arm64/ptrace: Preserve previous registers for short regset write
authorDave Martin <Dave.Martin@arm.com>
Wed, 18 Jan 2017 16:25:22 +0000 (16:25 +0000)
committerCatalin Marinas <catalin.marinas@arm.com>
Wed, 18 Jan 2017 18:05:08 +0000 (18:05 +0000)
commita672401c00f82e4e19704aff361d9bad18003714
tree9c3f17a8057785d063b1e6c4b55112b44997deb9
parent9dd73f72f218320c6c90da5f834996e7360dc227
arm64/ptrace: Preserve previous registers for short regset write

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

Cc: <stable@vger.kernel.org> # 4.3.x-
Fixes: 5d220ff9420f ("arm64: Better native ptrace support for compat tasks")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <Will.Deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arch/arm64/kernel/ptrace.c