diff options
| author | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2023-02-02 00:56:38 +0900 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2023-03-28 18:52:22 -0400 |
| commit | 39d954200bf6ad503c722e44d0be80c7b826fa42 (patch) | |
| tree | 01cc0df2f14044b41f9cedfb2c5b3fa6da26ec2c /kernel/trace | |
| parent | lib/test_fprobe: Add a test case for nr_maxactive (diff) | |
| download | linux-39d954200bf6ad503c722e44d0be80c7b826fa42.tar.gz linux-39d954200bf6ad503c722e44d0be80c7b826fa42.zip | |
fprobe: Skip exit_handler if entry_handler returns !0
Skip hooking function return and calling exit_handler if the
entry_handler() returns !0.
Link: https://lkml.kernel.org/r/167526699798.433354.10998365726830117303.stgit@mhiramat.roam.corp.google.com
Cc: Florent Revest <revest@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 15 | ||||
| -rw-r--r-- | kernel/trace/fprobe.c | 14 |
2 files changed, 22 insertions, 7 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index fa403c323501..d804172b709c 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2644,7 +2644,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, return err; } -static void +static int kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, struct pt_regs *regs, void *data) { @@ -2652,6 +2652,17 @@ kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, link = container_of(fp, struct bpf_kprobe_multi_link, fp); kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); + return 0; +} + +static void +kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, + struct pt_regs *regs, void *data) +{ + struct bpf_kprobe_multi_link *link; + + link = container_of(fp, struct bpf_kprobe_multi_link, fp); + kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); } static int symbols_cmp_r(const void *a, const void *b, const void *priv) @@ -2848,7 +2859,7 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr goto error; if (flags & BPF_F_KPROBE_MULTI_RETURN) - link->fp.exit_handler = kprobe_multi_link_handler; + link->fp.exit_handler = kprobe_multi_link_exit_handler; else link->fp.entry_handler = kprobe_multi_link_handler; diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index f222848571f2..9abb3905bc8e 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -27,7 +27,7 @@ static void fprobe_handler(unsigned long ip, unsigned long parent_ip, struct rethook_node *rh = NULL; struct fprobe *fp; void *entry_data = NULL; - int bit; + int bit, ret; fp = container_of(ops, struct fprobe, ops); if (fprobe_disabled(fp)) @@ -52,11 +52,15 @@ static void fprobe_handler(unsigned long ip, unsigned long parent_ip, } if (fp->entry_handler) - fp->entry_handler(fp, ip, ftrace_get_regs(fregs), entry_data); - - if (rh) - rethook_hook(rh, ftrace_get_regs(fregs), true); + ret = fp->entry_handler(fp, ip, ftrace_get_regs(fregs), entry_data); + /* If entry_handler returns !0, nmissed is not counted. */ + if (rh) { + if (ret) + rethook_recycle(rh); + else + rethook_hook(rh, ftrace_get_regs(fregs), true); + } out: ftrace_test_recursion_unlock(bit); } |