From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1992653B7 for ; Mon, 31 Jul 2023 07:17:43 +0000 (UTC) Received: from mail-wm1-x336.google.com (mail-wm1-x336.google.com [IPv6:2a00:1450:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C64251722; Mon, 31 Jul 2023 00:17:40 -0700 (PDT) Received: by mail-wm1-x336.google.com with SMTP id 5b1f17b1804b1-3fbc244d384so38516885e9.0; Mon, 31 Jul 2023 00:17:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1690787859; x=1691392659; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=n8WLnI9NId3N3IQiFQMWfeeUSr/hiuHAn49PsdG5OBk=; b=fWz9AGo64wf2+C7stN9V8xlGYS4jyeYSZJ8G3McUGqYEoWgaOcr/WYoGJihB+IvgQ5 zrRoDN05ZS7sjdNjgtlwTbetshiZpgTJJzbo7fHFXy8P5FCMpFcb/qq1fhRMp1Dcp/8/ bEj8fLGxqRjff8cDAgkwGM6/8C9vS+E0cDa9Jo7NjzXABkw20TB993m6EW77S36Glnd0 UCsvpAt9lMm1yb6xwJPs6QIDyVGtp7uXiEwKVBNw5mL6QaXZlYiUhcAjjqpe+Fx7wnuj pDlLRmjux6hHckW7kFTIEsvv95a4EAIzWQDHsgnOdky9tbq3MZlsxOKxJPjVBTrTaZpj b9nw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690787859; x=1691392659; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=n8WLnI9NId3N3IQiFQMWfeeUSr/hiuHAn49PsdG5OBk=; b=P0voO71UvwG4IyilYNyR+1wxPDS+OWvUch5Unu/SpIqHSAu7focnc6jauiQa8MxGX4 82bTrPWSovrLtqvi4u5499f3FbCDMDxhscwKRmRefCUwlsULYDqFVs1DLNZCIWNk/CZr 0Woh1WaHz7FXA8HM5MpG4ZH0hTzfC2ltEOKONUzIsCTqTtdiUZE6zsjsDQzkevOVePo+ hOQfCzF8Z3RamJiP8+pvHkBEcCmjtx/YXQnjXl5aUPBbFPE8qltiQDXWF3OQWruK9dlN QO2VX72sCpNxlnJVJbfVUgnQHKo0UOZspmNZXunGH639BmF3jIG8CkIuLx5xGkiY9gb9 qpXA== X-Gm-Message-State: ABy/qLZzR7TFtYPRD4XoIHhAril+MGghKqiC9px8TR8hRZPGD5HvxH/W GvvpnaVcrE2/3D7z9IP6Cng= X-Google-Smtp-Source: APBJJlE/tfGc7ouwVvYnFyNaWImrlPw9R+EtfJcUj5qbB9QBTsW4yLCrdtAsqwQmtmAlQ+oXjGTgvw== X-Received: by 2002:a7b:cd8c:0:b0:3fb:fa9f:5292 with SMTP id y12-20020a7bcd8c000000b003fbfa9f5292mr6305379wmj.25.1690787859243; Mon, 31 Jul 2023 00:17:39 -0700 (PDT) Received: from localhost ([165.225.194.214]) by smtp.gmail.com with ESMTPSA id y7-20020a05600c364700b003fe24681b10sm420838wmq.28.2023.07.31.00.17.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 31 Jul 2023 00:17:38 -0700 (PDT) From: Joel Granados X-Google-Original-From: Joel Granados To: mcgrof@kernel.org Cc: Catalin Marinas , Iurii Zaikin , Jozsef Kadlecsik , Sven Schnelle , Marcelo Ricardo Leitner , Steffen Klassert , Kees Cook , "D. Wythe" , mptcp@lists.linux.dev, Jakub Kicinski , Vasily Gorbik , Paolo Abeni , coreteam@netfilter.org, Jan Karcher , Alexander Aring , Will Deacon , Stefan Schmidt , Matthieu Baerts , bridge@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, Joerg Reuter , Julian Anastasov , David Ahern , netfilter-devel@vger.kernel.org, Wen Gu , linux-kernel@vger.kernel.org, Santosh Shilimkar , linux-wpan@vger.kernel.org, lvs-devel@vger.kernel.org, Karsten Graul , Miquel Raynal , Herbert Xu , linux-sctp@vger.kernel.org, Tony Lu , Pablo Neira Ayuso , Ralf Baechle , Florian Westphal , willy@infradead.org, Heiko Carstens , "David S. Miller" , linux-rdma@vger.kernel.org, Roopa Prabhu , Alexander Gordeev , Simon Horman , Mat Martineau , josh@joshtriplett.org, Christian Borntraeger , Eric Dumazet , linux-hams@vger.kernel.org, Wenjia Zhang , linux-fsdevel@vger.kernel.org, linux-s390@vger.kernel.org, Xin Long , Nikolay Aleksandrov , netdev@vger.kernel.org, rds-devel@oss.oracle.com, Joel Granados Subject: [PATCH v2 05/14] sysctl: Add a size arg to __register_sysctl_table Date: Mon, 31 Jul 2023 09:17:19 +0200 Message-Id: <20230731071728.3493794-6-j.granados@samsung.