From nobody Tue Apr 7 10:38:50 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 D6E2EECAAD2 for ; Mon, 29 Aug 2022 21:26:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229917AbiH2V0g (ORCPT ); Mon, 29 Aug 2022 17:26:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229826AbiH2V0P (ORCPT ); Mon, 29 Aug 2022 17:26:15 -0400 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11F3E6EF11 for ; Mon, 29 Aug 2022 14:25:52 -0700 (PDT) Received: by mail-pj1-x1049.google.com with SMTP id 92-20020a17090a09e500b001d917022847so3728626pjo.1 for ; Mon, 29 Aug 2022 14:25:52 -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; bh=tMRmbcwOZDIFaTPxLY27tBFqvxpOSXiDeb2XTcL9iTc=; b=c5Ge838GLG1Fn9WCiifxSW0yY2J286Z3nb7CHVsgQeKl819oavnaneDjs0pHM1pBgc 6/VXxA27srsSSYsH3q/5JQwqbG7gvhz/dxlqpfYYnChp/oSAOK1144eGZRxL5H4xfU4+ gXjPirwbsBHls6abdkbd/Ru5neoY+5POLJLE67tmQyRoTq3+UExyJwB4xZoCc8lFIPHT 1JLKkVoSr3hMYFs+x98zjjRcyw2xrS1rGfAXHEq+RyZfpGyhDpyGAbYsGbpBS3qHA7OY gUezPbUinXA9UrR8RhJyAbOsAhf2VqCoI/O3T8n1+HeqEuYCNoxrQ8z3jvR4TT/rnWyA atPg== 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; bh=tMRmbcwOZDIFaTPxLY27tBFqvxpOSXiDeb2XTcL9iTc=; b=WIUSLTwVEHYT0+Jviji8lyFug0u5mvHgjPSDqRHNXPXEfN+0/7ZqPLNXWJ5CAQX6NP 2vGXH3lecPomVFQR+ObmUZFy9+vKvykol2eAVIa5r0o0A69vTkO3MHlWA+hMbC+qMmMw hXNX79bRrt7cG4njvWGkq8pf0jkO+A0+DVKQrwFE4lOWFYAJdBa7LXdn12Wc6+FymxGi JcYxUuuPSSKif8eDDY+g6S8XT+yqL3G8jPWWvHiWCvz0nhn5HbP+qTHd9BFQYz4BRu4o McahDhNKQen4b89UoVfco1mcW/fYtVNYBUygn6pKbRCEEsTmeApTvYQq8chqqgAkZ8Ke WmWg== X-Gm-Message-State: ACgBeo0ZTkR5yWD+ZTR9YY+jKYDStAlOGEFerZGJwmHOvE/CK2xLJhj2 YcVRAwioMFlCcbCFsbx2O9rXAdhD5iE= X-Google-Smtp-Source: AA6agR6WFXWG6lBERn8fKgbng4pdY7+dFZ275Tti+4gL6MGpsob4z29fC0owAPSMM8vQ0mXhvHK4dQ+aJ1U= X-Received: from surenb-spec.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e30]) (user=surenb job=sendgmr) by 2002:a17:902:ab08:b0:173:320e:3316 with SMTP id ik8-20020a170902ab0800b00173320e3316mr17541232plb.38.1661808351535; Mon, 29 Aug 2022 14:25:51 -0700 (PDT) Date: Mon, 29 Aug 2022 21:25:12 +0000 In-Reply-To: <20220829212531.3184856-1-surenb@google.com> Mime-Version: 1.0 References: <20220829212531.3184856-1-surenb@google.com> X-Mailer: git-send-email 2.37.2.672.g94769d06f0-goog Message-ID: <20220829212531.3184856-10-surenb@google.com> Subject: [RFC PATCH 09/28] mm/mempolicy: mark VMA as locked when changing protection policy 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@techsingularity.net, 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, riel@surriel.com, 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" Protect VMA from concurrent page fault handler while performing VMA protection policy changes. Signed-off-by: Suren Baghdasaryan --- mm/mempolicy.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index b73d3248d976..6be1e5c75556 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -383,8 +383,10 @@ void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *= new) struct vm_area_struct *vma; =20 mmap_write_lock(mm); - for (vma =3D mm->mmap; vma; vma =3D vma->vm_next) + for (vma =3D mm->mmap; vma; vma =3D vma->vm_next) { + vma_mark_locked(vma); mpol_rebind_policy(vma->vm_policy, new); + } mmap_write_unlock(mm); } =20 @@ -632,6 +634,7 @@ unsigned long change_prot_numa(struct vm_area_struct *v= ma, struct mmu_gather tlb; int nr_updated; =20 + vma_mark_locked(vma); tlb_gather_mmu(&tlb, vma->vm_mm); =20 nr_updated =3D change_protection(&tlb, vma, addr, end, PAGE_NONE, @@ -765,6 +768,7 @@ static int vma_replace_policy(struct vm_area_struct *vm= a, if (IS_ERR(new)) return PTR_ERR(new); =20 + vma_mark_locked(vma); if (vma->vm_ops && vma->vm_ops->set_policy) { err =3D vma->vm_ops->set_policy(vma, new); if (err) --=20 2.37.2.672.g94769d06f0-goog