diff --git a/rust/Makefile b/rust/Makefile index 1f10f92737f2c0..967da95ba8b0d2 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -8,8 +8,8 @@ always-$(CONFIG_RUST) += exports_core_generated.h # Missing prototypes are expected in the helpers since these are exported # for Rust only, thus there is no header nor prototypes. -obj-$(CONFIG_RUST) += helpers.o -CFLAGS_REMOVE_helpers.o = -Wmissing-prototypes -Wmissing-declarations +obj-$(CONFIG_RUST) += helpers/helpers.o +CFLAGS_REMOVE_helpers/helpers.o = -Wmissing-prototypes -Wmissing-declarations always-$(CONFIG_RUST) += libmacros.so no-clean-files += libmacros.so @@ -299,7 +299,7 @@ $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_cflags = \ -I$(objtree)/$(obj) -Wno-missing-prototypes -Wno-missing-declarations $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_extra = ; \ sed -Ei 's/pub fn rust_helper_([a-zA-Z0-9_]*)/#[link_name="rust_helper_\1"]\n pub fn \1/g' $@ -$(obj)/bindings/bindings_helpers_generated.rs: $(src)/helpers.c FORCE +$(obj)/bindings/bindings_helpers_generated.rs: $(src)/helpers/helpers.c FORCE $(call if_changed_dep,bindgen) quiet_cmd_exports = EXPORTS $@ diff --git a/rust/helpers.c b/rust/helpers.c deleted file mode 100644 index 92d3c03ae1bd53..00000000000000 --- a/rust/helpers.c +++ /dev/null @@ -1,239 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Non-trivial C macros cannot be used in Rust. Similarly, inlined C functions - * cannot be called either. This file explicitly creates functions ("helpers") - * that wrap those so that they can be called from Rust. - * - * Even though Rust kernel modules should never use the bindings directly, some - * of these helpers need to be exported because Rust generics and inlined - * functions may not get their code generated in the crate where they are - * defined. Other helpers, called from non-inline functions, may not be - * exported, in principle. However, in general, the Rust compiler does not - * guarantee codegen will be performed for a non-inline function either. - * Therefore, this file exports all the helpers. In the future, this may be - * revisited to reduce the number of exports after the compiler is informed - * about the places codegen is required. - * - * All symbols are exported as GPL-only to guarantee no GPL-only feature is - * accidentally exposed. - * - * Sorted alphabetically. - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -__noreturn void rust_helper_BUG(void) -{ - BUG(); -} -EXPORT_SYMBOL_GPL(rust_helper_BUG); - -unsigned long rust_helper_copy_from_user(void *to, const void __user *from, - unsigned long n) -{ - return copy_from_user(to, from, n); -} -EXPORT_SYMBOL_GPL(rust_helper_copy_from_user); - -unsigned long rust_helper_copy_to_user(void __user *to, const void *from, - unsigned long n) -{ - return copy_to_user(to, from, n); -} -EXPORT_SYMBOL_GPL(rust_helper_copy_to_user); - -void rust_helper_mutex_lock(struct mutex *lock) -{ - mutex_lock(lock); -} -EXPORT_SYMBOL_GPL(rust_helper_mutex_lock); - -void rust_helper___spin_lock_init(spinlock_t *lock, const char *name, - struct lock_class_key *key) -{ -#ifdef CONFIG_DEBUG_SPINLOCK - __raw_spin_lock_init(spinlock_check(lock), name, key, LD_WAIT_CONFIG); -#else - spin_lock_init(lock); -#endif -} -EXPORT_SYMBOL_GPL(rust_helper___spin_lock_init); - -void rust_helper_spin_lock(spinlock_t *lock) -{ - spin_lock(lock); -} -EXPORT_SYMBOL_GPL(rust_helper_spin_lock); - -void rust_helper_spin_unlock(spinlock_t *lock) -{ - spin_unlock(lock); -} -EXPORT_SYMBOL_GPL(rust_helper_spin_unlock); - -void rust_helper_init_wait(struct wait_queue_entry *wq_entry) -{ - init_wait(wq_entry); -} -EXPORT_SYMBOL_GPL(rust_helper_init_wait); - -int rust_helper_signal_pending(struct task_struct *t) -{ - return signal_pending(t); -} -EXPORT_SYMBOL_GPL(rust_helper_signal_pending); - -struct page *rust_helper_alloc_pages(gfp_t gfp_mask, unsigned int order) -{ - return alloc_pages(gfp_mask, order); -} -EXPORT_SYMBOL_GPL(rust_helper_alloc_pages); - -void *rust_helper_kmap_local_page(struct page *page) -{ - return kmap_local_page(page); -} -EXPORT_SYMBOL_GPL(rust_helper_kmap_local_page); - -void rust_helper_kunmap_local(const void *addr) -{ - kunmap_local(addr); -} -EXPORT_SYMBOL_GPL(rust_helper_kunmap_local); - -refcount_t rust_helper_REFCOUNT_INIT(int n) -{ - return (refcount_t)REFCOUNT_INIT(n); -} -EXPORT_SYMBOL_GPL(rust_helper_REFCOUNT_INIT); - -void rust_helper_refcount_inc(refcount_t *r) -{ - refcount_inc(r); -} -EXPORT_SYMBOL_GPL(rust_helper_refcount_inc); - -bool rust_helper_refcount_dec_and_test(refcount_t *r) -{ - return refcount_dec_and_test(r); -} -EXPORT_SYMBOL_GPL(rust_helper_refcount_dec_and_test); - -__force void *rust_helper_ERR_PTR(long err) -{ - return ERR_PTR(err); -} -EXPORT_SYMBOL_GPL(rust_helper_ERR_PTR); - -bool rust_helper_IS_ERR(__force const void *ptr) -{ - return IS_ERR(ptr); -} -EXPORT_SYMBOL_GPL(rust_helper_IS_ERR); - -long rust_helper_PTR_ERR(__force const void *ptr) -{ - return PTR_ERR(ptr); -} -EXPORT_SYMBOL_GPL(rust_helper_PTR_ERR); - -const char *rust_helper_errname(int err) -{ - return errname(err); -} -EXPORT_SYMBOL_GPL(rust_helper_errname); - -struct task_struct *rust_helper_get_current(void) -{ - return current; -} -EXPORT_SYMBOL_GPL(rust_helper_get_current); - -void rust_helper_get_task_struct(struct task_struct *t) -{ - get_task_struct(t); -} -EXPORT_SYMBOL_GPL(rust_helper_get_task_struct); - -void rust_helper_put_task_struct(struct task_struct *t) -{ - put_task_struct(t); -} -EXPORT_SYMBOL_GPL(rust_helper_put_task_struct); - -struct kunit *rust_helper_kunit_get_current_test(void) -{ - return kunit_get_current_test(); -} -EXPORT_SYMBOL_GPL(rust_helper_kunit_get_current_test); - -void rust_helper_init_work_with_key(struct work_struct *work, work_func_t func, - bool onstack, const char *name, - struct lock_class_key *key) -{ - __init_work(work, onstack); - work->data = (atomic_long_t)WORK_DATA_INIT(); - lockdep_init_map(&work->lockdep_map, name, key, 0); - INIT_LIST_HEAD(&work->entry); - work->func = func; -} -EXPORT_SYMBOL_GPL(rust_helper_init_work_with_key); - -void * __must_check __realloc_size(2) -rust_helper_krealloc(const void *objp, size_t new_size, gfp_t flags) -{ - return krealloc(objp, new_size, flags); -} -EXPORT_SYMBOL_GPL(rust_helper_krealloc); - -/* - * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can - * use it in contexts where Rust expects a `usize` like slice (array) indices. - * `usize` is defined to be the same as C's `uintptr_t` type (can hold any - * pointer) but not necessarily the same as `size_t` (can hold the size of any - * single object). Most modern platforms use the same concrete integer type for - * both of them, but in case we find ourselves on a platform where - * that's not true, fail early instead of risking ABI or - * integer-overflow issues. - * - * If your platform fails this assertion, it means that you are in - * danger of integer-overflow bugs (even if you attempt to add - * `--no-size_t-is-usize`). It may be easiest to change the kernel ABI on - * your platform such that `size_t` matches `uintptr_t` (i.e., to increase - * `size_t`, because `uintptr_t` has to be at least as big as `size_t`). - */ -static_assert( - sizeof(size_t) == sizeof(uintptr_t) && - __alignof__(size_t) == __alignof__(uintptr_t), - "Rust