From: liuj97@gmail.com (Jiang Liu)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFT PATCH v2 3/4] arm64: reduce duplicated code when saving/restoring FPSIMD for signal handling
Date: Tue, 15 Oct 2013 00:01:20 +0800 [thread overview]
Message-ID: <525C1550.5090208@gmail.com> (raw)
In-Reply-To: <20131014154401.GG7682@arm.com>
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
next prev parent reply other threads:[~2013-10-14 16:01 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-13 14:20 [RFT PATCH v2 1/4] arm64: fix possible invalid FPSIMD initialization state Jiang Liu
2013-10-13 14:20 ` [RFT PATCH v2 2/4] arm64: restore FPSIMD to default state for kernel and signal contexts Jiang Liu
2013-10-14 15:16 ` Will Deacon
2013-10-14 15:30 ` Jiang Liu
2013-10-14 15:39 ` Will Deacon
2013-10-14 15:50 ` Jiang Liu
2013-10-14 15:23 ` Catalin Marinas
2013-10-13 14:20 ` [RFT PATCH v2 3/4] arm64: reduce duplicated code when saving/restoring FPSIMD for signal handling Jiang Liu
2013-10-14 15:44 ` Catalin Marinas
2013-10-14 16:01 ` Jiang Liu [this message]
2013-10-13 14:20 ` [RFT PATCH v2 4/4] arm64: reuse FPSIMD hardware context if possible Jiang Liu
2013-10-14 13:54 ` [RFT PATCH v2 1/4] arm64: fix possible invalid FPSIMD initialization state Catalin Marinas
2013-10-14 13:58 ` Jiang Liu
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