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=1794670955; b=MZTvH7/E1Fw4ni9CkI2ep8qEx6FVQx9BJoCToqPxlKeeYEa/eHHRECprU2NllXqY6Ban hnAtB4nyw2D73IxbEZkUF61Vu0rKjbx45NqEtRGGCWSQR91e9yHWHw7NgutbNdrnvJyHg k0Nt4FydsN7vH77Rrj6Sj9pMv291uHweNsrAQOs5xljjAXpomC9fQOqWWbw0xkyD0rXt+ mGRDaPu9QfdPsN86ETo/SzjHf7o7gxth5TNSy/QNGd3KkHJKZOtYS35CtxQNXy8cas1W8 pW2p9r/KcrD/WIRT2tM8//M8WNR9EnXzXgP44nG+bj4fS+9lLWYYvqllF281EqUirQw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794670955; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=VVnZ2YLn9x8r4fjngicQKfW0x/QchCQH/F4MjVyahNc=; b=ZvkF0ua6M1NcRlT4ph51uUrpGZFhLze8XcRcEfWiSXtvTVmXGCpDzjcP8dUn9rZ03hFg lJSx2bH1jSm/jo8mvaSvQ8f0AWGlA9lKfhsq2MUedsHkmi+DdQCt4Fx19I57zLvUgJr0w +3B3E8iTJ74zgjJcO2x13ZV6HFLyat+T6reCBrF+kQRSvNTGV6p7scjxOWvdMusuEyaGr 22rUU6tQolA/LE9orNMSeqHKPdqIAnWTnrU/s4OAy9XRVSC1J4SZcijWIE0oIpQ2sZKiX mojGuMRYSgpVlPP06KTtAh6ojL2jky+SRe4xw1m3CUIDzpor8d5XczbJbHh9pudZwlw== 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=OggpX2vE; 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 46AAF606A323 for ; Sat, 14 Nov 2026 15:42:35 +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=OggpX2vE Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C5D61F000C5; Sat, 14 Nov 2026 15:42:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794670955; bh=VVnZ2YLn9x8r4fjngicQKfW0x/QchCQH/F4MjVyahNc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=OggpX2vEQSYsyadwIADtmy4oSEf8hRxsaS3fkg41zhs05S3yIBlMRdsIt+w1YrOuk 18xJ3Plrmlmu5ogj//DH30aG3zkB6Z5htlT5BJ1EYABqPoGOnb4rMtMAtJFLnI3c/z 5ffu7k5h0eWhxw26mwzhhXYhoeYkGUK/koMiqSOCI/Os9iKUpt1Oq3Bd3FRK8ek7XT zWiVSns01Km2fDPwtovTvyo4vbxaPhmPQ74pH7sOT4ZYHXxL38Kp4kJMwTpJMIcAA8 hK1eUf3BY4XXPZVxr+RU4vp1q/BEqZap7A67FdV8A5hrqVASmUE8X4N0ZAedGMOl5k PeEdHyEIgWXiQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Josef Bacik , "Lorenzo Stoakes (ARM)" , Muhammad Usama Anjum , "David Hildenbrand (Arm)" , Sasha Levin Subject: [PATCH 5.10.y 2/2] mm/mmu_notifier: finish non-blocking interval invalidation on error Date: Sat, 14 Nov 2026 10:42:32 -0500 Message-ID: <20261114154209.3700331-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261114154209.3700331-1-sashal@kernel.org> References: <20261109202809-failed-5.10-6d65925777ec@kernel.org> <20261114154209.3700331-1-sashal@kernel.org> 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 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 0346fffecb6c6..3404dff497033 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -458,7 +458,8 @@ 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 b66b9ae21538f..7487d38840f4f 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -537,16 +537,25 @@ 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