code expects C `size_t` to match Rust `usize`" -); - -// This will soon be moved to a separate file, so no need to merge with above. -#include -#include - -void *rust_helper_blk_mq_rq_to_pdu(struct request *rq) -{ - return blk_mq_rq_to_pdu(rq); -} -EXPORT_SYMBOL_GPL(rust_helper_blk_mq_rq_to_pdu); - -struct request *rust_helper_blk_mq_rq_from_pdu(void *pdu) -{ - return blk_mq_rq_from_pdu(pdu); -} -EXPORT_SYMBOL_GPL(rust_helper_blk_mq_rq_from_pdu); diff --git a/rust/helpers/README.md b/rust/helpers/README.md new file mode 100644 index 00000000000000..940b24bb552d6d --- /dev/null +++ b/rust/helpers/README.md @@ -0,0 +1,17 @@ +# Rust Helpers + +Non-trivial C macros cannot be used in Rust. Similarly, inlined C functions +cannot be called either. The files in this directory explicitly create functions +("helpers") that wrap those so that they can be called from Rust. + +Even though Rust kernel modules should never use the bindings directly, some of +these helpers need to be exported because Rust generics and inlined functions +may not get their code generated in the crate where they are defined. Other +helpers, called from non-inline functions, may not be exported, in principle. +However, in general, the Rust compiler does not guarantee codegen will be +performed for a non-inline function either. Therefore, this file exports all the +helpers. In the future, this may be revisited to reduce the number of exports +after the compiler is informed about the places codegen is required. + +All symbols are exported as GPL-only to guarantee no GPL-only feature is +accidentally exposed. diff --git a/rust/helpers/blk.c b/rust/helpers/blk.c new file mode 100644 index 00000000000000..d99c965eb59bf6 --- /dev/null +++ b/rust/helpers/blk.c @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +void *rust_helper_blk_mq_rq_to_pdu(struct request *rq) +{ + return blk_mq_rq_to_pdu(rq); +} +EXPORT_SYMBOL_GPL(rust_helper_blk_mq_rq_to_pdu); + +struct request *rust_helper_blk_mq_rq_from_pdu(void *pdu) +{ + return blk_mq_rq_from_pdu(pdu); +} +EXPORT_SYMBOL_GPL(rust_helper_blk_mq_rq_from_pdu); diff --git a/rust/helpers/bug.c b/rust/helpers/bug.c new file mode 100644 index 00000000000000..e2afbad23dcda8 --- /dev/null +++ b/rust/helpers/bug.c @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +__noreturn void rust_helper_BUG(void) +{ + BUG(); +} +EXPORT_SYMBOL_GPL(rust_helper_BUG); diff --git a/rust/helpers/build_assert.c b/rust/helpers/build_assert.c new file mode 100644 index 00000000000000..6a54b2680b1457 --- /dev/null +++ b/rust/helpers/build_assert.c @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +/* + * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can + * use it in contexts where Rust expects a `usize` like slice (array) indices. + * `usize` is defined to be the same as C's `uintptr_t` type (can hold any + * pointer) but not necessarily the same as `size_t` (can hold the size of any + * single object). Most modern platforms use the same concrete integer type for + * both of them, but in case we find ourselves on a platform where + * that's not true, fail early instead of risking ABI or + * integer-overflow issues. + * + * If your platform fails this assertion, it means that you are in + * danger of integer-overflow bugs (even if you attempt to add + * `--no-size_t-is-usize`). It may be easiest to change the kernel ABI on + * your platform such that `size_t` matches `uintptr_t` (i.e., to increase + * `size_t`, because `uintptr_t` has to be at least as big as `size_t`). + */ +static_assert( + sizeof(size_t) == sizeof(uintptr_t) && + __alignof__(size_t) == __alignof__(uintptr_t), + "Rust code expects C `size_t` to match Rust `usize`" +); diff --git a/rust/helpers/build_bug.c b/rust/helpers/build_bug.c new file mode 100644 index 00000000000000..f3106f248485a5 --- /dev/null +++ b/rust/helpers/build_bug.c @@ -0,0 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +const char *rust_helper_errname(int err) +{ + return errname(err); +} +EXPORT_SYMBOL_GPL(rust_helper_errname); diff --git a/rust/helpers/err.c b/rust/helpers/err.c new file mode 100644 index 00000000000000..fba4e0be64f593 --- /dev/null +++ b/rust/helpers/err.c @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +__force void *rust_helper_ERR_PTR(long err) +{ + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(rust_helper_ERR_PTR); + +bool rust_helper_IS_ERR(__force const void *ptr) +{ + return IS_ERR(ptr); +} +EXPORT_SYMBOL_GPL(rust_helper_IS_ERR); + +long rust_helper_PTR_ERR(__force const void *ptr) +{ + return PTR_ERR(ptr); +} +EXPORT_SYMBOL_GPL(rust_helper_PTR_ERR); diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c new file mode 100644 index 00000000000000..74dd4275c23395 --- /dev/null +++ b/rust/helpers/helpers.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "blk.c" +#include "bug.c" +#include "build_assert.c" +#include "build_bug.c" +#include "err.c" +#include "kunit.c" +#include "mutex.c" +#include "page.c" +#include "refcount.c" +#include "signal.c" +#include "slab.c" +#include "spinlock.c" +#include "task.c" +#include "uaccess.c" +#include "wait.c" +#include "workqueue.c" diff --git a/rust/helpers/kunit.c b/rust/helpers/kunit.c new file mode 100644 index 00000000000000..905e4ff4424a5b --- /dev/null +++ b/rust/helpers/kunit.c @@ -0,0 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +struct kunit *rust_helper_kunit_get_current_test(void) +{ + return kunit_get_current_test(); +} +EXPORT_SYMBOL_GPL(rust_helper_kunit_get_current_test); diff --git a/rust/helpers/mutex.c b/rust/helpers/mutex.c new file mode 100644 index 00000000000000..29fd141c387d79 --- /dev/null +++ b/rust/helpers/mutex.c @@ -0,0 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +void rust_helper_mutex_lock(struct mutex *lock) +{ + mutex_lock(lock); +} +EXPORT_SYMBOL_GPL(rust_helper_mutex_lock); diff --git a/rust/helpers/page.c b/rust/helpers/page.c new file mode 100644 index 00000000000000..b3280c80b2839f --- /dev/null +++ b/rust/helpers/page.c @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +struct page *rust_helper_alloc_pages(gfp_t gfp_mask, unsigned int order) +{ + return alloc_pages(gfp_mask, order); +} +EXPORT_SYMBOL_GPL(rust_helper_alloc_pages); + +void *rust_helper_kmap_local_page(struct page *page) +{ + return kmap_local_page(page); +} +EXPORT_SYMBOL_GPL(rust_helper_kmap_local_page); + +void rust_helper_kunmap_local(const void *addr) +{ + kunmap_local(addr); +} +EXPORT_SYMBOL_GPL(rust_helper_kunmap_local); + + diff --git a/rust/helpers/refcount.c b/rust/helpers/refcount.c new file mode 100644 index 00000000000000..13ab64805f7792 --- /dev/null +++ b/rust/helpers/refcount.c @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +refcount_t rust_helper_REFCOUNT_INIT(int n) +{ + return (refcount_t)REFCOUNT_INIT(n); +} +EXPORT_SYMBOL_GPL(rust_helper_REFCOUNT_INIT); + +void rust_helper_refcount_inc(refcount_t *r) +{ + refcount_inc(r); +} +EXPORT_SYMBOL_GPL(rust_helper_refcount_inc); + +bool rust_helper_refcount_dec_and_test(refcount_t *r) +{ + return refcount_dec_and_test(r); +} +EXPORT_SYMBOL_GPL(rust_helper_refcount_dec_and_test); diff --git a/rust/helpers/signal.c b/rust/helpers/signal.c new file mode 