From f93ebd27472302ee292cdbc61c777505675be3bd Mon Sep 17 00:00:00 2001
From: Leon Hwang <hffilwlqm@gmail.com>
Date: Sun, 10 Nov 2024 14:58:26 +0800
Subject: [PATCH] bpf: Remove HAS_KPROBE_MULTI macro
Simplify bpf code.
And use Go to determine loading kprobe or kprobe.multi bpf prog.
Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
---
.gitignore | 1 -
bpf/kprobe_pwru.c | 34 +++++++++++++++-------------------
build.go | 1 -
internal/pwru/kprobe.go | 5 +++--
main.go | 18 +++++++++++-------
5 files changed, 29 insertions(+), 30 deletions(-)
diff --git a/.gitignore b/.gitignore
index 834a28eb..b84e6dd5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,5 @@ pwru
release
tags
kprobepwru_*
-kprobemultipwru_*
featurespwru_*
!pwru/
diff --git a/bpf/kprobe_pwru.c b/bpf/kprobe_pwru.c
index 71d3382f..8e66152d 100644
--- a/bpf/kprobe_pwru.c
+++ b/bpf/kprobe_pwru.c
@@ -492,7 +492,7 @@ handle_everything(struct sk_buff *skb, void *ctx, struct event_t *event, u64 *_s
}
static __always_inline int
-kprobe_skb(struct sk_buff *skb, struct pt_regs *ctx, bool has_get_func_ip, u64 *_stackid) {
+kprobe_skb(struct sk_buff *skb, struct pt_regs *ctx, const bool has_get_func_ip, u64 *_stackid) {
struct event_t event = {};
if (!handle_everything(skb, ctx, &event, _stackid, true))
@@ -510,19 +510,17 @@ kprobe_skb(struct sk_buff *skb, struct pt_regs *ctx, bool has_get_func_ip, u64 *
return BPF_OK;
}
-#ifdef HAS_KPROBE_MULTI
-#define PWRU_KPROBE_TYPE "kprobe.multi"
-#define PWRU_HAS_GET_FUNC_IP true
-#else
-#define PWRU_KPROBE_TYPE "kprobe"
-#define PWRU_HAS_GET_FUNC_IP false
-#endif /* HAS_KPROBE_MULTI */
-
-#define PWRU_ADD_KPROBE(X) \
- SEC(PWRU_KPROBE_TYPE "/skb-" #X) \
- int kprobe_skb_##X(struct pt_regs *ctx) { \
- struct sk_buff *skb = (struct sk_buff *) PT_REGS_PARM##X(ctx); \
- return kprobe_skb(skb, ctx, PWRU_HAS_GET_FUNC_IP, NULL); \
+#define PWRU_ADD_KPROBE(X) \
+ SEC("kprobe/skb-" #X) \
+ int kprobe_skb_##X(struct pt_regs *ctx) { \
+ struct sk_buff *skb = (struct sk_buff *) PT_REGS_PARM##X(ctx); \
+ return kprobe_skb(skb, ctx, false, NULL); \
+ } \
+ \
+ SEC("kprobe.multi/skb-" #X) \
+ int kprobe_multi_skb_##X(struct pt_regs *ctx) { \
+ struct sk_buff *skb = (struct sk_buff *) PT_REGS_PARM##X(ctx); \
+ return kprobe_skb(skb, ctx, true, NULL); \
}
PWRU_ADD_KPROBE(1)
@@ -531,21 +529,19 @@ PWRU_ADD_KPROBE(3)
PWRU_ADD_KPROBE(4)
PWRU_ADD_KPROBE(5)
+#undef PWRU_ADD_KPROBE
+
SEC("kprobe/skb_by_stackid")
int kprobe_skb_by_stackid(struct pt_regs *ctx) {
u64 stackid = get_stackid(ctx);
struct sk_buff **skb = bpf_map_lookup_elem(&stackid_skb, &stackid);
if (skb && *skb)
- return kprobe_skb(*skb, ctx, PWRU_HAS_GET_FUNC_IP, &stackid);
+ return kprobe_skb(*skb, ctx, false, &stackid);
return BPF_OK;
}
-#undef PWRU_KPROBE
-#undef PWRU_HAS_GET_FUNC_IP
-#undef PWRU_KPROBE_TYPE
