Patch Detail
get:
Show a patch.
patch:
Update a patch.
put:
Update a patch.
GET /api/patches/2217292/?format=api
{ "id": 2217292, "url": "http://patchwork.ozlabs.org/api/patches/2217292/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260327205457.604224-3-surenb@google.com/", "project": { "id": 2, "url": "http://patchwork.ozlabs.org/api/projects/2/?format=api", "name": "Linux PPC development", "link_name": "linuxppc-dev", "list_id": "linuxppc-dev.lists.ozlabs.org", "list_email": "linuxppc-dev@lists.ozlabs.org", "web_url": "https://github.com/linuxppc/wiki/wiki", "scm_url": "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git", "webscm_url": "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/", "list_archive_url": "https://lore.kernel.org/linuxppc-dev/", "list_archive_url_format": "https://lore.kernel.org/linuxppc-dev/{}/", "commit_url_format": "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id={}" }, "msgid": "<20260327205457.604224-3-surenb@google.com>", "list_archive_url": "https://lore.kernel.org/linuxppc-dev/20260327205457.604224-3-surenb@google.com/", "date": "2026-03-27T20:54:53", "name": "[v6,2/6] mm: use vma_start_write_killable() in mm syscalls", "commit_ref": null, "pull_url": null, "state": "handled-elsewhere", "archived": false, "hash": "f1da1d6cfa0c6f6c1309ac3d955cd8adfea11279", "submitter": { "id": 74729, "url": "http://patchwork.ozlabs.org/api/people/74729/?format=api", "name": "Suren Baghdasaryan", "email": "surenb@google.com" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260327205457.604224-3-surenb@google.com/mbox/", "series": [ { "id": 497828, "url": "http://patchwork.ozlabs.org/api/series/497828/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=497828", "date": "2026-03-27T20:54:51", "name": "Use killable vma write locking in most places", "version": 6, "mbox": "http://patchwork.ozlabs.org/series/497828/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/2217292/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/2217292/checks/", "tags": {}, "related": [], "headers": { "Return-Path": "\n <linuxppc-dev+bounces-18940-incoming=patchwork.ozlabs.org@lists.ozlabs.org>", "X-Original-To": [ "incoming@patchwork.ozlabs.org", "linuxppc-dev@lists.ozlabs.org" ], "Delivered-To": "patchwork-incoming@legolas.ozlabs.org", "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256\n header.s=20251104 header.b=QcdHuADn;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org\n (client-ip=2404:9400:21b9:f100::1; helo=lists.ozlabs.org;\n envelope-from=linuxppc-dev+bounces-18940-incoming=patchwork.ozlabs.org@lists.ozlabs.org;\n receiver=patchwork.ozlabs.org)", "lists.ozlabs.org;\n arc=none smtp.remote-ip=\"2607:f8b0:4864:20::134a\"", "lists.ozlabs.org;\n dmarc=pass (p=reject dis=none) header.from=google.com", "lists.