{"id":808477,"url":"http://patchwork.ozlabs.org/api/1.0/patches/808477/?format=json","project":{"id":7,"url":"http://patchwork.ozlabs.org/api/1.0/projects/7/?format=json","name":"Linux network development","link_name":"netdev","list_id":"netdev.vger.kernel.org","list_email":"netdev@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null},"msgid":"<20170831234822.26612-3-edumazet@google.com>","date":"2017-08-31T23:48:22","name":"[v2,net-next,2/2] net: convert (struct ubuf_info)->refcnt to refcount_t","commit_ref":null,"pull_url":null,"state":"accepted","archived":true,"hash":"f2de8a9d2f49963f55b8c2616130482e9cbe739e","submitter":{"id":13357,"url":"http://patchwork.ozlabs.org/api/1.0/people/13357/?format=json","name":"Eric Dumazet","email":"edumazet@google.com"},"delegate":{"id":34,"url":"http://patchwork.ozlabs.org/api/1.0/users/34/?format=json","username":"davem","first_name":"David","last_name":"Miller","email":"davem@davemloft.net"},"mbox":"http://patchwork.ozlabs.org/project/netdev/patch/20170831234822.26612-3-edumazet@google.com/mbox/","series":[{"id":927,"url":"http://patchwork.ozlabs.org/api/1.0/series/927/?format=json","date":"2017-08-31T23:48:20","name":"net: ubuf_info.refcnt conversion","version":2,"mbox":"http://patchwork.ozlabs.org/series/927/mbox/"}],"check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/808477/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"patchwork-incoming@ozlabs.org","Delivered-To":"patchwork-incoming@ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; helo=vger.kernel.org;\n\tenvelope-from=netdev-owner@vger.kernel.org;\n\treceiver=)","ozlabs.org; dkim=pass (2048-bit key;\n\tunprotected) header.d=google.com header.i=@google.com\n\theader.b=\"nW3TlKa6\"; dkim-atps=neutral"],"Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3xjzbV1t9Nz9s7p\n\tfor ;\n\tFri, 1 Sep 2017 09:48:38 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1752188AbdHaXsg (ORCPT );\n\tThu, 31 Aug 2017 19:48:36 -0400","from mail-pg0-f52.google.com ([74.125.83.52]:34601 \"EHLO\n\tmail-pg0-f52.google.com\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1752175AbdHaXsb (ORCPT\n\t); Thu, 31 Aug 2017 19:48:31 -0400","by mail-pg0-f52.google.com with SMTP id t193so3302214pgc.1\n\tfor ; Thu, 31 Aug 2017 16:48:31 -0700 (PDT)","from localhost ([2620:15c:2cb:201:df6:9252:fc0d:50b2])\n\tby smtp.gmail.com with ESMTPSA id\n\t188sm840179pfe.171.2017.08.31.16.48.30\n\t(version=TLS1_2 cipher=AES128-SHA bits=128/128);\n\tThu, 31 Aug 2017 16:48:30 -0700 (PDT)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=google.com; s=20161025;\n\th=from:to:cc:subject:date:message-id:in-reply-to:references;\n\tbh=31whvFlf4Im9A3poegahHNFKnM0ho21D1OgC4NB4lVw=;\n\tb=nW3TlKa6uUEv9EgRIgaFtPmB1cKW3OfpIU2YF1KLSmGJLbSi1MqJTHOqboZjxoaVNs\n\tAbxJJkPnxQA/vOT5YyvVE+diZE+m03+CibEhU7DSMA8KSCctETMmb+mMwexT4JpRYO5d\n\t3196t0em2Fw3Evq4u3WYJC3xF3/Heqjj2RfVG1U4UzFemXOA78F71aE6yve6Sy0Z5toH\n\ttwvWQyf9GgwOrsjXh+gmNmMOIjdDhNIycMe/nKpBmwJude2Ayzcr60vtqNtd0n1Cx4rF\n\tVKvqO/P63zW5ygcmRrDS6UCYgIZ7QC+GPiOYGfuQeY/N9+SKZpSLcBiSZlbmOOXINwYe\n\tLomg==","X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20161025;\n\th=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to\n\t:references;\n\tbh=31whvFlf4Im9A3poegahHNFKnM0ho21D1OgC4NB4lVw=;\n\tb=PDNo+GR6988isXlXaG6u0krY0Wy0lO5n2HajggKGb9IBL3iDXgTCrZ+Ml9j/57wh/O\n\tLXZ1rKHU6CVNX8I6dqYUHsZCViInlcJNNrtHLWSRhMLbEs3Bl3owg4VRZ/QUjxDiSd2I\n\tv9mLMmDARj2yn+Oc9orUPGugZAJ2ZJwTScg+yIVcvKBTr/Cfs3o4UaN57DArGy6XrtZG\n\tS6/0VUTR7+xrp+xcPeU1sTYwRU2HUOaW+GqE2YMzgTqFayFEFnQ/KlkCQWSXeNMoDUVP\n\tu+/MVr/amsC23Lkdk2vuNltNPBFnWPjwQBoH63trwiExIbx1b0+EbCfVsqD8Q2JhedPX\n\tXg4Q==","X-Gm-Message-State":"AHPjjUik8yFZxTsithcCPLscA4lp3wRwNjpmwMF2uXWaeVF1js5MT/Oq\n\tYsbGuQFSYHa+Pa/VrGGkuw==","X-Google-Smtp-Source":"ADKCNb46w+x53phiTdkKYiw9+270rwLnNGhcUg9Ls/tC5bO5Of9OMSTT9R1ajudZQBUbL65b7Mkk/w==","X-Received":"by 