From patchwork Mon Dec 17 22:46:27 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Michal_Such=C3=A1nek?= X-Patchwork-Id: 10734399 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 134BC161F for ; Mon, 17 Dec 2018 22:46:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0798429B81 for ; Mon, 17 Dec 2018 22:46:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F031029F47; Mon, 17 Dec 2018 22:46:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CDF4E29BF5 for ; Mon, 17 Dec 2018 22:46:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727909AbeLQWqt (ORCPT ); Mon, 17 Dec 2018 17:46:49 -0500 Received: from mx2.suse.de ([195.135.220.15]:60890 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728131AbeLQWqt (ORCPT ); Mon, 17 Dec 2018 17:46:49 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id AE832B03F; Mon, 17 Dec 2018 22:46:47 +0000 (UTC) From: Michal Suchanek To: linux-modules@vger.kernel.org Cc: Lucas De Marchi , Jean Delvare , Michal Suchanek Subject: [PATCH v3 1/3] depmod: prevent module dependency files missing during depmod invocation. Date: Mon, 17 Dec 2018 23:46:27 +0100 Message-Id: <20181217224629.22687-2-msuchanek@suse.de> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181217224629.22687-1-msuchanek@suse.de> References: <20181207154557.5865-1-msuchanek@suse.de> <20181217224629.22687-1-msuchanek@suse.de> MIME-Version: 1.0 Sender: owner-linux-modules@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Depmod deletes the module dependency files before moving the temporary files in their place. This results in user seeing no dependency files while they are updated. Remove the unlink call. The rename call should suffice to move the new file in place and unlink the old one. It should also do both atomically so there is no window when no dependency file exists. Signed-off-by: Michal Suchanek --- tools/depmod.c | 1 - 1 file changed, 1 deletion(-) diff --git a/tools/depmod.c b/tools/depmod.c index 989d9077926c..18c0d61b2db3 100644 --- a/tools/depmod.c +++ b/tools/depmod.c @@ -2451,7 +2451,6 @@ static int depmod_output(struct depmod *depmod, FILE *out) break; } - unlinkat(dfd, itr->name, 0); if (renameat(dfd, tmp, dfd, itr->name) != 0) { err = -errno; CRIT("renameat(%s, %s, %s, %s): %m\n", From patchwork Mon Dec 17 22:46:28 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Michal_Such=C3=A1nek?= X-Patchwork-Id: 10734401 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 35AE113B5 for ; Mon, 17 Dec 2018 22:46:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2A35929B81 for ; Mon, 17 Dec 2018 22:46:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1E63C29BF5; Mon, 17 Dec 2018 22:46:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 035B129F04 for ; Mon, 17 Dec 2018 22:46:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728131AbeLQWqt (ORCPT ); Mon, 17 Dec 2018 17:46:49 -0500 Received: from mx2.suse.de ([195.135.220.15]:60898 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1732023AbeLQWqt (ORCPT ); Mon, 17 Dec 2018 17:46:49 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id F20EEB041; Mon, 17 Dec 2018 22:46:47 +0000 (UTC) From: Michal Suchanek To: linux-modules@vger.kernel.org Cc: Lucas De Marchi , Jean Delvare , Michal Suchanek Subject: [PATCH v3 2/3] depmod: prevent module dependency files corruption due to parallel invocation. Date: Mon, 17 Dec 2018 23:46:28 +0100 Message-Id: <20181217224629.22687-3-msuchanek@suse.de> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181217224629.22687-1-msuchanek@suse.de> References: <20181207154557.5865-1-msuchanek@suse.de> <20181217224629.22687-1-msuchanek@suse.de> MIME-Version: 1.0 Sender: owner-linux-modules@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Depmod does not use unique filename for temporary files. There is no guarantee the user does not attempt to run mutiple depmod processes in parallel. If that happens a temporary file might be created by depmod(1st), truncated by depmod(2nd), and renamed to final name by depmod(1st) resulting in corrupted file seen by user. Due to missing mkstempat() this is more complex than it should be. Adding PID and timestamp to the filename should be reasonably reliable. Adding O_EXCL as mkstemp does fails creating the file rather than corrupting existing file. Signed-off-by: Michal Suchanek --- v3: - remove superfluous code to terminate the string - snprintf should do it - remove superfluous O_TRUNC - not needed with O_EXCL --- tools/depmod.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/tools/depmod.c b/tools/depmod.c index 18c0d61b2db3..0f7e33ccfd59 100644 --- a/tools/depmod.c +++ b/tools/depmod.