2.5-18.1

posix/execvp.c

@@ -1,4 +1,5 @@
-/* Copyright (C) 1991,92,1995-99,2002,2004 Free Software Foundation, Inc.
+/* Copyright (C) 1991,92, 1995-99, 2002, 2004, 2005, 2007
+   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
@@ -16,8 +17,10 @@
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
 
+#include <alloca.h>
 #include <unistd.h>
 #include <stdarg.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
@@ -28,27 +31,16 @@
    the shell to interpret it as a script.  */
 static void
 internal_function
-script_execute (const char *file, char *const argv[])
+scripts_argv (const char *file, char *const argv[], int argc, char **new_argv)
 {
-  /* Count the arguments.  */
-  int argc = 0;
-  while (argv[argc++])
-    ;
-
   /* Construct an argument list for the shell.  */
-  {
-    char *new_argv[argc + 1];
-    new_argv[0] = (char *) _PATH_BSHELL;
-    new_argv[1] = (char *) file;
-    while (argc > 1)
-      {
-	new_argv[argc] = argv[argc - 1];
-	--argc;
-      }
-
-    /* Execute the shell.  */
-    __execve (new_argv[0], new_argv, __environ);
-  }
+  new_argv[0] = (char *) _PATH_BSHELL;
+  new_argv[1] = (char *) file;
+  while (argc > 1)
+    {
+      new_argv[argc] = argv[argc - 1];
+      --argc;
+    }
 }
 
 
@@ -72,36 +64,74 @@ execvp (file, argv)
       __execve (file, argv, __environ);
 
       if (errno == ENOEXEC)
-	script_execute (file, argv);
+	{
+	  /* Count the arguments.  */
+	  int argc = 0;
+	  while (argv[argc++])
+	    ;
+	  size_t len = (argc + 1) * sizeof (char *);
+	  char **script_argv;
+	  void *ptr = NULL;
+	  if (__libc_use_alloca (len))
+	    script_argv = alloca (len);
+	  else
+	    script_argv = ptr = malloc (len);
+
+	  if (script_argv != NULL)
+	    {
+	      scripts_argv (file, argv, argc, script_argv);
+	      __execve (script_argv[0], script_argv, __environ);
+
+	      free (ptr);
+	    }
+	}
     }
   else
     {
-      int got_eacces = 0;
-      char *path, *p, *name;
-      size_t len;
       size_t pathlen;
+      size_t alloclen = 0;
+      char *path = getenv ("PATH");
+      if (path == NULL)
+	{
+	  pathlen = confstr (_CS_PATH, (char *) NULL, 0);
+	  alloclen = pathlen + 1;
+	}
+      else
+	pathlen = strlen (path);
+
+      size_t len = strlen (file) + 1;
+      alloclen += pathlen + len + 1;
+
+      char *name;
+      char *path_malloc = NULL;
+      if (__libc_use_alloca (alloclen))
+	name = alloca (alloclen);
+      else
+	{
+	  path_malloc = name = malloc (alloclen);
+	  if (name == NULL)
+	    return -1;
+	}
 
-      path = getenv ("PATH");
       if (path == NULL)
 	{
 	  /* There is no `PATH' in the environment.
 	     The default search path is the current directory
 	     followed by the path `confstr' returns for `_CS_PATH'.  */
-	  len = confstr (_CS_PATH, (char *) NULL, 0);
-	  path = (char *) __alloca (1 + len);
+	  path = name + pathlen + len + 1;
 	  path[0] = ':';
-	  (void) confstr (_CS_PATH, path + 1, len);
+	  (void) confstr (_CS_PATH, path + 1, pathlen);
 	}
 
-      len = strlen (file) + 1;
-      pathlen = strlen (path);
-      name = __alloca (pathlen + len + 1);
       /* Copy the file name at the top.  */
       name = (char *) memcpy (name + pathlen + 1, file, len);
       /* And add the slash.  */
       *--name = '/';
 
-      p = path;
+      char **script_argv = NULL;
+      void *script_argv_malloc = NULL;
+      bool got_eacces = false;
+      char *p = path;
       do
 	{
 	  char *startp;
@@ -116,11 +146,34 @@ execvp (file, argv)
 	  else
 	    startp = (char *) memcpy (name - (p - path), path, p - path);
 
-	  /* Try to execute this name.  If it works, execv will not return.  */
+	  /* Try to execute this name.  If it works, execve will not return. */
 	  __execve (startp, argv, __environ);
 
 	  if (errno == ENOEXEC)
-	    script_execute (startp, argv);
+	    {
+	      if (script_argv == NULL)
+		{
+		  /* Count the arguments.  */
+		  int argc = 0;
+		  while (argv[argc++])
+		    ;
+		  size_t arglen = (argc + 1) * sizeof (char *);
+		  if (__libc_use_alloca (alloclen + arglen))
+		    script_argv = alloca (arglen);
+		  else
+		    script_argv = script_argv_malloc = malloc (arglen);
+		  if (script_argv == NULL)
+		    {
+		      /* A possible EACCES error is not as important as
+			 the ENOMEM.  */
+		      got_eacces = false;
+		      break;
+		    }
+		  scripts_argv (startp, argv, argc, script_argv);
+		}
+
+	      __execve (script_argv[0], script_argv, __environ);
+	    }
 
 	  switch (errno)
 	    {
@@ -128,7 +181,7 @@ execvp (file, argv)
 	      /* Record the we got a `Permission denied' error.  If we end
 		 up finding no executable we can use, we want to diagnose
 		 that we did find one but were denied access.  */
-	      got_eacces = 1;
+	      got_eacces = true;
 	    case ENOENT:
 	    case ESTALE:
 	    case ENOTDIR:
@@ -154,8 +207,11 @@ execvp (file, argv)
       /* We tried every element and none of them worked.  */
       if (got_eacces)
 	/* At least one failure was due to permissions, so report that
-           error.  */
+	   error.  */
 	__set_errno (EACCES);
+
+      free (script_argv_malloc);
+      free (path_malloc);
     }
 
   /* Return the error from the last attempt (probably ENOENT).  */