10.84.131.36 with SMTP id 33mr178517pld.322.1504223311249;\n\tThu, 31 Aug 2017 16:48:31 -0700 (PDT)","From":"Eric Dumazet ","To":"\"David S . Miller\" ","Cc":"netdev , Willem de Bruijn ,\n\tEric Dumazet , Eric Dumazet ","Subject":"[PATCH v2 net-next 2/2] net: convert (struct ubuf_info)->refcnt to\n\trefcount_t","Date":"Thu, 31 Aug 2017 16:48:22 -0700","Message-Id":"<20170831234822.26612-3-edumazet@google.com>","X-Mailer":"git-send-email 2.14.1.581.gf28d330327-goog","In-Reply-To":"<20170831234822.26612-1-edumazet@google.com>","References":"<20170831234822.26612-1-edumazet@google.com>","Sender":"netdev-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"netdev@vger.kernel.org"},"content":"refcount_t type and corresponding API should be\nused instead of atomic_t when the variable is used as\na reference counter. This allows to avoid accidental\nrefcounter overflows that might lead to use-after-free\nsituations.\n\nv2: added the change in drivers/vhost/net.c as spotted\nby Willem.\n\nSigned-off-by: Eric Dumazet \n---\n drivers/vhost/net.c | 2 +-\n include/linux/skbuff.h | 5 +++--\n net/core/skbuff.c | 6 +++---\n 3 files changed, 7 insertions(+), 6 deletions(-)","diff":"diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c\nindex ba08b78ed630c429ccf415af69bf27f2433af4f0..8d2bcae53a2ec9ea1c876625e581bcd429abe365 100644\n--- a/drivers/vhost/net.c\n+++ b/drivers/vhost/net.c\n@@ -533,7 +533,7 @@ static void handle_tx(struct vhost_net *net)\n \t\t\tubuf->callback = vhost_zerocopy_callback;\n \t\t\tubuf->ctx = nvq->ubufs;\n \t\t\tubuf->desc = nvq->upend_idx;\n-\t\t\tatomic_set(&ubuf->refcnt, 1);\n+\t\t\trefcount_set(&ubuf->refcnt, 1);\n \t\t\tmsg.msg_control = ubuf;\n \t\t\tmsg.msg_controllen = sizeof(ubuf);\n \t\t\tubufs = nvq->ubufs;\ndiff --git a/include/linux/skbuff.h b/include/linux/skbuff.h\nindex 7594e19bce622a38dc39c054093c3da15b99b67b..316a92b45351f53709886ee0099cbc83b66f1b15 100644\n--- a/include/linux/skbuff.h\n+++ b/include/linux/skbuff.h\n@@ -22,6 +22,7 @@\n #include \n #include \n #include \n+#include \n \n #include \n #include \n@@ -456,7 +457,7 @@ struct ubuf_info {\n \t\t\tu32 bytelen;\n \t\t};\n \t};\n-\tatomic_t refcnt;\n+\trefcount_t refcnt;\n \n \tstruct mmpin {\n \t\tstruct user_struct *user;\n@@ -472,7 +473,7 @@ struct ubuf_info *sock_zerocopy_realloc(struct sock *sk, size_t size,\n \n static inline void sock_zerocopy_get(struct ubuf_info *uarg)\n {\n-\tatomic_inc(&uarg->refcnt);\n+\trefcount_inc(&uarg->refcnt);\n }\n \n void sock_zerocopy_put(struct ubuf_info *uarg);\ndiff --git a/net/core/skbuff.c b/net/core/skbuff.c\nindex 1a754d7896ceac1eb85e3b13c1422b4d6a88fedf..06b9ddca3188442d1d1d2052fc060cf5b1e2a6f4 100644\n--- a/net/core/skbuff.c\n+++ b/net/core/skbuff.c\n@@ -963,7 +963,7 @@ struct ubuf_info *sock_zerocopy_alloc(struct sock *sk, size_t size)\n \tuarg->len = 1;\n \tuarg->bytelen = size;\n \tuarg->zerocopy = 1;\n-\tatomic_set(&uarg->refcnt, 1);\n+\trefcount_set(&uarg->refcnt, 1);\n \tsock_hold(sk);\n \n \treturn uarg;\n@@ -1086,7 +1086,7 @@ EXPORT_SYMBOL_GPL(sock_zerocopy_callback);\n \n void sock_zerocopy_put(struct ubuf_info *uarg)\n {\n-\tif (uarg && atomic_dec_and_test(&uarg->refcnt)) {\n+\tif (uarg && refcount_dec_and_test(&uarg->refcnt)) {\n \t\tif (uarg->callback)\n \t\t\tuarg->callback(uarg, uarg->zerocopy);\n \t\telse\n@@ -1483,7 +1483,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,\n \t\tif (skb_orphan_frags(skb, gfp_mask))\n \t\t\tgoto nofrags;\n \t\tif (skb_zcopy(skb))\n-\t\t\tatomic_inc(&skb_uarg(skb)->refcnt);\n+\t\t\trefcount_inc(&skb_uarg(skb)->refcnt);\n \t\tfor (i = 0; i < skb_shinfo(skb)->nr_frags; i++)\n \t\t\tskb_frag_ref(skb, i);\n \n","prefixes":["v2","net-next","2/2"]}