From patchwork Wed Feb 14 15:17:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13556673 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.gnu.org (lists.gnu.org [209.51.188.17]) (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 320B7C48BED for ; Wed, 14 Feb 2024 15:19:35 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1raH1L-00084A-3h; Wed, 14 Feb 2024 10:17:59 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1raH1J-000842-Q6 for qemu-devel@nongnu.org; Wed, 14 Feb 2024 10:17:57 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1raH1G-0000Re-R5 for qemu-devel@nongnu.org; Wed, 14 Feb 2024 10:17:56 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707923873; 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=TLnNO5ulewL8SdL9pqVb1gTlxm0dqDjONy8Cj8nYHpE=; b=fEVqVVUvE8GYQ3O7p5sn8TtEAhxnQ0Q1xvldfYOoOExASYkq4GYpqc1mZ1C7MkP7HE6J3h JCNC6xd/E/PJJ9KzmADEl/SiIG7bdtqxmLhA5mYxXXHyb3vdEfww2oTZcfFfvmZRjsTlJG JFBz7wrjNKopzJIlqTkzPBwMBbxbcFk= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-257-s5xpLaBYO2yYhnQ0fXVuEQ-1; Wed, 14 Feb 2024 10:17:49 -0500 X-MC-Unique: s5xpLaBYO2yYhnQ0fXVuEQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id 473C43812582; Wed, 14 Feb 2024 15:17:49 +0000 (UTC) Received: from t14s.fritz.box (unknown [10.39.194.174]) by smtp.corp.redhat.com (Postfix) with ESMTP id ADD2F1C060B1; Wed, 14 Feb 2024 15:17:46 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Cc: David Hildenbrand , "Michael S . Tsirkin" , Jason Wang , Stefan Hajnoczi , Stefano Garzarella , Germano Veit Michel , Raphael Norwitz , Raphael Norwitz Subject: [PATCH v2 14/14] libvhost-user: Mark mmap'ed region memory as MADV_DONTDUMP Date: Wed, 14 Feb 2024 16:17:01 +0100 Message-ID: <20240214151701.29906-15-david@redhat.com> In-Reply-To: <20240214151701.29906-1-david@redhat.com> References: <20240214151701.29906-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 Received-SPF: pass client-ip=170.10.129.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.531, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org We already use MADV_NORESERVE to deal with sparse memory regions. Let's also set madvise(MADV_DONTDUMP), otherwise a crash of the process can result in us allocating all memory in the mmap'ed region for dumping purposes. This change implies that the mmap'ed rings won't be included in a coredump. If ever required for debugging purposes, we could mark only the mapped rings MADV_DODUMP. Ignore errors during madvise() for now. Reviewed-by: Raphael Norwitz Acked-by: Stefano Garzarella Signed-off-by: David Hildenbrand --- subprojects/libvhost-user/libvhost-user.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c index 61fb3050b3..a879149fef 100644 --- a/subprojects/libvhost-user/libvhost-user.c +++ b/subprojects/libvhost-user/libvhost-user.c @@ -460,6 +460,12 @@ _vu_add_mem_reg(VuDev *dev, VhostUserMemoryRegion *msg_region, int fd) DPRINT(" mmap_addr: 0x%016"PRIx64"\n", (uint64_t)(uintptr_t)mmap_addr); +#if defined(__linux__) + /* Don't include all guest memory in a coredump. */ + madvise(mmap_addr, msg_region->memory_size + mmap_offset, + MADV_DONTDUMP); +#endif + /* Shift all affected entries by 1 to open a hole at idx. */ r = &dev->regions[idx]; memmove(r + 1, r, sizeof(VuDevRegion) * (dev->nregions - idx));