From nobody Mon Apr 6 23:07:08 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C899ECAAD1 for ; Thu, 1 Sep 2022 17:37:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234729AbiIARh4 (ORCPT ); Thu, 1 Sep 2022 13:37:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234684AbiIARgV (ORCPT ); Thu, 1 Sep 2022 13:36:21 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94EF64D251 for ; Thu, 1 Sep 2022 10:36:12 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-335420c7bfeso234911327b3.16 for ; Thu, 01 Sep 2022 10:36:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date; bh=OeaHSvnl3LkKr4l31U2Volg5xaVk+RMFLZSi6dgjePI=; b=YWMUacgHyaw45xClfelut3B8D4opaNKe1Jn1EvQGqzRnq9IAzY1SbxxDOw3yyYq+BA clLIFH+vCJyTvZqkcuk+nPAAVvk+cIcjjJaBgcqIDZI820XVBHBVS4HV09O0+jx02gz/ GF82/kOz5NOA2SL5LGwa69qRF4uUvf5PcNaP24Dp6cprq2xiDwA1y9+n/C6LME/0C0u+ LXVRqnwXAQFfakRcmYHnZMbYxKQr/xy2mJHdmdiugDAKPQMxfZlI1xF8c8WSAaPgs+Sf 8cODiZAHBJrDioo32O0YL9A9GYzXrzP7oLTKiCYFarAedegbhpTrR5084qGw0ahgqNnD Ah8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date; bh=OeaHSvnl3LkKr4l31U2Volg5xaVk+RMFLZSi6dgjePI=; b=SrCdPFex/VHfsUMQ/QjiBxqSCEze6iFsHcsIa3uzDYNXl1nDgRo5EyeIFkpyboG+Zp tGd3nWyy1DnSQRV4Qez5MbOk2zVcKHE/SvbqcBeDc1Unb9IQFsGwXBWzg/HcmoeB3GCD 8eIGCF9SGtKWKH6GMXgusvR2q9jgYGgS8PlUQVLcLuF2PeqE8okeuv6tFB9Jt5c0p3Yq DhnUXRx20TwsmL9heHE5k3DSNrH2kgKHOwOyC1RKgW1pl1XN1EHwm2dBSo3GG0ItjVEU KyY2agRZFrw5zWW4OsZBSfrtj69HMTaCktYpnUy3Bgx9Xhuad/G3U7taO1huYJHmclxw YB3Q== X-Gm-Message-State: ACgBeo3mbndfTgfv/kj8fGMsc/hmjNM0R6XL+6bDciLWEVyt4pnMtMhi 94SXN+a95MmKJFCyfeSCKgBKS2EN4TI= X-Google-Smtp-Source: AA6agR5WRy5fZ7FOeYwPAz+MoQjsxloN5BfCZpV2SaYdV4girws1lZ0WYC4kcT46D4arwsdXcJqkq+Ln5bw= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:200:1bfc:e7ee:6530:4449]) (user=surenb job=sendgmr) by 2002:a25:6744:0:b0:696:52a9:2d84 with SMTP id b65-20020a256744000000b0069652a92d84mr20473184ybc.256.1662053771488; Thu, 01 Sep 2022 10:36:11 -0700 (PDT) Date: Thu, 1 Sep 2022 10:35:07 -0700 In-Reply-To: <20220901173516.702122-1-surenb@google.com> Mime-Version: 1.0 References: <20220901173516.702122-1-surenb@google.com> X-Mailer: git-send-email 2.37.2.789.g6183377224-goog Message-ID: <20220901173516.702122-20-surenb@google.com> Subject: [RFC PATCH RESEND 19/28] mm: disallow do_swap_page to handle page faults under VMA lock From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: michel@lespinasse.org, jglisse@google.com, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@suse.de, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, laurent.dufour@fr.ibm.com, paulmck@kernel.org, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, rientjes@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, surenb@google.com, kernel-team@android.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Due to the possibility of do_swap_page dropping mmap_lock, abort fault handling under VMA lock and retry holding mmap_lock. This can be handled more gracefully in the future. Signed-off-by: Suren Baghdasaryan Reviewed-by: Laurent Dufour --- mm/memory.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/memory.c b/mm/memory.c index 9ac9944e8c62..29d2f49f922a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3738,6 +3738,11 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) vm_fault_t ret =3D 0; void *shadow =3D NULL; =20 + if (vmf->flags & FAULT_FLAG_VMA_LOCK) { + ret =3D VM_FAULT_RETRY; + goto out; + } + if (!pte_unmap_same(vmf)) goto out; =20 --=20 2.37.2.789.g6183377224-goog