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=1794590410; b=oWS/tNSTqMyttQ8CXZsI68dzgI8ce1VXtgGYMocWcPfF0zjTKFbu9DZyJfRhVL0KtPKG //xjf7D5TFmsOEzZkljEe1RU5uTT5r8jgOpRSXzdR6Ufuwe/lhhCLdbUXJt5W9b7rcVBv JsWfN/tu9Vm1ym7go1p8Gzw7WkpCGxgDT73Qd28KyiWWx8MCdF05JHxB8QvO3aEZNpM+8 Dxq2Gu6HfN15ZDs5zUcm/ni5/waCS7f265XYH2ivI8kZZ3oYQXc4RX9DAzWyVeACKu5Kj meOskYQUbYuxOP4ylqoly23j/VPb1v0n4xw95VDoyK8cBUb+uLhO57bEORdFjdMEJMA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590410; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=iFJNrMsssIw8ix2MGAF+MG7N1wr4E4o6AM8Ic5BSd9Y=; b=It0eXFSUj30wTQbK7bgqE7PXR51LtBZuimRGCP7tP14TXs347m12bLKCux5iHFwQ12w1 YY4ryE7GiC6BDc10dyAcZS9QOUdRvRvhWniwhkDunRSVIwL7tnrG1BtJVOT2v5NlnRM5g YxIKv3QV8HQ6XLsZs1mW3dS0et5RH91mV4RBbu6NvF+u9OFJYylm2YbLpiGvFTEr0rpid J98oiD3iv5622+1hU2LwTp/qU873hsBnwcK1yaY7NwzXCjPgn5Q7HaVexrvy1fJMBYIXy SdqjL90ITXdlPvpRu4yOFphxktlBuZoo3x/MF76bGdR2Goz/3M2hB47qLWzrEatxAkQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=Evp9yrb0; 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 DD913606E654; Fri, 13 Nov 2026 17:20:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=Evp9yrb0 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 89BBB1F000C8; Fri, 13 Nov 2026 17:20:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794590410; bh=iFJNrMsssIw8ix2MGAF+MG7N1wr4E4o6AM8Ic5BSd9Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Evp9yrb03AnvW5huVUTF2AXxYlbQv4n/jfUZM0XwRBkyEeNA2L5rc1jPCxKOGIWt0 TnfDZyCSLltcgkihOSwJ0g6gAaC4cdQ7u17/SltbqcJq5VrUEz6zfOhp5cqA56joN3 KomRCUT09dfkP6dhH0DSSYSFyYrxbxnQfT2ma/2E= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Josef Bacik , "Lorenzo Stoakes (ARM)" , Muhammad Usama Anjum , "David Hildenbrand (Arm)" , Sasha Levin Subject: [PATCH 6.18 377/686] mm/mmu_notifier: finish non-blocking interval invalidation on error Date: Fri, 13 Nov 2026 10:48:30 -0500 Message-ID: <20261113153833.685558885@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153820.902362109@linuxfoundation.org> References: <20261113153820.902362109@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josef Bacik [ Upstream commit 6d65925777ecae9d7a571a327e41c63f3940a0c7 ] 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) Signed-off-by: Sasha Levin --- 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 d1094c2d5fb61..c46f44340da79 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -444,7 +444,8 @@ 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 8e0125dc05227..8a3fefe18618e 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -522,16 +522,25 @@ 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