From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794272950; b=j6GL15tqwWziNEKDhzjNCp+aiUeKtOgtajvQe7lQjgl/OaJFB4CWXww0B+ZJLP9xuG1P yxhFsGIUjOPj2NwTfkXfesLXTwsCpNR52FUa222MWBN9xlz0h8hbTwy5hreJvD5Y4LH9u lfv260cqDFuByVd/tqbDU8f8Qx5TCnDB/cRYShgQNRr3d1I1L/cvr73HSoNDQxANf0AIa je8wYS/M9VslDUcABtcjJa7k7H15fXcA41wunl3k9BABXvYH1rqV8nHQAe+cO3RmoZyig 1XG1GsiThf3cRK9NyNsVKdNATKCLUoqHl/h00i3H8cn46J8Bt69iwMHfp24tGVrhhVA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794272950; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=wFWRiiecKgHUwz7/WpmTBYT6NiqQAp84rqYeZTbKBic=; b=F9dWTkDtSv3wjjtjB6eeh7J7u7k8X6PtLHWRIbxfEtY9iopLu+qKaMsAnzRUwDf06LDk T4ktVlHotAiLtCQlb/Yi1mSdS4Ku+s2CHHb/DOJirhVTI+LKGzH8hRYaOAXzSizV4jbdP bC8LzDrkZkhjrZLRXyMAgzuS/M3YCpond23MHQ2Ke6ea8TgIDxmTJBDwo/VpSqkilW3P4 vvVA9L0nYOxbdJD3f87sPjC02k49Dqh+ZojYpF4iiMru7I6bcxpvgfI9R9Q/ZvV5mbXli X+1TfwKiWZze06t7XYI/9qjZ9sFQiFCI+Opccs4Pfu7eY3fe9sazNWttLtL+OcL67xw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=mnWjNRIR; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2E693606A31C for ; Tue, 10 Nov 2026 01:09:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=mnWjNRIR Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F9AA1F0089F; Tue, 10 Nov 2026 01:09:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794272950; bh=wFWRiiecKgHUwz7/WpmTBYT6NiqQAp84rqYeZTbKBic=; h=From:To:Cc:Subject:Date; b=mnWjNRIRIbjFDFolFQaWx3GdAwehqbrv0Upouz5/ytuHHp9On+P9tNkB6i1VcXyX1 MJeD7EYBo/TZUlX6QxygtHXjqYRWxLY3etlavw4LrVCJXas7cTkim2yu+zMk4SlJOs p9k01MEeMYfm03Sbt8hgxjLCswyfqVwCNlSQmkwCWLzOQtR7OiIApCRFRVybWT5Jr9 Kg5iX9YVvAYDR3VV9nDiAdwFRBukFNmDmZxMPjoNIad+5BbtyIjZ0wqIMtG1Ay2HlN vnv0ad35GuaLPeGBm7uNBY6jBuFTRiZ45MoDO2SQHkiFDlBosTKBZ1skNU81UIhDP9 HqAmWOReQbFcw== From: Sasha Levin To: gourry@gourry.net, usama.anjum@arm.com, david@kernel.org Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] mm/userfaultfd: compare exact registration modes before skipping" failed to apply to 6.12-stable tree Date: Mon, 9 Nov 2026 20:09:08 -0500 Message-ID: <20261109200908-failed-6.12-05f64f211a25@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x 05f64f211a25f7d9771d4fde109aad97174a1cf3 # git commit -s git send-email --to '' --in-reply-to '20261109200908-failed-6.12-05f64f211a25@kernel.org' --subject-prefix 'PATCH 6.12.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 05f64f211a25f7d9771d4fde109aad97174a1cf3 Mon Sep 17 00:00:00 2001 From: Gregory Price Date: Sat, 31 Oct 2026 10:39:55 +0100 Subject: [PATCH] mm/userfaultfd: compare exact registration modes before skipping 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 ] Tested-by: Muhammad Usama Anjum Link: https://patch.msgid.link/20261031-fixes_core-v3-26-d6437171ecc3@kernel.org 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 03f1b15bfe63e..dac696bda19f0 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; /* -- 2.53.0