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authorJiang Liu <jiang.liu@huawei.com>2013-09-27 09:04:41 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2013-09-27 18:21:37 +0100
commit6db83cea1c975b9a102e17def7d2795814e1ae2b (patch)
tree8bb027ee7d2738649783800354f88de59580d9cd /arch
parentfc18047c732f6becba92618a397555927687efd3 (diff)
downloadblackbird-op-linux-6db83cea1c975b9a102e17def7d2795814e1ae2b.tar.gz
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arm64: fix possible invalid FPSIMD initialization state
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>
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 1f2e4d5a5c0f..bb785d23dbde 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -80,8 +80,10 @@ 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();
}
#ifdef CONFIG_KERNEL_MODE_NEON
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