-
SEC("kprobe/skb_lifetime_termination")
int kprobe_skb_lifetime_termination(struct pt_regs *ctx) {
struct sk_buff *skb = (typeof(skb)) PT_REGS_PARM1(ctx);
diff --git a/build.go b/build.go
index 126334d6..baa02454 100644
--- a/build.go
+++ b/build.go
@@ -3,7 +3,6 @@
//go:generate sh -c "echo Generating for $TARGET_GOARCH"
//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -target $TARGET_GOARCH -cc clang -no-strip KProbePWRU ./bpf/kprobe_pwru.c -- -I./bpf/headers -Wno-address-of-packed-member
-//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -target $TARGET_GOARCH -cc clang -no-strip KProbeMultiPWRU ./bpf/kprobe_pwru.c -- -DHAS_KPROBE_MULTI -I./bpf/headers -Wno-address-of-packed-member
//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -target $TARGET_GOARCH -cc clang -no-strip FeaturesPWRU ./bpf/features.c -- -I./bpf/headers -Wno-address-of-packed-member
package main
diff --git a/internal/pwru/kprobe.go b/internal/pwru/kprobe.go
index 6d8351b4..8dc926bf 100644
--- a/internal/pwru/kprobe.go
+++ b/internal/pwru/kprobe.go
@@ -201,9 +201,10 @@ func AttachKprobeMulti(ctx context.Context, bar *pb.ProgressBar, kprobes []Kprob
}
func NewKprober(ctx context.Context, funcs Funcs, coll *ebpf.Collection, a2n Addr2Name, useKprobeMulti bool, batch uint) *kprober {
- msg := "kprobe"
+ msg, probeMethod := "kprobe", "kprobe"
if useKprobeMulti {
msg = "kprobe-multi"
+ probeMethod = "kprobe_multi"
}
log.Printf("Attaching kprobes (via %s)...\n", msg)
@@ -213,7 +214,7 @@ func NewKprober(ctx context.Context, funcs Funcs, coll *ebpf.Collection, a2n Add
pwruKprobes := make([]Kprobe, 0, len(funcs))
funcsByPos := GetFuncsByPos(funcs)
for pos, fns := range funcsByPos {
- fn, ok := coll.Programs[fmt.Sprintf("kprobe_skb_%d", pos)]
+ fn, ok := coll.Programs[fmt.Sprintf("%s_skb_%d", probeMethod, pos)]
if ok {
pwruKprobes = append(pwruKprobes, Kprobe{HookFuncs: fns, Prog: fn})
} else {
diff --git a/main.go b/main.go
index 2aa18137..83c0565f 100644
--- a/main.go
+++ b/main.go
@@ -122,17 +122,21 @@ func main() {
opts.Programs.LogLevel = ebpf.LogLevelInstruction
opts.Programs.LogSize = ebpf.DefaultVerifierLogSize * 100
- var bpfSpec *ebpf.CollectionSpec
- switch {
- case (flags.OutputSkb || flags.OutputShinfo) && useKprobeMulti:
- bpfSpec, err = LoadKProbeMultiPWRU()
- default:
- bpfSpec, err = LoadKProbePWRU()
- }
+ bpfSpec, err := LoadKProbePWRU()
if err != nil {
log.Fatalf("Failed to load bpf spec: %v", err)
}
+ if useKprobeMulti {
+ for i := 1; i <= 5; i++ {
+ delete(bpfSpec.Programs, fmt.Sprintf("kprobe_skb_%d", i))
+ }
+ } else {
+ for i := 1; i <= 5; i++ {
+ delete(bpfSpec.Programs, fmt.Sprintf("kprobe_multi_skb_%d", i))
+ }
+ }
+
for name, program := range bpfSpec.Programs {
// Skip the skb-tracking ones that should not inject pcap-filter.
switch name {