summaryrefslogtreecommitdiff
path: root/src/process
diff options
context:
space:
mode:
authorRich Felker <dalias@aerifal.cx>2013-02-03 18:21:04 -0500
committerRich Felker <dalias@aerifal.cx>2013-02-03 18:21:04 -0500
commita8799356d560d3b02a19a4bda4a638a4a9a80856 (patch)
tree1aadcc506af8b0a041435d80795fc553a4927040 /src/process
parent4862864fc1a6d162b297db09c216b136db83d7dd (diff)
downloadmusl-a8799356d560d3b02a19a4bda4a638a4a9a80856.tar.gz
base system() on posix_spawn
this avoids duplicating the fragile logic for executing an external program without fork.
Diffstat (limited to 'src/process')
-rw-r--r--src/process/system.c67
1 files changed, 26 insertions, 41 deletions
diff --git a/src/process/system.c b/src/process/system.c
index 0cc8b810..0aa34cd0 100644
--- a/src/process/system.c
+++ b/src/process/system.c
@@ -2,6 +2,7 @@
#include <fcntl.h>
#include <signal.h>
#include <sys/wait.h>
+#include <spawn.h>
#include <errno.h>
#include "pthread_impl.h"
#include "libc.h"
@@ -12,57 +13,41 @@ static void dummy_0()
weak_alias(dummy_0, __acquire_ptc);
weak_alias(dummy_0, __release_ptc);
-pid_t __vfork(void);
-void __testcancel(void);
+extern char **environ;
int system(const char *cmd)
{
pid_t pid;
- sigset_t old;
+ sigset_t old, reset;
struct sigaction sa = { .sa_handler = SIG_IGN }, oldint, oldquit;
- int status = -1, i;
+ int status = 0x7f00, ret;
+ posix_spawnattr_t attr;
- __testcancel();
+ pthread_testcancel();
if (!cmd) return 1;
sigaction(SIGINT, &sa, &oldint);
sigaction(SIGQUIT, &sa, &oldquit);
- sigprocmask(SIG_BLOCK, SIGALL_SET, &old);
-
- __acquire_ptc();
- pid = __vfork();
-
- if (pid) __release_ptc();
-
- if (pid > 0) {
- sigset_t new = old;
- sigaddset(&new, SIGCHLD);
- sigprocmask(SIG_BLOCK, &new, 0);
- while (waitpid(pid, &status, 0) && errno == EINTR);
- }
-
- if (pid) {
- sigaction(SIGINT, &oldint, NULL);
- sigaction(SIGQUIT, &oldquit, NULL);
- sigprocmask(SIG_SETMASK, &old, NULL);
- return status;
- }
-
- /* Before we can unblock signals in the child, all signal
- * handlers must be eliminated -- even implementation-internal
- * ones. Otherwise, a signal handler could run in the child
- * and clobber the parent's memory (due to vfork). */
- for (i=1; i<=8*__SYSCALL_SSLEN; i++) {
- struct sigaction sa;
- __libc_sigaction(i, 0, &sa);
- if (sa.sa_handler!=SIG_IGN && sa.sa_handler!=SIG_DFL) {
- sa.sa_handler = SIG_DFL;
- __libc_sigaction(i, &sa, 0);
- }
- }
-
+ sigaddset(&sa.sa_mask, SIGCHLD);
+ sigprocmask(SIG_BLOCK, &sa.sa_mask, &old);
+
+ sigemptyset(&reset);
+ if (oldint.sa_handler != SIG_IGN) sigaddset(&reset, SIGINT);
+ if (oldquit.sa_handler != SIG_IGN) sigaddset(&reset, SIGQUIT);
+ posix_spawnattr_init(&attr);
+ posix_spawnattr_setsigmask(&attr, &old);
+ posix_spawnattr_setsigdefault(&attr, &reset);
+ posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGDEF|POSIX_SPAWN_SETSIGMASK);
+ ret = posix_spawn(&pid, "/bin/sh", 0, &attr,
+ (char *[]){"sh", "-c", (char *)cmd, 0}, environ);
+ posix_spawnattr_destroy(&attr);
+
+ if (!ret) while (waitpid(pid, &status, 0)<0 && errno == EINTR);
+ sigaction(SIGINT, &oldint, NULL);
+ sigaction(SIGQUIT, &oldquit, NULL);
sigprocmask(SIG_SETMASK, &old, NULL);
- execl("/bin/sh", "sh", "-c", cmd, (char *)0);
- _exit(127);
+
+ if (ret) errno = ret;
+ return status;
}