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| author | Ludovic Courtès <ludo@gnu.org> | 2023-03-28 23:43:31 +0200 |
|---|---|---|
| committer | Ludovic Courtès <ludo@gnu.org> | 2023-04-02 15:36:33 +0200 |
| commit | 7d7067fe15a6dc82068cbafb11846a2de2896a83 (patch) | |
| tree | 6fce9eda2696b40c3841508cda48342cc06890a9 | |
| parent | 21ad54b694c676ba608166be137b677bbb747eac (diff) | |
| download | guile-7d7067fe15a6dc82068cbafb11846a2de2896a83.tar.gz | |
Remove racy optimized file descriptor closing loop in 'spawn'.
This reverts 9332b632407894c2e1951cce1bc678f19e1fa8e4, thereby
reinstating the performance issue in <https://bugs.gnu.org/59321>.
This optimization was subject to race conditions in multi-threaded code:
new file descriptors could pop up at any time and thus leak in the
child.
* libguile/posix.c (close_inherited_fds): Remove.
(close_inherited_fds_slow): Rename to...
(close_inherited_fds): ... this.
| -rw-r--r-- | libguile/posix.c | 30 |
1 files changed, 1 insertions, 29 deletions
diff --git a/libguile/posix.c b/libguile/posix.c index 68e9bfade..b5830c43b 100644 --- a/libguile/posix.c +++ b/libguile/posix.c @@ -1323,7 +1323,7 @@ SCM_DEFINE (scm_fork, "primitive-fork", 0, 0, 0, #endif /* HAVE_FORK */ static void -close_inherited_fds_slow (posix_spawn_file_actions_t *actions, int max_fd) +close_inherited_fds (posix_spawn_file_actions_t *actions, int max_fd) { while (--max_fd > 2) { @@ -1346,34 +1346,6 @@ close_inherited_fds_slow (posix_spawn_file_actions_t *actions, int max_fd) } } -static void -close_inherited_fds (posix_spawn_file_actions_t *actions, int max_fd) -{ - DIR *dirp; - struct dirent *d; - int fd; - - /* Try to use the platform-specific list of open file descriptors, so - we don't need to use the brute force approach. */ - dirp = opendir ("/proc/self/fd"); - - if (dirp == NULL) - return close_inherited_fds_slow (actions, max_fd); - - while ((d = readdir (dirp)) != NULL) - { - fd = atoi (d->d_name); - - /* Skip "." and "..", garbage entries, stdin/stdout/stderr. */ - if (fd <= 2) - continue; - - posix_spawn_file_actions_addclose (actions, fd); - } - - closedir (dirp); -} - static pid_t do_spawn (char *exec_file, char **exec_argv, char **exec_env, int in, int out, int err, int spawnp) |