diff mbox series

[1/2] posix: Remove spawni.c

Message ID 20210617175751.1619846-1-adhemerval.zanella@linaro.org
State New
Headers show
Series [1/2] posix: Remove spawni.c | expand

Commit Message

Adhemerval Zanella June 17, 2021, 5:57 p.m. UTC
Although it provide an alternate implementation that communicates
using pipe() instead of shared memory, no port uses and it adds extra
burden for posix_spawn() extensions.
---
 sysdeps/posix/spawni.c | 339 -----------------------------------------
 1 file changed, 339 deletions(-)
 delete mode 100644 sysdeps/posix/spawni.c
diff mbox series

Patch

diff --git a/sysdeps/posix/spawni.c b/sysdeps/posix/spawni.c
deleted file mode 100644
index a649788668..0000000000
--- a/sysdeps/posix/spawni.c
+++ /dev/null
@@ -1,339 +0,0 @@ 
-/* Guts of POSIX spawn interface.  Generic POSIX.1 version.
-   Copyright (C) 2000-2021 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library 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
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <spawn.h>
-#include <assert.h>
-#include <fcntl.h>
-#include <paths.h>
-#include <string.h>
-#include <sys/resource.h>
-#include <sys/wait.h>
-#include <sys/param.h>
-#include <sys/mman.h>
-#include <not-cancel.h>
-#include <local-setxid.h>
-#include <shlib-compat.h>
-#include <nptl/pthreadP.h>
-#include <dl-sysdep.h>
-#include <libc-pointer-arith.h>
-#include <ldsodefs.h>
-#include "spawn_int.h"
-
-
-/* The Unix standard contains a long explanation of the way to signal
-   an error after the fork() was successful.  Since no new wait status
-   was wanted there is no way to signal an error using one of the
-   available methods.  The committee chose to signal an error by a
-   normal program exit with the exit code 127.  */
-#define SPAWN_ERROR	127
-
-struct posix_spawn_args
-{
-  sigset_t oldmask;
-  const char *file;
-  int (*exec) (const char *, char *const *, char *const *);
-  const posix_spawn_file_actions_t *fa;
-  const posix_spawnattr_t *restrict attr;
-  char *const *argv;
-  ptrdiff_t argc;
-  char *const *envp;
-  int xflags;
-  int pipe[2];
-};
-
-/* Older version requires that shell script without shebang definition
-   to be called explicitly using /bin/sh (_PATH_BSHELL).  */
-static void
-maybe_script_execute (struct posix_spawn_args *args)
-{
-  if (SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_15)
-      && (args->xflags & SPAWN_XFLAGS_TRY_SHELL) && errno == ENOEXEC)
-    {
-      char *const *argv = args->argv;
-      ptrdiff_t argc = args->argc;
-
-      /* Construct an argument list for the shell.  */
-      char *new_argv[argc + 2];
-      new_argv[0] = (char *) _PATH_BSHELL;
-      new_argv[1] = (char *) args->file;
-      if (argc > 1)
-	memcpy (new_argv + 2, argv + 1, argc * sizeof (char *));
-      else
-	new_argv[2] = NULL;
-
-      /* Execute the shell.  */
-      args->exec (new_argv[0], new_argv, args->envp);
-    }
-}
-
-/* Function used in the clone call to setup the signals mask, posix_spawn
-   attributes, and file actions.  */
-static int
-__spawni_child (void *arguments)
-{
-  struct posix_spawn_args *args = arguments;
-  const posix_spawnattr_t *restrict attr = args->attr;
-  const posix_spawn_file_actions_t *file_actions = args->fa;
-  int ret;
-
-  __close (args->pipe[0]);
-
-  /* Set signal default action.  */
-  if ((attr->__flags & POSIX_SPAWN_SETSIGDEF) != 0)
-    {
-      /* We have to iterate over all signals.  This could possibly be
-	 done better but it requires system specific solutions since
