From 99dfe80a2a246c600440a815741fd2e74a8b4977 Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Thu, 5 Jan 2017 16:50:57 +0000 Subject: [PATCH] powerpc/ptrace: Preserve previous fprs/vsrs on 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. Fixes: c6e6771b87d4 ("powerpc: Introduce VSX thread_struct and CONFIG_VSX") Cc: stable@vger.kernel.org # v2.6.27+ Signed-off-by: Dave Martin Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/ptrace.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index e4744ff38a17..10543eb1f8f3 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -463,6 +463,10 @@ static int fpr_set(struct task_struct *target, const struct user_regset *regset, flush_fp_to_thread(target); + for (i = 0; i < 32 ; i++) + buf[i] = target->thread.TS_FPR(i); + buf[32] = target->thread.fp_state.fpscr; + /* copy to local buffer then write that out */ i = user_regset_copyin(&pos, &count, &kbuf, &ubuf, buf, 0, -1); if (i) @@ -672,6 +676,9 @@ static int vsr_set(struct task_struct *target, const struct user_regset *regset, flush_altivec_to_thread(target); flush_vsx_to_thread(target); + for (i = 0; i < 32 ; i++) + buf[i] = target->thread.fp_state.fpr[i][TS_VSRLOWOFFSET]; + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, buf, 0, 32 * sizeof(double)); if (!ret)