diff options
| author | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2025-07-29 08:47:03 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-20 18:36:34 +0200 |
| commit | 3d95aed41fec10a5effa7ff9081baa82e4c88a9c (patch) | |
| tree | 2812e3af3bc89c39fb1487d08086c879773a9b17 | |
| parent | 71bb5d8af052e8076e73c417a547c32a6a2a5e78 (diff) | |
tracing: fprobe: Fix infinite recursion using preempt_*_notrace()
commit a3e892ab0fc287389176eabdcd74234508f6e52d upstream.
Since preempt_count_add/del() are tracable functions, it is not allowed
to use preempt_disable/enable() in ftrace handlers. Without this fix,
probing on `preempt_count_add%return` will cause an infinite recursion
of fprobes.
To fix this problem, use preempt_disable/enable_notrace() in
fprobe_return().
Link: https://lore.kernel.org/all/175374642359.1471729.1054175011228386560.stgit@mhiramat.tok.corp.google.com/
Fixes: 4346ba160409 ("fprobe: Rewrite fprobe on function-graph tracer")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/trace/fprobe.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index ba7ff14f5339..f9b3aa9afb17 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -352,7 +352,7 @@ static void fprobe_return(struct ftrace_graph_ret *trace, size_words = SIZE_IN_LONG(size); ret_ip = ftrace_regs_get_instruction_pointer(fregs); - preempt_disable(); + preempt_disable_notrace(); curr = 0; while (size_words > curr) { @@ -368,7 +368,7 @@ static void fprobe_return(struct ftrace_graph_ret *trace, } curr += size; } - preempt_enable(); + preempt_enable_notrace(); } NOKPROBE_SYMBOL(fprobe_return); |