMA matching pass of a symbolizer,
collecting a subset of covering VMAs for a given set of addresses as
efficiently as possible.  This tool served both as a testing ground, as
well as a benchmarking tool.  It implements everything both for currently
existing text-based /proc/<pid>/maps interface, as well as for newly-added
PROCMAP_QUERY ioctl().  This revision dropped the tool from the patch set
and, once the API lands upstream, this tool might be added separately on
Github as an example.

Based on discussion on earlier revisions of this patch set, it turned out
that this ioctl() API is competitive with highly-optimized text-based
pre-processing pattern that perf tool is using.  Based on perf discussion,
this revision adds more flexibility in specifying a subset of VMAs that
are of interest.  Now it's possible to specify desired permissions of VMAs
(e.g., request only executable ones) and/or restrict to only a subset of
VMAs that have file backing.  This further improves the efficiency when
using this new API thanks to more selective (executable VMAs only)
querying.

In addition to a custom benchmarking tool, and experimental perf
integration (available at [0]), Daniel Mueller has since also implemented
an experimental integration into blazesym (see [1]), a library used for
stack trace symbolization by our server fleet-wide profiler and another
on-device profiler agent that runs on weaker ARM devices.  The latter
ARM-based device profiler is especially sensitive to performance, and so
we benchmarked and compared text-based /proc/<pid>/maps solution to the
equivalent one using PROCMAP_QUERY ioctl().

Results are very encouraging, giving us 5x improvement for end-to-end
so-called "address normalization" pass, which is the part of the
symbolization process that happens locally on ARM device, before being
sent out for further heavier-weight processing on more powerful remote
server.  Note that this is not an artificial microbenchmark.  It's a full
end-to-end API call being measured with real-world data on real-world
device.

  TEXT-BASED
  ==========
  Benchmarking main/normalize_process_no_build_ids_uncached_maps
  main/normalize_process_no_build_ids_uncached_maps
	  time:   [49.777 µs 49.982 µs 50.250 µs]

  IOCTL-BASED
  ===========
  Benchmarking main/normalize_process_no_build_ids_uncached_maps
  main/normalize_process_no_build_ids_uncached_maps
	  time:   [10.328 µs 10.391 µs 10.457 µs]
	  change: [−79.453% −79.304% −79.166%] (p = 0.00 < 0.02)
	  Performance has improved.

You can see above that we see the drop from 50µs down to 10µs for
exactly the same amount of work, with the same data and target process.

With the aforementioned custom tool, we see about ~40x improvement (it
might vary a bit, depending on a specific captured set of addresses).  And
even for perf-based benchmark it's on par or slightly ahead when using
permission-based filtering (fetching only executable VMAs).

Earlier revisions attempted to use per-VMA locking, if kernel was compiled
with CONFIG_PER_VMA_LOCK=y, but it turned out that anon_vma_name() is not
yet compatible with per-VMA locking and assumes mmap_lock to be taken,
which makes the use of per-VMA locking for this API premature.  It was
agreed ([2]) to continue for now with just mmap_lock, but the code
structure is such that it should be easy to add per-VMA locking support
once all the pieces are ready.

One thing that did not change was basing this new API as an ioctl()
command on /proc/<pid>/maps file.  An ioctl-based API on top of pidfd was
considered, but has its own downsides.  Implementing ioctl() directly on
pidfd will cause access permission checks on every single ioctl(), which
leads to performance concerns and potential spam of capable() audit
messages.  It also prevents a nice pattern, possible with
/proc/<pid>/maps, in which application opens /proc/self/maps FD (requiring
no additional capabilities) and passed this FD to profiling agent for
querying.  To achieve similar pattern, a new file would have to be created
from pidf just for VMA querying, which is considered to be inferior to
just querying /proc/<pid>/maps FD as proposed in current approach.  These
aspects were discussed in the hallway track at recent LSF/MM/BPF 2024 and
sticking to procfs ioctl() was the final agreement we arrived at.

  [0] https://github.com/anakryiko/linux/commits/procfs-proc-maps-ioctl-v2/
  [1] libbpf/blazesym#675
  [2] https://lore.kernel.org/bpf/7rm3izyq2vjp5evdjc7c6z4crdd3oerpiknumdnmmemwyiwx7t@hleldw7iozi3/


This patch (of 6):

Extract generic logic to fetch relevant pieces of data to describe VMA
name.  This could be just some string (either special constant or
user-provided), or a string with some formatted wrapping text (e.g.,
"[anon_shmem:<something>]"), or, commonly, file path.  seq_file-based
logic has different methods to handle all three cases, but they are
currently mixed in with extracting underlying sources of data.

This patch splits this into data fetching and data formatting, so that
data fetching can be reused later on.

There should be no functional changes.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Liam R. Howlett <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Mike Rapoport (IBM) <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
konradybcio pushed a commit that referenced this issue Jul 19, 2024
This adds a check before freeing the rx->skb in flush and close
functions to handle the kernel crash seen while removing driver after FW
download fails or before FW download completes.

dmesg log:
[   54.634586] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000080
[   54.643398] Mem abort info:
[   54.646204]   ESR = 0x0000000096000004
[   54.649964]   EC = 0x25: DABT (current EL), IL = 32 bits
[   54.655286]   SET = 0, FnV = 0
[   54.658348]   EA = 0, S1PTW = 0
[   54.661498]   FSC = 0x04: level 0 translation fault
[   54.666391] Data abort info:
[   54.669273]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[   54.674768]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[   54.674771]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[   54.674775] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000048860000
[   54.674780] [0000000000000080] pgd=0000000000000000, p4d=0000000000000000
[   54.703880] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[   54.710152] Modules linked in: btnxpuart(-) overlay fsl_jr_uio caam_jr caamkeyblob_desc caamhash_desc caamalg_desc crypto_engine authenc libdes crct10dif_ce polyval_ce polyval_generic snd_soc_imx_spdif snd_soc_imx_card snd_soc_ak5558 snd_soc_ak4458 caam secvio error snd_soc_fsl_micfil snd_soc_fsl_spdif snd_soc_fsl_sai snd_soc_fsl_utils imx_pcm_dma gpio_ir_recv rc_core sch_fq_codel fuse
[   54.744357] CPU: 3 PID: 72 Comm: kworker/u9:0 Not tainted 6.6.3-otbr-g128004619037 #2
[   54.744364] Hardware name: FSL i.MX8MM EVK board (DT)
[   54.744368] Workqueue: hci0 hci_power_on
[   54.757244] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   54.757249] pc : kfree_skb_reason+0x18/0xb0
[   54.772299] lr : btnxpuart_flush+0x40/0x58 [btnxpuart]
[   54.782921] sp : ffff8000805ebca0
[   54.782923] x29: ffff8000805ebca0 x28: ffffa5c6cf1869c0 x27: ffffa5c6cf186000
[   54.782931] x26: ffff377b84852400 x25: ffff377b848523c0 x24: ffff377b845e7230
[   54.782938] x23: ffffa5c6ce8dbe08 x22: ffffa5c6ceb65410 x21: 00000000ffffff92
[   54.782945] x20: ffffa5c6ce8dbe98 x19: ffffffffffffffac x18: ffffffffffffffff
[   54.807651] x17: 0000000000000000 x16: ffffa5c6ce2824ec x15: ffff8001005eb857
[   54.821917] x14: 0000000000000000 x13: ffffa5c6cf1a02e0 x12: 0000000000000642
[   54.821924] x11: 0000000000000040 x10: ffffa5c6cf19d690 x9 : ffffa5c6cf19d688
[   54.821931] x8 : ffff377b86000028 x7 : 0000000000000000 x6 : 0000000000000000
[   54.821938] x5 : ffff377b86000000 x4 : 0000000000000000 x3 : 0000000000000000
[   54.843331] x2 : 0000000000000000 x1 : 0000000000000002 x0 : ffffffffffffffac
[   54.857599] Call trace:
[   54.857601]  kfree_skb_reason+0x18/0xb0
[   54.863878]  btnxpuart_flush+0x40/0x58 [btnxpuart]
[   54.863888]  hci_dev_open_sync+0x3a8/0xa04
[   54.872773]  hci_power_on+0x54/0x2e4
[   54.881832]  process_one_work+0x138/0x260
[   54.881842]  worker_thread+0x32c/0x438
[   54.881847]  kthread+0x118/0x11c
[   54.881853]  ret_from_fork+0x10/0x20
[   54.896406] Code: a9be7bfd 910003fd f9000bf3 aa0003f3 (b940d400)
[   54.896410] ---[ end trace 0000000000000000 ]---

