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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 62402D10399 for ; Fri, 25 Oct 2024 15:35:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=o2WsInUwYp2wblsTkxMX+ZSecik0itgN2Rql0fl5FlY=; b=nDjzUUef+QVBoT OZsxB9emAgUZ/q8gCs7U3vjXy/6x+KtC0wNvbD1b/VNQMYEw/JAntTi3k8XgNmS19ajXbBlolLaXx rz1Uqzpu4imIdhbJ6wrang55pOySpfvaqage34zgit1dYqUjnXD2ZehWUTx0Pn5DT4hr0nG6seYGU aElGKxl0v/l1UxEGodbmAtuMkxFfxfcDP6XYcbiKPeXF1T+4FsF4FrDFsKC72BlwZRnNVy/fuOx50 aS5BZeMAUUd3zt4LU7v0Ge5YvWj4/n9dMehuVqs4RwCriW2/GxnotwiVUNE/LmGm1BmYMpsLROD6A MHYiUukfUj0XgbVyv0Bg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t4MLQ-00000004GQG-3FJf; Fri, 25 Oct 2024 15:35:20 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t4Lys-00000004AeK-4021 for kexec@lists.infradead.org; Fri, 25 Oct 2024 15:12:04 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1729869121; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VrMChLaTWQQV1P3cCXF0g4Mb1STd5YPEt4ibYFFJxW4=; b=fgJhnSnEQSTql4I4+FerEDjUXmI19VK+NxbhKXl3Hq6GJ/HQv1ipTufu8pTDSZv2RyjO2B WctAAgGWqxj+/xDsNihW+2AwG5llF5XDzMQS+8l8jTskh8afRSaXlhu0eUowl7xRdruy6a o2epJmpChMRnBbUAjXp/xWUjtESmFg0= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-35-oROdk647PWOwfbs1qWmB5g-1; Fri, 25 Oct 2024 11:11:58 -0400 X-MC-Unique: oROdk647PWOwfbs1qWmB5g-1 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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 mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1D5A8193585B; Fri, 25 Oct 2024 15:11:53 +0000 (UTC) Received: from t14s.redhat.com (unknown [10.22.65.27]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 1F17D3000198; Fri, 25 Oct 2024 15:11:44 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linux-s390@vger.kernel.org, virtualization@lists.linux.dev, kvm@vger.kernel.org, linux-fsdevel@vger.kernel.org, kexec@lists.infradead.org, David Hildenbrand , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?q?Eugenio=20P=C3=A9rez?= , Baoquan He , Vivek Goyal , Dave Young , Thomas Huth , Cornelia Huck , Janosch Frank , Claudio Imbrenda , Eric Farman , Andrew Morton Subject: [PATCH v1 01/11] fs/proc/vmcore: convert vmcore_cb_lock into vmcore_mutex Date: Fri, 25 Oct 2024 17:11:23 +0200 Message-ID: <20241025151134.1275575-2-david@redhat.com> In-Reply-To: <20241025151134.1275575-1-david@redhat.com> References: <20241025151134.1275575-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241025_081203_197154_D4DB444A X-CRM114-Status: UNSURE ( 9.90 ) X-CRM114-Notice: Please train this message. X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org We want to protect vmcore modifications from concurrent opening of the vmcore, and also serialize vmcore modiciations. Let's convert the spinlock into a mutex, because some of the operations we'll be protecting might sleep (e.g., memory allocations) and might take a bit longer. Signed-off-by: David Hildenbrand --- fs/proc/vmcore.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index b52d85f8ad59..110ce193d20f 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -62,7 +62,8 @@ core_param(novmcoredd, vmcoredd_disabled, bool, 0); /* Device Dump Size */ static size_t vmcoredd_orig_sz; -static DEFINE_SPINLOCK(vmcore_cb_lock); +static DEFINE_MUTEX(vmcore_mutex); + DEFINE_STATIC_SRCU(vmcore_cb_srcu); /* List of registered vmcore callbacks. */ static LIST_HEAD(vmcore_cb_list); @@ -72,7 +73,7 @@ static bool vmcore_opened; void register_vmcore_cb(struct vmcore_cb *cb) { INIT_LIST_HEAD(&cb->next); - spin_lock(&vmcore_cb_lock); + mutex_lock(&vmcore_mutex); list_add_tail(&cb->next, &vmcore_cb_list); /* * Registering a vmcore callback after the vmcore was opened is @@ -80,13 +81,13 @@ void register_vmcore_cb(struct vmcore_cb *cb) */ if (vmcore_opened) pr_warn_once("Unexpected vmcore callback registration\n"); - spin_unlock(&vmcore_cb_lock); + mutex_unlock(&vmcore_mutex); } EXPORT_SYMBOL_GPL(register_vmcore_cb); void unregister_vmcore_cb(struct vmcore_cb *cb) { - spin_lock(&vmcore_cb_lock); + mutex_lock(&vmcore_mutex); list_del_rcu(&cb->next); /* * Unregistering a vmcore callback after the vmcore was opened is @@ -95,7 +96,7 @@ void unregister_vmcore_cb(struct vmcore_cb *cb) */ if (vmcore_opened) pr_warn_once("Unexpected vmcore callback unregistration\n"); - spin_unlock(&vmcore_cb_lock); + mutex_unlock(&vmcore_mutex); synchronize_srcu(&vmcore_cb_srcu); } @@ -120,9 +121,9 @@ static bool pfn_is_ram(unsigned long pfn) static int open_vmcore(struct inode *inode, struct file *file) { - spin_lock(&vmcore_cb_lock); + mutex_lock(&vmcore_mutex); vmcore_opened = true; - spin_unlock(&vmcore_cb_lock); + mutex_unlock(&vmcore_mutex); return 0; } -- 2.46.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec