s390/ftrace/jprobes: Fix conflict between jprobes and function graph tracing
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.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index 250f597..dd6306c 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -690,6 +690,15 @@
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 @@
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 */