| From 8902ffeb9eb0fe44de430f6d3f17b1181b0fa298 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Mon, 29 Apr 2024 14:28:45 +0200 |
| Subject: s390/stacktrace: Skip first user stack frame |
| |
| From: Heiko Carstens <hca@linux.ibm.com> |
| |
| [ Upstream commit 87eceb17a987802aeee718be4decd19b56fc8e33 ] |
| |
| When walking user stack frames the first stack frame (where the stack |
| pointer points to) should be skipped: the return address of the current |
| function is saved in the previous stack frame, not the current stack frame, |
| which is allocated for to be called functions. |
| |
| Fixes: aa44433ac4ee ("s390: add USER_STACKTRACE support") |
| Reviewed-by: Jens Remus <jremus@linux.ibm.com> |
| Signed-off-by: Heiko Carstens <hca@linux.ibm.com> |
| Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| arch/s390/kernel/stacktrace.c | 8 ++++---- |
| 1 file changed, 4 insertions(+), 4 deletions(-) |
| |
| diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c |
| index e580d4cd2729a..1c9e3b7739a22 100644 |
| --- a/arch/s390/kernel/stacktrace.c |
| +++ b/arch/s390/kernel/stacktrace.c |
| @@ -95,6 +95,10 @@ void arch_stack_walk_user_common(stack_trace_consume_fn consume_entry, void *coo |
| while (1) { |
| if (__get_user(sp, &sf->back_chain)) |
| break; |
| + /* Sanity check: ABI requires SP to be 8 byte aligned. */ |
| + if (!sp || sp & 0x7) |
| + break; |
| + sf = (void __user *)sp; |
| if (__get_user(ip, &sf->gprs[8])) |
| break; |
| if (ip & 0x1) { |
| @@ -110,10 +114,6 @@ void arch_stack_walk_user_common(stack_trace_consume_fn consume_entry, void *coo |
| } |
| if (!store_ip(consume_entry, cookie, entry, perf, ip)) |
| return; |
| - /* Sanity check: ABI requires SP to be aligned 8 bytes. */ |
| - if (!sp || sp & 0x7) |
| - break; |
| - sf = (void __user *)sp; |
| first = false; |
| } |
| pagefault_enable(); |
| -- |
| 2.43.0 |
| |
