s390/kernel: fix ptrace peek/poke for floating point registers
authorMartin Schwidefsky <schwidefsky@de.ibm.com>
Tue, 27 Oct 2015 12:13:38 +0000 (13:13 +0100)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Tue, 3 Nov 2015 13:40:42 +0000 (14:40 +0100)
commit55a423b6f105fa323168f15f4bb67f23b21da44e
tree518b2d2983596039f5ab0ba4d1d069aa8b7cc0b8
parentef12cb904e096335ef179bfe30e637a9c2464343
s390/kernel: fix ptrace peek/poke for floating point registers

git commit 155e839a814834a3b4b31e729f4716e59d3d2dd4
"s390/kernel: dynamically allocate FP register save area"
introduced a regression in regard to ptrace.

If the vector register extension is not present or unused the
ptrace peek of a floating pointer register return incorrect data
and the ptrace poke to a floating pointer register overwrites the
task structure starting at task->thread.fpu.fprs.

Cc: stable@kernel.org # v4.3
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/kernel/ptrace.c