[PATCH 3.16 237/370] arm64/ptrace: Avoid uninitialised struct padding in fpr_set()

[Ben Hutchings]

3.16.42-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Dave Martin <Dave.Martin@xxxxxxx>

commit aeb1f39d814b2e21e5e5706a48834bfd553d0059 upstream.

This patch adds an explicit __reserved[] field to user_fpsimd_state
to replace what was previously unnamed padding.

This ensures that data in this region are propagated across
assignment rather than being left possibly uninitialised at the
destination.

Fixes: 60ffc30d5652 ("arm64: Exception handling")
Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx>
Acked-by: Will Deacon <Will.Deacon@xxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 arch/arm64/include/uapi/asm/ptrace.h | 1 +
 1 file changed, 1 insertion(+)

--- a/arch/arm64/include/uapi/asm/ptrace.h
+++ b/arch/arm64/include/uapi/asm/ptrace.h
@@ -75,6 +75,7 @@ struct user_fpsimd_state {
 	__uint128_t	vregs[32];
 	__u32		fpsr;
 	__u32		fpcr;
+	__u32		__reserved[2];
 };
 
 struct user_hwdebug_state {