Signed-off-by: Neeraj Sanjay Kale <[email protected]>
Tested-by: Guillaume Legoupil <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
konradybcio pushed a commit that referenced this issue Jul 19, 2024
When tries to demote 1G hugetlb folios, a lockdep warning is observed:

============================================
WARNING: possible recursive locking detected
6.10.0-rc6-00452-ga4d0275fa660-dirty torvalds#79 Not tainted
--------------------------------------------
bash/710 is trying to acquire lock:
ffffffff8f0a7850 (&h->resize_lock){+.+.}-{3:3}, at: demote_store+0x244/0x460

but task is already holding lock:
ffffffff8f0a6f48 (&h->resize_lock){+.+.}-{3:3}, at: demote_store+0xae/0x460

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&h->resize_lock);
  lock(&h->resize_lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by bash/710:
 #0: ffff8f118439c3f0 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x64/0xe0
 #1: ffff8f11893b9e88 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xf8/0x1d0
 #2: ffff8f1183dc4428 (kn->active#98){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x100/0x1d0
 #3: ffffffff8f0a6f48 (&h->resize_lock){+.+.}-{3:3}, at: demote_store+0xae/0x460

stack backtrace:
CPU: 3 PID: 710 Comm: bash Not tainted 6.10.0-rc6-00452-ga4d0275fa660-dirty torvalds#79
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x68/0xa0
 __lock_acquire+0x10f2/0x1ca0
 lock_acquire+0xbe/0x2d0
 __mutex_lock+0x6d/0x400
 demote_store+0x244/0x460
 kernfs_fop_write_iter+0x12c/0x1d0
 vfs_write+0x380/0x540
 ksys_write+0x64/0xe0
 do_syscall_64+0xb9/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa61db14887
RSP: 002b:00007ffc56c48358 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fa61db14887
RDX: 0000000000000002 RSI: 000055a030050220 RDI: 0000000000000001
RBP: 000055a030050220 R08: 00007fa61dbd1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007fa61dc1b780 R14: 00007fa61dc17600 R15: 00007fa61dc16a00
 </TASK>

Lockdep considers this an AA deadlock because the different resize_lock
mutexes reside in the same lockdep class, but this is a false positive.
Place them in distinct classes to avoid these warnings.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 8531fc6 ("hugetlb: add hugetlb demote page support")
Signed-off-by: Miaohe Lin <[email protected]>
Acked-by: Muchun Song <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
konradybcio pushed a commit that referenced this issue Jul 19, 2024
When tries to demote 1G hugetlb folios, a lockdep warning is observed:

============================================
WARNING: possible recursive locking detected
6.10.0-rc6-00452-ga4d0275fa660-dirty torvalds#79 Not tainted
--------------------------------------------
bash/710 is trying to acquire lock:
ffffffff8f0a7850 (&h->resize_lock){+.+.}-{3:3}, at: demote_store+0x244/0x460

but task is already holding lock:
ffffffff8f0a6f48 (&h->resize_lock){+.+.}-{3:3}, at: demote_store+0xae/0x460

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&h->resize_lock);
  lock(&h->resize_lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by bash/710:
 #0: ffff8f118439c3f0 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x64/0xe0
 #1: ffff8f11893b9e88 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xf8/0x1d0
 #2: ffff8f1183dc4428 (kn->active#98){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x100/0x1d0
 #3: ffffffff8f0a6f48 (&h->resize_lock){+.+.}-{3:3}, at: demote_store+0xae/0x460

stack backtrace:
CPU: 3 PID: 710 Comm: bash Not tainted 6.10.0-rc6-00452-ga4d0275fa660-dirty torvalds#79
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x68/0xa0
 __lock_acquire+0x10f2/0x1ca0
 lock_acquire+0xbe/0x2d0
 __mutex_lock+0x6d/0x400
 demote_store+0x244/0x460
 kernfs_fop_write_iter+0x12c/0x1d0
 vfs_write+0x380/0x540
 ksys_write+0x64/0xe0
 do_syscall_64+0xb9/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa61db14887
RSP: 002b:00007ffc56c48358 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fa61db14887
RDX: 0000000000000002 RSI: 000055a030050220 RDI: 0000000000000001
RBP: 000055a030050220 R08: 00007fa61dbd1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007fa61dc1b780 R14: 00007fa61dc17600 R15: 00007fa61dc16a00
 </TASK>

Lockdep considers this an AA deadlock because the different resize_lock
mutexes reside in the same lockdep class, but this is a false positive.
Place them in distinct classes to avoid these warnings.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 8531fc6 ("hugetlb: add hugetlb demote page support")
Signed-off-by: Miaohe Lin <[email protected]>
Acked-by: Muchun Song <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
konradybcio pushed a commit that referenced this issue Jul 25, 2024
…/git/gregkh/tty

Pull tty / serial updates from Greg KH:
 "Here is a small set of tty and serial driver updates for 6.11-rc1. Not
  much happened this cycle, unlike the previous kernel release which had
  lots of "excitement" in this part of the kernel. Included in here are
  the following changes:

   - dt binding updates for new platforms

   - 8250 driver updates

   - various small serial driver fixes and updates

   - printk/console naming and matching attempt #2 (was reverted for
     6.10-final, should be good to go this time around, acked by the
     relevant maintainers).

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (22 commits)
  Documentation: kernel-parameters: Add DEVNAME:0.0 format for serial ports
  serial: core: Add serial_base_match_and_update_preferred_console()
  printk: Add match_devname_and_update_preferred_console()
  serial: sc16is7xx: hardware reset chip if reset-gpios is defined in DT
  dt-bindings: serial: sc16is7xx: add reset-gpios
  dt-bindings: serial: vt8500-uart: convert to json-schema
  serial: 8250_platform: Explicitly show we initialise ISA ports only once
  tty: add missing MODULE_DESCRIPTION() macros
  dt-bindings: serial: mediatek,uart: add MT7988
  serial: sh-sci: Add support for RZ/V2H(P) SoC
  dt-bindings: serial: Add documentation for Renesas RZ/V2H(P) (R9A09G057) SCIF support
  dt-bindings: serial: renesas,scif: Make 'interrupt-names' property as required
  dt-bindings: serial: renesas,scif: Validate 'interrupts' and 'interrupt-names'
  dt-bindings: serial: renesas,scif: Move ref for serial.yaml at the end
  riscv: dts: starfive: jh7110: Add the core reset and jh7110 compatible for uarts
  serial: 8250_dw: Use reset array API to get resets
  dt-bindings: serial: snps-dw-apb-uart: Add one more reset signal for StarFive JH7110 SoC
  serial: 8250: Extract platform driver
  serial: 8250: Extract RSA bits
  serial: imx: stop casting struct uart_port to struct imx_port
  ...
konradybcio pushed a commit that referenced this issue Jul 25, 2024
In z_erofs_get_gbuf(), the current task may be migrated to another
CPU between `z_erofs_gbuf_id()` and `spin_lock(&gbuf->lock)`.

