From patchwork Thu Jan 25 22:29:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 1891046 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4TLbBh2xQ2z23gB for ; Fri, 26 Jan 2024 09:30:50 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rT8EK-0007WD-HL; Thu, 25 Jan 2024 17:29:52 -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 1rT8EI-0007Vq-JO; Thu, 25 Jan 2024 17:29:50 -0500 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rT8EG-0001x0-NT; Thu, 25 Jan 2024 17:29:50 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 4D8EE47563; Fri, 26 Jan 2024 01:30:29 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id B5E586BA53; Fri, 26 Jan 2024 01:29:42 +0300 (MSK) Received: (nullmailer pid 147069 invoked by uid 1000); Thu, 25 Jan 2024 22:29:42 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-trivial@nongnu.org, Michael Tokarev Subject: [PATCH trivial 1/2] close_all_open_fd(): move to oslib-posix.c Date: Fri, 26 Jan 2024 01:29:35 +0300 Message-Id: <94fcee0d7595865b3a6fab744982ad47715e5faf.1706221377.git.mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Initially in async-teardown.c, but the same construct is used elsewhere too. Signed-off-by: Michael Tokarev --- include/sysemu/os-posix.h | 1 + system/async-teardown.c | 37 +------------------------------------ util/oslib-posix.c | 36 ++++++++++++++++++++++++++++++++++++ 3 files changed, 38 insertions(+), 36 deletions(-) diff --git a/include/sysemu/os-posix.h b/include/sysemu/os-posix.h index dff32ae185..4c91d03f44 100644 --- a/include/sysemu/os-posix.h +++ b/include/sysemu/os-posix.h @@ -53,6 +53,7 @@ bool os_set_runas(const char *user_id); void os_set_chroot(const char *path); void os_setup_post(void); int os_mlock(void); +void os_close_all_open_fd(int minfd); /** * qemu_alloc_stack: diff --git a/system/async-teardown.c b/system/async-teardown.c index 396963c091..41d3d94935 100644 --- a/system/async-teardown.c +++ b/system/async-teardown.c @@ -26,40 +26,6 @@ static pid_t the_ppid; -/* - * Close all open file descriptors. - */ -static void close_all_open_fd(void) -{ - struct dirent *de; - int fd, dfd; - DIR *dir; - -#ifdef CONFIG_CLOSE_RANGE - int r = close_range(0, ~0U, 0); - if (!r) { - /* Success, no need to try other ways. */ - return; - } -#endif - - dir = opendir("/proc/self/fd"); - if (!dir) { - /* If /proc is not mounted, there is nothing that can be done. */ - return; - } - /* Avoid closing the directory. */ - dfd = dirfd(dir); - - for (de = readdir(dir); de; de = readdir(dir)) { - fd = atoi(de->d_name); - if (fd != dfd) { - close(fd); - } - } - closedir(dir); -} - static void hup_handler(int signal) { /* Check every second if this process has been reparented. */ @@ -85,9 +51,8 @@ static int async_teardown_fn(void *arg) /* * Close all file descriptors that might have been inherited from the * main qemu process when doing clone, needed to make libvirt happy. - * Not using close_range for increased compatibility with older kernels. */ - close_all_open_fd(); + os_close_all_open_fd(0); /* Set up a handler for SIGHUP and unblock SIGHUP. */ sigaction(SIGHUP, &sa, NULL); diff --git a/util/oslib-posix.c b/util/oslib-posix.c index 7c297003b9..09d0ce4da6 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -27,6 +27,7 @@ */ #include "qemu/osdep.h" +#include #include #include @@ -106,6 +107,41 @@ int qemu_get_thread_id(void) #endif } +/* + * Close all open file descriptors starting with minfd and up. + * Not using close_range for increased compatibility with older kernels. + */ +void os_close_all_open_fd(int minfd) +{ + struct dirent *de; + int fd, dfd; + DIR *dir; + +#ifdef CONFIG_CLOSE_RANGE + int r = close_range(minfd, ~0U, 0); + if (!r) { + /* Success, no need to try other ways. */ + return; + } +#endif + + dir = opendir("/proc/self/fd"); + if (!dir) { + /* If /proc is not mounted, there is nothing that can be done. */ + return; + } + /* Avoid closing the directory. */ + dfd = dirfd(dir); + + for (de = readdir(dir); de; de = readdir(dir)) { + fd = atoi(de->d_name); + if (fd >= minfd && fd != dfd) { + close(fd); + } + } + closedir(dir); +} + int qemu_daemon(int nochdir, int noclose) { return daemon(nochdir, noclose); From patchwork Thu Jan 25 22:29:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 1891048 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4TLbC42xJbz23gC for ; Fri, 26 Jan 2024 09:31:12 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rT8Ei-0007g7-2p; Thu, 25 Jan 2024 17:30:16 -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 1rT8EM-0007Ws-TF; Thu, 25 Jan 2024 17:29:55 -0500 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rT8EL-0001xP-BB; Thu, 25 Jan 2024 17:29:54 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 50A5B47564; Fri, 26 Jan 2024 01:30:29 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id CDD826BA54; Fri, 26 Jan 2024 01:29:42 +0300 (MSK) Received: (nullmailer pid 147072 invoked by uid 1000); Thu, 25 Jan 2024 22:29:42 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-trivial@nongnu.org, Michael Tokarev Subject: [PATCH trivial 2/2] net/tap: use os_close_all_open_fd() instead of open-coding it Date: Fri, 26 Jan 2024 01:29:36 +0300 Message-Id: <14aa02474bc5127910810969b87b659d766e2969.1706221377.git.mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Current code loops over every file descriptor up to SC_OPEN_MAX/RLIMIT_NOFILE which might be huge and the loop might be slow. But we already have os_close_all_open_fd() which is fast. Use it. Signed-off-by: Michael Tokarev --- net/tap.c | 15 ++------------- 1 file changed, 2 insertions(+), 13 deletions(-) diff --git a/net/tap.c b/net/tap.c index c698b70475..11c85c50dc 100644 --- a/net/tap.c +++ b/net/tap.c @@ -459,13 +459,7 @@ static void launch_script(const char *setup_script, const char *ifname, return; } if (pid == 0) { - int open_max = sysconf(_SC_OPEN_MAX), i; - - for (i = 3; i < open_max; i++) { - if (i != fd) { - close(i); - } - } + os_close_all_open_fd(3); parg = args; *parg++ = (char *)setup_script; *parg++ = (char *)ifname; @@ -549,16 +543,11 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, return -1; } if (pid == 0) { - int open_max = sysconf(_SC_OPEN_MAX), i; char *fd_buf = NULL; char *br_buf = NULL; char *helper_cmd = NULL; - for (i = 3; i < open_max; i++) { - if (i != sv[1]) { - close(i); - } - } + os_close_all_open_fd(3); fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]);