| From: Artem Savkov <asavkov@redhat.com> |
| Date: Wed, 25 Jul 2018 16:20:38 +0200 |
| Subject: tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() |
| failure |
| |
| commit 57ea2a34adf40f3a6e88409aafcf803b8945619a upstream. |
| |
| If enable_trace_kprobe fails to enable the probe in enable_k(ret)probe |
| it returns an error, but does not unset the tp flags it set previously. |
| This results in a probe being considered enabled and failures like being |
| unable to remove the probe through kprobe_events file since probes_open() |
| expects every probe to be disabled. |
| |
| Link: http://lkml.kernel.org/r/20180725102826.8300-1-asavkov@redhat.com |
| Link: http://lkml.kernel.org/r/20180725142038.4765-1-asavkov@redhat.com |
| |
| Cc: Ingo Molnar <mingo@redhat.com> |
| Fixes: 41a7dd420c57 ("tracing/kprobes: Support ftrace_event_file base multibuffer") |
| Acked-by: Masami Hiramatsu <mhiramat@kernel.org> |
| Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> |
| Signed-off-by: Artem Savkov <asavkov@redhat.com> |
| Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| kernel/trace/trace_kprobe.c | 13 +++++++++++-- |
| 1 file changed, 11 insertions(+), 2 deletions(-) |
| |
| --- a/kernel/trace/trace_kprobe.c |
| +++ b/kernel/trace/trace_kprobe.c |
| @@ -361,11 +361,10 @@ static struct trace_kprobe *find_trace_k |
| static int |
| enable_trace_kprobe(struct trace_kprobe *tk, struct ftrace_event_file *file) |
| { |
| + struct event_file_link *link; |
| int ret = 0; |
| |
| if (file) { |
| - struct event_file_link *link; |
| - |
| link = kmalloc(sizeof(*link), GFP_KERNEL); |
| if (!link) { |
| ret = -ENOMEM; |
| @@ -385,6 +384,16 @@ enable_trace_kprobe(struct trace_kprobe |
| else |
| ret = enable_kprobe(&tk->rp.kp); |
| } |
| + |
| + if (ret) { |
| + if (file) { |
| + list_del_rcu(&link->list); |
| + kfree(link); |
| + tk->tp.flags &= ~TP_FLAG_TRACE; |
| + } else { |
| + tk->tp.flags &= ~TP_FLAG_PROFILE; |
| + } |
| + } |
| out: |
| return ret; |
| } |