[PATCH 3.12 005/113] tile/ptrace: Preserve previous registers for short regset write

From: Jiri Slaby
Date: Mon Mar 06 2017 - 04:12:45 EST


From: Dave Martin <Dave.Martin@xxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit fd7c99142d77dc4a851879a66715abf12a3193fb upstream.

Ensure that if userspace supplies insufficient data to
PTRACE_SETREGSET to fill all the registers, the thread's old
registers are preserved.

Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx>
Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
arch/tile/kernel/ptrace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c
index de98c6ddf136..2343126c4ad2 100644
--- a/arch/tile/kernel/ptrace.c
+++ b/arch/tile/kernel/ptrace.c
@@ -110,7 +110,7 @@ static int tile_gpr_set(struct task_struct *target,
const void *kbuf, const void __user *ubuf)
{
int ret;
- struct pt_regs regs;
+ struct pt_regs regs = *task_pt_regs(target);

ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0,
sizeof(regs));
--
2.12.0