On Mon, 18 Jul 2016 15:26:41 +0200 Jiri Olsa <[email protected]> wrote:
> This fixes the same issue Steven already fixed for x86 > in following commit: > > 237d28db036e ftrace/jprobes/x86: Fix conflict between jprobes and function > graph tracing > > It fixes the crash, that happens when function graph tracing > and jprobes are used simultaneously. Please refer to above > commit for details. I'm guessing that this should go in via the s390 tree. Acked-by: Steven Rostedt <[email protected]> -- Steve > > Signed-off-by: Jiri Olsa <[email protected]> > --- > arch/s390/kernel/kprobes.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c > index 250f5972536a..dd6306c51bd6 100644 > --- a/arch/s390/kernel/kprobes.c > +++ b/arch/s390/kernel/kprobes.c > @@ -690,6 +690,15 @@ int setjmp_pre_handler(struct kprobe *p, struct pt_regs > *regs) > stack = (unsigned long) regs->gprs[15]; > > memcpy(kcb->jprobes_stack, (void *) stack, MIN_STACK_SIZE(stack)); > + > + /* > + * jprobes use jprobe_return() which skips the normal return > + * path of the function, and this messes up the accounting of the > + * function graph tracer to get messed up. > + * > + * Pause function graph tracing while performing the jprobe function. > + */ > + pause_graph_tracing(); > return 1; > } > NOKPROBE_SYMBOL(setjmp_pre_handler); > @@ -705,6 +714,9 @@ int longjmp_break_handler(struct kprobe *p, struct > pt_regs *regs) > struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); > unsigned long stack; > > + /* It's OK to start function graph tracing again */ > + unpause_graph_tracing(); > + > stack = (unsigned long) kcb->jprobe_saved_regs.gprs[15]; > > /* Put the regs back */
