diff options
| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-07-26 19:07:32 +0300 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-07-27 16:36:20 +0300 |
| commit | 87107a25a2f857693156f075da6e2a1438f4b4a0 (patch) | |
| tree | cd873d9dd4fd322f7b1eec85fc8cc97d2b83e6b5 /kernel/trace/trace_kprobe.c | |
| parent | 72809cbf6748830ae4a59a45bcb2367a6c24d74d (diff) | |
| download | linux-87107a25a2f857693156f075da6e2a1438f4b4a0.tar.xz | |
tracing/kprobes: Simplify the logic of enable_trace_kprobe()
The function enable_trace_kprobe() performs slightly differently if the file
parameter is passed in as NULL on non-NULL. Instead of checking file twice,
move the code between the two tests into a static inline helper function to
make the code easier to follow.
Link: http://lkml.kernel.org/r/20180725224728.7b1d5db2@vmware.local.home
Link: http://lkml.kernel.org/r/20180726121152.4dd54330@gandalf.local.home
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_kprobe.c')
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 42 |
1 files changed, 24 insertions, 18 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 6b71860f3998..0534eb8b7640 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -393,6 +393,20 @@ static struct trace_kprobe *find_trace_kprobe(const char *event, return NULL; } +static inline int __enable_trace_kprobe(struct trace_kprobe *tk) +{ + int ret = 0; + + if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { + if (trace_kprobe_is_return(tk)) + ret = enable_kretprobe(&tk->rp); + else + ret = enable_kprobe(&tk->rp.kp); + } + + return ret; +} + /* * Enable trace_probe * if the file is NULL, enable "perf" handler, or enable "trace" handler. @@ -400,7 +414,7 @@ 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 = NULL; + struct event_file_link *link; int ret = 0; if (file) { @@ -414,26 +428,18 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) list_add_tail_rcu(&link->list, &tk->tp.files); tk->tp.flags |= TP_FLAG_TRACE; - } else - tk->tp.flags |= TP_FLAG_PROFILE; - - if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { - if (trace_kprobe_is_return(tk)) - ret = enable_kretprobe(&tk->rp); - else - ret = enable_kprobe(&tk->rp.kp); - } - - if (ret) { - if (file) { - /* Notice the if is true on not WARN() */ - if (!WARN_ON_ONCE(!link)) - list_del_rcu(&link->list); + ret = __enable_trace_kprobe(tk); + if (ret) { + list_del_rcu(&link->list); kfree(link); tk->tp.flags &= ~TP_FLAG_TRACE; - } else { - tk->tp.flags &= ~TP_FLAG_PROFILE; } + + } else { + tk->tp.flags |= TP_FLAG_PROFILE; + ret = __enable_trace_kprobe(tk); + if (ret) + tk->tp.flags &= ~TP_FLAG_PROFILE; } out: return ret; |