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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7439CC61DB3 for ; Mon, 9 Jan 2023 20:58:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237846AbjAIU55 (ORCPT ); Mon, 9 Jan 2023 15:57:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237750AbjAIU53 (ORCPT ); Mon, 9 Jan 2023 15:57:29 -0500 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 939FA8CBFE for ; Mon, 9 Jan 2023 12:54:55 -0800 (PST) Received: by mail-pl1-x649.google.com with SMTP id p15-20020a170902a40f00b00192b2bbb7f8so7044568plq.14 for ; Mon, 09 Jan 2023 12:54:55 -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=L7MiPLggwHMt078/i5i4Bbk0h7mxL/B1TX4Loq0bJkA=; b=k/y/f651ouIVm5VYXSBuN3WGA3r0siHAwbforN7cl7XldyaXSobuMoKnfRbHsUp2Zw mT4Fy24gz9zLv4V1qPdlGMDZmt4uQYDL7SMguN64hvgl+OPwnYaemI3hYYgdYfqYy2ZE RZpsDEbxomOp03K+XTMpAlOj5/FuHalix+oD7gvliXvyOvoSifjWwtoSfq337yDgZBWx NsM/wn5sH1zgbh2ZxdX6VDsXj4dH/jKa39D017jsbV+IQ14YXnxgSRRt8KTb8ppwgMfm uVAI77HN37Vy1v+4HMEL/4fAI+3c+Ki/ub6d+F+N4Xj5NK0ZJDRKlJXLfRFrsnczSTJ7 ObUQ== 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=L7MiPLggwHMt078/i5i4Bbk0h7mxL/B1TX4Loq0bJkA=; b=LIku4FFdTFF6ymPF/7eEdvuaGF8VODd4zef9wPwsWVyN7n+ez8iX7vNQ4cRwj49n/k S9dhCO6YwLOlSl1OEg4pAFziyAGRcTBpnFllDmX5QNp/mlXXXCP30MZgibaroBbzgQTx JxrScvPbZ0FfPgc3yiF+5qF2IMLi9B8AV5IV5gitb0sWbt5L71vFek5fhEQy4iPKiWy3 bVVIRm6BMeY9Yq2PUP/uFJtp1oaz5yNFwNPcT1h4xgDVDnjVMVQfLlr5o6E9EyX8THpV bUVE1aTY/VpxvbmnKhYJaKl+lHR/WkiTheus8dYDk76RlgCPWPbYrKyKV77VbA6WSlr0 pGMw== X-Gm-Message-State: AFqh2kqEEjVZrY1eS4yk6w+QgWCxkZDLDq4JdXtn1x1wUPKKsbZv0E5E yhRxaQFOEi28pTpvRUGJUgqfZyJKbhM= X-Google-Smtp-Source: AMrXdXscxn+TZfW1mPWgpj2/8Haqh4tY58OgT8gYBU0unalxDUYH6+O0E4BOyMrkarY33KKQg8fQ3JxSbTo= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:200:9393:6f7a:d410:55ca]) (user=surenb job=sendgmr) by 2002:a17:902:8e88:b0:190:becc:7e76 with SMTP id bg8-20020a1709028e8800b00190becc7e76mr6134633plb.1.1673297686693; Mon, 09 Jan 2023 12:54:46 -0800 (PST) Date: Mon, 9 Jan 2023 12:53:21 -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: <20230109205336.3665937-27-surenb@google.com> Subject: [PATCH 26/41] kernel/fork: assert no VMA readers during its destruction 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, 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, punit.agrawal@bytedance.com, lstoakes@gmail.com, peterjung1337@gmail.com, rientjes@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, jannh@google.com, shakeelb@google.com, tatashin@google.com, edumazet@google.com, gthelen@google.com, gurua@google.com, arjunroy@google.com, soheil@google.com, hughlynch@google.com, leewalsh@google.com, posk@google.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com, surenb@google.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Assert there are no holders of VMA lock for reading when it is about to be destroyed. Signed-off-by: Suren Baghdasaryan --- include/linux/mm.h | 8 ++++++++ kernel/fork.c | 2 ++ 2 files changed, 10 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 594e835bad9c..c464fc8a514c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -680,6 +680,13 @@ static inline void vma_assert_write_locked(struct vm_area_struct *vma) VM_BUG_ON_VMA(vma->vm_lock_seq != READ_ONCE(vma->vm_mm->mm_lock_seq), vma); } +static inline void vma_assert_no_reader(struct vm_area_struct *vma) +{ + VM_BUG_ON_VMA(rwsem_is_locked(&vma->lock) && + vma->vm_lock_seq != READ_ONCE(vma->vm_mm->mm_lock_seq), + vma); +} + #else /* CONFIG_PER_VMA_LOCK */ static inline void vma_init_lock(struct vm_area_struct *vma) {} @@ -688,6 +695,7 @@ static inline bool vma_read_trylock(struct vm_area_struct *vma) { return false; } static inline void vma_read_unlock(struct vm_area_struct *vma) {} static inline void vma_assert_write_locked(struct vm_area_struct *vma) {} +static inline void vma_assert_no_reader(struct vm_area_struct *vma) {} #endif /* CONFIG_PER_VMA_LOCK */ diff --git a/kernel/fork.c b/kernel/fork.c index 1591dd8a0745..6d9f14e55ecf 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -485,6 +485,8 @@ static void __vm_area_free(struct rcu_head *head) { struct vm_area_struct *vma = container_of(head, struct vm_area_struct, vm_rcu); + /* The vma should either have no lock holders or be write-locked. */ + vma_assert_no_reader(vma); kmem_cache_free(vm_area_cachep, vma); } #endif -- 2.39.0