Therefore, z_erofs_put_gbuf() will trigger the following issue
which was found by stress test:

<2>[772156.434168] kernel BUG at fs/erofs/zutil.c:58!
..
<4>[772156.435007]
<4>[772156.439237] CPU: 0 PID: 3078 Comm: stress Kdump: loaded Tainted: G            E      6.10.0-rc7+ #2
<4>[772156.439239] Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 1.0.0 01/01/2017
<4>[772156.439241] pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
<4>[772156.439243] pc : z_erofs_put_gbuf+0x64/0x70 [erofs]
<4>[772156.439252] lr : z_erofs_lz4_decompress+0x600/0x6a0 [erofs]
..
<6>[772156.445958] stress (3127): drop_caches: 1
<4>[772156.446120] Call trace:
<4>[772156.446121]  z_erofs_put_gbuf+0x64/0x70 [erofs]
<4>[772156.446761]  z_erofs_lz4_decompress+0x600/0x6a0 [erofs]
<4>[772156.446897]  z_erofs_decompress_queue+0x740/0xa10 [erofs]
<4>[772156.447036]  z_erofs_runqueue+0x428/0x8c0 [erofs]
<4>[772156.447160]  z_erofs_readahead+0x224/0x390 [erofs]
..

Fixes: f36f301 ("erofs: rename per-CPU buffers to global buffer pool and make it configurable")
Cc: <[email protected]> # 6.10+
Cc: Chunhai Guo <[email protected]>
Signed-off-by: Gao Xiang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
konradybcio pushed a commit that referenced this issue Jul 29, 2024
When using cachefiles, lockdep may emit something similar to the circular
locking dependency notice below.  The problem appears to stem from the
following:

 (1) Cachefiles manipulates xattrs on the files in its cache when called
     from ->writepages().

 (2) The setxattr() and removexattr() system call handlers get the name
     (and value) from userspace after taking the sb_writers lock, putting
     accesses of the vma->vm_lock and mm->mmap_lock inside of that.

 (3) The afs filesystem uses a per-inode lock to prevent multiple
     revalidation RPCs and in writeback vs truncate to prevent parallel
     operations from deadlocking against the server on one side and local
     page locks on the other.

Fix this by moving the getting of the name and value in {get,remove}xattr()
outside of the sb_writers lock.  This also has the minor benefits that we
don't need to reget these in the event of a retry and we never try to take
the sb_writers lock in the event we can't pull the name and value into the
kernel.

Alternative approaches that might fix this include moving the dispatch of a
write to the cache off to a workqueue or trying to do without the
validation lock in afs.  Note that this might also affect other filesystems
that use netfslib and/or cachefiles.

 ======================================================
 WARNING: possible circular locking dependency detected
 6.10.0-build2+ torvalds#956 Not tainted
 ------------------------------------------------------
 fsstress/6050 is trying to acquire lock:
 ffff888138fd82f0 (mapping.invalidate_lock#3){++++}-{3:3}, at: filemap_fault+0x26e/0x8b0

 but task is already holding lock:
 ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #4 (&vma->vm_lock->lock){++++}-{3:3}:
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        down_write+0x3b/0x50
        vma_start_write+0x6b/0xa0
        vma_link+0xcc/0x140
        insert_vm_struct+0xb7/0xf0
        alloc_bprm+0x2c1/0x390
        kernel_execve+0x65/0x1a0
        call_usermodehelper_exec_async+0x14d/0x190
        ret_from_fork+0x24/0x40
        ret_from_fork_asm+0x1a/0x30

 -> #3 (&mm->mmap_lock){++++}-{3:3}:
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        __might_fault+0x7c/0xb0
        strncpy_from_user+0x25/0x160
        removexattr+0x7f/0x100
        __do_sys_fremovexattr+0x7e/0xb0
        do_syscall_64+0x9f/0x100
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

 -> #2 (sb_writers#14){.+.+}-{0:0}:
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        percpu_down_read+0x3c/0x90
        vfs_iocb_iter_write+0xe9/0x1d0
        __cachefiles_write+0x367/0x430
        cachefiles_issue_write+0x299/0x2f0
        netfs_advance_write+0x117/0x140
        netfs_write_folio.isra.0+0x5ca/0x6e0
        netfs_writepages+0x230/0x2f0
        afs_writepages+0x4d/0x70
        do_writepages+0x1e8/0x3e0
        filemap_fdatawrite_wbc+0x84/0xa0
        __filemap_fdatawrite_range+0xa8/0xf0
        file_write_and_wait_range+0x59/0x90
        afs_release+0x10f/0x270
        __fput+0x25f/0x3d0
        __do_sys_close+0x43/0x70
        do_syscall_64+0x9f/0x100
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

 -> #1 (&vnode->validate_lock){++++}-{3:3}:
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        down_read+0x95/0x200
        afs_writepages+0x37/0x70
        do_writepages+0x1e8/0x3e0
        filemap_fdatawrite_wbc+0x84/0xa0
        filemap_invalidate_inode+0x167/0x1e0
        netfs_unbuffered_write_iter+0x1bd/0x2d0
        vfs_write+0x22e/0x320
        ksys_write+0xbc/0x130
        do_syscall_64+0x9f/0x100
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

 -> #0 (mapping.invalidate_lock#3){++++}-{3:3}:
        check_noncircular+0x119/0x160
        check_prev_add+0x195/0x430
        __lock_acquire+0xaf0/0xd80
        lock_acquire.part.0+0x103/0x280
        down_read+0x95/0x200
        filemap_fault+0x26e/0x8b0
        __do_fault+0x57/0xd0
        do_pte_missing+0x23b/0x320
        __handle_mm_fault+0x2d4/0x320
        handle_mm_fault+0x14f/0x260
        do_user_addr_fault+0x2a2/0x500
        exc_page_fault+0x71/0x90
        asm_exc_page_fault+0x22/0x30

 other info that might help us debug this:

 Chain exists of:
   mapping.invalidate_lock#3 --> &mm->mmap_lock --> &vma->vm_lock->lock

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   rlock(&vma->vm_lock->lock);
                                lock(&mm->mmap_lock);
                                lock(&vma->vm_lock->lock);
   rlock(mapping.invalidate_lock#3);

  *** DEADLOCK ***

 1 lock held by fsstress/6050:
  #0: ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250

 stack backtrace:
 CPU: 0 PID: 6050 Comm: fsstress Not tainted 6.10.0-build2+ torvalds#956
 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x57/0x80
  check_noncircular+0x119/0x160
  ? queued_spin_lock_slowpath+0x4be/0x510
  ? __pfx_check_noncircular+0x10/0x10
  ? __pfx_queued_spin_lock_slowpath+0x10/0x10
  ? mark_lock+0x47/0x160
  ? init_chain_block+0x9c/0xc0
  ? add_chain_block+0x84/0xf0
  check_prev_add+0x195/0x430
  __lock_acquire+0xaf0/0xd80
  ? __pfx___lock_acquire+0x10/0x10
  ? __lock_release.isra.0+0x13b/0x230
  lock_acquire.part.0+0x103/0x280
  ? filemap_fault+0x26e/0x8b0
  ? __pfx_lock_acquire.part.0+0x10/0x10
  ? rcu_is_watching+0x34/0x60
  ? lock_acquire+0xd7/0x120
  down_read+0x95/0x200
  ? filemap_fault+0x26e/0x8b0
  ? __pfx_down_read+0x10/0x10
  ? __filemap_get_folio+0x25/0x1a0
  filemap_fault+0x26e/0x8b0
  ? __pfx_filemap_fault+0x10/0x10
  ? find_held_lock+0x7c/0x90
  ? __pfx___lock_release.isra.0+0x10/0x10
  ? __pte_offset_map+0x99/0x110
  __do_fault+0x57/0xd0
  do_pte_missing+0x23b/0x320
  __handle_mm_fault+0x2d4/0x320
  ? __pfx___handle_mm_fault+0x10/0x10
  handle_mm_fault+0x14f/0x260
  do_user_addr_fault+0x2a2/0x500
  exc_page_fault+0x71/0x90
  asm_exc_page_fault+0x22/0x30

Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
cc: Alexander Viro <[email protected]>
cc: Christian Brauner <[email protected]>
cc: Jan Kara <[email protected]>
cc: Jeff Layton <[email protected]>
cc: Gao Xiang <[email protected]>
cc: Matthew Wilcox <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
[brauner: fix minor issues]
Signed-off-by: Christian Brauner <[email protected]>
konradybcio pushed a commit that referenced this issue Jul 29, 2024
In z_erofs_get_gbuf(), the current task may be migrated to another
CPU between `z_erofs_gbuf_id()` and `spin_lock(&gbuf->lock)`.

