1  /* Copyright (C) 1991-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <unistd.h>
      19  #include <errno.h>
      20  #include <stdarg.h>
      21  #include <sys/param.h>
      22  #include <stddef.h>
      23  
      24  /* Execute PATH with all arguments after PATH until
      25     a NULL pointer and environment from `environ'.  */
      26  int
      27  execl (const char *path, const char *arg, ...)
      28  {
      29    ptrdiff_t argc;
      30    va_list ap;
      31    va_start (ap, arg);
      32    for (argc = 1; va_arg (ap, const char *); argc++)
      33      {
      34        if (argc == INT_MAX)
      35  	{
      36  	  va_end (ap);
      37  	  errno = E2BIG;
      38  	  return -1;
      39  	}
      40      }
      41    va_end (ap);
      42  
      43    /* Avoid dynamic memory allocation due two main issues:
      44       1. The function should be async-signal-safe and a running on a signal
      45          handler with a fail outcome might lead to malloc bad state.
      46       2. It might be used in a vfork/clone(VFORK) scenario where using
      47          malloc also might lead to internal bad state.  */
      48    ptrdiff_t i;
      49    char *argv[argc + 1];
      50    va_start (ap, arg);
      51    argv[0] = (char *) arg;
      52    for (i = 1; i <= argc; i++)
      53      argv[i] = va_arg (ap, char *);
      54    va_end (ap);
      55  
      56    return __execve (path, argv, __environ);
      57  }
      58  libc_hidden_def (execl)