On Wed, 25 Jul 2018 16:20:38 +0200
Artem Savkov <asav...@redhat.com> wrote:
> 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.
>
> Signed-off-by: Artem Savkov <asav...@redhat.com>
Masami,
Can you ack this?
Thanks!
-- Steve
> ---
> kernel/trace/trace_kprobe.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 21f718472942..27ace4513c43 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -400,11 +400,10 @@ 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;
> int ret = 0;
>
> if (file) {
> - struct event_file_link *link;
> -
> link = kmalloc(sizeof(*link), GFP_KERNEL);
> if (!link) {
> ret = -ENOMEM;
> @@ -424,6 +423,16 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct
> trace_event_file *file)
> 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;
> }