Therefore, z_erofs_put_gbuf() will trigger the following issue
which was found by stress test:

<2>[772156.434168] kernel BUG at fs/erofs/zutil.c:58!
..
<4>[772156.435007]
<4>[772156.439237] CPU: 0 PID: 3078 Comm: stress Kdump: loaded Tainted: G            E      6.10.0-rc7+ #2
<4>[772156.439239] Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 1.0.0 01/01/2017
<4>[772156.439241] pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
<4>[772156.439243] pc : z_erofs_put_gbuf+0x64/0x70 [erofs]
<4>[772156.439252] lr : z_erofs_lz4_decompress+0x600/0x6a0 [erofs]
..
<6>[772156.445958] stress (3127): drop_caches: 1
<4>[772156.446120] Call trace:
<4>[772156.446121]  z_erofs_put_gbuf+0x64/0x70 [erofs]
<4>[772156.446761]  z_erofs_lz4_decompress+0x600/0x6a0 [erofs]
<4>[772156.446897]  z_erofs_decompress_queue+0x740/0xa10 [erofs]
<4>[772156.447036]  z_erofs_runqueue+0x428/0x8c0 [erofs]
<4>[772156.447160]  z_erofs_readahead+0x224/0x390 [erofs]
..

Fixes: f36f301 ("erofs: rename per-CPU buffers to global buffer pool and make it configurable")
Cc: <[email protected]> # 6.10+
Reviewed-by: Chunhai Guo <[email protected]>
Reviewed-by: Sandeep Dhavale <[email protected]>
Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Gao Xiang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
konradybcio pushed a commit that referenced this issue Aug 23, 2024
Ido Schimmel says:

====================
Preparations for FIB rule DSCP selector

This patchset moves the masking of the upper DSCP bits in 'flowi4_tos'
to the core instead of relying on callers of the FIB lookup API to do
it.

This will allow us to start changing users of the API to initialize the
'flowi4_tos' field with all six bits of the DSCP field. In turn, this
will allow us to extend FIB rules with a new DSCP selector.

By masking the upper DSCP bits in the core we are able to maintain the
behavior of the TOS selector in FIB rules and routes to only match on
the lower DSCP bits.

While working on this I found two users of the API that do not mask the
upper DSCP bits before performing the lookup. The first is an ancient
netlink family that is unlikely to be used. It is adjusted in patch #1
to mask both the upper DSCP bits and the ECN bits before calling the
API.

The second user is a nftables module that differs in this regard from
its equivalent iptables module. It is adjusted in patch #2 to invoke the
API with the upper DSCP bits masked, like all other callers. The
relevant selftest passed, but in the unlikely case that regressions are
reported because of this change, we can restore the existing behavior
using a new flow information flag as discussed here [1].

The last patch moves the masking of the upper DSCP bits to the core,
making the first two patches redundant, but I wanted to post them
separately to call attention to the behavior change for these two users
of the FIB lookup API.

Future patchsets (around 3) will start unmasking the upper DSCP bits
throughout the networking stack before adding support for the new FIB
rule DSCP selector.

Changes from v1 [2]:

Patch #3: Include <linux/ip.h> in <linux/in_route.h> instead of
including it in net/ip_fib.h

[1] https://lore.kernel.org/netdev/ZpqpB8vJU%2FQ6LSqa@debian/
[2] https://lore.kernel.org/netdev/[email protected]/
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
konradybcio pushed a commit that referenced this issue Aug 23, 2024
Patch series "zram: introduce custom comp backends API", v6.

This series introduces support for run-time compression algorithms tuning,
so users, for instance, can adjust compression/acceleration levels and
provide pre-trained compression/decompression dictionaries which certain
algorithms support.

At this point we stop supporting (old/deprecated) comp API.  We may add
new acomp API support in the future, but before that zram needs to undergo
some major rework (we are not ready for async compression).

Some benchmarks for reference (look at column #2)

*** zstd
/sys/block/zram0/mm_stat
1750650880 504575194 514392064        0 514392064        1        0    34204    34204

*** zstd level=-1
/sys/block/zram0/mm_stat
1750638592 591816152 603758592        0 603758592        1        0    34288    34288

*** zstd level=8
/sys/block/zram0/mm_stat
1750659072 486924248 496377856        0 496377856        1        0    34204    34204

*** zstd dict=/home/ss/zstd-dict-amd64
/sys/block/zram0/mm_stat
1750634496 465853994 475230208        0 475230208        1        0    34185    34185

*** zstd level=8 dict=/home/ss/zstd-dict-amd64
/sys/block/zram0/mm_stat
1750650880 430760956 439967744        0 439967744        1        0    34185    34185

*** lz4
/sys/block/zram0/mm_stat
1750663168 664194239 676970496        0 676970496        1        0    34288    34288

*** lz4 dict=/home/ss/lz4-dict-amd64
/sys/block/zram0/mm_stat
1750650880 619901052 632061952        0 632061952        1        0    34278    34278

*** lz4 level=5 dict=/home/ss/lz4-dict-amd64
/sys/block/zram0/mm_stat
1750650880 727180082 740884480        0 740884480        1        0    34438    34438


This patch (of 6):

We need to export a number of API functions that enable advanced zstd
usage - C/D dictionaries, dictionaries sharing between contexts, etc.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Nick Terrell <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Nhat Pham <[email protected]>
Cc: Nitin Gupta <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
konradybcio pushed a commit that referenced this issue Aug 23, 2024
…ptions

Patch series "mm: split PTE/PMD PT table Kconfig cleanups+clarifications".

This series is a follow up to the fixes:
	"[PATCH v1 0/2] mm/hugetlb: fix hugetlb vs. core-mm PT locking"

When working on the fixes, I wondered why 8xx is fine (-> never uses split
PT locks) and how PT locking even works properly with PMD page table
sharing (-> always requires split PMD PT locks).

Let's improve the split PT lock detection, make hugetlb properly depend on
it and make 8xx bail out if it would ever get enabled by accident.

As an alternative to patch #3 we could extend the Kconfig
SPLIT_PTE_PTLOCKS option from patch #2 -- but enforcing it closer to the
code that actually implements it feels a bit nicer for documentation
purposes, and there is no need to actually disable it because it should
always be disabled (!SMP).

Did a bunch of cross-compilations to make sure that split PTE/PMD PT locks
are still getting used where we would expect them.

[1] https://lkml.kernel.org/r/[email protected]


This patch (of 3):

Let's clean that up a bit and prepare for depending on
CONFIG_SPLIT_PMD_PTLOCKS in other Kconfig options.

More cleanups would be reasonable (like the arch-specific "depends on" for
CONFIG_SPLIT_PTE_PTLOCKS), but we'll leave that for another day.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Reviewed-by: Russell King (Oracle) <[email protected]>
Reviewed-by: Qi Zheng <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: "Naveen N. Rao" <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
konradybcio pushed a commit that referenced this issue Aug 23, 2024
Eduard Zingerman says:

====================
__jited test tag to check disassembly after jit

Some of the logic in the BPF jits might be non-trivial.
It might be useful to allow testing this logic by comparing
generated native code with expected code template.
This patch set adds a macro __jited() that could be used for
test_loader based tests in a following manner:

    SEC("tp")
    __arch_x86_64
    __jited("   endbr64")
    __jited("   nopl    (%rax,%rax)")
    __jited("   xorq    %rax, %rax")
    ...
    __naked void some_test(void) { ... }

Also add a test for jit code generated for tail calls handling to
demonstrate the feature.

The feature uses LLVM libraries to do the disassembly.
At selftests compilation time Makefile detects if these libraries are
available. When libraries are not available tests using __jit_x86()
are skipped.
Current CI environment does not include llvm development libraries,
but changes to add these are trivial.

This was previously discussed here:
https://lore.kernel.org/bpf/[email protected]/

Patch-set includes a few auxiliary steps:
- patches #2 and #3 fix a few bugs in test_loader behaviour;
- patch #4 replaces __regex macro with ability to specify regular
  expressions in __msg and __xlated using "{{" "}}" escapes;
- patch torvalds#8 updates __xlated to match disassembly lines consequently,
  same way as __jited does.