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256\n header.s=20251104 header.b=QcdHuADn;\n\tdkim-atps=neutral", "lists.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=flex--surenb.bounces.google.com\n (client-ip=2607:f8b0:4864:20::134a; helo=mail-dy1-x134a.google.com;\n envelope-from=3qe7gaqykdpyqspclzemmejc.amkjglsvnna-bctjgqrq.mxjyzq.mpe@flex--surenb.bounces.google.com;\n receiver=lists.ozlabs.org)" ], "Received": [ "from lists.ozlabs.org (lists.ozlabs.org\n [IPv6:2404:9400:21b9:f100::1])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fjCb13gByz1y1x\n\tfor <incoming@patchwork.ozlabs.org>; Sat, 28 Mar 2026 07:55:25 +1100 (AEDT)", "from boromir.ozlabs.org (localhost [127.0.0.1])\n\tby lists.ozlabs.org (Postfix) with ESMTP id 4fjCZj5bb3z2yVt;\n\tSat, 28 Mar 2026 07:55:09 +1100 (AEDT)", "from mail-dy1-x134a.google.com (mail-dy1-x134a.google.com\n [IPv6:2607:f8b0:4864:20::134a])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest\n SHA256)\n\t(No client certificate requested)\n\tby lists.ozlabs.org (Postfix) with ESMTPS id 4fjCZh3Zckz2yjV\n\tfor <linuxppc-dev@lists.ozlabs.org>; Sat, 28 Mar 2026 07:55:08 +1100 (AEDT)", "by mail-dy1-x134a.google.com with SMTP id\n 5a478bee46e88-2c0ba59a830so2705481eec.0\n for <linuxppc-dev@lists.ozlabs.org>;\n Fri, 27 Mar 2026 13:55:08 -0700 (PDT)" ], "ARC-Seal": "i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1774644909;\n\tcv=none;\n b=BW+epmGAKSTZuPKT5d4jLBxQLpqfidNsKCKeVhTwFEudKxeKw40W8SnLs2WUHqd1b36LnccyS7rEZ8PE2JueGl0YX3VTYuw13Spn1uErR9KuqV+M9ZTX2UxM/kXTO8mEv29MIMNl/9cyImtebA6bVJXU048bOrDZh8QL2osZdcCIHlWHkr7+orMr1IFcFGf0aBeposLkZuJ9JDNtbu3DbLwRurdtskHxPDBiILp2QRgBHzAmpmQbXhh2dmUnMcruUM6PsDNDHHevlKB8bFOuROI162RX2voTzOOvgYcH9ZiPI/iGTyjWfgoSq5on1CBH59qwdPfHf5bRJQWel+YRgA==", "ARC-Message-Signature": "i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707;\n\tt=1774644909; c=relaxed/relaxed;\n\tbh=6+n3Djg+u5/v209SkkHKUKK85Ins0KyBj2RQsN4UbGc=;\n\th=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From:\n\t To:Cc:Content-Type;\n b=fx3mxlMhJDsFfNkkvWoquw3Zk/olvr/i9HnHKjTx9SLWbEOJaU9CHD6bFyLRCT62GDk31BDEytAZUwOfxOVABXqmEwEV6owbbTEL/wGB5ZSjT7IUG37oWyTHO9ZA1nknl3q8hjytaELJRX0MkgIyNFaMUyzx/4FWV0gllgv8Nfp7Dv4ihbFnZ0/I/GS77Nrr/UWDsyz5iISyO0nve2hZnjIfsxO7KeXai8KFxbz6FaXajstbpgcpglTHXjgoAWR4XPAYIxJnqspKde8MaotHbexq7ZTcbeI5eX0SSR3Iv7jNnjUeb6FWaVLiLi+rnoySvP4PMF/cbt1P7FfCwiVrAg==", "ARC-Authentication-Results": "i=1; lists.ozlabs.org;\n dmarc=pass (p=reject dis=none) header.from=google.com;\n dkim=pass (2048-bit key;\n unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256\n header.s=20251104 header.b=QcdHuADn; dkim-atps=neutral;\n spf=pass (client-ip=2607:f8b0:4864:20::134a; helo=mail-dy1-x134a.google.com;\n