On Wed, 20 Jan 2021 11:20:04 -0500
Steven Rostedt <rost...@goodmis.org> wrote:
>
> You forgot to include Masami on Cc again. Masami maintains kprobes. Please
> include him on any updates, as he needs to review them, and give his
> acknowledgment before acceptance.
>
> I need to update MAINTAINERS files to include trace_kprobe under KPROBES.
> And I also don't see any UPROBES section there. That needs to be done as
> well.
Uprobes is under kernel/events/, which seems to be handled by
performance event subsystem. Maybe we should ask them too.
Or, can I be a reviewer (R:) for tracing subsystem?
>
> On Wed, 20 Jan 2021 23:56:44 +0800
> Jianlin Lv <jianlin...@arm.com> wrote:
>
> > When trying to create kretprobe with the wrong function symbol in tracefs;
> > The error is triggered in the register_trace_kprobe() and recorded as
> > FAIL_REG_PROBE issue,
> >
> > Example:
> > $ cd /sys/kernel/debug/tracing
> > $ echo 'r:myprobe ERROR_SYMBOL_XXX ret=%x0' >> kprobe_events
> > bash: echo: write error: Invalid argument
> > $ cat error_log
> > [142797.347877] trace_kprobe: error: Failed to register probe event
> > Command: r:myprobe ERROR_SYMBOL_XXX ret=%x0
> > ^
> >
> > This error can be detected in the parameter parsing stage, the effect of
> > applying this patch is as follows:
> >
> > $ echo 'r:myprobe ERROR_SYMBOL_XXX ret=%x0' >> kprobe_events
> > bash: echo: write error: Invalid argument
> > $ cat error_log
> > [415.89]trace_kprobe: error: Retprobe address must be an function entry
> > Command: r:myprobe ERROR_SYMBOL_XXX ret=%x0
> > ^
> >
> > Signed-off-by: Jianlin Lv <jianlin...@arm.com>
> >
> > v2:add !strchr(symbol, ':') to check really bad symbol or not.
>
> Also, the "changes since" section should be below the "---" so that they
> don't get pulled into the commit.
Except that, this looks good to me.
Acked-by: Masami Hiramatsu <mhira...@kernel.org>
Thank you,
>
> Thanks!
>
> -- Steve
>
>
> > ---
> > kernel/trace/trace_kprobe.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> > index e6fba1798771..bce63d5ecaec 100644
> > --- a/kernel/trace/trace_kprobe.c
> > +++ b/kernel/trace/trace_kprobe.c
> > @@ -830,7 +830,7 @@ static int trace_kprobe_create(int argc, const char
> > *argv[])
> > flags |= TPARG_FL_RETURN;
> > if (kprobe_on_func_entry(NULL, symbol, offset))
> > flags |= TPARG_FL_FENTRY;
> > - if (offset && is_return && !(flags & TPARG_FL_FENTRY)) {
> > + if (!strchr(symbol, ':') && is_return && !(flags &
> > TPARG_FL_FENTRY)) {
> > trace_probe_log_err(0, BAD_RETPROBE);
> > goto parse_error;
> > }
>
--
Masami Hiramatsu <mhira...@kernel.org>
