From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A4E460A260A for ; Thu, 29 Oct 2026 20:39:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=R382U9wT; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=B+gNQr3I 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:Cc:To:In-Reply-To:References :Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=kUEfRiVPdPCg2/KqbNX9PPOiFF/eP69nxT6xONTBQFk=; b=R382U9wTYbcN88 bJxut/AvrqUTXNyUoAjK0/wZlUNM1b9LaMWg5/2u1IZqYbN1vqMllvsIVukT0b2K55aKOYcKJF7u4 sdWEXx2q6IeknBwCTAzxm4QjjWL82JKLozzxuQa/hUkoVlTOqJn8AZhFLBLoieJxpEZma5hxsvVqB afepbsXneuYwhpQpHQBgqYZqR4bdzqeASeQVoeQ/VHvIvqQiIFFZZMORGuwR2vG/RyGDY6PUp1nFQ gEbOr2M5i8mB7CTiLVCPEwzgDTpABZ5rmo0Qx2m+qjUNwfm3N19reOUYMTbh/1nvquoel2von7edF +1gFNjIej73MLwbpndnw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMWuh-0000000ALcE-3b9T; Thu, 29 Oct 2026 20:39:55 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMWuh-0000000ALc7-1YKs for kexec@lists.infradead.org; Thu, 29 Oct 2026 20:39:55 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 8334160629; Thu, 29 Oct 2026 20:39:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3CA2A1F01824; Thu, 29 Oct 2026 20:39:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793306394; bh=kUEfRiVPdPCg2/KqbNX9PPOiFF/eP69nxT6xONTBQFk=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=B+gNQr3IgYPjaHbppcw9o3+A/kH5KGFoMEXaT3pmXT0FTMtlv+J0pbqsgNG8qOKhI EzZv32DWC5UMbUTC6nahg8i99r8SlIDGC3mhtb/aPJleJt9pQnXfM7DC3eqXrVeT7x EdKUlx6xc9n+S59O83153Y6MLC9vkrBo3YohvFsMgyPF2XXX8arnY4I/NzKyuM/JEz 3ygSXzPCjFoKhHuKLnRUhILHFjQnmeRktJ+2iXs0kQOeWBYEibfl7ylO2Cg8X4ctvj stH0v8Jp4kfpNdJepSKPR7w68ibQTVHXls/i3r3UYfHi7GEl6lgKmrtsNLIYxmrLpp X+MiazDsOENog== From: "David Hildenbrand (Arm)" Date: Thu, 29 Oct 2026 21:33:21 +0100 Subject: [PATCH v2 26/47] mm/userfaultfd: compare exact registration modes before skipping X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261029-fixes_core-v2-26-a64ce7f83abb@kernel.org> References: <20261029-fixes_core-v2-0-a64ce7f83abb@kernel.org> In-Reply-To: <20261029-fixes_core-v2-0-a64ce7f83abb@kernel.org> To: Andrew Morton , Johannes Weiner , Michal Hocko , Qi Zheng , Shakeel Butt , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Peter Zijlstra , Jann Horn , Pedro Falcato , Hugh Dickins , Pasha Tatashin , Pratyush Yadav , "Matthew Wilcox (Oracle)" , Jan Kara , Zi Yan , Lance Yang , Rik van Riel , Harry Yoo , Alistair Popple , Nico Pache , Ryan Roberts , Dev Jain , Usama Arif , Kiryl Shutsemau , Matthew Brost , John Hubbard , Peter Xu , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Oscar Salvador , Minchan Kim , Muchun Song , Xu Xin , Chengming Zhou , Chris Li , Kemeng Shi , Nhat Pham , Youngjun Park , Gregory Price , Joshua Hahn , Rakie Kim , Ying Huang , Jason Gunthorpe Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, stable@vger.kernel.org, "David Hildenbrand (Arm)" X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1463; i=david@kernel.org; h=from:subject:message-id; bh=EB1on15q6q+0KCAB0yKS0tRudcnaZpRwYV9wTcssTD0=; b=owGbwMvMwCF2/OVpCdfQ3ZWMp9WSGLIer203CXiXELbMN4o57IvJUo3yzuqG+rPOik++eEpsO TjZ80ZFRykLgxgHg6yYIktQ8H2Dly/X1Va78THDzGFlAhnCwMUpABNZu4PhfzavpnbcmeVGF7QM sr8/+8rw5RZPRxITd/OkpnP6gn7Fcxj+e2b1ZInfnHld9ZtWi3l+277N38xu99RKLNbot+cSfFn GDAA= X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" X-Spam-Status: No, score=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 From: Gregory Price Changing registration from MISSING|WP to WP returns success but leaves MISSING enabled. The no-op check sees that WP is already set and skips the update, so later accesses to missing pages still wait for userspace. Skip the update only when the current and requested UFFD modes match exactly. Fixes: 63b2d4174c4a ("userfaultfd: wp: add the writeprotect API to userfaultfd ioctl") Cc: stable@vger.kernel.org Signed-off-by: Gregory Price (Meta) [ david: apply fixup from Lorenzo ] Signed-off-by: David Hildenbrand (Arm) --- mm/userfaultfd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 03f1b15bfe63..dac696bda19f 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -2291,6 +2291,7 @@ static int userfaultfd_register_range(struct userfaultfd_ctx *ctx, for_each_vma_range(vmi, vma, end) { const bool any_mode_removed = vma->vm_flags & __VM_UFFD_FLAGS & ~vm_flags; + const vma_flags_t curr_vma_flags = vma_flags_and_mask(&vma->flags, __VMA_UFFD_FLAGS); cond_resched(); @@ -2304,7 +2305,7 @@ static int userfaultfd_register_range(struct userfaultfd_ctx *ctx, * userfaultfd and with the right tracking mode too. */ if (vma->vm_userfaultfd_ctx.ctx == ctx && - vma_test_all_mask(vma, vma_flags)) + vma_flags_same_pair(&curr_vma_flags, &vma_flags)) goto skip; /* -- 2.43.0