envelope-from=3qe7gaqykdpyqspclzemmejc.amkjglsvnna-bctjgqrq.mxjyzq.mpe@flex--surenb.bounces.google.com;\n receiver=lists.ozlabs.org) smtp.mailfrom=flex--surenb.bounces.google.com", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n d=google.com; s=20251104; t=1774644906; x=1775249706;\n darn=lists.ozlabs.org;\n h=cc:to:from:subject:message-id:references:mime-version:in-reply-to\n :date:from:to:cc:subject:date:message-id:reply-to;\n bh=6+n3Djg+u5/v209SkkHKUKK85Ins0KyBj2RQsN4UbGc=;\n b=QcdHuADnochZnffrH2SMHTyc32erGNd82FDO+PfD5pQVViIHC/bRmmRQJBg+LkEycw\n 9ZSulJPDBwt3NQQjsXMaqpz7YXTr+P9lHDJ+8/Jfc8XoNCAMlxUQfPf+JFjOjgfu4hXc\n 2+Y41HqJkhyCiXfmONhqJLoh2sy7JLRcujs2mEn5ECxBP1eiNcDv0kQTW2cH8wwWLjiw\n r3YParJ0SDhganHJWQMbIxe5XH/DZAxShpWcdIEy2u3k188k3PowVsSR3pgOidAvzBN+\n gssT7oNYZdbUzBvDvbLoo7jTrIhvYnTXc+ehaZAMzz3D5ZZK/Afdi/ufJB1NSJ9Ukbps\n 9MGA==", "X-Google-DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n d=1e100.net; s=20251104; t=1774644906; x=1775249706;\n h=cc:to:from:subject:message-id:references:mime-version:in-reply-to\n :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to;\n bh=6+n3Djg+u5/v209SkkHKUKK85Ins0KyBj2RQsN4UbGc=;\n b=s/wIjR3RKEeUJqZhUx5elBN0b/xX/Z6hv8gPNyDtUZ0MiusRTvsxNdXr43ppzcE6K5\n 0IjRcgZP19HOrZFMgXIH5Ij4fjv6fS6hO0q4AP4dGpwZN3YD0MQhrbjFsrmrFQ8InIRT\n 6lwUSu+NZI1FbRXP5z6yF6TqBH7H1L2k8uMIsXK0REfXEFOvK3ZpgaW+V7NkiNcDbvPn\n 8xrUMJ7qfPwb8EuMU/DOeuT9YvsD631lZcHTX3KkfdCI+9NiwdzHubW9SdXq+C065pgl\n 2rmAUuFKa2MmPCXAhACMh13txlMH15PY609EAECo0ttN5T6CED7gW4PlNdx7FetAwfRa\n NHlA==", "X-Forwarded-Encrypted": "i=1;\n AJvYcCVY8OGgcNBDT39mC9Zkege2OTf0e90YwCpTkKxcvJDElJdJOAOU+0U4QrHBeSRfj9xBuaXLuBebPAhp+NE=@lists.ozlabs.org", "X-Gm-Message-State": "AOJu0YxpON7NMRTMTs/vNKFkq+PYfi4JBw7JMvHBC5pzEJQApVWFaG/A\n\tUQ0dxCTcQ7n5HUMrn4aTLOkmewHeYoFQuUnTgLdxNt5jqKXGZaF7arM/XBznpLOjVtK/8CmJFkT\n\ti/ZqD2Q==", "X-Received": "from dybsr8.prod.google.com\n ([2002:a05:7301:7188:b0:2c0:b345:9b22])\n (user=surenb job=prod-delivery.src-stubby-dispatcher) by\n 2002:a05:7301:fa04:b0:2c1:6cfd:73da\n with SMTP id 5a478bee46e88-2c185fa842amr1935438eec.32.1774644905874; Fri, 27\n Mar 2026 13:55:05 -0700 (PDT)", "Date": "Fri, 27 Mar 2026 13:54:53 -0700", "In-Reply-To": "<20260327205457.604224-1-surenb@google.com>", "X-Mailing-List": "linuxppc-dev@lists.ozlabs.org", "List-Id": "<linuxppc-dev.lists.ozlabs.org>", "List-Help": "<mailto:linuxppc-dev+help@lists.ozlabs.org>", "List-Owner": "<mailto:linuxppc-dev+owner@lists.ozlabs.org>", "List-Post": "<mailto:linuxppc-dev@lists.ozlabs.org>", "List-Archive": "<https://lore.kernel.org/linuxppc-dev/>,\n <https://lists.ozlabs.org/pipermail/linuxppc-dev/>", "List-Subscribe": "<mailto:linuxppc-dev+subscribe@lists.ozlabs.org>,\n <mailto:linuxppc-dev+subscribe-digest@lists.ozlabs.org>,\n <mailto:linuxppc-dev+subscribe-nomail@lists.ozlabs.org>", "List-Unsubscribe": "<mailto:linuxppc-dev+unsubscribe@lists.ozlabs.org>", "Precedence": "list", "Mime-Version": "1.0", "References": "<20260327205457.604224-1-surenb@google.com>", "X-Mailer": "git-send-email 2.53.0.1018.g2bb0e51243-goog", "Message-ID": "<20260327205457.604224-3-surenb@google.com>", "Subject": "[PATCH v6 2/6] mm: use vma_start_write_killable() in mm syscalls", "From": "Suren Baghdasaryan <surenb@google.com>", "To": "akpm@linux-foundation.org", "Cc": "willy@infradead.org, david@kernel.org, ziy@nvidia.com,\n\tmatthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com,\n\tbyungchul@sk.com, gourry@gourry.net, ying.huang@linux.alibaba.com,\n\tapopple@nvidia.com, ljs@kernel.org, baolin.wang@linux.alibaba.com,\n\tLiam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com,\n\tdev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, vbabka@suse.cz,\n\tjannh@google.com, rppt@kernel.org, mhocko@suse.com, pfalcato@suse.de,\n\tkees@kernel.org, maddy@linux.ibm.com, npiggin@gmail.com, mpe@ellerman.id.au,\n\tchleroy@kernel.org, borntraeger@linux.ibm.com, frankja@linux.ibm.com,\n\timbrenda@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com,\n\tagordeev@linux.ibm.com, svens@linux.ibm.com, gerald.schaefer@linux.ibm.com,\n\tlinux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org,\n\tlinux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, surenb@google.com", "Content-Type": "text/plain; charset=\"UTF-8\"", "X-Spam-Status": "No, score=-7.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED,\n\tDKIM_VALID,DKIM_VALID_AU,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,\n\tUSER_IN_DEF_DKIM_WL autolearn=disabled version=4.0.1 OzLabs 8", "X-Spam-Checker-Version": "SpamAssassin 4.0.1 (2024-03-25) on lists.ozlabs.org" }, "content": "Replace vma_start_write() with vma_start_write_killable() in syscalls,\nimproving reaction time to the kill signal.\n\nIn a number of places we now lock VMA earlier than before to avoid\ndoing work and undoing it later if a fatal signal is pending. This\nis safe because the moves are happening within sections where we\nalready hold the mmap_write_lock, so the moves do not change the\nlocking order relative to other kernel locks.\n\nSuggested-by: Matthew Wilcox <willy@infradead.org>\nSigned-off-by: Suren Baghdasaryan <surenb@google.com>\n---\n mm/madvise.c | 13 ++++++++++---\n mm/memory.c | 2 ++\n mm/mempolicy.c | 11 +++++++++--\n mm/mlock.c | 30 ++++++++++++++++++++++++------\n mm/mprotect.c | 25 +++++++++++++++++--------\n mm/mremap.c | 8 +++++---\n mm/mseal.c | 24 +++++++++++++++++++-----\n 7 files changed, 86 insertions(+), 27 deletions(-)", "diff": "diff --git a/mm/madvise.c b/mm/madvise.c\nindex 69708e953cf5..f2c7b0512cdf 100644\n--- a/mm/madvise.c\n+++ b/mm/madvise.c\n@@ -172,10 +172,17 @@ static int madvise_update_vma(vm_flags_t new_flags,\n \tif (IS_ERR(vma))\n \t\treturn PTR_ERR(vma);\n \n-\tmadv_behavior->vma = vma;\n+\t/*\n+\t * If a new vma was created during vma_modify_XXX, the resulting\n+\t * vma is already locked. Skip re-locking new vma in this case.