-	 the sigset_t data type can be very different on different
-	 architectures.  */
-      int sig;
-      struct sigaction sa;
-
-      memset (&sa, '\0', sizeof (sa));
-      sa.sa_handler = SIG_DFL;
-
-      for (sig = 1; sig <= _NSIG; ++sig)
-	if (__sigismember (&attr->__sd, sig) != 0
-	    && __sigaction (sig, &sa, NULL) != 0)
-	  goto fail;
-    }
-
-#ifdef _POSIX_PRIORITY_SCHEDULING
-  /* Set the scheduling algorithm and parameters.  */
-  if ((attr->__flags & (POSIX_SPAWN_SETSCHEDPARAM | POSIX_SPAWN_SETSCHEDULER))
-      == POSIX_SPAWN_SETSCHEDPARAM)
-    {
-      if (__sched_setparam (0, &attr->__sp) == -1)
-	goto fail;
-    }
-  else if ((attr->__flags & POSIX_SPAWN_SETSCHEDULER) != 0)
-    {
-      if (__sched_setscheduler (0, attr->__policy, &attr->__sp) == -1)
-	goto fail;
-    }
-#endif
-
-  /* Set the process session ID.  */
-  if ((attr->__flags & POSIX_SPAWN_SETSID) != 0
-      && __setsid () < 0)
-    goto fail;
-
-  /* Set the process group ID.  */
-  if ((attr->__flags & POSIX_SPAWN_SETPGROUP) != 0
-      && __setpgid (0, attr->__pgrp) != 0)
-    goto fail;
-
-  /* Set the effective user and group IDs.  */
-  if ((attr->__flags & POSIX_SPAWN_RESETIDS) != 0
-      && (local_seteuid (__getuid ()) != 0
-	  || local_setegid (__getgid ())) != 0)
-    goto fail;
-
-  /* Execute the file actions.  */
-  if (file_actions != NULL)
-    {
-      int cnt;
-      struct rlimit64 fdlimit;
-      bool have_fdlimit = false;
-
-      for (cnt = 0; cnt < file_actions->__used; ++cnt)
-	{
-	  struct __spawn_action *action = &file_actions->__actions[cnt];
-
-	  switch (action->tag)
-	    {
-	    case spawn_do_close:
-	      if (__close_nocancel (action->action.close_action.fd) != 0)
-		{
-		  if (have_fdlimit == 0)
-		    {
-		      __getrlimit64 (RLIMIT_NOFILE, &fdlimit);
-		      have_fdlimit = true;
-		    }
-
-		  /* Only signal errors for file descriptors out of range.  */
-		  if (action->action.close_action.fd < 0
-		      || action->action.close_action.fd >= fdlimit.rlim_cur)
-		    goto fail;
-		}
-	      break;
-
-	    case spawn_do_open:
-	      {
-		/* POSIX states that if fildes was already an open file descriptor,
-		   it shall be closed before the new file is opened.  This avoid
-		   pontential issues when posix_spawn plus addopen action is called
-		   with the process already at maximum number of file descriptor
-		   opened and also for multiple actions on single-open special
-		   paths (like /dev/watchdog).  */
-		__close_nocancel (action->action.open_action.fd);
-
-		int new_fd = __open_nocancel (action->action.open_action.path,
-					      action->action.open_action.oflag
-					      | O_LARGEFILE,
-					      action->action.open_action.mode);
-
-		if (new_fd == -1)
-		  goto fail;
-
-		/* Make sure the desired file descriptor is used.  */
-		if (new_fd != action->action.open_action.fd)
-		  {
-		    if (__dup2 (new_fd, action->action.open_action.fd)
-			!= action->action.open_action.fd)
-		      goto fail;
-
-		    if (__close_nocancel (new_fd) != 0)
-		      goto fail;
-		  }
-	      }
-	      break;
-
-	    case spawn_do_dup2:
-	      /* Austin Group issue #411 requires adddup2 action with source
-		 and destination being equal to remove close-on-exec flag.  */
-	      if (action->action.dup2_action.fd
-		  == action->action.dup2_action.newfd)
-		{
-		  int fd = action->action.dup2_action.newfd;
-		  int flags = __fcntl (fd, F_GETFD, 0);
-		  if (flags == -1)
-		    goto fail;
-		  if (__fcntl (fd, F_SETFD, flags & ~FD_CLOEXEC) == -1)
