[PATCH 4.16 045/272] sh: fix debug trap failure to process signals before return to user

Greg Kroah-Hartman
2018-05-28T11:08:15Z

From: Rich Felker <dalias@libc.org>

[ Upstream commit 96a598996f6ac518ac79839ecbb17c91af91f4f7 ]

When responding to a debug trap (breakpoint) in userspace, the
kernel's trap handler raised SIGTRAP but returned from the trap via a
code path that ignored pending signals, resulting in an infinite loop
re-executing the trapping instruction.

Signed-off-by: Rich Felker <dalias@libc.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/sh/kernel/entry-common.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/sh/kernel/entry-common.S
+++ b/arch/sh/kernel/entry-common.S
@@ -255,7 +255,7 @@ debug_trap:
mov.l @r8, r8
jsr @r8
nop
- bra __restore_all
+ bra ret_from_exception
nop
CFI_ENDPROC