nsz Git - musl/blob - src/process/posix_spawn.c

   1 #include <spawn.h>
   2 #include <unistd.h>
   3 #include <signal.h>
   4 #include <stdint.h>
   5 #include <fcntl.h>
   6 #include "syscall.h"
   7 #include "fdop.h"
   8
   9 extern char **environ;
  10
  11 pid_t __vfork(void);
  12
  13 int __posix_spawnx(pid_t *restrict res, const char *restrict path,
  14         int (*exec)(const char *, char *const *),
  15         const posix_spawn_file_actions_t *fa,
  16         const posix_spawnattr_t *restrict attr,
  17         char *const argv[restrict], char *const envp[restrict])
  18 {
  19         pid_t pid;
  20         sigset_t oldmask;
  21         int i;
  22         posix_spawnattr_t dummy_attr = { 0 };
  23
  24         if (!attr) attr = &dummy_attr;
  25
  26         sigprocmask(SIG_BLOCK, (void *)(uint64_t []){-1}, &oldmask);
  27         pid = __vfork();
  28
  29         if (pid) {
  30                 sigprocmask(SIG_SETMASK, &oldmask, 0);
  31                 if (pid < 0) return -pid;
  32                 *res = pid;
  33                 return 0;
  34         }
  35
  36         for (i=1; i<=64; i++) {
  37                 struct sigaction sa;
  38                 sigaction(i, 0, &sa);
  39                 if (sa.sa_handler!=SIG_IGN ||
  40                     ((attr->__flags & POSIX_SPAWN_SETSIGDEF)
  41                      && sigismember(&attr->__def, i) )) {
  42                         sa.sa_handler = SIG_DFL;
  43                         sigaction(i, &sa, 0);
  44                 }
  45         }
  46
  47         if ((attr->__flags&POSIX_SPAWN_SETPGROUP) && setpgid(0, attr->__pgrp))
  48                 _exit(127);
  49
  50         /* Use syscalls directly because pthread state is not consistent
  51          * for making calls to the library wrappers... */
  52         if ((attr->__flags&POSIX_SPAWN_RESETIDS) && (
  53                 __syscall(SYS_setgid, __syscall(SYS_getgid)) ||
  54                 __syscall(SYS_setuid, __syscall(SYS_getuid)) ))
  55                 _exit(127);
  56
  57         if (fa && fa->__actions) {
  58                 struct fdop *op;
  59                 int ret, fd;
  60                 for (op = fa->__actions; op->next; op = op->next);
  61                 for (; op; op = op->prev) {
  62                         switch(op->cmd) {
  63                         case FDOP_CLOSE:
  64                                 ret = __syscall(SYS_close, op->fd);
  65                                 break;
  66                         case FDOP_DUP2:
  67                                 ret = __syscall(SYS_dup2, op->fd, op->newfd)<0;
  68                                 break;
  69                         case FDOP_OPEN:
  70                                 fd = __syscall(SYS_open, op->path,
  71                                         op->oflag | O_LARGEFILE, op->mode);
  72                                 if (fd == op->fd) {
  73                                         ret = 0;
  74                                 } else {
  75                                         ret = __syscall(SYS_dup2, fd, op->fd)<0;
  76                                         __syscall(SYS_close, fd);
  77                                 }
  78                                 break;
  79                         }
  80                         if (ret) _exit(127);
  81                 }
  82         }
  83
  84         sigprocmask(SIG_SETMASK, (attr->__flags & POSIX_SPAWN_SETSIGMASK)
  85                 ? &attr->__mask : &oldmask, 0);
  86
  87         if (envp) environ = (char **)envp;
  88         exec(path, argv);
  89         _exit(127);
  90
  91         return 0;
  92 }
  93
  94 int posix_spawn(pid_t *restrict res, const char *restrict path,
  95         const posix_spawn_file_actions_t *fa,
  96         const posix_spawnattr_t *restrict attr,
  97         char *const argv[restrict], char *const envp[restrict])
  98 {
  99         return __posix_spawnx(res, path, execv, fa, attr, argv, envp);
 100 }