[PATCH 4.9 10/16] sparc/ptrace: Preserve previous registers for short regset write

Greg Kroah-Hartman
2017-03-30T10:16:48Z

From: Dave Martin <Dave.Martin@arm.com>

commit d3805c546b275c8cc7d40f759d029ae92c7175f2 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@arm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/sparc/kernel/ptrace_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/sparc/kernel/ptrace_64.c
+++ b/arch/sparc/kernel/ptrace_64.c
@@ -313,7 +313,7 @@ static int genregs64_set(struct task_str
}

if (!ret) {
- unsigned long y;
+ unsigned long y = regs->y;

ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&y,