Changes v2->v3:
- changed macro name from __jit_x86 to __jited with __arch_* to
  specify disassembly arch (Yonghong);
- __jited matches disassembly lines consequently with "..."
  allowing to skip some number of lines (Andrii);
- __xlated matches disassembly lines consequently, same as __jited;
- "{{...}}" regex brackets instead of __regex macro;
- bug fixes for old commits.

Changes v1->v2:
- stylistic changes suggested by Yonghong;
- fix for -Wformat-truncation related warning when compiled with
  llvm15 (Yonghong).

v1: https://lore.kernel.org/bpf/[email protected]/
v2: https://lore.kernel.org/bpf/[email protected]/
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
konradybcio pushed a commit that referenced this issue Sep 30, 2024
Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock
on x86 due to a chain of locks and SRCU synchronizations.  Translating the
below lockdep splat, CPU1 torvalds#6 will wait on CPU0 #1, CPU0 torvalds#8 will wait on
CPU2 #3, and CPU2 torvalds#7 will wait on CPU1 #4 (if there's a writer, due to the
fairness of r/w semaphores).

    CPU0                     CPU1                     CPU2
1   lock(&kvm->slots_lock);
2                                                     lock(&vcpu->mutex);
3                                                     lock(&kvm->srcu);
4                            lock(cpu_hotplug_lock);
5                            lock(kvm_lock);
6                            lock(&kvm->slots_lock);
7                                                     lock(cpu_hotplug_lock);
8   sync(&kvm->srcu);

Note, there are likely more potential deadlocks in KVM x86, e.g. the same
pattern of taking cpu_hotplug_lock outside of kvm_lock likely exists with
__kvmclock_cpufreq_notifier():

  cpuhp_cpufreq_online()
  |
  -> cpufreq_online()
     |
     -> cpufreq_gov_performance_limits()
        |
        -> __cpufreq_driver_target()
           |
           -> __target_index()
              |
              -> cpufreq_freq_transition_begin()
                 |
                 -> cpufreq_notify_transition()
                    |
                    -> ... __kvmclock_cpufreq_notifier()

But, actually triggering such deadlocks is beyond rare due to the
combination of dependencies and timings involved.  E.g. the cpufreq
notifier is only used on older CPUs without a constant TSC, mucking with
the NX hugepage mitigation while VMs are running is very uncommon, and
doing so while also onlining/offlining a CPU (necessary to generate
contention on cpu_hotplug_lock) would be even more unusual.

The most robust solution to the general cpu_hotplug_lock issue is likely
to switch vm_list to be an RCU-protected list, e.g. so that x86's cpufreq
notifier doesn't to take kvm_lock.  For now, settle for fixing the most
blatant deadlock, as switching to an RCU-protected list is a much more
involved change, but add a comment in locking.rst to call out that care
needs to be taken when walking holding kvm_lock and walking vm_list.

  ======================================================
  WARNING: possible circular locking dependency detected
  6.10.0-smp--c257535a0c9d-pip torvalds#330 Tainted: G S         O
  ------------------------------------------------------
  tee/35048 is trying to acquire lock:
  ff6a80eced71e0a8 (&kvm->slots_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x179/0x1e0 [kvm]

  but task is already holding lock:
  ffffffffc07abb08 (kvm_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x14a/0x1e0 [kvm]

  which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

  -> #3 (kvm_lock){+.+.}-{3:3}:
         __mutex_lock+0x6a/0xb40
         mutex_lock_nested+0x1f/0x30
         kvm_dev_ioctl+0x4fb/0xe50 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #2 (cpu_hotplug_lock){++++}-{0:0}:
         cpus_read_lock+0x2e/0xb0
         static_key_slow_inc+0x16/0x30
         kvm_lapic_set_base+0x6a/0x1c0 [kvm]
         kvm_set_apic_base+0x8f/0xe0 [kvm]
         kvm_set_msr_common+0x9ae/0xf80 [kvm]
         vmx_set_msr+0xa54/0xbe0 [kvm_intel]
         __kvm_set_msr+0xb6/0x1a0 [kvm]
         kvm_arch_vcpu_ioctl+0xeca/0x10c0 [kvm]
         kvm_vcpu_ioctl+0x485/0x5b0 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #1 (&kvm->srcu){.+.+}-{0:0}:
         __synchronize_srcu+0x44/0x1a0
         synchronize_srcu_expedited+0x21/0x30
         kvm_swap_active_memslots+0x110/0x1c0 [kvm]
         kvm_set_memslot+0x360/0x620 [kvm]
         __kvm_set_memory_region+0x27b/0x300 [kvm]
         kvm_vm_ioctl_set_memory_region+0x43/0x60 [kvm]
         kvm_vm_ioctl+0x295/0x650 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #0 (&kvm->slots_lock){+.+.}-{3:3}:
         __lock_acquire+0x15ef/0x2e30
         lock_acquire+0xe0/0x260
         __mutex_lock+0x6a/0xb40
         mutex_lock_nested+0x1f/0x30
         set_nx_huge_pages+0x179/0x1e0 [kvm]
         param_attr_store+0x93/0x100
         module_attr_store+0x22/0x40
         sysfs_kf_write+0x81/0xb0
         kernfs_fop_write_iter+0x133/0x1d0
         vfs_write+0x28d/0x380
         ksys_write+0x70/0xe0
         __x64_sys_write+0x1f/0x30
         x64_sys_call+0x281b/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

Cc: Chao Gao <[email protected]>
Fixes: 0bf5049 ("KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock")
Cc: [email protected]
Reviewed-by: Kai Huang <[email protected]>
Acked-by: Kai Huang <[email protected]>
Tested-by: Farrah Chen <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
konradybcio pushed a commit that referenced this issue Sep 30, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

v2: with kdoc fixes per Paolo Abeni.

The following patchset contains Netfilter fixes for net:

Patch #1 and #2 handle an esoteric scenario: Given two tasks sending UDP
packets to one another, two packets of the same flow in each direction
handled by different CPUs that result in two conntrack objects in NEW
state, where reply packet loses race. Then, patch #3 adds a testcase for
this scenario. Series from Florian Westphal.

1) NAT engine can falsely detect a port collision if it happens to pick
   up a reply packet as NEW rather than ESTABLISHED. Add extra code to
   detect this and suppress port reallocation in this case.

2) To complete the clash resolution in the reply direction, extend conntrack
   logic to detect clashing conntrack in the reply direction to existing entry.

3) Adds a test case.

Then, an assorted list of fixes follow:

4) Add a selftest for tproxy, from Antonio Ojea.

5) Guard ctnetlink_*_size() functions under
   #if defined(CONFIG_NETFILTER_NETLINK_GLUE_CT) || defined(CONFIG_NF_CONNTRACK_EVENTS)
   From Andy Shevchenko.

6) Use -m socket --transparent in iptables tproxy documentation.
   From XIE Zhibang.

7) Call kfree_rcu() when releasing flowtable hooks to address race with
   netlink dump path, from Phil Sutter.

8) Fix compilation warning in nf_reject with CONFIG_BRIDGE_NETFILTER=n.
   From Simon Horman.

9) Guard ctnetlink_label_size() under CONFIG_NF_CONNTRACK_EVENTS which
   is its only user, to address a compilation warning. From Simon Horman.

10) Use rcu-protected list iteration over basechain hooks from netlink
    dump path.

11) Fix memcg for nf_tables, use GFP_KERNEL_ACCOUNT is not complete.

12) Remove old nfqueue conntrack clash resolution. Instead trying to
    use same destination address consistently which requires double DNAT,
    use the existing clash resolution which allows clashing packets
    go through with different destination. Antonio Ojea originally
    reported an issue from the postrouting chain, I proposed a fix:
    https://lore.kernel.org/netfilter-devel/ZuwSwAqKgCB2a51-@calendula/T/
    which he reported it did not work for him.

