Messages in this thread | | | Date | Fri, 25 Oct 2019 09:21:10 -0500 | From | Josh Poimboeuf <> | Subject | Re: [PATCH] stacktrace: don't skip first entry on noncurrent tasks |
| |
On Fri, Oct 25, 2019 at 08:52:26AM +0200, Jiri Slaby wrote: > When doing cat /proc/<PID>/stack, the output is missing the first entry. > When the current code walks the stack starting in stack_trace_save_tsk, > it skips all scheduler functions (that's OK) plus one more function. But > this one function should be skipped only for the 'current' task as it is > stack_trace_save_tsk proper. > > The original code (before the common infrastructure) skipped one > function only for the 'current' task -- see save_stack_trace_tsk before > 3599fe12a125. So do so also in the new infrastructure now. > > Signed-off-by: Jiri Slaby <jslaby@suse.cz> > Fixes: 214d8ca6ee85 ("stacktrace: Provide common infrastructure") > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Josh Poimboeuf <jpoimboe@redhat.com> > --- > kernel/stacktrace.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c > index 6d1f68b7e528..d06a2e4d0142 100644 > --- a/kernel/stacktrace.c > +++ b/kernel/stacktrace.c > @@ -141,7 +141,8 @@ unsigned int stack_trace_save_tsk(struct task_struct *tsk, unsigned long *store, > struct stacktrace_cookie c = { > .store = store, > .size = size, > - .skip = skipnr + 1, > + /* skip this function if they are tracing us */ > + .skip = skipnr + !!(current == tsk), > }; > > if (!try_get_task_stack(tsk))
I think a similar change is needed for the other !CONFIG_ARCH_STACKWALK version of stack_trace_save_tsk() in that file?
-- Josh
| |