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| author |   Jiang Liu <jiang.liu@huawei.com> | 2013-09-27 09:04:41 +0100 |
|---|---|---|
| committer |   Catalin Marinas <catalin.marinas@arm.com> | 2013-09-27 18:21:37 +0100 |
| commit | 6db83cea1c975b9a102e17def7d2795814e1ae2b (patch) | |
| tree | 8bb027ee7d2738649783800354f88de59580d9cd /arch/arm64 | |
| parent | arm64: use correct register width when retrieving ASID (diff) | |
| download | linux-dev-6db83cea1c975b9a102e17def7d2795814e1ae2b.tar.xz linux-dev-6db83cea1c975b9a102e17def7d2795814e1ae2b.zip | |
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/arm64')
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 2 |
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(¤t->thread.fpsimd_state, 0, sizeof(struct fpsimd_state)); fpsimd_load_state(¤t->thread.fpsimd_state); + preempt_enable(); } #ifdef CONFIG_KERNEL_MODE_NEON |