Patch "powerpc/ptrace: Preserve previous fprs/vsrs on short regset write" has been added to the 4.9-stable tree

Patch "powerpc/ptrace: Preserve previous fprs/vsrs on short regset write" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    powerpc/ptrace: Preserve previous fprs/vsrs on short regset write

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     powerpc-ptrace-preserve-previous-fprs-vsrs-on-short-regset-write.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 99dfe80a2a246c600440a815741fd2e74a8b4977 Mon Sep 17 00:00:00 2001
From: Dave Martin <Dave.Martin@arm.com>
Date: Thu, 5 Jan 2017 16:50:57 +0000
Subject: powerpc/ptrace: Preserve previous fprs/vsrs on short regset write

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

commit 99dfe80a2a246c600440a815741fd2e74a8b4977 upstream.

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")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/powerpc/kernel/ptrace.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -463,6 +463,10 @@ static int fpr_set(struct task_struct *t
 
 	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 *t
 	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)


Patches currently in stable-queue which might be from Dave.Martin@arm.com are

queue-4.9/arm64-ptrace-preserve-previous-registers-for-short-regset-write-3.patch
queue-4.9/arm64-ptrace-reject-attempts-to-set-incomplete-hardware-breakpoint-fields.patch
queue-4.9/powerpc-ptrace-preserve-previous-tm-fprs-vsrs-on-short-regset-write.patch
queue-4.9/arm64-ptrace-preserve-previous-registers-for-short-regset-write-2.patch
queue-4.9/arm64-ptrace-avoid-uninitialised-struct-padding-in-fpr_set.patch
queue-4.9/arm64-ptrace-preserve-previous-registers-for-short-regset-write.patch
queue-4.9/powerpc-ptrace-preserve-previous-fprs-vsrs-on-short-regset-write.patch