From: Maciej W. Rozycki <macro@mips.com>
Date: Mon, 11 Dec 2017 22:55:40 +0000 (+0000)
Subject: MIPS: Also verify sizeof `elf_fpreg_t' with PTRACE_SETREGSET
X-Git-Tag: archive/raspbian/4.9.80-2+rpi1~7^2~291
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success/%22http:/www.example.com/cgi/success?a=commitdiff_plain;h=1f4cff1c364ba4d1b197af88fca63b8736a9d601;p=linux-4.9.git

MIPS: Also verify sizeof `elf_fpreg_t' with PTRACE_SETREGSET

commit 006501e039eec411842bb3150c41358867d320c2 upstream.

Complement commit d614fd58a283 ("mips/ptrace: Preserve previous
registers for short regset write") and like with the PTRACE_GETREGSET
ptrace(2) request also apply a BUILD_BUG_ON check for the size of the
`elf_fpreg_t' type in the PTRACE_SETREGSET request handler.

Signed-off-by: Maciej W. Rozycki <macro@mips.com>
Fixes: d614fd58a283 ("mips/ptrace: Preserve previous registers for short regset write")
Cc: James Hogan <james.hogan@mips.com>
Cc: Paul Burton <Paul.Burton@mips.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17929/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 800342a16b12..99bc1ce2f40a 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -467,6 +467,7 @@ static int fpr_get_msa(struct task_struct *target,
 	u64 fpr_val;
 	int err;
 
+	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
 	for (i = 0; i < NUM_FPU_REGS; i++) {
 		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
 		err = user_regset_copyout(pos, count, kbuf, ubuf,