\n+\t */\n+\tif (vma == madv_behavior->vma) {\n+\t\tif (vma_start_write_killable(vma))\n+\t\t\treturn -EINTR;\n+\t} else {\n+\t\tmadv_behavior->vma = vma;\n+\t}\n \n-\t/* vm_flags is protected by the mmap_lock held in write mode. */\n-\tvma_start_write(vma);\n \tvma->flags = new_vma_flags;\n \tif (set_new_anon_name)\n \t\treturn replace_anon_vma_name(vma, anon_name);\ndiff --git a/mm/memory.c b/mm/memory.c\nindex e44469f9cf65..9f99ec634831 100644\n--- a/mm/memory.c\n+++ b/mm/memory.c\n@@ -366,6 +366,8 @@ void free_pgd_range(struct mmu_gather *tlb,\n * page tables that should be removed. This can differ from the vma mappings on\n * some archs that may have mappings that need to be removed outside the vmas.\n * Note that the prev->vm_end and next->vm_start are often used.\n+ * We don't use vma_start_write_killable() because page tables should be freed\n+ * even if the task is being killed.\n *\n * The vma_end differs from the pg_end when a dup_mmap() failed and the tree has\n * unrelated data to the mm_struct being torn down.\ndiff --git a/mm/mempolicy.c b/mm/mempolicy.c\nindex fd08771e2057..c38a90487531 100644\n--- a/mm/mempolicy.c\n+++ b/mm/mempolicy.c\n@@ -1784,7 +1784,8 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le\n \t\treturn -EINVAL;\n \tif (end == start)\n \t\treturn 0;\n-\tmmap_write_lock(mm);\n+\tif (mmap_write_lock_killable(mm))\n+\t\treturn -EINTR;\n \tprev = vma_prev(&vmi);\n \tfor_each_vma_range(vmi, vma, end) {\n \t\t/*\n@@ -1801,13 +1802,19 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le\n \t\t\terr = -EOPNOTSUPP;\n \t\t\tbreak;\n \t\t}\n+\t\t/*\n+\t\t * Lock the VMA early to avoid extra work if fatal signal\n+\t\t * is pending.\n+\t\t */\n+\t\terr = vma_start_write_killable(vma);\n+\t\tif (err)\n+\t\t\tbreak;\n \t\tnew = mpol_dup(old);\n \t\tif (IS_ERR(new)) {\n \t\t\terr = PTR_ERR(new);\n \t\t\tbreak;\n \t\t}\n \n-\t\tvma_start_write(vma);\n \t\tnew->home_node = home_node;\n \t\terr = mbind_range(&vmi, vma, &prev, start, end, new);\n \t\tmpol_put(new);\ndiff --git a/mm/mlock.c b/mm/mlock.c\nindex 8c227fefa2df..2ed454db7cf7 100644\n--- a/mm/mlock.c\n+++ b/mm/mlock.c\n@@ -419,8 +419,10 @@ static int mlock_pte_range(pmd_t *pmd, unsigned long addr,\n *\n * Called for mlock(), mlock2() and mlockall(), to set @vma VM_LOCKED;\n * called for munlock() and munlockall(), to clear VM_LOCKED from @vma.\n+ *\n+ * Return: 0 on success, -EINTR if fatal signal is pending.