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 62BFCC55171 for ; Sun, 2 Aug 2026 07:40:49 +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=5LbYy5ro5NDFE3DG1YbB/j5IpRtLd57Aeh6qzOqIXCU=; b=pArFIlk6SRVbUGffo16I4K7Dzc lQ39h+s3+VdgkBNxRrhbNgxQLKkQcKywsdTRk7oiKlRy0MedAVQsy2t0kDpsZmzcRhPyusmOxEO6Q 1CX/6pMglzVtpWovS/+xIz3MB8Ra36km9Uv1UV4+ZvhSEO2J2gbTjYlM5S5exURIqCAdAujrQ/l+K F0aq9ZgE3p3YT6Ra0bYqOX2DQtvJOb0MkJz0lAUEzsAZqHxz7nEhBA0l83MUlABvRCNg6aCvWzDrw 5p44vxxWbSObnxKiazRJwJOl+inhmymze7iQDFOLIbuLhKmTVVE36QsO5NuqW5FFJkZ24b/tKZ2Oi yYVq9Gmg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wqQoH-0000000FSQ3-2niL; Sun, 02 Aug 2026 07:40:37 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wqQoG-0000000FSPW-3UOp for linux-arm-kernel@lists.infradead.org; Sun, 02 Aug 2026 07:40:36 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 5AB1A41AFA; Sun, 2 Aug 2026 07:40:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8E4A1F00ACA; Sun, 2 Aug 2026 07:40:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785656435; bh=5LbYy5ro5NDFE3DG1YbB/j5IpRtLd57Aeh6qzOqIXCU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ZlkYsLplRph3ACb5Y0qShIVauT+VeZYT7DAbyEWRuhNCXupiQXKQeGe48Rp1BoU6o ykH+8hNRMTh3IOq4fgDP11Taaedt3v6TjdFpDBnso8tmFbWPf72X7Dxxz8H9n869lI +o7o4gH44rsEYbf3t0hLdy3zAYU5NrpZ9ts9yUAo6FY+2xzcL24dqG2D+1XtPaA+dr A/Ar28oyD7OKALChWX2DBVAWVLtv4G83BYcrutcRRwl2Tun5geNoLv9MbF01cNbQH0 k4mNwEi99GsQEEmwZoveFbRu00OqMa32HK19GG7MCJHW4L/hQP/o9zozMKLK3BZYcl 8u+jNC2kvyE9g== From: "Barry Song (Xiaomi)" To: akpm@linux-foundation.org, linux-mm@kvack.org Cc: x86@kernel.org, linux-arm-kernel@lists.infradead.org, surenb@google.com, liam@infradead.org, ljs@kernel.org, vbabka@kernel.org, shakeel.butt@linux.dev, david@kernel.org, linux-kernel@vger.kernel.org, zhanghongru@xiaomi.com, willy@infradead.org, zhangbo56@xiaomi.com, "Barry Song (Xiaomi)" Subject: [RFC PATCH v1 1/2] x86/mm: use VMA lock for kernel faults on user addresses Date: Sun, 2 Aug 2026 15:40:17 +0800 Message-Id: <20260802074018.73887-2-baohua@kernel.org> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20260802074018.73887-1-baohua@kernel.org> References: <20260802074018.73887-1-baohua@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 Use the VMA lock for kernel faults on user addresses. This also makes the existing code below meaningful: /* Quick path to respond to signals */ if (fault_signal_pending(fault, regs)) { if (!user_mode(regs)) kernelmode_fixup_or_oops(regs, error_code, address, SIGBUS, BUS_ADRERR, ARCH_DEFAULT_PKEY); return; } Right now, the code above is dead because !user_mode always takes the mmap_lock path. Co-developed-by: Bo Zhang Signed-off-by: Bo Zhang Signed-off-by: Barry Song (Xiaomi) --- arch/x86/mm/fault.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 45b99c3b1442..c22b74e0eeaf 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1328,9 +1328,6 @@ void do_user_addr_fault(struct pt_regs *regs, } #endif - if (!(flags & FAULT_FLAG_USER)) - goto lock_mmap; - vma = lock_vma_under_rcu(mm, address); if (!vma) goto lock_mmap; -- 2.39.3 (Apple Git-146)