From: "Ludovic Courtès" <ludo@gnu.org>
To: 61095@debbugs.gnu.org
Cc: "Ludovic Courtès" <ludo@gnu.org>,
"Josselin Poiret" <dev@jpoiret.xyz>,
"Omar Polo" <op@omarpolo.com>,
"Andrew Whatson" <whatson@tailcall.au>
Subject: bug#61095: [PATCH 3/3] Use 'posix_spawn_file_actions_addclosefrom_np' where available.
Date: Thu, 30 Mar 2023 00:30:57 +0200 [thread overview]
Message-ID: <20230329223057.28100-3-ludo@gnu.org> (raw)
In-Reply-To: <20230329223057.28100-1-ludo@gnu.org>
* configure.ac: Check for 'posix_spawn_file_actions_addclosefrom_np'.
* libguile/posix.c (HAVE_ADDCLOSEFROM): New macro.
(close_inherited_fds): Wrap in #ifdef HAVE_ADDCLOSEFROM.
(do_spawn) [HAVE_ADDCLOSEFROM]: Use 'posix_spawn_file_actions_addclosefrom_np'.
---
configure.ac | 4 +++-
libguile/posix.c | 14 ++++++++++++++
2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/configure.ac b/configure.ac
index d5ce1c4ac..4a93be979 100644
--- a/configure.ac
+++ b/configure.ac
@@ -515,6 +515,7 @@ AC_CHECK_HEADERS([crt_externs.h])
# sched_getaffinity, sched_setaffinity - GNU extensions (glibc)
# sendfile - non-POSIX, found in glibc
# pipe2 - non-POSIX, found in glibc (GNU/Linux and GNU/Hurd)
+# posix_spawn_file_actions_addclosefrom_np - glibc >= 2.34
#
AC_CHECK_FUNCS([DINFINITY DQNAN cexp chsize clog clog10 ctermid \
fesetround ftime ftruncate fchown fchownat fchmod fchdir readlinkat \
@@ -528,7 +529,8 @@ AC_CHECK_FUNCS([DINFINITY DQNAN cexp chsize clog clog10 ctermid \
index bcopy rindex truncate isblank _NSGetEnviron \
strcoll_l strtod_l strtol_l newlocale uselocale utimensat \
fstatat futimens openat \
- sched_getaffinity sched_setaffinity sendfile pipe2])
+ sched_getaffinity sched_setaffinity sendfile pipe2
+ posix_spawn_file_actions_addclosefrom_np])
# The newlib C library uses _NL_ prefixed locale langinfo constants.
AC_CHECK_DECLS([_NL_NUMERIC_GROUPING], [], [], [[#include <langinfo.h>]])
diff --git a/libguile/posix.c b/libguile/posix.c
index b5830c43b..3adc743c4 100644
--- a/libguile/posix.c
+++ b/libguile/posix.c
@@ -1322,6 +1322,12 @@ SCM_DEFINE (scm_fork, "primitive-fork", 0, 0, 0,
#undef FUNC_NAME
#endif /* HAVE_FORK */
+#ifdef HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSEFROM_NP
+# define HAVE_ADDCLOSEFROM 1
+#endif
+
+#ifndef HAVE_ADDCLOSEFROM
+
static void
close_inherited_fds (posix_spawn_file_actions_t *actions, int max_fd)
{
@@ -1346,6 +1352,8 @@ close_inherited_fds (posix_spawn_file_actions_t *actions, int max_fd)
}
}
+#endif
+
static pid_t
do_spawn (char *exec_file, char **exec_argv, char **exec_env,
int in, int out, int err, int spawnp)
@@ -1389,7 +1397,13 @@ do_spawn (char *exec_file, char **exec_argv, char **exec_env,
posix_spawn_file_actions_adddup2 (&actions, fd_slot[1], 1);
posix_spawn_file_actions_adddup2 (&actions, fd_slot[2], 2);
+#ifdef HAVE_ADDCLOSEFROM
+ /* This function appears in glibc 2.34. It's both free from race
+ conditions and more efficient than the alternative. */
+ posix_spawn_file_actions_addclosefrom_np (&actions, 3);
+#else
close_inherited_fds (&actions, max_fd);
+#endif
int res = -1;
if (spawnp)
--
2.39.2
next prev parent reply other threads:[~2023-03-29 22:30 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-27 11:51 bug#61095: possible misuse of posix_spawn API on non-linux OSes Omar Polo
2023-01-27 12:25 ` Omar Polo
2023-03-28 9:34 ` Ludovic Courtès
2023-03-28 16:10 ` Josselin Poiret via Bug reports for GUILE, GNU's Ubiquitous Extension Language
2023-03-29 22:30 ` Ludovic Courtès
2023-03-29 22:30 ` bug#61095: [PATCH 1/3] 'spawn' closes only open file descriptors on non-GNU/Linux systems Ludovic Courtès
2023-03-29 22:30 ` bug#61095: [PATCH 2/3] Remove racy optimized file descriptor closing loop in 'spawn' Ludovic Courtès
2023-03-29 22:30 ` Ludovic Courtès [this message]
2023-03-30 20:21 ` bug#61095: possible misuse of posix_spawn API on non-linux OSes Josselin Poiret via Bug reports for GUILE, GNU's Ubiquitous Extension Language
2023-03-31 17:45 ` Omar Polo
2023-04-02 13:44 ` Ludovic Courtès
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