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230731071728.3493794-1-j.granados@samsung.com> References: <20230731071728.3493794-1-j.granados@samsung.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net We make these changes in order to prepare __register_sysctl_table and its callers for when we remove the sentinel element (empty element at the end of ctl_table arrays). We don't actually remove any sentinels in this commit, but we *do* make sure to use ARRAY_SIZE so the table_size is available when the removal occurs. We add a table_size argument to __register_sysctl_table and adjust callers, all of which pass ctl_table pointers and need an explicit call to ARRAY_SIZE. We implement a size calculation in register_net_sysctl in order to forward the size of the array pointer received from the network register calls. The new table_size argument does not yet have any effect in the init_header call which is still dependent on the sentinel's presence. table_size *does* however drive the `kzalloc` allocation in __register_sysctl_table with no adverse effects as the allocated memory is either one element greater than the calculated ctl_table array (for the calls in ipc_sysctl.c, mq_sysctl.c and ucount.c) or the exact size of the calculated ctl_table array (for the call from sysctl_net.c and register_sysctl). This approach will allows us to "just" remove the sentinel without further changes to __register_sysctl_table as table_size will represent the exact size for all the callers at that point. Signed-off-by: Joel Granados --- fs/proc/proc_sysctl.c | 23 ++++++++++++----------- include/linux/sysctl.h | 2 +- ipc/ipc_sysctl.c | 4 +++- ipc/mq_sysctl.c | 4 +++- kernel/ucount.c | 3 ++- net/sysctl_net.c | 8 +++++++- 6 files changed, 28 insertions(+), 16 deletions(-) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index fa1438f1a355..b8dd78e344ff 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -1312,6 +1312,7 @@ static struct ctl_dir *sysctl_mkdir_p(struct ctl_dir *dir, const char *path) * should not be free'd after registration. So it should not be * used on stack. It can either be a global or dynamically allocated * by the caller and free'd later after sysctl unregistration. + * @table_size : The number of elements in table * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. @@ -1354,27 +1355,20 @@ static struct ctl_dir *sysctl_mkdir_p(struct ctl_dir *dir, const char *path) */ struct ctl_table_header *__register_sysctl_table( struct ctl_table_set *set, - const char *path, struct ctl_table *table) + const char *path, struct ctl_table *table, size_t table_size) { struct ctl_table_root *root = set->dir.header.root; struct ctl_table_header *header; - struct ctl_table_header h_tmp; struct ctl_dir *dir; - struct ctl_table *entry; struct ctl_node *node; - int nr_entries = 0; - - h_tmp.ctl_table = table; - list_for_each_table_entry(entry, (&h_tmp)) - nr_entries++; header = kzalloc(sizeof(struct ctl_table_header) + - sizeof(struct ctl_node)*nr_entries, GFP_KERNEL_ACCOUNT); + sizeof(struct