From ffa28f9cf503e22bfe621b062d29cbdb9a0aa786 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Fri, 2 Aug 2024 16:54:18 +0200 Subject: [PATCH] qemu/osdep: Split qemu_close_all_open_fd() and add fallback MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In order to make it cleaner, split qemu_close_all_open_fd() logic into multiple subfunctions (close with close_range(), with /proc/self/fd and fallback). Signed-off-by: Clément Léger Reviewed-by: Richard Henderson Message-ID: <20240802145423.3232974-3-cleger@rivosinc.com> Signed-off-by: Richard Henderson --- util/oslib-posix.c | 50 ++++++++++++++++++++++++++++++++++------------ 1 file changed, 37 insertions(+), 13 deletions(-) diff --git a/util/oslib-posix.c b/util/oslib-posix.c index 1e867efa47..9b79fc7cff 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -808,27 +808,16 @@ int qemu_msync(void *addr, size_t length, int fd) return msync(addr, length, MS_SYNC); } -/* - * Close all open file descriptors. - */ -void qemu_close_all_open_fd(void) +static bool qemu_close_all_open_fd_proc(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; + return false; } /* Avoid closing the directory. */ dfd = dirfd(dir); @@ -840,4 +829,39 @@ void qemu_close_all_open_fd(void) } } closedir(dir); + + return true; +} + +static bool qemu_close_all_open_fd_close_range(void) +{ +#ifdef CONFIG_CLOSE_RANGE + int r = close_range(0, ~0U, 0); + if (!r) { + /* Success, no need to try other ways. */ + return true; + } +#endif + return false; +} + +static void qemu_close_all_open_fd_fallback(void) +{ + int open_max = sysconf(_SC_OPEN_MAX), i; + + /* Fallback */ + for (i = 0; i < open_max; i++) { + close(i); + } +} + +/* + * Close all open file descriptors. + */ +void qemu_close_all_open_fd(void) +{ + if (!qemu_close_all_open_fd_close_range() && + !qemu_close_all_open_fd_proc()) { + qemu_close_all_open_fd_fallback(); + } }