From: Vladimir Murzin <vladimir.murzin@arm.com>
To: Jinjie Ruan <ruanjinjie@huawei.com>,
Mark Rutland <mark.rutland@arm.com>,
Breno Leitao <leitao@debian.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
rmikey@meta.com, kernel-team@meta.com,
Ada Couprie Diaz <ada.coupriediaz@arm.com>
Subject: Re: [PATCH RFC] arm64: entry: PSTATE_I_SET is leaking on pseudo NMI mode
Date: Mon, 10 Aug 2026 14:04:30 +0100 [thread overview]
Message-ID: <3e5f1532-ea17-4994-8cd0-5ce1d42e9049@arm.com> (raw)
In-Reply-To: <7b16d183-86d5-481e-b212-977ad0598ac7@huawei.com>
On 8/10/26 13:44, Jinjie Ruan wrote:
>> Agreed on the need for a clearer explanation.
>>
>> Perhaps local_irq_disable() isn't the right API here, and we should
>> use local_daif_restore(DAIF_PROCCTX_NOIRQ) instead?
> The local_irq_disable() here is pair with the local_irq_enable() in
> preempt_schedule_irq(). So I think it is not correct to replace them
> separately.
>
> The pseudo NMI does not consider how to do local_irq_disable() /enable()
> when the interrupt is masked by the DAIF.I bit as I reported before.
Unless I missed anything local_daif_restore(DAIF_PROCCTX_NOIRQ) would
clear DAIF.{IF} and set PMR to GIC_PRIO_IRQOFF which is the state we
expect from local_irq_disable() so we can do local_irq_{en,dis}able()
later on.
Cheers
Vladimir
next prev parent reply other threads:[~2026-08-10 13:04 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-07 11:45 [PATCH RFC] arm64: entry: PSTATE_I_SET is leaking on pseudo NMI mode Breno Leitao
2026-08-07 13:40 ` Will Deacon
2026-08-07 13:57 ` Mark Rutland
2026-08-07 14:49 ` Vladimir Murzin
2026-08-10 12:44 ` Jinjie Ruan
2026-08-10 13:04 ` Vladimir Murzin [this message]
2026-08-11 2:47 ` Jinjie Ruan
2026-08-07 14:58 ` Breno Leitao
2026-08-07 16:29 ` Breno Leitao
2026-08-10 11:43 ` Will Deacon
2026-08-10 12:42 ` Vladimir Murzin
2026-08-10 15:05 ` Will Deacon
2026-08-10 16:39 ` Vladimir Murzin
2026-08-10 12:51 ` Jinjie Ruan
2026-08-10 12:59 ` Breno Leitao
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