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=1794591191; b=gwoTdvomfqe4oat2aYumZa/gNHsOA7YRgmRy5zznFKIB9vXgoogyivK89qQCQ1G2nCYg CsNWZ+ZjxgSoDiHfWUx2jjq5tDmJ2DVQN7mNQBY5znT6Xz1w+ZraiBWWkoNl8WVDCtgae ZkXXv2FwBV3F+RGiKWGJSVIv6DldKlvzPxL/8TukPq2sK1WpNoB3wNI69AWJxs40le33z Z/3A19hIsuk7+m0AaD9kTEUg8UjpxOTQ+yHSqr4iD0Pct9ON1mYDSrbNeSzatMROn96Ts lUaDo6h8fPmroSLfWhmV8Cx+Yl6mvCk/6vwaCnj3Py3KHzWWoXPlrF6sFn+6l1vSAOQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794591191; 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=nl7IkTuePy8kWNdng/wf7TTxoS/MwmWXyR6bn94O+ls=; b=p3nUS986+FsgEwFXkpdSAI3kc1MnhURTMFWMKVKcHHiPJcc6qkL2BVpo5jk2tt4qwtrk rA92TGdZrq9zHPUJZom61K6zE3ii8B/kXgxxDU1XmDE2Kv7y/SZ3a9tQWdlvEdEUALrVx Obv+PRaawdb3Wh9PN+sgkxwpBe5i/Nf+SssktVFbVPSULGQgZfamEtsm6Yw9LbidpRDz8 F6ZIO+KvnlQDkr5wEdbH254TnwUA/pqWtinxE4mqXjWTl7pXKIdrNSkWnOsI8t+L3sxEj pY6R6ZCssgG6Bx87nh/tV8YCJWgWpfTRSZ7wdTGBgB5KW7wI3G8oMyZ3KosvG2RfLqA== 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=aI6wSMyT; 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 99DD16075E09; Fri, 13 Nov 2026 17:33:11 +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=aI6wSMyT Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4593C1F000C5; Fri, 13 Nov 2026 17:33:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794591191; bh=nl7IkTuePy8kWNdng/wf7TTxoS/MwmWXyR6bn94O+ls=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aI6wSMyTUVNBAqSeHVEnss0plKjy3Qjd6IvywGjd1w7y4PF77DHaQIZ53qX8wIx3y zKGfcZJnkfNPfsbljO7QI6sawjhCx+mi+hxDVSXpU8aYTxQiJjXS0HVg4eKOVbqAm1 XKvu9GwTW2/9drLkfEPykMBU/USSGYzr0HX46VSo= 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 6.12 327/670] mm/mmu_notifier: finish non-blocking interval invalidation on error Date: Fri, 13 Nov 2026 10:48:11 -0500 Message-ID: <20261113153822.964922288@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153811.177190860@linuxfoundation.org> References: <20261113153811.177190860@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-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 d39ebb10caeb6..fe486d52d48e8 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 fc18fe2745050..e614ecafb8817 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