13) Adds a selftest for patch 12.

14) Fixes ipvs.sh selftest.

netfilter pull request 24-09-26

* tag 'nf-24-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  selftests: netfilter: Avoid hanging ipvs.sh
  kselftest: add test for nfqueue induced conntrack race
  netfilter: nfnetlink_queue: remove old clash resolution logic
  netfilter: nf_tables: missing objects with no memcg accounting
  netfilter: nf_tables: use rcu chain hook list iterator from netlink dump path
  netfilter: ctnetlink: compile ctnetlink_label_size with CONFIG_NF_CONNTRACK_EVENTS
  netfilter: nf_reject: Fix build warning when CONFIG_BRIDGE_NETFILTER=n
  netfilter: nf_tables: Keep deleted flowtable hooks until after RCU
  docs: tproxy: ignore non-transparent sockets in iptables
  netfilter: ctnetlink: Guard possible unused functions
  selftests: netfilter: nft_tproxy.sh: add tcp tests
  selftests: netfilter: add reverse-clash resolution test case
  netfilter: conntrack: add clash resolution for reverse collisions
  netfilter: nf_nat: don't try nat source port reallocation for reverse dir clash
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
konradybcio pushed a commit that referenced this issue Sep 30, 2024
Target slot selection for recompression is just a simple iteration over
zram->table entries (stored pages) from slot 0 to max slot.  Given that
zram->table slots are written in random order and are not sorted by size,
a simple iteration over slots selects suboptimal targets for
recompression.  This is not a problem if we recompress every single
zram->table slot, but we never do that in reality.  In reality we limit
the number of slots we can recompress (via max_pages parameter) and hence
proper slot selection becomes very important.  The strategy is quite
simple, suppose we have two candidate slots for recompression, one of size
48 bytes and one of size 2800 bytes, and we can recompress only one, then
it certainly makes more sense to pick 2800 entry for recompression. 
Because even if we manage to compress 48 bytes objects even further the
savings are going to be very small.  Potential savings after good
re-compression of 2800 bytes objects are much higher.

This patch reworks slot selection and introduces the strategy described
above: among candidate slots always select the biggest ones first.

For that the patch introduces zram_pp_ctl (post-processing) structure
which holds NUM_PP_BUCKETS pp buckets of slots.  Slots are assigned to a
particular group based on their sizes - the larger the size of the slot
the higher the group index.  This, basically, sorts slots by size in liner
time (we still perform just one iteration over zram->table slots).  When
we select slot for recompression we always first lookup in higher pp
buckets (those that hold the largest slots).  Which achieves the desired
behavior.

TEST
====

A very simple demonstration: zram is configured with zstd, and zstd with
dict as a recompression stream.  A limited (max 4096 pages) recompression
is performed then, with a log of sizes of slots that were recompressed. 
You can see that patched zram selects slots for recompression in
significantly different manner, which leads to higher memory savings (see
column #2 of mm_stat output).

BASE
----

*** initial state of zram device
/sys/block/zram0/mm_stat
1750994944 504491413 514203648        0 514203648        1        0    34204    34204

*** recompress idle max_pages=4096
/sys/block/zram0/mm_stat
1750994944 504262229 514953216        0 514203648        1        0    34204    34204

Sizes of selected objects for recompression:
... 45 58 24 226 91 40 24 24 24 424 2104 93 2078 2078 2078 959 154 ...

PATCHED
-------

*** initial state of zram device
/sys/block/zram0/mm_stat
1750982656 504492801 514170880        0 514170880        1        0    34204    34204

*** recompress idle max_pages=4096
/sys/block/zram0/mm_stat
1750982656 503716710 517586944        0 514170880        1        0    34204    34204

Sizes of selected objects for recompression:
... 3680 3694 3667 3590 3614 3553 3537 3548 3550 3542 3543 3537 ...

Note, pp-slots are not strictly sorted, there is a PP_BUCKET_SIZE_RANGE
variation of sizes within particular bucket.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
konradybcio pushed a commit that referenced this issue Sep 30, 2024
Writeback suffers from the same problem as recompression did before -
target slot selection for writeback is just a simple iteration over
zram->table entries (stored pages) which selects suboptimal targets for
writeback.  This is especially problematic for writeback, because we
uncompress objects before writeback so each of them takes 4K out of
limited writeback storage.  For example, when we take a 48 bytes slot and
store it as a 4K object to writeback device we only save 48 bytes of
memory (release from zsmalloc pool).  We naturally want to pick the
largest objects for writeback, because then each writeback will release
the largest amount of memory.

This patch applies the same solution and strategy as for recompression
target selection: pp control (post-process) with 16 buckets of candidate
pp slots.  Slots are assigned to pp buckets based on sizes - the larger
the slot the higher the group index.  This gives us sorted by size lists
of candidate slots (in linear time), so that among post-processing
candidate slots we always select the largest ones first and maximize the
memory saving.

TEST
====

A very simple demonstration: zram is configured with a writeback device. 
A limited writeback (wb_limit 2500 pages) is performed then, with a log of
sizes of slots that were written back.  You can see that patched zram
selects slots for recompression in significantly different manner, which
leads to higher memory savings (see column #2 of mm_stat output).

BASE
----

*** initial state of zram device
/sys/block/zram0/mm_stat
1750327296 619765836 631902208        0 631902208        1        0    34278    34278

*** writeback idle wb_limit 2500
/sys/block/zram0/mm_stat
1750327296 617622333 631578624        0 631902208        1        0    34278    34278

Sizes of selected objects for writeback:
... 193 349 46 46 46 46 852 1002 543 162 107 49 34 34 34 ...

PATCHED
-------

*** initial state of zram device
/sys/block/zram0/mm_stat
1750319104 619760957 631992320        0 631992320        1        0    34278    34278

*** writeback idle wb_limit 2500
/sys/block/zram0/mm_stat
1750319104 612672056 626135040        0 631992320        1        0    34278    34278

Sizes of selected objects for writeback:
... 3667 3580 3581 3580 3581 3581 3581 3231 3211 3203 3231 3246 ...

Note, pp-slots are not strictly sorted, there is a PP_BUCKET_SIZE_RANGE
variation of sizes within particular bucket.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
MarijnS95 pushed a commit that referenced this issue Oct 6, 2024
Remove intel_dp_mst_suspend/resume from runtime suspend resume
sequences. It is incorrect as it depends on AUX transfers which
itself depend on the device being runtime resumed. This is
also why we see a lock_dep splat here.

<4> [76.011119] kworker/4:2/192 is trying to acquire lock:
<4> [76.011122] ffff8881120b3210 (&mgr->lock#2){+.+.}-{3:3}, at:
drm_dp_mst_topology_mgr_suspend+0x33/0xd0 [drm_display_helper]
<4> [76.011142]
but task is already holding lock:
<4> [76.011144] ffffffffa0bc3420
(xe_pm_runtime_lockdep_map){+.+.}-{0:0}, at:
xe_pm_runtime_suspend+0x51/0x3f0 [xe]
<4> [76.011223]
which lock already depends on the new lock.
<4> [76.011226]
the existing dependency chain (in reverse order) is:
<4> [76.011229]
-> #2 (xe_pm_runtime_lockdep_map){+.+.}-{0:0}:
<4> [76.011233]        pm_runtime_lockdep_prime+0x2f/0x50 [xe]
<4> [76.011306]        xe_pm_runtime_resume_and_get+0x29/0x90 [xe]
<4> [76.011377]        intel_display_power_get+0x24/0x70 [xe]
<4> [76.011466]        intel_digital_port_connected_locked+0x4c/0xf0
[xe]
<4> [76.011551]        intel_dp_aux_xfer+0xb8/0x7c0 [xe]
<4> [76.011633]        intel_dp_aux_transfer+0x166/0x2e0 [xe]
<4> [76.011715]        drm_dp_dpcd_access+0x87/0x150
[drm_display_helper]
<4> [76.011726]        drm_dp_dpcd_probe+0x3d/0xf0 [drm_display_helper]
<4> [76.011737]        drm_dp_dpcd_read+0xdd/0x130 [drm_display_helper]
<4> [76.011747]        intel_dp_get_colorimetry_status+0x3a/0x70 [xe]
<4> [76.011886]        intel_dp_init_connector+0x4ff/0x1030 [xe]
<4> [76.011969]        intel_ddi_init+0xc5b/0x1030 [xe]
<4> [76.012058]        intel_bios_for_each_encoder+0x36/0x60 [xe]
<4> [76.012145]        intel_setup_outputs+0x201/0x460 [xe]
<4> [76.012233]        intel_display_driver_probe_nogem+0x155/0x1e0 [xe]
<4> [76.012320]        xe_display_init_noaccel+0x27/0x70 [xe]

