ARM: fix PTRACE_SETVFPREGS on SMP systems

PTRACE_SETVFPREGS fails to properly mark the VFP register set to be
reloaded, because it undoes one of the effects of vfp_flush_hwstate().

Specifically vfp_flush_hwstate() sets thread->vfpstate.hard.cpu to
an invalid CPU number, but vfp_set() overwrites this with the original
CPU number, thereby rendering the hardware state as apparently "valid",
even though the software state is more recent.

Fix this by reverting the previous change.

Cc: <stable@vger.kernel.org>
Fixes: 8130b9d7b9 ("ARM: 7308/1: vfp: flush thread hwstate before copying ptrace registers")
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Simon Marchi <simon.marchi@ericsson.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Russell King 2016-05-30 23:14:56 +01:00
parent ec953b70f3
commit e2dfb4b880

View file

@ -733,8 +733,8 @@ static int vfp_set(struct task_struct *target,
if (ret)
return ret;
vfp_flush_hwstate(thread);
thread->vfpstate.hard = new_vfp;
vfp_flush_hwstate(thread);
return 0;
}