Vincent Palatin 644c154186 x86, fpu: Avoid FPU lazy restore after suspend ... When a cpu enters S3 state, the FPU state is lost. After resuming for S3, if we try to lazy restore the FPU for a process running on the same CPU, this will result in a corrupted FPU context. Ensure that "fpu_owner_task" is properly invalided when (re-)initializing a CPU, so nobody will try to lazy restore a state which doesn't exist in the hardware. Tested with a 64-bit kernel on a 4-core Ivybridge CPU with eagerfpu=off, by doing thousands of suspend/resume cycles with 4 processes doing FPU operations running. Without the patch, a process is killed after a few hundreds cycles by a SIGFPE. Cc: Duncan Laurie <dlaurie@chromium.org> Cc: Olof Johansson <olofj@chromium.org> Cc: <stable@kernel.org> v3.4+ # for 3.4 need to replace this_cpu_write by percpu_write Signed-off-by: Vincent Palatin <vpalatin@chromium.org> Link: http://lkml.kernel.org/r/1354306532-1014-1-git-send-email-vpalatin@chromium.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>		2012-11-30 13:48:05 -08:00
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asm	x86, fpu: Avoid FPU lazy restore after suspend	2012-11-30 13:48:05 -08:00
uapi/asm	UAPI: (Scripted) Set up UAPI Kbuild files	2012-10-02 18:01:35 +01:00