Signed-off-by: Suraj Kandpal <[email protected]>
Reviewed-by: Rodrigo Vivi <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
MarijnS95 pushed a commit that referenced this issue Oct 6, 2024
Do not do intel_fbdev_set_suspend during runtime_suspend/resume
functions. This cause a big circular lock_dep splat.

kworker/0:4/198 is trying to acquire lock:
<4> [77.185594] ffffffff83398500 (console_lock){+.+.}-{0:0}, at:
intel_fbdev_set_suspend+0x169/0x1f0 [xe]
<4> [77.185947]
but task is already holding lock:
<4> [77.185949] ffffffffa09e9460
(xe_pm_runtime_lockdep_map){+.+.}-{0:0}, at:
xe_pm_runtime_suspend+0x51/0x3f0 [xe]
<4> [77.186262]
which lock already depends on the new lock.
<4> [77.186264]
the existing dependency chain (in reverse order) is:
<4> [77.186266]
-> #2 (xe_pm_runtime_lockdep_map){+.+.}-{0:0}:
<4> [77.186276]        pm_runtime_lockdep_prime+0x2f/0x50 [xe]
<4> [77.186572]        xe_pm_runtime_resume_and_get+0x29/0x90 [xe]
<4> [77.186867]        intelfb_create+0x150/0x390 [xe]
<4> [77.187197]
__drm_fb_helper_initial_config_and_unlock+0x31c/0x5e0 [drm_kms_helper]
<4> [77.187243]        drm_fb_helper_initial_config+0x3d/0x50
[drm_kms_helper]
<4> [77.187274]        intel_fbdev_client_hotplug+0xb1/0x140 [xe]
<4> [77.187603]        drm_client_register+0x87/0xd0 [drm]
<4> [77.187704]        intel_fbdev_setup+0x51c/0x640 [xe]
<4> [77.188033]        intel_display_driver_register+0xb7/0xf0 [xe]
<4> [77.188438]        xe_display_register+0x21/0x40 [xe]
<4> [77.188809]        xe_device_probe+0xa8d/0xbf0 [xe]
<4> [77.189035]        xe_pci_probe+0x333/0x5b0 [xe]
<4> [77.189330]        local_pci_probe+0x48/0xb0
<4> [77.189341]        pci_device_probe+0xc8/0x280
<4> [77.189351]        really_probe+0xf8/0x390
<4> [77.189362]        __driver_probe_device+0x8a/0x170
<4> [77.189373]        driver_probe_device+0x23/0xb0

Signed-off-by: Suraj Kandpal <[email protected]>
Reviewed-by: Rodrigo Vivi <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
MarijnS95 pushed a commit that referenced this issue Oct 6, 2024
On the node of an NFS client, some files saved in the mountpoint of the
NFS server were copied to another location of the same NFS server.
Accidentally, the nfs42_complete_copies() got a NULL-pointer dereference
crash with the following syslog:

[232064.838881] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232064.839360] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116
[232066.588183] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058
[232066.588586] Mem abort info:
[232066.588701]   ESR = 0x0000000096000007
[232066.588862]   EC = 0x25: DABT (current EL), IL = 32 bits
[232066.589084]   SET = 0, FnV = 0
[232066.589216]   EA = 0, S1PTW = 0
[232066.589340]   FSC = 0x07: level 3 translation fault
[232066.589559] Data abort info:
[232066.589683]   ISV = 0, ISS = 0x00000007
[232066.589842]   CM = 0, WnR = 0
[232066.589967] user pgtable: 64k pages, 48-bit VAs, pgdp=00002000956ff400
[232066.590231] [0000000000000058] pgd=08001100ae100003, p4d=08001100ae100003, pud=08001100ae100003, pmd=08001100b3c00003, pte=0000000000000000
[232066.590757] Internal error: Oops: 96000007 [#1] SMP
[232066.590958] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm vhost_net vhost vhost_iotlb tap tun ipt_rpfilter xt_multiport ip_set_hash_ip ip_set_hash_net xfrm_interface xfrm6_tunnel tunnel4 tunnel6 esp4 ah4 wireguard libcurve25519_generic veth xt_addrtype xt_set nf_conntrack_netlink ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_bitmap_port ip_set_hash_ipport dummy ip_set ip_vs_sh ip_vs_wrr ip_vs_rr ip_vs iptable_filter sch_ingress nfnetlink_cttimeout vport_gre ip_gre ip_tunnel gre vport_geneve geneve vport_vxlan vxlan ip6_udp_tunnel udp_tunnel openvswitch nf_conncount dm_round_robin dm_service_time dm_multipath xt_nat xt_MASQUERADE nft_chain_nat nf_nat xt_mark xt_conntrack xt_comment nft_compat nft_counter nf_tables nfnetlink ocfs2 ocfs2_nodemanager ocfs2_stackglue iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ipmi_ssif nbd overlay 8021q garp mrp bonding tls rfkill sunrpc ext4 mbcache jbd2
[232066.591052]  vfat fat cas_cache cas_disk ses enclosure scsi_transport_sas sg acpi_ipmi ipmi_si ipmi_devintf ipmi_msghandler ip_tables vfio_pci vfio_pci_core vfio_virqfd vfio_iommu_type1 vfio dm_mirror dm_region_hash dm_log dm_mod nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc fuse xfs libcrc32c ast drm_vram_helper qla2xxx drm_kms_helper syscopyarea crct10dif_ce sysfillrect ghash_ce sysimgblt sha2_ce fb_sys_fops cec sha256_arm64 sha1_ce drm_ttm_helper ttm nvme_fc igb sbsa_gwdt nvme_fabrics drm nvme_core i2c_algo_bit i40e scsi_transport_fc megaraid_sas aes_neon_bs
[232066.596953] CPU: 6 PID: 4124696 Comm: 10.253.166.125- Kdump: loaded Not tainted 5.15.131-9.cl9_ocfs2.aarch64 #1
[232066.597356] Hardware name: Great Wall .\x93\x8e...RF6260 V5/GWMSSE2GL1T, BIOS T656FBE_V3.0.18 2024-01-06
[232066.597721] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[232066.598034] pc : nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.598327] lr : nfs4_reclaim_open_state+0x12c/0x800 [nfsv4]
[232066.598595] sp : ffff8000f568fc70
[232066.598731] x29: ffff8000f568fc70 x28: 0000000000001000 x27: ffff21003db33000
[232066.599030] x26: ffff800005521ae0 x25: ffff0100f98fa3f0 x24: 0000000000000001
[232066.599319] x23: ffff800009920008 x22: ffff21003db33040 x21: ffff21003db33050
[232066.599628] x20: ffff410172fe9e40 x19: ffff410172fe9e00 x18: 0000000000000000
[232066.599914] x17: 0000000000000000 x16: 0000000000000004 x15: 0000000000000000
[232066.600195] x14: 0000000000000000 x13: ffff800008e685a8 x12: 00000000eac0c6e6
[232066.600498] x11: 0000000000000000 x10: 0000000000000008 x9 : ffff8000054e5828
[232066.600784] x8 : 00000000ffffffbf x7 : 0000000000000001 x6 : 000000000a9eb14a
[232066.601062] x5 : 0000000000000000 x4 : ffff70ff8a14a800 x3 : 0000000000000058
[232066.601348] x2 : 0000000000000001 x1 : 54dce46366daa6c6 x0 : 0000000000000000
[232066.601636] Call trace:
[232066.601749]  nfs4_reclaim_open_state+0x220/0x800 [nfsv4]
[232066.601998]  nfs4_do_reclaim+0x1b8/0x28c [nfsv4]
[232066.602218]  nfs4_state_manager+0x928/0x10f0 [nfsv4]
[232066.602455]  nfs4_run_state_manager+0x78/0x1b0 [nfsv4]
[232066.602690]  kthread+0x110/0x114
[232066.602830]  ret_from_fork+0x10/0x20
[232066.602985] Code: 1400000d f9403f20 f9402e61 91016003 (f9402c00)
[232066.603284] SMP: stopping secondary CPUs
[232066.606936] Starting crashdump kernel...
[232066.607146] Bye!

