From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C6498C43458 for ; Fri, 10 Jul 2026 07:57:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: Content-Transfer-Encoding:Content-Type:In-Reply-To:From:References:To:Subject :MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=pyYC1iMrBwdNnUzlPwAf62D4fFDGiJfRBxsWNmJqGik=; b=LyOxE4AFCv/SNJ XveUYnfXoJpb7Lrc3l4b4+1HVLDmvarKQkaWymvfk6b3PRWajnOoax4CYpXujx5cYuou6Oeu1sj2y IUdsoA1zhVbSNJw+s+SLtlXG76VjvyTn1tvkRXdWGv4MooVkKujW4g7MsSIO/mMqsdyo8+lTxp7vE AYrn2kjU7FzTCKoi2GFnL355z+lT5/uKsnoz1IZWzX7AaJag1PYDmZafr25ktA9xmkMDnMWqQNr5V U3dIrq6PRRcYcGys5Yc5SdCei2LcfOAjvJR7YUgLVXM14IbykGuCjlqHGBhB5Mu/yuVEHJ0laIwTs CafoWmdJpyvqYf0+he4g==; 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Fri, 10 Jul 2026 15:57:22 +0800 (CST) Received: from [10.67.109.254] (10.67.109.254) by dggpemf500011.china.huawei.com (7.185.36.131) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 10 Jul 2026 15:57:22 +0800 Message-ID: <495a9d3f-ad12-4927-84c0-6f8f89cf9a06@huawei.com> Date: Fri, 10 Jul 2026 15:57:21 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 07/36] arm64: entry: mask DAIF before returning from C EL1 handlers To: Vladimir Murzin , References: <20260709121333.23507-1-vladimir.murzin@arm.com> <20260709121333.23507-8-vladimir.murzin@arm.com> From: Jinjie Ruan In-Reply-To: <20260709121333.23507-8-vladimir.murzin@arm.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.109.254] X-ClientProxiedBy: kwepems200002.china.huawei.com (7.221.188.68) To dggpemf500011.china.huawei.com (7.185.36.131) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260710_005731_546005_C8613409 X-CRM114-Status: GOOD ( 15.82 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, maz@kernel.org, will@kernel.org, catalin.marinas@arm.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 7/9/2026 8:13 PM, Vladimir Murzin wrote: > From: Ada Couprie Diaz > > Most EL1 exceptions already call `local_daif_mask()` before returning, > with the exception of debug exception handlers which do not change > DAIF, and the IRQ/FIQ/Error handlers. > > However, DAIF get masked in `kernel_exit()` in all cases when > returning from EL1 C handlers anyway. > > Move this masking from assembly to C by adding `local_daif_mask()` > before `irqentry_nmi_exit()` when it is called by EL1 handlers. > > Remove the `disable_daif` assembly macro, as this was its only use. > > Signed-off-by: Ada Couprie Diaz > Signed-off-by: Vladimir Murzin > --- > arch/arm64/include/asm/assembler.h | 4 ---- > arch/arm64/kernel/entry-common.c | 2 ++ > arch/arm64/kernel/entry.S | 4 ---- > 3 files changed, 2 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h > index effae53e9739..0b58b550e8dc 100644 > --- a/arch/arm64/include/asm/assembler.h > +++ b/arch/arm64/include/asm/assembler.h > @@ -34,10 +34,6 @@ > wx\n .req w\n > .endr > > - .macro disable_daif > - msr daifset, #0xf > - .endm > - > /* > * Save/restore interrupts. > */ > diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c > index ceb4eb11232a..2be42d7f4eaa 100644 > --- a/arch/arm64/kernel/entry-common.c > +++ b/arch/arm64/kernel/entry-common.c > @@ -495,6 +495,7 @@ static __always_inline void __el1_pnmi(struct pt_regs *regs, > > state = irqentry_nmi_enter(regs); > do_interrupt_handler(regs, handler); > + local_daif_mask(); > irqentry_nmi_exit(regs, state); > } > > @@ -540,6 +541,7 @@ asmlinkage void noinstr el1h_64_error_handler(struct pt_regs *regs) > local_daif_restore(DAIF_ERRCTX); > state = irqentry_nmi_enter(regs); > do_serror(regs, esr); > + local_daif_mask(); > irqentry_nmi_exit(regs, state); This is similar to my patch below: https://lore.kernel.org/all/20260703100135.2512312-4-ruanjinjie@huawei.com/ I think there are at least three problems： 1、disable_daif is missing for el1h_64_sync_handler() and __el1_irq() 2、The order after moving to the C code is incorrect. disable_daif should be the exit point for C, that is, after irqentry_nmi_exit(), it is unclear why this order change occurred ? 3、local_daif_mask () has added some pseudo NMI operations and trace_hardirqs_off (). > } > > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index e0db14e9c843..f63049ac32dc 100644 > --- a/arch/arm64/kernel/entry.S > +++ b/arch/arm64/kernel/entry.S > @@ -333,10 +333,6 @@ alternative_else_nop_endif > .endm > > .macro kernel_exit, el > - .if \el != 0 > - disable_daif > - .endif > - > #ifdef CONFIG_ARM64_PSEUDO_NMI > alternative_if_not ARM64_HAS_GIC_PRIO_MASKING > b .Lskip_pmr_restore\@