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 552D3C5AD7B for ; Mon, 10 Aug 2026 12:52:07 +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=n43/aKJ8eBUxUBD79l6UcJWpeqmmhi7C6KTZf2OBbS8=; b=lfaEPbsCl+hTmg +aHXAQRM/WD0wYuB/DJ/p5QlSyEiMMMX86SJ0r5dIwXEECd6IM/WrMJoieTQSiwQWBjs/0cLmvokx DThVNnbxwscyGOCLqFAG5D0wPgrJ+Fbn+UQnAf4BMpk3VSVLph9KYl6ySbHCmdgZY5gHZgKyyGxUN NyDtZYkgHUgB3ZPXoAODMQ6dvBJoE8lkb1WQrRvh/tdV53K6I0kGDJ3dPM+cTqmWkb1yaJoqTHAny +NCyRXzWVR2a/2XCEhIJ+UOkSahXVSL5JPUvmVwgCjJ20HklimJb5Y/Fw8sotLNyKWDE//kW4zgZg bmGAXYf3+1MyuB0lxlMQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wtPTv-0000000Bpei-3kVP; Mon, 10 Aug 2026 12:51:55 +0000 Received: from canpmsgout03.his.huawei.com ([113.46.200.218]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wtPTo-0000000Bpdv-3N7T for linux-arm-kernel@lists.infradead.org; Mon, 10 Aug 2026 12:51:53 +0000 dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=n43/aKJ8eBUxUBD79l6UcJWpeqmmhi7C6KTZf2OBbS8=; b=RdObbmdFVKOHTKxX52sYHajGprEIe7f7G201ZRemSi9eiJFBr4OCR9QsXnshR/NBpmdDAAXFJ m1z7QSOat5nN9rf1iD9RBNqUThFd8TgKUkLigbuWCbQ8/0lHvFq0l5J1hfD5ngLjAXfLaVa3WnB V+iOsFZkRHF1hGrBpELsVU8= Received: from mail.maildlp.com (unknown [172.19.162.140]) by canpmsgout03.his.huawei.com (SkyGuard) with ESMTPS id 4hJZ9l6vrhzpT0F; Mon, 10 Aug 2026 20:40:59 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id 4D96B2025F; Mon, 10 Aug 2026 20:51:40 +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; Mon, 10 Aug 2026 20:51:39 +0800 Message-ID: <61786f30-5827-4785-ae68-febbdf0de900@huawei.com> Date: Mon, 10 Aug 2026 20:51:38 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC] arm64: entry: PSTATE_I_SET is leaking on pseudo NMI mode To: Will Deacon , Breno Leitao References: <20260807-arm64_fix-v1-1-d069ccf9d71b@debian.org> From: Jinjie Ruan In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.109.254] X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) 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-20260810_055149_633123_E001AB14 X-CRM114-Status: GOOD ( 15.24 ) 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 , Vladimir Murzin , rmikey@meta.com, "Peter Zijlstra \(Intel\)" , Catalin Marinas , kernel-team@meta.com, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 在 2026/8/10 19:43, Will Deacon 写道: > On Fri, Aug 07, 2026 at 09:29:12AM -0700, Breno Leitao wrote: >> On Fri, Aug 07, 2026 at 07:58:21AM -0700, Breno Leitao wrote: >>> Meanwhile, I will try to ftrace the writes to PMR and regs->pmr to get >>> a better grasp of the states machine we are in (probably on Monday). >> >> It seems LLM found a very easy to reproduce this: >> >> bash-5.1# dmesg >> >> bash-5.1# cd /sys/kernel/tracing >> echo 'r:pmr vfs_read bad=+0($retval):u64' >> kprobe_events >> echo 1 > events/kprobes/pmr/enable > > Nice, that triggers straightforwardly in QEMU for me. The diff below > (which implements my suggestion from [1]) seems to fix the issue, but > it would be good to hear feedback from one of the Arm folks. > > Will > > [1] https://lore.kernel.org/all/anXgWRmcjwPKG7N5@willie-the-truck/ > > --->8 > > diff --git a/arch/arm64/include/asm/daifflags.h b/arch/arm64/include/asm/daifflags.h > index 795b35128467..691ee5f86dbe 100644 > --- a/arch/arm64/include/asm/daifflags.h > +++ b/arch/arm64/include/asm/daifflags.h > @@ -132,7 +132,7 @@ static __always_inline void local_daif_inherit(struct pt_regs *regs) > trace_hardirqs_on(); > > if (system_uses_irq_prio_masking()) > - gic_write_pmr(regs->pmr); > + gic_write_pmr(regs->pmr & ~GIC_PRIO_PSR_I_SET); If the DAIF.I is restored below and the GIC_PRIO_PSR_I_SET in the pmr is cleared here, it seems to introduce inconsistency with current Pseudo NMI code. > > /* > * We can't use local_daif_restore(regs->pstate) here as >