Analysing the vmcore, we know that nfs4_copy_state listed by destination
nfs_server->ss_copies was added by the field copies in handle_async_copy(),
and we found a waiting copy process with the stack as:
PID: 3511963  TASK: ffff710028b47e00  CPU: 0   COMMAND: "cp"
 #0 [ffff8001116ef740] __switch_to at ffff8000081b92f4
 #1 [ffff8001116ef760] __schedule at ffff800008dd0650
 #2 [ffff8001116ef7c0] schedule at ffff800008dd0a00
 #3 [ffff8001116ef7e0] schedule_timeout at ffff800008dd6aa0
 #4 [ffff8001116ef860] __wait_for_common at ffff800008dd166c
 #5 [ffff8001116ef8e0] wait_for_completion_interruptible at ffff800008dd1898
 torvalds#6 [ffff8001116ef8f0] handle_async_copy at ffff8000055142f4 [nfsv4]
 torvalds#7 [ffff8001116ef970] _nfs42_proc_copy at ffff8000055147c8 [nfsv4]
 torvalds#8 [ffff8001116efa80] nfs42_proc_copy at ffff800005514cf0 [nfsv4]
 torvalds#9 [ffff8001116efc50] __nfs4_copy_file_range.constprop.0 at ffff8000054ed694 [nfsv4]

The NULL-pointer dereference was due to nfs42_complete_copies() listed
the nfs_server->ss_copies by the field ss_copies of nfs4_copy_state.
So the nfs4_copy_state address ffff0100f98fa3f0 was offset by 0x10 and
the data accessed through this pointer was also incorrect. Generally,
the ordered list nfs4_state_owner->so_states indicate open(O_RDWR) or
open(O_WRITE) states are reclaimed firstly by nfs4_reclaim_open_state().
When destination state reclaim is failed with NFS_STATE_RECOVERY_FAILED
and copies are not deleted in nfs_server->ss_copies, the source state
may be passed to the nfs42_complete_copies() process earlier, resulting
in this crash scene finally. To solve this issue, we add a list_head
nfs_server->ss_src_copies for a server-to-server copy specially.

Fixes: 0e65a32 ("NFS: handle source server reboot")
Signed-off-by: Yanjun Zhang <[email protected]>
Reviewed-by: Trond Myklebust <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>
MarijnS95 pushed a commit that referenced this issue Oct 6, 2024
Target slot selection for recompression is just a simple iteration over
zram->table entries (stored pages) from slot 0 to max slot.  Given that
zram->table slots are written in random order and are not sorted by size,
a simple iteration over slots selects suboptimal targets for
recompression.  This is not a problem if we recompress every single
zram->table slot, but we never do that in reality.  In reality we limit
the number of slots we can recompress (via max_pages parameter) and hence
proper slot selection becomes very important.  The strategy is quite
simple, suppose we have two candidate slots for recompression, one of size
48 bytes and one of size 2800 bytes, and we can recompress only one, then
it certainly makes more sense to pick 2800 entry for recompression. 
Because even if we manage to compress 48 bytes objects even further the
savings are going to be very small.  Potential savings after good
re-compression of 2800 bytes objects are much higher.

This patch reworks slot selection and introduces the strategy described
above: among candidate slots always select the biggest ones first.

For that the patch introduces zram_pp_ctl (post-processing) structure
which holds NUM_PP_BUCKETS pp buckets of slots.  Slots are assigned to a
particular group based on their sizes - the larger the size of the slot
the higher the group index.  This, basically, sorts slots by size in liner
time (we still perform just one iteration over zram->table slots).  When
we select slot for recompression we always first lookup in higher pp
buckets (those that hold the largest slots).  Which achieves the desired
behavior.

TEST
====

A very simple demonstration: zram is configured with zstd, and zstd with
dict as a recompression stream.  A limited (max 4096 pages) recompression
is performed then, with a log of sizes of slots that were recompressed. 
You can see that patched zram selects slots for recompression in
significantly different manner, which leads to higher memory savings (see
column #2 of mm_stat output).

BASE
----

*** initial state of zram device
/sys/block/zram0/mm_stat
1750994944 504491413 514203648        0 514203648        1        0    34204    34204

*** recompress idle max_pages=4096
/sys/block/zram0/mm_stat
1750994944 504262229 514953216        0 514203648        1        0    34204    34204

Sizes of selected objects for recompression:
... 45 58 24 226 91 40 24 24 24 424 2104 93 2078 2078 2078 959 154 ...

PATCHED
-------

*** initial state of zram device
/sys/block/zram0/mm_stat
1750982656 504492801 514170880        0 514170880        1        0    34204    34204

*** recompress idle max_pages=4096
/sys/block/zram0/mm_stat
1750982656 503716710 517586944        0 514170880        1        0    34204    34204

Sizes of selected objects for recompression:
... 3680 3694 3667 3590 3614 3553 3537 3548 3550 3542 3543 3537 ...

Note, pp-slots are not strictly sorted, there is a PP_BUCKET_SIZE_RANGE
variation of sizes within particular bucket.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Dan Carpenter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
MarijnS95 pushed a commit that referenced this issue Oct 6, 2024
Writeback suffers from the same problem as recompression did before -
target slot selection for writeback is just a simple iteration over
zram->table entries (stored pages) which selects suboptimal targets for
writeback.  This is especially problematic for writeback, because we
uncompress objects before writeback so each of them takes 4K out of
limited writeback storage.  For example, when we take a 48 bytes slot and
store it as a 4K object to writeback device we only save 48 bytes of
memory (release from zsmalloc pool).  We naturally want to pick the
largest objects for writeback, because then each writeback will release
the largest amount of memory.

This patch applies the same solution and strategy as for recompression
target selection: pp control (post-process) with 16 buckets of candidate
pp slots.  Slots are assigned to pp buckets based on sizes - the larger
the slot the higher the group index.  This gives us sorted by size lists
of candidate slots (in linear time), so that among post-processing
candidate slots we always select the largest ones first and maximize the
memory saving.

TEST
====

A very simple demonstration: zram is configured with a writeback device. 
A limited writeback (wb_limit 2500 pages) is performed then, with a log of
sizes of slots that were written back.  You can see that patched zram
selects slots for recompression in significantly different manner, which
leads to higher memory savings (see column #2 of mm_stat output).

BASE
----

*** initial state of zram device
/sys/block/zram0/mm_stat
1750327296 619765836 631902208        0 631902208        1        0    34278    34278

*** writeback idle wb_limit 2500
/sys/block/zram0/mm_stat
1750327296 617622333 631578624        0 631902208        1        0    34278    34278

Sizes of selected objects for writeback:
... 193 349 46 46 46 46 852 1002 543 162 107 49 34 34 34 ...

PATCHED
-------

*** initial state of zram device
/sys/block/zram0/mm_stat
1750319104 619760957 631992320        0 631992320        1        0    34278    34278

*** writeback idle wb_limit 2500
/sys/block/zram0/mm_stat
1750319104 612672056 626135040        0 631992320        1        0    34278    34278

Sizes of selected objects for writeback:
... 3667 3580 3581 3580 3581 3581 3581 3231 3211 3203 3231 3246 ...

Note, pp-slots are not strictly sorted, there is a PP_BUCKET_SIZE_RANGE
variation of sizes within particular bucket.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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