From patchwork Fri May 14 15:16:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xuan Zhuo X-Patchwork-Id: 12258071 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26A10C43460 for ; Fri, 14 May 2021 15:16:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 036A761396 for ; Fri, 14 May 2021 15:16:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232697AbhENPRx (ORCPT ); Fri, 14 May 2021 11:17:53 -0400 Received: from out30-131.freemail.mail.aliyun.com ([115.124.30.131]:39764 "EHLO out30-131.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232430AbhENPRw (ORCPT ); Fri, 14 May 2021 11:17:52 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R181e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=alimailimapcm10staff010182156082;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0UYrcWNT_1621005398; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0UYrcWNT_1621005398) by smtp.aliyun-inc.com(127.0.0.1); Fri, 14 May 2021 23:16:38 +0800 From: Xuan Zhuo To: netdev@vger.kernel.org Cc: "Michael S. Tsirkin" , Jason Wang , "David S. Miller" , Jakub Kicinski , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Xuan Zhuo , virtualization@lists.linux-foundation.org, bpf@vger.kernel.org Subject: [PATCH net 1/2] virtio-net: fix for unable to handle page fault for address Date: Fri, 14 May 2021 23:16:36 +0800 Message-Id: <20210514151637.117596-2-xuanzhuo@linux.alibaba.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210514151637.117596-1-xuanzhuo@linux.alibaba.com> References: <20210514151637.117596-1-xuanzhuo@linux.alibaba.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org In merge mode, when xdp is enabled, if the headroom of buf is smaller than virtnet_get_headroom(), xdp_linearize_page() will be called but the variable of "headroom" is still 0, which leads to wrong logic after entering page_to_skb(). [ 16.600944] BUG: unable to handle page fault for address: ffffecbfff7b43c8[ 16.602175] #PF: supervisor read access in kernel mode [ 16.603350] #PF: error_code(0x0000) - not-present page [ 16.604200] PGD 0 P4D 0 [ 16.604686] Oops: 0000 [#1] SMP PTI [ 16.605306] CPU: 4 PID: 715 Comm: sh Tainted: G B 5.12.0+ #312 [ 16.606429] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/04 [ 16.608217] RIP: 0010:unmap_page_range+0x947/0xde0 [ 16.609014] Code: 00 00 08 00 48 83 f8 01 45 19 e4 41 f7 d4 41 83 e4 03 e9 a4 fd ff ff e8 b7 63 ed ff 4c 89 e0 48 c1 e0 065 [ 16.611863] RSP: 0018:ffffc90002503c58 EFLAGS: 00010286 [ 16.612720] RAX: ffffecbfff7b43c0 RBX: 00007f19f7203000 RCX: ffffffff812ff359 [ 16.613853] RDX: ffff888107778000 RSI: 0000000000000000 RDI: 0000000000000005 [ 16.614976] RBP: ffffea000425e000 R08: 0000000000000000 R09: 3030303030303030 [ 16.616124] R10: ffffffff82ed7d94 R11: 6637303030302052 R12: 7c00000afffded0f [ 16.617276] R13: 0000000000000001 R14: ffff888119ee7010 R15: 00007f19f7202000 [ 16.618423] FS: 0000000000000000(0000) GS:ffff88842fd00000(0000) knlGS:0000000000000000 [ 16.619738] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 16.620670] CR2: ffffecbfff7b43c8 CR3: 0000000103220005 CR4: 0000000000370ee0 [ 16.621792] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 16.622920] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 16.624047] Call Trace: [ 16.624525] ? release_pages+0x24d/0x730 [ 16.625209] unmap_single_vma+0xa9/0x130 [ 16.625885] unmap_vmas+0x76/0xf0 [ 16.626480] exit_mmap+0xa0/0x210 [ 16.627129] mmput+0x67/0x180 [ 16.627673] do_exit+0x3d1/0xf10 [ 16.628259] ? do_user_addr_fault+0x231/0x840 [ 16.629000] do_group_exit+0x53/0xd0 [ 16.629631] __x64_sys_exit_group+0x1d/0x20 [ 