Subject: [RFT PATCH v2 3/4] arm64: reduce duplicated code when saving/restoring FPSIMD for signal handling

From: [email-masked] (Jiang Liu)
Date: Tue, 15 Oct 2013 00:01:20 +0800

On 10/14/2013 11:44 PM, Catalin Marinas wrote:
> On Sun, Oct 13, 2013 at 03:20:19PM +0100, Jiang Liu wrote:
>> +void fpsimd_prepare_sigctx(struct fpsimd_state *state)
>> +{
>> +	/* dump the hardware registers to the fpsimd_state structure */
>> +	fpsimd_save_state(state);
>> +	fpsimd_clear_fpsr();
>> +}
> 
> What don't particularly like is that you save the FP context and then
> corrupt it. Can we get preempted after this function and before we save
> it on the signal stack?
> 
Yeah, good point!
There's a race window to get preempted, will fix it.
Thanks!
Gerry