ctl_node)*table_size, GFP_KERNEL_ACCOUNT); if (!header) return NULL; node = (struct ctl_node *)(header + 1); - init_header(header, root, set, node, table, nr_entries); + init_header(header, root, set, node, table, table_size); if (sysctl_check_table(path, header)) goto fail; @@ -1423,8 +1417,15 @@ struct ctl_table_header *__register_sysctl_table( */ struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) { + int count = 0; + struct ctl_table *entry; + struct ctl_table_header t_hdr; + + t_hdr.ctl_table = table; + list_for_each_table_entry(entry, (&t_hdr)) + count++; return __register_sysctl_table(&sysctl_table_root.default_set, - path, table); + path, table, count); } EXPORT_SYMBOL(register_sysctl); diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 33252ad58ebe..0495c858989f 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -226,7 +226,7 @@ extern void retire_sysctl_set(struct ctl_table_set *set); struct ctl_table_header *__register_sysctl_table( struct ctl_table_set *set, - const char *path, struct ctl_table *table); + const char *path, struct ctl_table *table, size_t table_size); struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table); void unregister_sysctl_table(struct ctl_table_header * table); diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c index ef313ecfb53a..8c62e443f78b 100644 --- a/ipc/ipc_sysctl.c +++ b/ipc/ipc_sysctl.c @@ -259,7 +259,9 @@ bool setup_ipc_sysctls(struct ipc_namespace *ns) tbl[i].data = NULL; } - ns->ipc_sysctls = __register_sysctl_table(&ns->ipc_set, "kernel", tbl); + ns->ipc_sysctls = __register_sysctl_table(&ns->ipc_set, + "kernel", tbl, + ARRAY_SIZE(ipc_sysctls)); } if (!ns->ipc_sysctls) { kfree(tbl); diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c index fbf6a8b93a26..ebb5ed81c151 100644 --- a/ipc/mq_sysctl.c +++ b/ipc/mq_sysctl.c @@ -109,7 +109,9 @@ bool setup_mq_sysctls(struct ipc_namespace *ns) tbl[i].data = NULL; } - ns->mq_sysctls = __register_sysctl_table(&ns->mq_set, "fs/mqueue", tbl); + ns->mq_sysctls = __register_sysctl_table(&ns->mq_set, + "fs/mqueue", tbl, + ARRAY_SIZE(mq_sysctls)); } if (!ns->mq_sysctls) { kfree(tbl); diff --git a/kernel/ucount.c b/kernel/ucount.c index ee8e57fd6f90..2b80264bb79f 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -104,7 +104,8 @@ bool setup_userns_sysctls(struct user_namespace *ns) for (i = 0; i < UCOUNT_COUNTS; i++) { tbl[i].data = &ns->ucount_max[i]; } - ns->sysctls = __register_sysctl_table(&ns->set, "user", tbl); + ns->sysctls = __register_sysctl_table(&ns->set, "user", tbl, + ARRAY_SIZE(user_table)); } if (!ns->sysctls) { kfree(tbl); diff --git a/net/sysctl_net.c b/net/sysctl_net.c index 4b45ed631eb8..8ee4b74bc009 100644 --- a/net/sysctl_net.c +++ b/net/sysctl_net.c @@ -163,10 +163,16 @@ static void ensure_safe_net_sysctl(struct net *net, const char *path, struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, struct ctl_table *table) { + int count = 0; + struct ctl_table *entry; + if (!net_eq(net, &init_net)) ensure_safe_net_sysctl(net, path, table); - return __register_sysctl_table(&net->sysctls, path, table); + for (entry = table; entry->procname; entry++) + count++; + + return __register_sysctl_table(&net->sysctls, path, table, count); } EXPORT_SYMBOL_GPL(register_net_sysctl); -- 2.30.2