\n */\n-static void mlock_vma_pages_range(struct vm_area_struct *vma,\n+static int mlock_vma_pages_range(struct vm_area_struct *vma,\n \tunsigned long start, unsigned long end,\n \tvma_flags_t *new_vma_flags)\n {\n@@ -442,7 +444,9 @@ static void mlock_vma_pages_range(struct vm_area_struct *vma,\n \t */\n \tif (vma_flags_test(new_vma_flags, VMA_LOCKED_BIT))\n \t\tvma_flags_set(new_vma_flags, VMA_IO_BIT);\n-\tvma_start_write(vma);\n+\tif (vma_start_write_killable(vma))\n+\t\treturn -EINTR;\n+\n \tvma_flags_reset_once(vma, new_vma_flags);\n \n \tlru_add_drain();\n@@ -453,6 +457,7 @@ static void mlock_vma_pages_range(struct vm_area_struct *vma,\n \t\tvma_flags_clear(new_vma_flags, VMA_IO_BIT);\n \t\tvma_flags_reset_once(vma, new_vma_flags);\n \t}\n+\treturn 0;\n }\n \n /*\n@@ -506,11 +511,15 @@ static int mlock_fixup(struct vma_iterator *vmi, struct vm_area_struct *vma,\n \t */\n \tif (vma_flags_test(&new_vma_flags, VMA_LOCKED_BIT) &&\n \t vma_flags_test(&old_vma_flags, VMA_LOCKED_BIT)) {\n+\t\tret = vma_start_write_killable(vma);\n+\t\tif (ret)\n+\t\t\tgoto out; /* mm->locked_vm is fine as nr_pages == 0 */\n \t\t/* No work to do, and mlocking twice would be wrong */\n-\t\tvma_start_write(vma);\n \t\tvma->flags = new_vma_flags;\n \t} else {\n-\t\tmlock_vma_pages_range(vma, start, end, &new_vma_flags);\n+\t\tret = mlock_vma_pages_range(vma, start, end, &new_vma_flags);\n+\t\tif (ret)\n+\t\t\tmm->locked_vm -= nr_pages;\n \t}\n out:\n \t*prev = vma;\n@@ -739,9 +748,18 @@ static int apply_mlockall_flags(int flags)\n \n \t\terror = mlock_fixup(&vmi, vma, &prev, vma->vm_start, vma->vm_end,\n \t\t\t\t newflags);\n-\t\t/* Ignore errors, but prev needs fixing up. */\n-\t\tif (error)\n+\t\tif (error) {\n+\t\t\t/*\n+\t\t\t * If we failed due to a pending fatal signal, return\n+\t\t\t * now. If we locked the vma before signal arrived, it\n+\t\t\t * will be unlocked when we drop mmap_write_lock.\n+\t\t\t */\n+\t\t\tif (fatal_signal_pending(current))\n+\t\t\t\treturn -EINTR;\n+\n+\t\t\t/* Ignore errors, but prev needs fixing up. */\n \t\t\tprev = vma;\n+\t\t}\n \t\tcond_resched();\n \t}\n out:\ndiff --git a/mm/mprotect.c b/mm/mprotect.c\nindex 110d47a36d4b..d6227877465f 100644\n--- a/mm/mprotect.c\n+++ b/mm/mprotect.c\n@@ -700,6 +700,7 @@ mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb,\n \tconst vma_flags_t old_vma_flags = READ_ONCE(vma->flags);\n \tvma_flags_t new_vma_flags = legacy_to_vma_flags(newflags);\n \tlong nrpages = (end - start) >> PAGE_SHIFT;\n+\tstruct vm_area_struct *new_vma;\n \tunsigned int mm_cp_flags = 0;\n \tunsigned long charged = 0;\n \tint error;\n@@ -756,19 +757,27 @@ mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb,\n \t\tvma_flags_clear(&new_vma_flags, VMA_ACCOUNT_BIT);\n \t}\n \n-\tvma = vma_modify_flags(vmi, *pprev, vma, start, end, &new_vma_flags);\n-\tif (IS_ERR(vma)) {\n-\t\terror = PTR_ERR(vma);\n+\tnew_vma = vma_modify_flags(vmi, *pprev, vma, start, end,\n+\t\t\t\t &new_vma_flags);\n+\tif (IS_ERR(new_vma)) {\n+\t\terror = PTR_ERR(new_vma);\n \t\tgoto fail;\n \t}\n \n-\t*pprev = vma;\n-\n \t/*\n-\t * vm_flags and vm_page_prot are protected by the mmap_lock\n-\t * held in write mode.