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 B2ED1C5AC7A for ; Fri, 7 Aug 2026 09:58:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:CC: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=nUVN8bE46YEYReQkt9kTI3JLIfp+2d1gEpoUDSdg5gA=; b=fHfjgrIIsDGWDP+X0L1aU9OPxR Rnd4YWwmoVxnFaMeexAZAJPk1H4moSm2BQseTp/jJBIHg8YHs4hq3o5SxDpVlNBmtH67hz9DPcpyg 7t6IoiJCzOIhawX7k9756266S6SnTwVFulSF3SF58nm3zzf0qApgEuL2mvkIDwhKkfUgSfr27pIO6 JTHevLLeHijJvKN6wCvl0ebHBvyCqxjiWYCGOsLbzgPCoIK07yJSVEY/bL39sk7utKu/qcOEXYfbv 0binjsM/Xr2OvB/WGLqFZzEJZ2CjHwiyek/mbM3lecMcGsbOCyF9H2l9oMjGGVd4RinYkFqS9CDdo QRJh5tkg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wsHLZ-00000007ZWn-29ee; Fri, 07 Aug 2026 09:58:37 +0000 Received: from canpmsgout06.his.huawei.com ([113.46.200.221]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wsHLW-00000007ZVe-3TdI for linux-arm-kernel@lists.infradead.org; Fri, 07 Aug 2026 09:58:36 +0000 dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=nUVN8bE46YEYReQkt9kTI3JLIfp+2d1gEpoUDSdg5gA=; b=HRBnb5sjNtcag129YEGv23uhLHjutWJzveRBQVkcpbcndMqKjdFOrE/3etbwkTyfHLcLGKSky bpfr5lP0vhvxZycZV0sakquVv/7FFZPrNYDwv6uw/SsAsn/6FLg5KdwxgvGHkJT+fbhnie+9QLh uhDwmIIH3DxeLdXdxd3SWc8= Received: from mail.maildlp.com (unknown [172.19.162.144]) by canpmsgout06.his.huawei.com (SkyGuard) with ESMTPS id 4hGfTK3hHBzRhWY; Fri, 7 Aug 2026 17:47:49 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id C25D640538; Fri, 7 Aug 2026 17:58:21 +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, 7 Aug 2026 17:58:20 +0800 Message-ID: <12ab0600-abcf-4e6e-85b9-57a7d35f7007@huawei.com> Date: Fri, 7 Aug 2026 17:58:19 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH v2 34/45] arm64: nmi: Add handling of superpriority interrupts as NMIs To: Vladimir Murzin , CC: , , , , References: <20260727163453.7969-1-vladimir.murzin@arm.com> <20260727163453.7969-35-vladimir.murzin@arm.com> <73f0c621-44ff-403f-9cae-d94095accf6c@arm.com> From: Jinjie Ruan In-Reply-To: <73f0c621-44ff-403f-9cae-d94095accf6c@arm.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.109.254] X-ClientProxiedBy: kwepems500001.china.huawei.com (7.221.188.70) 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-20260807_025835_030162_B5E9B215 X-CRM114-Status: UNSURE ( 7.52 ) X-CRM114-Notice: Please train this message. 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 在 2026/8/3 20:33, Vladimir Murzin 写道: > On 7/28/26 13:25, Jinjie Ruan wrote: >>> @@ -924,6 +967,20 @@ static void noinstr el0_interrupt(struct pt_regs *regs, >>> */ >>> arm64_debug_exc_context(NOIRQ_CONTEXT); >>> arm64_exit_to_user_mode(regs, arm64_exc_hwstate_of_context(NOIRQ_CONTEXT)); >>> +} >>> + >>> +static void noinstr el0_interrupt(struct pt_regs *regs, >>> + void (*handler)(struct pt_regs *)) >>> +{ >>> + if (regs->pc & BIT(55)) >>> + arm64_apply_bp_hardening(); >> It seems only after enter_from_user_mode() or irqentry_nmi_enter(), it >> is safe to call normal kernel code. > > I do not think there is issue with that. Here is call chain: > > arm64_apply_bp_hardening() // always_inline > -> alternative_has_cap_unlikely() // always_inline > -> cpucap_is_possible() // always_inline > -> fn() > - qcom_link_stack_sanitisation // noinstr > - call_hvc_arch_workaround_1 // noinstr > - call_smc_arch_workaround_1 // noinstr > > That's also in line with el0_ia(), el0_pc() and el0_softstp() > which call arm64_apply_bp_hardening() before enter_from_user_mode() Make sense Reviewed-by: Jinjie Ruan > > Cheers > Vladimir >