diff options
| author | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2023-04-09 11:28:31 +0900 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2023-05-17 20:42:59 +0900 |
| commit | 6049674b5720edbbb13a7cb3e2f3d2affaa40c19 (patch) | |
| tree | cada351874cb8acddaccac482287ff360b82648d | |
| parent | ac9a78681b921877518763ba0e89202254349d1b (diff) | |
| download | linux-6049674b5720edbbb13a7cb3e2f3d2affaa40c19.tar.gz | |
tracing: fprobe: Initialize ret valiable to fix smatch error
The commit 39d954200bf6 ("fprobe: Skip exit_handler if entry_handler returns
!0") introduced a hidden dependency of 'ret' local variable in the
fprobe_handler(), Smatch warns the `ret` can be accessed without
initialization.
kernel/trace/fprobe.c:59 fprobe_handler()
error: uninitialized symbol 'ret'.
kernel/trace/fprobe.c
49 fpr->entry_ip = ip;
50 if (fp->entry_data_size)
51 entry_data = fpr->data;
52 }
53
54 if (fp->entry_handler)
55 ret = fp->entry_handler(fp, ip, ftrace_get_regs(fregs), entry_data);
ret is only initialized if there is an ->entry_handler
56
57 /* If entry_handler returns !0, nmissed is not counted. */
58 if (rh) {
rh is only true if there is an ->exit_handler. Presumably if you have
and ->exit_handler that means you also have a ->entry_handler but Smatch
is not smart enough to figure it out.
--> 59 if (ret)
^^^
Warning here.
60 rethook_recycle(rh);
61 else
62 rethook_hook(rh, ftrace_get_regs(fregs), true);
63 }
64 out:
65 ftrace_test_recursion_unlock(bit);
66 }
Link: https://lore.kernel.org/all/168100731160.79534.374827110083836722.stgit@devnote2/
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/all/85429a5c-a4b9-499e-b6c0-cbd313291c49@kili.mountain
Fixes: 39d954200bf6 ("fprobe: Skip exit_handler if entry_handler returns !0")
Acked-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
| -rw-r--r-- | kernel/trace/fprobe.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index 9abb3905bc8e17..293184227394ed 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, ret; + int bit, ret = 0; fp = container_of(ops, struct fprobe, ops); if (fprobe_disabled(fp)) |