100644 index 00000000000000..d44e8096b8a96b --- /dev/null +++ b/rust/helpers/signal.c @@ -0,0 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +int rust_helper_signal_pending(struct task_struct *t) +{ + return signal_pending(t); +} +EXPORT_SYMBOL_GPL(rust_helper_signal_pending); diff --git a/rust/helpers/slab.c b/rust/helpers/slab.c new file mode 100644 index 00000000000000..3e0a1a173d8a7d --- /dev/null +++ b/rust/helpers/slab.c @@ -0,0 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +void * __must_check __realloc_size(2) +rust_helper_krealloc(const void *objp, size_t new_size, gfp_t flags) +{ + return krealloc(objp, new_size, flags); +} +EXPORT_SYMBOL_GPL(rust_helper_krealloc); diff --git a/rust/helpers/spinlock.c b/rust/helpers/spinlock.c new file mode 100644 index 00000000000000..04fd8ddb4986d4 --- /dev/null +++ b/rust/helpers/spinlock.c @@ -0,0 +1,27 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +void rust_helper___spin_lock_init(spinlock_t *lock, const char *name, + struct lock_class_key *key) +{ +#ifdef CONFIG_DEBUG_SPINLOCK + __raw_spin_lock_init(spinlock_check(lock), name, key, LD_WAIT_CONFIG); +#else + spin_lock_init(lock); +#endif +} +EXPORT_SYMBOL_GPL(rust_helper___spin_lock_init); + +void rust_helper_spin_lock(spinlock_t *lock) +{ + spin_lock(lock); +} +EXPORT_SYMBOL_GPL(rust_helper_spin_lock); + +void rust_helper_spin_unlock(spinlock_t *lock) +{ + spin_unlock(lock); +} +EXPORT_SYMBOL_GPL(rust_helper_spin_unlock); diff --git a/rust/helpers/task.c b/rust/helpers/task.c new file mode 100644 index 00000000000000..b176c347f0d41c --- /dev/null +++ b/rust/helpers/task.c @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +struct task_struct *rust_helper_get_current(void) +{ + return current; +} +EXPORT_SYMBOL_GPL(rust_helper_get_current); + +void rust_helper_get_task_struct(struct task_struct *t) +{ + get_task_struct(t); +} +EXPORT_SYMBOL_GPL(rust_helper_get_task_struct); + +void rust_helper_put_task_struct(struct task_struct *t) +{ + put_task_struct(t); +} +EXPORT_SYMBOL_GPL(rust_helper_put_task_struct); diff --git a/rust/helpers/uaccess.c b/rust/helpers/uaccess.c new file mode 100644 index 00000000000000..3d004ac1c18057 --- /dev/null +++ b/rust/helpers/uaccess.c @@ -0,0 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +unsigned long rust_helper_copy_from_user(void *to, const void __user *from, + unsigned long n) +{ + return copy_from_user(to, from, n); +} +EXPORT_SYMBOL_GPL(rust_helper_copy_from_user); + +unsigned long rust_helper_copy_to_user(void __user *to, const void *from, + unsigned long n) +{ + return copy_to_user(to, from, n); +} +EXPORT_SYMBOL_GPL(rust_helper_copy_to_user); diff --git a/rust/helpers/wait.c b/rust/helpers/wait.c new file mode 100644 index 00000000000000..bf361f40c7cbc6 --- /dev/null +++ b/rust/helpers/wait.c @@ -0,0 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +void rust_helper_init_wait(struct wait_queue_entry *wq_entry) +{ + init_wait(wq_entry); +} +EXPORT_SYMBOL_GPL(rust_helper_init_wait); diff --git a/rust/helpers/workqueue.c b/rust/helpers/workqueue.c new file mode 100644 index 00000000000000..12e2ee66aa4f60 --- /dev/null +++ b/rust/helpers/workqueue.c @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +void rust_helper_init_work_with_key(struct work_struct *work, work_func_t func, + bool onstack, const char *name, + struct lock_class_key *key) +{ + __init_work(work, onstack); + work->data = (atomic_long_t)WORK_DATA_INIT(); + lockdep_init_map(&work->lockdep_map, name, key, 0); + INIT_LIST_HEAD(&work->entry); + work->func = func; +} +EXPORT_SYMBOL_GPL(rust_helper_init_work_with_key);