powerpc/ptrace: Preserve previous fprs/vsrs on short regset write
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>
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index b1ec62f..18a643e 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -463,6 +463,10 @@
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 @@
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)