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