*
* Modified for uClibc by Erik Andersen <andersee@debian.org>
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-#include <paths.h>
#include "busybox.h" /* uses applet tables */
/* This does a fork/exec in one call, using vfork(). Returns PID of new child,
* -1 for failure. Runs argv[0], searching path if that has no / in it. */
-pid_t spawn(char **argv)
+pid_t FAST_FUNC spawn(char **argv)
{
/* Compiler should not optimize stores here */
volatile int failed;
pid_t pid;
-// Ain't it a good place to fflush(NULL)?
+ fflush_all();
/* Be nice to nommu machines. */
failed = 0;
* (but don't run atexit() stuff, which would screw up parent.)
*/
failed = errno;
+ /* mount, for example, does not want the message */
+ /*bb_perror_msg("can't execute '%s'", argv[0]);*/
_exit(111);
}
/* parent */
* Interested party can wait on pid and learn exit code.
* If 111 - then it (most probably) failed to exec */
if (failed) {
+ safe_waitpid(pid, NULL, 0); /* prevent zombie */
errno = failed;
return -1;
}
}
/* Die with an error message if we can't spawn a child process. */
-pid_t xspawn(char **argv)
+pid_t FAST_FUNC xspawn(char **argv)
{
pid_t pid = spawn(argv);
if (pid < 0)
return pid;
}
-// Wait for the specified child PID to exit, returning child's error return.
-int wait4pid(int pid)
-{
- int status;
-
- if (pid <= 0) {
- /*errno = ECHILD; -- wrong. */
- /* we expect errno to be already set from failed [v]fork/exec */
- return -1;
- }
- if (waitpid(pid, &status, 0) == -1)
- return -1;
- if (WIFEXITED(status))
- return WEXITSTATUS(status);
- if (WIFSIGNALED(status))
- return WTERMSIG(status) + 1000;
- return 0;
-}
-
-int wait_nohang(int *wstat)
-{
- return waitpid(-1, wstat, WNOHANG);
-}
-
-int wait_pid(int *wstat, int pid)
-{
- int r;
-
- do
- r = waitpid(pid, wstat, 0);
- while ((r == -1) && (errno == EINTR));
- return r;
-}
-
#if ENABLE_FEATURE_PREFER_APPLETS
-void save_nofork_data(struct nofork_save_area *save)
+struct nofork_save_area {
+ jmp_buf die_jmp;
+ const char *applet_name;
+ uint32_t option_mask32;
+ int die_sleep;
+ uint8_t xfunc_error_retval;
+};
+static void save_nofork_data(struct nofork_save_area *save)
{
memcpy(&save->die_jmp, &die_jmp, sizeof(die_jmp));
save->applet_name = applet_name;
save->xfunc_error_retval = xfunc_error_retval;
save->option_mask32 = option_mask32;
save->die_sleep = die_sleep;
- save->saved = 1;
}
-
-void restore_nofork_data(struct nofork_save_area *save)
+static void restore_nofork_data(struct nofork_save_area *save)
{
memcpy(&die_jmp, &save->die_jmp, sizeof(die_jmp));
applet_name = save->applet_name;
die_sleep = save->die_sleep;
}
-int run_nofork_applet_prime(struct nofork_save_area *old, int applet_no, char **argv)
+int FAST_FUNC run_nofork_applet(int applet_no, char **argv)
{
int rc, argc;
+ struct nofork_save_area old;
+
+ save_nofork_data(&old);
applet_name = APPLET_NAME(applet_no);
+
xfunc_error_retval = EXIT_FAILURE;
- /*option_mask32 = 0; - not needed */
- /* special flag for xfunc_die(). If xfunc will "die"
- * in NOFORK applet, xfunc_die() sees negative
- * die_sleep and longjmp here instead. */
- die_sleep = -1;
+
+ /* In case getopt() or getopt32() was already called:
+ * reset the libc getopt() function, which keeps internal state.
+ *
+ * BSD-derived getopt() functions require that optind be set to 1 in
+ * order to reset getopt() state. This used to be generally accepted
+ * way of resetting getopt(). However, glibc's getopt()
+ * has additional getopt() state beyond optind, and requires that
+ * optind be set to zero to reset its state. So the unfortunate state of
+ * affairs is that BSD-derived versions of getopt() misbehave if
+ * optind is set to 0 in order to reset getopt(), and glibc's getopt()
+ * will core dump if optind is set 1 in order to reset getopt().
+ *
+ * More modern versions of BSD require that optreset be set to 1 in
+ * order to reset getopt(). Sigh. Standards, anyone?
