95 lines
2.3 KiB
C
95 lines
2.3 KiB
C
/* Program execution for Emacs.
|
||
|
||
Copyright (C) 2023-2024 Free Software Foundation, Inc.
|
||
|
||
This file is part of GNU Emacs.
|
||
|
||
GNU Emacs is free software: you can redistribute it and/or modify
|
||
it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation, either version 3 of the License, or (at
|
||
your option) any later version.
|
||
|
||
GNU Emacs is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */
|
||
|
||
#include <config.h>
|
||
#include <unistd.h>
|
||
#include <stdlib.h>
|
||
#include <stdio.h>
|
||
#include <sys/wait.h>
|
||
|
||
#include "exec.h"
|
||
|
||
/* exec1 is a program which takes another program and its arguments,
|
||
forks, and executes that program, all while tracing it and its
|
||
children to use the program execution mechanism defined in exec.c.
|
||
|
||
This is necessary to bypass security restrictions which prohibit
|
||
Emacs from loading executables from certain directories, by, in
|
||
effect, replacing the executable loader in the Linux kernel. */
|
||
|
||
|
||
|
||
int
|
||
main (int argc, char **argv)
|
||
{
|
||
pid_t pid, pid1;
|
||
extern char **environ;
|
||
int wstatus;
|
||
|
||
pid1 = getpid ();
|
||
pid = fork ();
|
||
|
||
if (!pid)
|
||
{
|
||
/* Set the process group used to the parent. */
|
||
if (setpgid (0, pid1))
|
||
perror ("setpgid");
|
||
|
||
tracing_execve (argv[2], argv + 2, environ);
|
||
|
||
/* An error occurred. Exit with failure. */
|
||
exit (127);
|
||
}
|
||
else
|
||
{
|
||
/* Provide the file name of the loader. */
|
||
exec_init (argv[1]);
|
||
|
||
if (after_fork (pid))
|
||
exit (127);
|
||
|
||
/* Start waiting for the process to exit. */
|
||
|
||
while (true)
|
||
{
|
||
pid1 = exec_waitpid (-1, &wstatus, 0);
|
||
|
||
/* If the child process exits normally, exit with its status
|
||
code. If not, raise the signal that caused it to
|
||
exit. */
|
||
|
||
if (pid == pid1)
|
||
{
|
||
if (WIFEXITED (wstatus))
|
||
exit (WEXITSTATUS (wstatus));
|
||
else /* if WIFSIGNALED (wstatus) */
|
||
{
|
||
raise (WTERMSIG (wstatus));
|
||
|
||
/* Just in case the signal raised doesn't cause an
|
||
exit. */
|
||
exit (127);
|
||
}
|
||
}
|
||
|
||
/* Otherwise, continue looping. */
|
||
}
|
||
}
|
||
}
|