Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.10 122/129] arm64: fix possible invalid FPSIMD initialization state | Date | Mon, 6 Jan 2014 14:39:11 -0800 |
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3.10-stable review patch. If anyone has any objections, please let me know.
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From: Jiang Liu <jiang.liu@huawei.com>
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>
--- arch/arm64/kernel/fpsimd.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -79,8 +79,10 @@ void fpsimd_thread_switch(struct task_st 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(); } /*
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