[PATCH v2 1/6] x86/stacktrace: do not unwind after user regs

From: Jiri Slaby
Date: Mon May 14 2018 - 10:07:01 EST


Josh pointed out, that there is no way a frame can be after user regs.
So remove the last unwind and the check.

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/kernel/stacktrace.c | 9 ---------
1 file changed, 9 deletions(-)

diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 093f2ea5dd56..8948b7d9c064 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -113,15 +113,6 @@ __save_stack_trace_reliable(struct stack_trace *trace,
if (!user_mode(regs))
return -EINVAL;

- /*
- * The last frame contains the user mode syscall
- * pt_regs. Skip it and finish the unwind.
- */
- unwind_next_frame(&state);
- if (!unwind_done(&state)) {
- STACKTRACE_DUMP_ONCE(task);
- return -EINVAL;
- }
break;
}

--
2.16.3