diff options
| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-07-25 22:28:56 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-06 16:24:30 +0200 |
| commit | dab04fda26530ee686b14b02aa2c5e716cef153c (patch) | |
| tree | d508799830a46dd83766e3cec5a2168f872f6872 | |
| parent | d9bbd8076836b1c3e648132afe73185f945b89a7 (diff) | |
tracing: Quiet gcc warning about maybe unused link variable
commit 2519c1bbe38d7acacc9aacba303ca6f97482ed53 upstream.
Commit 57ea2a34adf4 ("tracing/kprobes: Fix trace_probe flags on
enable_trace_kprobe() failure") added an if statement that depends on another
if statement that gcc doesn't see will initialize the "link" variable and
gives the warning:
"warning: 'link' may be used uninitialized in this function"
It is really a false positive, but to quiet the warning, and also to make
sure that it never actually is used uninitialized, initialize the "link"
variable to NULL and add an if (!WARN_ON_ONCE(!link)) where the compiler
thinks it could be used uninitialized.
Cc: stable@vger.kernel.org
Fixes: 57ea2a34adf4 ("tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index a357d7e93934..f0ee722be520 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -349,7 +349,7 @@ static struct trace_kprobe *find_trace_kprobe(const char *event, static int enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) { - struct event_file_link *link; + struct event_file_link *link = NULL; int ret = 0; if (file) { @@ -375,7 +375,9 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) if (ret) { if (file) { - list_del_rcu(&link->list); + /* Notice the if is true on not WARN() */ + if (!WARN_ON_ONCE(!link)) + list_del_rcu(&link->list); kfree(link); tk->tp.flags &= ~TP_FLAG_TRACE; } else { |