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 6966EC44507 for ; Thu, 9 Jul 2026 12:15:36 +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: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Qdp//1e9Iy4wAq5+210miQNkEWlNveFTFW87G09ua08=; b=RXFi32ZN/slmGz0tc+AWO019Ye P7R6Znz4MoSHKeyCVqG/sPBG8EHS2p5jesG7EYdURAGLPvqmTo6+eNDTSsBB2BI9g5q5uut3N7B4/ fkRsRWmId6PJXYbdQ9ug2odFvq21PqjXQjsn4g8BGRe2NfTyY+G7+CYLuQqk/EkxGgyhklKmOa2k7 0NYFCa3Pjt+q7bptjVYe44vdEnv21Ok0a6YgM9MJyrEsdA2te3Y7ZlMEogEWwxIATfB6zHEhAFgeJ d/3IEv1nXCn6TYP3RSMAto8GuhfeiUmmwbz9NqKE4gNfKbWsb4b7SX+Y/1S+kW9F7A7X+iMysNT6o 48iaZlzQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1whnf7-00000002MgF-3KTn; Thu, 09 Jul 2026 12:15:29 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1whneO-00000002L6S-0waw for linux-arm-kernel@lists.infradead.org; Thu, 09 Jul 2026 12:14:45 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6CC663569; Thu, 9 Jul 2026 05:14:39 -0700 (PDT) Received: from login2.euhpc2.arm.com (login2.euhpc2.arm.com [10.58.100.22]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B754A3F7B4; Thu, 9 Jul 2026 05:14:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1783599283; bh=n3hrOfPHC0XzLILE26mS38U5iY3Ld8yHlVHKUa57SvE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VZiWuSHyqJZ3xRAJ7a8TYwgJpWnQBdDJ+ZAgXkqGGbhEyuyq6s+c81KTJEKDEVNTQ tIRdYSby7RJdGI1sM7xknzoIPRpBdv9KuZLomJ8k/rIrUX0+B8cVVbFexpeKrf4EUe 6JLDRGJpx7X4YdWG2TCHHhwaMbsODvLOcpmtLC4A= From: Vladimir Murzin To: linux-arm-kernel@lists.infradead.org Cc: mark.rutland@arm.com, maz@kernel.org, will@kernel.org, catalin.marinas@arm.com, ruanjinjie@huawei.com Subject: [RFC PATCH 34/36] arm64: kprobes: Disable NMIs Date: Thu, 9 Jul 2026 13:13:31 +0100 Message-Id: <20260709121333.23507-35-vladimir.murzin@arm.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20260709121333.23507-1-vladimir.murzin@arm.com> References: <20260709121333.23507-1-vladimir.murzin@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260709_051444_358020_C7C9F72D X-CRM114-Status: UNSURE ( 9.97 ) 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 Kprobes masks all DAIF exceptions to keep things simple and avoid nested exceptions. With FEAT_NMI, that is no longer enough. Mask ALLINT as well to ensure things stay simple. Signed-off-by: Vladimir Murzin --- arch/arm64/kernel/probes/kprobes.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index d9d25d184309..defbe6061546 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -193,17 +193,27 @@ static void __kprobes set_current_kprobe(struct kprobe *p) * the kprobe state is per-CPU and doesn't get migrated. */ static void __kprobes kprobes_save_local_irqflag(struct kprobe_ctlblk *kcb, - struct pt_regs *regs) + struct pt_regs *regs) { - kcb->saved_irqflag = regs->pstate & DAIF_MASK; - regs->pstate |= DAIF_MASK; + arm64_exc_hwstate_t next = arm64_exc_hwstate_of_context(CRITICAL_CONTEXT); + + kcb->saved_irqflag = arm64_inherit_exc_hwstate(regs).flags; + + regs->pstate &= ~(DAIF_MASK | PSR_ALLINT_BIT); + + regs->pstate |= next.daif; + regs->pstate |= next.allint; } static void __kprobes kprobes_restore_local_irqflag(struct kprobe_ctlblk *kcb, - struct pt_regs *regs) + struct pt_regs *regs) { - regs->pstate &= ~DAIF_MASK; - regs->pstate |= kcb->saved_irqflag; + arm64_exc_hwstate_t prev = {.flags = kcb->saved_irqflag}; + + regs->pstate &= ~(DAIF_MASK | PSR_ALLINT_BIT); + + regs->pstate |= prev.daif; + regs->pstate |= prev.allint; } static void __kprobes setup_singlestep(struct kprobe *p, -- 2.34.1