16.630354] do_syscall_64+0x3c/0x80 [ 16.630988] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 16.631828] RIP: 0033:0x7f1a043d0191 [ 16.632464] Code: Unable to access opcode bytes at RIP 0x7f1a043d0167. [ 16.633502] RSP: 002b:00007ffe3d993308 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 16.634737] RAX: ffffffffffffffda RBX: 00007f1a044c9490 RCX: 00007f1a043d0191 [ 16.635857] RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 [ 16.636986] RBP: 0000000000000000 R08: ffffffffffffff88 R09: 0000000000000001 [ 16.638120] R10: 0000000000000008 R11: 0000000000000246 R12: 00007f1a044c9490 [ 16.639245] R13: 0000000000000001 R14: 00007f1a044c9968 R15: 0000000000000000 [ 16.640408] Modules linked in: [ 16.640958] CR2: ffffecbfff7b43c8 [ 16.641557] ---[ end trace bc4891c6ce46354c ]--- [ 16.642335] RIP: 0010:unmap_page_range+0x947/0xde0 [ 16.643135] Code: 00 00 08 00 48 83 f8 01 45 19 e4 41 f7 d4 41 83 e4 03 e9 a4 fd ff ff e8 b7 63 ed ff 4c 89 e0 48 c1 e0 065 [ 16.645983] RSP: 0018:ffffc90002503c58 EFLAGS: 00010286 [ 16.646845] RAX: ffffecbfff7b43c0 RBX: 00007f19f7203000 RCX: ffffffff812ff359 [ 16.647970] RDX: ffff888107778000 RSI: 0000000000000000 RDI: 0000000000000005 [ 16.649091] RBP: ffffea000425e000 R08: 0000000000000000 R09: 3030303030303030 [ 16.650250] R10: ffffffff82ed7d94 R11: 6637303030302052 R12: 7c00000afffded0f [ 16.651394] R13: 0000000000000001 R14: ffff888119ee7010 R15: 00007f19f7202000 [ 16.652529] FS: 0000000000000000(0000) GS:ffff88842fd00000(0000) knlGS:0000000000000000 [ 16.653887] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 16.654841] CR2: ffffecbfff7b43c8 CR3: 0000000103220005 CR4: 0000000000370ee0 [ 16.655992] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 16.657150] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 16.658290] Kernel panic - not syncing: Fatal exception [ 16.659613] Kernel Offset: disabled [ 16.660234] ---[ end Kernel panic - not syncing: Fatal exception ]--- Fixes: fb32856b16ad ("virtio-net: page_to_skb() use build_skb when there's sufficient tailroom") Signed-off-by: Xuan Zhuo Acked-by: Michael S. Tsirkin --- drivers/net/virtio_net.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 9b6a4a875c55..3e46c12dde08 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -380,7 +380,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, struct page *page, unsigned int offset, unsigned int len, unsigned int truesize, bool hdr_valid, unsigned int metasize, - unsigned int headroom) + bool whole_page) { struct sk_buff *skb; struct virtio_net_hdr_mrg_rxbuf *hdr; @@ -398,12 +398,12 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, else hdr_padded_len = sizeof(struct padded_vnet_hdr); - /* If headroom is not 0, there is an offset between the beginning of the + /* If whole_page, there is an offset between the beginning of the * data and the allocated space, otherwise the data and the allocated * space are aligned. */ - if (headroom) { - /* Buffers with headroom use PAGE_SIZE as alloc size, + if (whole_page) { + /* Buffers with whole_page use PAGE_SIZE as alloc size, * see add_recvbuf_mergeable() + get_mergeable_buf_len() */ truesize = PAGE_SIZE; @@ -958,7 +958,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, put_page(page); head_skb = page_to_skb(vi, rq, xdp_page, offset, len, PAGE_SIZE, false, - metasize, headroom); + metasize, true); return head_skb; } break; @@ -1016,7 +1016,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, } head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog, - metasize, headroom); + metasize, !!headroom); curr_skb = head_skb; if (unlikely(!curr_skb))