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authorJiang Liu <jiang.liu@huawei.com>2013-09-27 09:04:41 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-01-09 12:24:26 -0800
commit2bf5861acf602fe6201ac1f82955ac7283e56b6f (patch)
treea9ce744c6ef2bd2b42ac4a54d712e4f2fe6e22f1 /arch
parent79f783f05539479676406d3d42c3d86bd203f083 (diff)
arm64: fix possible invalid FPSIMD initialization state
commit 6db83cea1c975b9a102e17def7d2795814e1ae2b upstream. If context switching happens during executing fpsimd_flush_thread(), stale value in FPSIMD registers will be saved into current thread's fpsimd_state by fpsimd_thread_switch(). That may cause invalid initialization state for the new process, so disable preemption when executing fpsimd_flush_thread(). Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Jiang Liu <liuj97@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/kernel/fpsimd.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index e8b8357aedb4..2fa308e4a1fa 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -79,8 +79,10 @@ void fpsimd_thread_switch(struct task_struct *next)
void fpsimd_flush_thread(void)
{
+ preempt_disable();
memset(&current->thread.fpsimd_state, 0, sizeof(struct fpsimd_state));
fpsimd_load_state(&current->thread.fpsimd_state);
+ preempt_enable();
}
/*