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