Messages in this thread Patch in this message | | | From | Jiang Liu <> | Subject | [RFT PATCH v2 1/4] arm64: fix possible invalid FPSIMD initialization state | Date | Sun, 13 Oct 2013 22:20:17 +0800 |
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From: Jiang Liu <jiang.liu@huawei.com>
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> --- arch/arm64/kernel/fpsimd.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 1f2e4d5..bb785d2 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(¤t->thread.fpsimd_state, 0, sizeof(struct fpsimd_state)); fpsimd_load_state(¤t->thread.fpsimd_state); + preempt_enable(); } #ifdef CONFIG_KERNEL_MODE_NEON -- 1.8.1.2
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