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include @@ -2398,6 +2399,9 @@ static int depmod_output(struct depmod *depmod, FILE *out) }; const char *dname = depmod->cfg->dirname; int dfd, err = 0; + struct timeval tv; + + gettimeofday(&tv, NULL); if (out != NULL) dfd = -1; @@ -2416,11 +2420,12 @@ static int depmod_output(struct depmod *depmod, FILE *out) int r, ferr; if (fp == NULL) { - int flags = O_CREAT | O_TRUNC | O_WRONLY; + int flags = O_CREAT | O_EXCL | O_WRONLY; int mode = 0644; int fd; - snprintf(tmp, sizeof(tmp), "%s.tmp", itr->name); + snprintf(tmp, sizeof(tmp), "%s.%i.%li.%li", itr->name, getpid(), + tv.tv_usec, tv.tv_sec); fd = openat(dfd, tmp, flags, mode); if (fd < 0) { ERR("openat(%s, %s, %o, %o): %m\n", From patchwork Mon Dec 17 22:46:29 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Michal_Such=C3=A1nek?= X-Patchwork-Id: 10734403 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 49ED71850 for ; Mon, 17 Dec 2018 22:46:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3D4A229B81 for ; Mon, 17 Dec 2018 22:46:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 31E1529FA9; Mon, 17 Dec 2018 22:46:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 67C6329C69 for ; Mon, 17 Dec 2018 22:46:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732023AbeLQWqu (ORCPT ); Mon, 17 Dec 2018 17:46:50 -0500 Received: from mx2.suse.de ([195.135.220.15]:60906 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1732095AbeLQWqt (ORCPT ); Mon, 17 Dec 2018 17:46:49 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 41254B043; Mon, 17 Dec 2018 22:46:48 +0000 (UTC) From: Michal Suchanek To: linux-modules@vger.kernel.org Cc: Lucas De Marchi , Jean Delvare , Michal Suchanek Subject: [PATCH v3 3/3] depmod: shut up gcc insufficinet buffer warning. Date: Mon, 17 Dec 2018 23:46:29 +0100 Message-Id: <20181217224629.22687-4-msuchanek@suse.de> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181217224629.22687-1-msuchanek@suse.de> References: <20181207154557.5865-1-msuchanek@suse.de> <20181217224629.22687-1-msuchanek@suse.de> MIME-Version: 1.0 Sender: owner-linux-modules@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP In a couple of places depmod concatenates the module directory and filename with snprintf. This can technically overflow creating wrong path if module directory name is long. Use openat instead as is done elsewhere in depmod. This avoids the snprintf, the extra buffer on stack, and the gcc warning. Signed-off-by: Michal Suchanek --- v3: - remove superfluous whitespace --- tools/depmod.c | 51 ++++++++++++++++++++++++++++++++++---------------- 1 file changed, 35 insertions(+), 16 deletions(-) diff --git a/tools/depmod.c b/tools/depmod.c index 0f7e33ccfd59..0cf845a0dbc7 100644 --- a/tools/depmod.c +++ b/tools/depmod.c @@ -1389,19 +1389,42 @@ static int depmod_modules_build_array(struct depmod *depmod) return 0; } +static FILE *dfdopen(const char *dname, const char *filename, int flags, const char *mode) +{ + int fd, dfd; + FILE *ret; + + dfd = open(dname, O_RDONLY); + if (dfd < 0) { + WRN("could not open directory %s: %m\n", dname); + return NULL; + } + + fd = openat(dfd, filename, flags); + if (fd < 0) { + WRN("could not open %s at %s: %m\n", filename, dname); + ret = NULL; + } else { + ret = fdopen(fd, mode); + if (!ret) + WRN("could not associate stream with %s: %m\n", filename); + } + close(dfd); + return ret; +} + + + static void depmod_modules_sort(struct depmod *depmod) { - char order_file[PATH_MAX], line[PATH_MAX]; + char line[PATH_MAX]; + const char * order_file = "modules.order"; FILE *fp; unsigned idx = 0, total = 0; - snprintf(order_file, sizeof(order_file), "%s/modules.order", - depmod->cfg->dirname); - fp = fopen(order_file, "r"); - if (fp == NULL) { - WRN("could not open %s: %m\n", order_file); + fp = dfdopen(depmod->cfg->dirname, order_file, O_RDONLY, "r"); + if (fp == NULL) return; - } while (fgets(line, sizeof(line), fp) != NULL) { size_t len = strlen(line); @@ -1409,8 +1432,8 @@ static void depmod_modules_sort(struct depmod *depmod) if (len == 0) continue; if (line[len - 1] != '\n') { - ERR("%s:%u corrupted line misses '\\n'\n", - order_file, idx); + ERR("%s/%s:%u corrupted line misses '\\n'\n", + depmod->cfg->dirname, order_file, idx); goto corrupted; } } @@ -2287,18 +2310,14 @@ static int output_builtin_bin(struct depmod *depmod, FILE *out) { FILE *in; struct index_node *idx; - char infile[PATH_MAX], line[PATH_MAX], modname[PATH_MAX]; + char line[PATH_MAX], modname[PATH_MAX]; if (out == stdout) return 0; - snprintf(infile, sizeof(infile), "%s/modules.builtin", - depmod->cfg->dirname); - in = fopen(infile, "r"); - if (in == NULL) { - WRN("could not open %s: %m\n", infile); + in = dfdopen(depmod->cfg->dirname, "modules.builtin", O_RDONLY, "r"); + if (in == NULL) return 0; - } idx = index_create(); if (idx == NULL) {