+ */
+#ifdef __GLIBC__
+ optind = 0;
+#else /* BSD style */
+ optind = 1;
+ /* optreset = 1; */
+#endif
+ /* optarg = NULL; opterr = 1; optopt = 63; - do we need this too? */
+ /* (values above are what they initialized to in glibc and uclibc) */
+ /* option_mask32 = 0; - not needed, no applet depends on it being 0 */
argc = 1;
while (argv[argc])
argc++;
+ /* Special flag for xfunc_die(). If xfunc will "die"
+ * in NOFORK applet, xfunc_die() sees negative
+ * die_sleep and longjmp here instead. */
+ die_sleep = -1;
+
rc = setjmp(die_jmp);
if (!rc) {
/* Some callers (xargs)
char *tmp_argv[argc+1];
memcpy(tmp_argv, argv, (argc+1) * sizeof(tmp_argv[0]));
/* Finally we can call NOFORK applet's main() */
- rc = applet_mains[applet_no](argc, tmp_argv);
+ rc = applet_main[applet_no](argc, tmp_argv);
} else { /* xfunc died in NOFORK applet */
/* in case they meant to return 0... */
if (rc == -2222)
rc = 0;
}
- /* Restoring globals */
- restore_nofork_data(old);
- return rc;
-}
+ /* Restoring some globals */
+ restore_nofork_data(&old);
-int run_nofork_applet(int applet_no, char **argv)
-{
- struct nofork_save_area old;
+ /* Other globals can be simply reset to defaults */
+#ifdef __GLIBC__
+ optind = 0;
+#else /* BSD style */
+ optind = 1;
+#endif
- /* Saving globals */
- save_nofork_data(&old);
- return run_nofork_applet_prime(&old, applet_no, argv);
+ return rc & 0xff; /* don't confuse people with "exitcodes" >255 */
}
#endif /* FEATURE_PREFER_APPLETS */
-int spawn_and_wait(char **argv)
+int FAST_FUNC spawn_and_wait(char **argv)
{
int rc;
#if ENABLE_FEATURE_PREFER_APPLETS
int a = find_applet_by_name(argv[0]);
if (a >= 0 && (APPLET_IS_NOFORK(a)
-#if BB_MMU
+# if BB_MMU
|| APPLET_IS_NOEXEC(a) /* NOEXEC trick needs fork() */
-#endif
+# endif
)) {
-#if BB_MMU
+# if BB_MMU
if (APPLET_IS_NOFORK(a))
-#endif
+# endif
{
return run_nofork_applet(a, argv);
}
-#if BB_MMU
+# if BB_MMU
/* MMU only */
/* a->noexec is true */
rc = fork();
/* child */
xfunc_error_retval = EXIT_FAILURE;
run_applet_no_and_exit(a, argv);
-#endif
+# endif
}
#endif /* FEATURE_PREFER_APPLETS */
rc = spawn(argv);
}
#if !BB_MMU
-void re_exec(char **argv)
+void FAST_FUNC re_exec(char **argv)
{
/* high-order bit of first char in argv[0] is a hidden
* "we have (already) re-execed, don't do it again" flag */
argv[0][0] |= 0x80;
execv(bb_busybox_exec_path, argv);
- bb_perror_msg_and_die("exec %s", bb_busybox_exec_path);
+ bb_perror_msg_and_die("can't execute '%s'", bb_busybox_exec_path);
}
-void forkexit_or_rexec(char **argv)
+pid_t FAST_FUNC fork_or_rexec(char **argv)
{
pid_t pid;
/* Maybe we are already re-execed and come here again? */
if (re_execed)
- return;
-
- pid = vfork();
- if (pid < 0) /* wtf? */
- bb_perror_msg_and_die("vfork");
+ return 0;
+ pid = xvfork();
if (pid) /* parent */
- exit(0);
+ return pid;
/* child - re-exec ourself */
re_exec(argv);
}
-#else
-/* Dance around (void)...*/
-#undef forkexit_or_rexec
-void forkexit_or_rexec(void)
-{
- pid_t pid;
- pid = fork();
- if (pid < 0) /* wtf? */
- bb_perror_msg_and_die("fork");
- if (pid) /* parent */
- exit(0);
- /* child */
-}
-#define forkexit_or_rexec(argv) forkexit_or_rexec()
#endif
/* Due to a #define in libbb.h on MMU systems we actually have 1 argument -
* char **argv "vanishes" */
-void bb_daemonize_or_rexec(int flags, char **argv)
+void FAST_FUNC bb_daemonize_or_rexec(int flags, char **argv)
{
int fd;
close(2);
}
- fd = xopen(bb_dev_null, O_RDWR);
+ fd = open(bb_dev_null, O_RDWR);
+ if (fd < 0) {
+ /* NB: we can be called as bb_sanitize_stdio() from init
+ * or mdev, and there /dev/null may legitimately not (yet) exist!
+ * Do not use xopen above, but obtain _ANY_ open descriptor,
+ * even bogus one as below. */
+ fd = xopen("/", O_RDONLY); /* don't believe this can fail */
+ }
while ((unsigned)fd < 2)
fd = dup(fd); /* have 0,1,2 open at least to /dev/null */
if (!(flags & DAEMON_ONLY_SANITIZE)) {
- forkexit_or_rexec(argv);
- /* if daemonizing, make sure we detach from stdio & ctty */
+ if (fork_or_rexec(argv))
+ exit(EXIT_SUCCESS); /* parent */
+ /* if daemonizing, detach from stdio & ctty */
setsid();
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
+ if (flags & DAEMON_DOUBLE_FORK) {
+ /* On Linux, session leader can acquire ctty
+ * unknowingly, by opening a tty.
+ * Prevent this: stop being a session leader.
+ */
+ if (fork_or_rexec(argv))
+ exit(EXIT_SUCCESS); /* parent */
+ }
}
while (fd > 2) {
close(fd--);
}
}
-void bb_sanitize_stdio(void)
+void FAST_FUNC bb_sanitize_stdio(void)
{
bb_daemonize_or_rexec(DAEMON_ONLY_SANITIZE, NULL);
}
projects / platform / upstream / busybox.git / blobdiff