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Commit 99dfe80a authored by Dave Martin's avatar Dave Martin Committed by Michael Ellerman
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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: c6e6771b ("powerpc: Introduce VSX thread_struct and CONFIG_VSX")
Cc: stable@vger.kernel.org # v2.6.27+
Signed-off-by: default avatarDave Martin <Dave.Martin@arm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 27593d72

arch/powerpc/kernel/ptrace.c

+7 −0
Original line number Diff line number Diff line
@@ -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)