-		    goto fail;
-		}
-	      else if (__dup2 (action->action.dup2_action.fd,
-			       action->action.dup2_action.newfd)
-		       != action->action.dup2_action.newfd)
-		goto fail;
-	      break;
-
-	    case spawn_do_chdir:
-	      if (__chdir (action->action.chdir_action.path) != 0)
-		goto fail;
-	      break;
-
-	    case spawn_do_fchdir:
-	      if (__fchdir (action->action.fchdir_action.fd) != 0)
-		goto fail;
-	      break;
-	    }
-	}
-    }
-
-  /* Set the initial signal mask of the child if POSIX_SPAWN_SETSIGMASK
-     is set, otherwise restore the previous one.  */
-  __sigprocmask (SIG_SETMASK, (attr->__flags & POSIX_SPAWN_SETSIGMASK)
-		 ? &attr->__ss : &args->oldmask, 0);
-
-  args->exec (args->file, args->argv, args->envp);
-
-  /* This is compatibility function required to enable posix_spawn run
-     script without shebang definition for older posix_spawn versions
-     (2.15).  */
-  maybe_script_execute (args);
-
-fail:
-  /* errno should have an appropriate non-zero value; otherwise,
-     there's a bug in glibc or the kernel.  For lack of an error code
-     (EINTERNALBUG) describing that, use ECHILD.  Another option would
-     be to set args->err to some negative sentinel and have the parent
-     abort(), but that seems needlessly harsh.  */
-  ret = errno ? : ECHILD;
-  if (ret)
-    /* Since sizeof errno < PIPE_BUF, the write is atomic. */
-    while (__write_nocancel (args->pipe[1], &ret, sizeof (ret)) < 0);
-
-  _exit (SPAWN_ERROR);
-}
-
-/* Spawn a new process executing PATH with the attributes describes in *ATTRP.
-   Before running the process perform the actions described in FILE-ACTIONS. */
-int
-__spawnix (pid_t *pid, const char *file,
-	   const posix_spawn_file_actions_t *file_actions,
-	   const posix_spawnattr_t *attrp, char *const argv[],
-	   char *const envp[], int xflags,
-	   int (*exec) (const char *, char *const *, char *const *))
-{
-  struct posix_spawn_args args;
-  int ec;
-
-  if (__pipe2 (args.pipe, O_CLOEXEC))
-    return errno;
-
-  /* Disable asynchronous cancellation.  */
-  int state;
-  __libc_ptf_call (__pthread_setcancelstate,
-                   (PTHREAD_CANCEL_DISABLE, &state), 0);
-
-  ptrdiff_t argc = 0;
-  ptrdiff_t limit = INT_MAX - 1;
-  while (argv[argc++] != NULL)
-    if (argc == limit)
-      {
-	errno = E2BIG;
-	return errno;
-      }
-
-  args.file = file;
-  args.exec = exec;
-  args.fa = file_actions;
-  args.attr = attrp ? attrp : &(const posix_spawnattr_t) { 0 };
-  args.argv = argv;
-  args.argc = argc;
-  args.envp = envp;
-  args.xflags = xflags;
-
-  /* Generate the new process.  */
-  pid_t new_pid = __fork ();
-
-  if (new_pid == 0)
-    __spawni_child (&args);
-  else if (new_pid > 0)
-    {
-      __close (args.pipe[1]);
-
-      if (__read (args.pipe[0], &ec, sizeof ec) != sizeof ec)
-	ec = 0;
-      else
-	__waitpid (new_pid, &(int) { 0 }, 0);
-    }
-  else
-    ec = errno;
-
-  __close (args.pipe[0]);
-
-  if ((ec == 0) && (pid != NULL))
-    *pid = new_pid;
-
-  __libc_ptf_call (__pthread_setcancelstate, (state, NULL), 0);
-
-  return ec;
-}
-
-int
-__spawni (pid_t * pid, const char *file,
-	  const posix_spawn_file_actions_t * acts,
-	  const posix_spawnattr_t * attrp, char *const argv[],
-	  char *const envp[], int xflags)
-{
-  /* It uses __execvpex to avoid run ENOEXEC in non compatibility mode (it
-     will be handled by maybe_script_execute).  */
-  return __spawnix (pid, file, acts, attrp, argv, envp, xflags,
-		    xflags & SPAWN_XFLAGS_USE_PATH ? __execvpex : __execve);
-}