From mboxrd@z Thu Jan 1 00:00:00 1970 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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8C05CC5479D for ; Mon, 9 Jan 2023 21:17:29 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4NrRbr09Ncz3fqm for ; Tue, 10 Jan 2023 08:17:28 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20210112 header.b=nfh/0wSN; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=flex--surenb.bounces.google.com (client-ip=2607:f8b0:4864:20::b4a; helo=mail-yb1-xb4a.google.com; envelope-from=3fh-8ywykdckxzwjsglttlqj.htrqnszcuuh-ijaqnxyx.teqfgx.twl@flex--surenb.bounces.google.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20210112 header.b=nfh/0wSN; dkim-atps=neutral Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4NrR5f2tmPz3cdP for ; Tue, 10 Jan 2023 07:54:46 +1100 (AEDT) Received: by mail-yb1-xb4a.google.com with SMTP id r8-20020a252b08000000b007b989d5e105so6927863ybr.11 for ; Mon, 09 Jan 2023 12:54:46 -0800 (PST) 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:message-id:reply-to; bh=89ITsq4nUiN8d4MMzUNaP/VKvoRvGlIDiLzssAyWMSw=; b=nfh/0wSN7du3H+jbnftiNBYsH0L/ZzvAjrQDNKD6/Ux50j22Vuiz0S8HvVp3TvO1vo K/T56ndCuYOiwpC071dddEQYgomwd4Y1mEzWyHgdRsI4Zm5Szg4pGbhhjtZTIjjKwBZ2 DuLjlMuvIIQ0lWiW9Nfxk/1vqmTgUUR+Vpz2r/N+XxIUJS4L6MBvWuo91YhKUizAdsFD /Z7UYgJwWP6aH5EHzLl9AB9L/N1SliUIF0AbaZQSGUEgi4Q4Dc2tmxMGPV7cLiqwxdNW 0MiPjg6rJc2LN6ARMi2zMWyKxfOe4Y81VTcKlWoejCss5A49BpopZcqw0LB7HbZRjJwk DoGw== 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:message-id:reply-to; bh=89ITsq4nUiN8d4MMzUNaP/VKvoRvGlIDiLzssAyWMSw=; b=Kh7KyIWzk/oD2lw1CHiUC8/WrWjmbgH5DLp2bKVZAT64XwdIo51vgxbGbVn7zkxJuR cjWbkxN6EyDVXkBh4zolfo+9INigki9HMupN7bEvyuDRFA9JYQjkdrfCInfGjdA497df SvduCKHYMY+emUdd69xxQbJjTXswd7nKCNyPnGmzsyDuxpizDPrNwwHB7OnlAFLY2U+M I5rKQXUYyVDHY2AyPzVPZ+Vo8Svgn953d9h81Sf7o3c7tnZMTGm15Ya3Bhn71b/jcdQQ abAZaH3uFTcam5lq5bik6vtmX27liF7oGHIIRqL1L2cz7R4mKylU6BMDXXRkEo/djkFl 8qaw== X-Gm-Message-State: AFqh2koAOf7CdhY+KmrIGXHAV8fLvx69MDN/By4tEn2m0jl8E+D6TvpM VK0aznt8aeTCuu0rM8bM5p0GwI8FxAo= X-Google-Smtp-Source: AMrXdXvWplK/QqycNgSSdeBDfganGdyEUrMbsmwVLuA4csVljoZeQRUCGyXX2t9p/6nnKr16T46cKc1FR2o= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:200:9393:6f7a:d410:55ca]) (user=surenb job=sendgmr) by 2002:a0d:eacb:0:b0:485:126c:3834 with SMTP id t194-20020a0deacb000000b00485126c3834mr6100451ywe.360.1673297684211; Mon, 09 Jan 2023 12:54:44 -0800 (PST) Date: Mon, 9 Jan 2023 12:53:20 -0800 In-Reply-To: <20230109205336.3665937-1-surenb@google.com> Mime-Version: 1.0 References: <20230109205336.3665937-1-surenb@google.com> X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog Message-ID: <20230109205336.3665937-26-surenb@google.com> Subject: [PATCH 25/41] mm/mmap: write-lock adjacent VMAs if they can grow into unmapped area From: Suren Baghdasaryan To: akpm@linux-foundation.org Content-Type: text/plain; charset="UTF-8" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: michel@lespinasse.org, joelaf@google.com, songliubraving@fb.com, mhocko@suse.com, leewalsh@google.com, david@redhat.com, peterz@infradead.org, bigeasy@linutronix.de, peterx@redhat.com, dhowells@redhat.com, linux-mm@kvack.org, edumazet@google.com, jglisse@google.com, punit.agrawal@bytedance.com, arjunroy@google.com, dave@stgolabs.net, minchan@google.com, x86@kernel.org, hughd@google.com, willy@infradead.org, gurua@google.com, laurent.dufour@fr.ibm.com, linux-arm-kernel@lists.infradead.org, rientjes@google.com, axelrasmussen@google.com, kernel-team@android.com, soheil@google.com, paulmck@kernel.org, jannh@google.com, liam.howlett@oracle.com, shakeelb@google.com, luto@kernel.org, gthelen@google.com, ldufour@linux.ibm.com, surenb@google.com, vbabka@suse.cz, posk@google.com, lstoakes@gmail.com, peterjung1337@gmail.com, linuxppc-dev@lists.ozlabs.org, kent.overstreet@linux.dev, hughlynch@google.com, linux-kernel@vger.kernel.org, hannes@cmpxchg.org, tatashin@google.com, mgorman@techsingu larity.net Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" While unmapping VMAs, adjacent VMAs might be able to grow into the area being unmapped. In such cases write-lock adjacent VMAs to prevent this growth. Signed-off-by: Suren Baghdasaryan --- mm/mmap.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 0d767ce043af..30c7d1c5206e 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2461,11 +2461,13 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma, * down_read(mmap_lock) and collide with the VMA we are about to unmap. */ if (downgrade) { - if (next && (next->vm_flags & VM_GROWSDOWN)) + if (next && (next->vm_flags & VM_GROWSDOWN)) { + vma_write_lock(next); downgrade = false; - else if (prev && (prev->vm_flags & VM_GROWSUP)) + } else if (prev && (prev->vm_flags & VM_GROWSUP)) { + vma_write_lock(prev); downgrade = false; - else + } else mmap_write_downgrade(mm); } -- 2.39.0