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=1794273219; b=C5PL9DHDX+Ltj2A0Sb3fz35s1wViGfFIkROa3hfVx8zOu+kR+RKxD5fXNUCbSLZJF2SW 5IjTdptdoaxBIAQD8PSTSAtkIZeVF+222aNQyssnYu2P4oCoAddkD5wCYT7UrYedPBiLX 5I6uPSHEp5/+wym3X1BSzyOZxooa2kuyVQN26nOgbzqTYmOC3t3jVq3ZpxBTAOYL/raHI O7wfemcFrw4fmXqktF9uBO1zAoYD9AqueveHW2ckBJzOBGoa8zdqa6bzC6Xzf1zhKFx3b t10yC+KxEUlGCF94YCGQ9rOmIEI1RXQMe6kID83Ui8A0v/hs4fjoegJUb6N5L1Xlx6w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794273219; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=cyNM7Iqa639LNBgkeaY+7ZnCRSDIK5nF0mHB0zBvfL4=; b=gpaQsUdeIs5KAV5vHMKKpxIyQZAMYTcNq07aoXXCb+MjuvoBSPXTK7ULA1pDTsTV7dRo chdomnWKTA8BUxLqW1VFF7LMKmYnTYQRzMVlQcSpGFsoM8iJvJTZt+3pdNFPbB2ZFw5XG q7imcNtKy7cc2gkWsJu07lrK5czKp3mDJZDknePBK56trOFeuvamXjJE3ewqaQiYLyS64 Lwez2tYKpT83Akkdt8l8VViWvYMFjuDuQvReMRWG6LYpZYjoLRy2N9wJWHJWkr1X+UJnj yFqV3X7y0ZNR2OrS0Sn+4d+QEx2LQCnwYl50KOnJOpDH8tJa67dysgvfqGrt29GbIBg== 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=gWmT5FU1; 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 E2A79606A321 for ; Tue, 10 Nov 2026 01:13:38 +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=gWmT5FU1 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25BE11F0089F; Tue, 10 Nov 2026 01:13:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794273218; bh=cyNM7Iqa639LNBgkeaY+7ZnCRSDIK5nF0mHB0zBvfL4=; h=From:To:Cc:Subject:Date; b=gWmT5FU13FwY054soOBHruD1IpJ8dH58gmpQd0HmzQu12kVr6pDfZbTLrdD+xU5MN m/0+yLelCtjZBL4Vj1XobiRYGkoRuvF/gjSH+UFv2tFXeLOESYhXqTZt22sFOl/9qD I2gtyqayOSsyyjNuPqHTSRKnvN8HZAaTupFytQ94xCkYcVs6ywqQOvBw9ugXbAwAqO 1IZlkBIkGVjSsXOVbS5kDnzpyDp1ccQN87cLv5vY8XJjrUazggyLneARMC70MtGh7z I3ZW4abFg8PNGVPxmkXUyrI3JPgpLSOCvgvoCenLc559SmRqNGPKJX78zh7UftHxSw f24nR6QxQCxOQ== From: Sasha Levin To: josef@toxicpanda.com, ljs@kernel.org, usama.anjum@arm.com, david@kernel.org Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] mm/mmu_notifier: finish non-blocking interval invalidation on error" failed to apply to 6.6-stable tree Date: Mon, 9 Nov 2026 20:13:36 -0500 Message-ID: <20261109201336-failed-6.6-6d65925777ec@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 6.6-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-6.6.y git checkout FETCH_HEAD git cherry-pick -x 6d65925777ecae9d7a571a327e41c63f3940a0c7 # git commit -s git send-email --to '' --in-reply-to '20261109201336-failed-6.6-6d65925777ec@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 6d65925777ecae9d7a571a327e41c63f3940a0c7 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Sat, 31 Oct 2026 10:39:57 +0100 Subject: [PATCH] mm/mmu_notifier: finish non-blocking interval invalidation on error When an ordinary MMU notifier rejects a non-blocking invalidation, the interval invalidation started beforehand is left unfinished: the caller skips mmu_notifier_invalidate_range_end(). Subsequent interval notifier operations can then wait forever. The only in-tree trigger is nouveau SVM, which uses both notifier types and rejects non-blocking invalidations. Reaping via the OOM reaper or process_mrelease() can therefore leave the GPU fault worker stuck, holding a reference that prevents the dying process's address space and memory from being freed. End the interval invalidation when an ordinary notifier fails a non-blocking invalidation, like mn_itree_invalidate() already does when an interval notifier fails. Make that handling clearer in the documentation of mmu_notifier_invalidate_range_start_nonblock(). Fix generated by an LLM and sent by Josef Bacik in private. Fixes: 99cb252f5e68 ("mm/mmu_notifier: add an interval tree notifier") Cc: stable@vger.kernel.org Signed-off-by: Josef Bacik [ david: simplify description, update function doc ] Acked-by: Lorenzo Stoakes (ARM) Tested-by: Muhammad Usama Anjum Link: https://patch.msgid.link/20261031-fixes_core-v3-28-d6437171ecc3@kernel.org Signed-off-by: David Hildenbrand (Arm) --- include/linux/mmu_notifier.h | 3 ++- mm/mmu_notifier.c | 17 +++++++++++++---- 2 files changed, 15 insertions(+), 5 deletions(-) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index a11a44eef521e..5db78e5761c5c 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -483,7 +483,8 @@ mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range) /* * This version of mmu_notifier_invalidate_range_start() avoids blocking, but it * can return an error if a notifier can't proceed without blocking, in which - * case you're not allowed to modify PTEs in the specified range. + * case you're not allowed to modify PTEs in the specified range or call + * mmu_notifier_invalidate_range_end(). * * This is mainly intended for OOM handling. */ diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index df69ba6e797f7..2e20f88e162d7 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -569,16 +569,25 @@ int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range) { struct mmu_notifier_subscriptions *subscriptions = range->mm->notifier_subscriptions; - int ret; + const bool has_itree = subscriptions->has_itree; + int ret = 0; - if (subscriptions->has_itree) { + if (has_itree) { ret = mn_itree_invalidate(subscriptions, range); if (ret) return ret; } if (!hlist_empty(&subscriptions->list)) - return mn_hlist_invalidate_range_start(subscriptions, range); - return 0; + ret = mn_hlist_invalidate_range_start(subscriptions, range); + + /* + * On error, the non-blocking caller is not allowed to call + * invalidate_range_end(), as in mn_itree_invalidate(). + */ + if (ret && has_itree && !mmu_notifier_range_blockable(range)) + mn_itree_inv_end(subscriptions); + + return ret; } static void -- 2.53.0