\n+\t * If a new vma was created during vma_modify_flags, the resulting\n+\t * vma is already locked. Skip re-locking new vma in this case.\n \t */\n-\tvma_start_write(vma);\n+\tif (new_vma == vma) {\n+\t\terror = vma_start_write_killable(vma);\n+\t\tif (error)\n+\t\t\tgoto fail;\n+\t} else {\n+\t\tvma = new_vma;\n+\t}\n+\n+\t*pprev = vma;\n+\n \tvma_flags_reset_once(vma, &new_vma_flags);\n \tif (vma_wants_manual_pte_write_upgrade(vma))\n \t\tmm_cp_flags |= MM_CP_TRY_CHANGE_WRITABLE;\ndiff --git a/mm/mremap.c b/mm/mremap.c\nindex e9c8b1d05832..0860102bddab 100644\n--- a/mm/mremap.c\n+++ b/mm/mremap.c\n@@ -1348,6 +1348,11 @@ static unsigned long move_vma(struct vma_remap_struct *vrm)\n \tif (err)\n \t\treturn err;\n \n+\t/* We don't want racing faults. */\n+\terr = vma_start_write_killable(vrm->vma);\n+\tif (err)\n+\t\treturn err;\n+\n \t/*\n \t * If accounted, determine the number of bytes the operation will\n \t * charge.\n@@ -1355,9 +1360,6 @@ static unsigned long move_vma(struct vma_remap_struct *vrm)\n \tif (!vrm_calc_charge(vrm))\n \t\treturn -ENOMEM;\n \n-\t/* We don't want racing faults. */\n-\tvma_start_write(vrm->vma);\n-\n \t/* Perform copy step. */\n \terr = copy_vma_and_data(vrm, &new_vma);\n \t/*\ndiff --git a/mm/mseal.c b/mm/mseal.c\nindex 603df53ad267..1ea19fd3d384 100644\n--- a/mm/mseal.c\n+++ b/mm/mseal.c\n@@ -70,14 +70,28 @@ static int mseal_apply(struct mm_struct *mm,\n \n \t\tif (!vma_test(vma, VMA_SEALED_BIT)) {\n \t\t\tvma_flags_t vma_flags = vma->flags;\n+\t\t\tstruct vm_area_struct *new_vma;\n \n \t\t\tvma_flags_set(&vma_flags, VMA_SEALED_BIT);\n \n-\t\t\tvma = vma_modify_flags(&vmi, prev, vma, curr_start,\n-\t\t\t\t\t curr_end, &vma_flags);\n-\t\t\tif (IS_ERR(vma))\n-\t\t\t\treturn PTR_ERR(vma);\n-\t\t\tvma_start_write(vma);\n+\t\t\tnew_vma = vma_modify_flags(&vmi, prev, vma, curr_start,\n+\t\t\t\t\t\t curr_end, &vma_flags);\n+\t\t\tif (IS_ERR(new_vma))\n+\t\t\t\treturn PTR_ERR(new_vma);\n+\n+\t\t\t/*\n+\t\t\t * If a new vma was created during vma_modify_flags,\n+\t\t\t * the resulting vma is already locked.\n+\t\t\t * Skip re-locking new vma in this case.\n+\t\t\t */\n+\t\t\tif (new_vma == vma) {\n+\t\t\t\tint err = vma_start_write_killable(vma);\n+\t\t\t\tif (err)\n+\t\t\t\t\treturn err;\n+\t\t\t} else {\n+\t\t\t\tvma = new_vma;\n+\t\t\t}\n+\n \t\t\tvma_set_flags(vma, VMA_SEALED_BIT);\n \t\t}\n \n", "prefixes": [ "v6", "2/6" ] }