2005-01-20 Ulrich Drepper <drepper@redhat.com>

	* posix/execl.c: Do not allocate potentially large buffers on the
	stack.
	* posix/execle.c: Likewise.
	* posix/execlp.c: Likewise.
	* posix/execlp.c: Likewise.
	(script_execute): Removed.
	(allocate_scripts_argv): New function.  Called at most once to
	allocate memory, not every time a script is run.  Adjust caller.

diff --git a/posix/execl.c b/posix/execl.c
index 62fd45db588f3123152dbd31e4aa5f0b613f3a8d..cffd7142581508cdf35af5dd4710e13be9813e36 100644 (file)
--- a/posix/execl.c
+++ b/posix/execl.c
@@ -16,10 +16,10 @@
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
 
-#include <alloca.h>
 #include <unistd.h>
 #include <stdarg.h>
 #include <stddef.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include <stackinfo.h>
@@ -33,46 +33,44 @@
 int
 execl (const char *path, const char *arg, ...)
 {
-  size_t argv_max = 1024;
-  const char **argv = alloca (argv_max * sizeof (const char *));
-  unsigned int i;
+#define INITIAL_ARGV_MAX 1024
+  size_t argv_max = INITIAL_ARGV_MAX;
+  const char *initial_argv[INITIAL_ARGV_MAX];
+  const char **argv = initial_argv;
   va_list args;
 
   argv[0] = arg;
 
   va_start (args, arg);
-  i = 0;
+  unsigned int i = 0;
   while (argv[i++] != NULL)
     {
       if (i == argv_max)
        {
-         const char **nptr = alloca ((argv_max *= 2) * sizeof (const char *));
-
-#ifndef _STACK_GROWS_UP
-         if ((char *) nptr + argv_max == (char *) argv)
+         argv_max *= 2;
+         const char **nptr = realloc (argv == initial_argv ? NULL : argv,
+                                      argv_max * sizeof (const char *));
+         if (nptr == NULL)
            {
-             /* Stack grows down.  */
-             argv = (const char **) memcpy (nptr, argv,
-                                            i * sizeof (const char *));
-             argv_max += i;
+             if (argv != initial_argv)
+               free (argv);
+             return -1;
            }
-         else
-#endif
-#ifndef _STACK_GROWS_DOWN
-           if ((char *) argv + i == (char *) nptr)
-           /* Stack grows up.  */
-           argv_max += i;
-         else
-#endif
-           /* We have a hole in the stack.  */
-           argv = (const char **) memcpy (nptr, argv,
-                                          i * sizeof (const char *));
+         if (argv == initial_argv)
+           /* We have to copy the already filled-in data ourselves.  */
+           memcpy (nptr, argv, i * sizeof (const char *));
+
+         argv = nptr;
        }
 
       argv[i] = va_arg (args, const char *);
     }
   va_end (args);
 
-  return __execve (path, (char *const *) argv, __environ);
+  int ret = __execve (path, (char *const *) argv, __environ);
+  if (argv != initial_argv)
+    free (argv);
+
+  return ret;
 }
 libc_hidden_def (execl)

diff --git a/posix/execle.c b/posix/execle.c
index 2199ebeb746068230bf06c3408108daba6871beb..e956bb63cd3430886fcecf3a4fce23b595b7ea61 100644 (file)
--- a/posix/execle.c
+++ b/posix/execle.c
@@ -16,10 +16,10 @@
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
 
-#include <alloca.h>
 #include <unistd.h>
 #include <stdarg.h>
 #include <stddef.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include <stackinfo.h>
@@ -29,48 +29,45 @@
 int
 execle (const char *path, const char *arg, ...)
 {
-  size_t argv_max = 1024;
-  const char **argv = alloca (argv_max * sizeof (const char *));
-  const char *const *envp;
-  unsigned int i;
+#define INITIAL_ARGV_MAX 1024
+  size_t argv_max = INITIAL_ARGV_MAX;
+  const char *initial_argv[INITIAL_ARGV_MAX];
+  const char **argv = initial_argv;
   va_list args;
   argv[0] = arg;
 
   va_start (args, arg);
-  i = 0;
+  unsigned int i = 0;
   while (argv[i++] != NULL)
     {
       if (i == argv_max)
        {
-         const char **nptr = alloca ((argv_max *= 2) * sizeof (const char *));
-
-#ifndef _STACK_GROWS_UP
-         if ((char *) nptr + argv_max == (char *) argv)
+         argv_max *= 2;
+         const char **nptr = realloc (argv == initial_argv ? NULL : argv,
+                                      argv_max * sizeof (const char *));
+         if (nptr == NULL)
            {
-             /* Stack grows down.  */
-             argv = (const char **) memcpy (nptr, argv,
-                                            i * sizeof (const char *));
-             argv_max += i;
+             if (argv != initial_argv)
+               free (argv);
+             return -1;
            }
-         else
-#endif
-#ifndef _STACK_GROWS_DOWN
-           if ((char *) argv + i == (char *) nptr)
-           /* Stack grows up.  */
-           argv_max += i;
-         else
-#endif
-           /* We have a hole in the stack.  */
-           argv = (const char **) memcpy (nptr, argv,
-                                          i * sizeof (const char *));
+         if (argv == initial_argv)
+           /* We have to copy the already filled-in data ourselves.  */
+           memcpy (nptr, argv, i * sizeof (const char *));
+
+         argv = nptr;
        }
 
       argv[i] = va_arg (args, const char *);
     }
 
-  envp = va_arg (args, const char *const *);
+  const char *const *envp = va_arg (args, const char *const *);
   va_end (args);
 
-  return __execve (path, (char *const *) argv, (char *const *) envp);
+  int ret = __execve (path, (char *const *) argv, (char *const *) envp);
+  if (argv != initial_argv)
+    free (argv);
+
+  return ret;
 }
 libc_hidden_def (execle)

diff --git a/posix/execlp.c b/posix/execlp.c
index ba8fc74c90e8e58e8de2f7a2f3a8944dcda9e907..c530397aa0f701f4902f3b99b54ca9f23665cde4 100644 (file)
--- a/posix/execlp.c
+++ b/posix/execlp.c
@@ -16,10 +16,10 @@
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
 
-#include <alloca.h>
 #include <unistd.h>
 #include <stdarg.h>
 #include <stddef.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include <stackinfo.h>
@@ -30,46 +30,44 @@
 int
 execlp (const char *file, const char *arg, ...)
 {
-  size_t argv_max = 1024;
-  const char **argv = alloca (argv_max * sizeof (const char *));
-  unsigned int i;
+#define INITIAL_ARGV_MAX 1024
+  size_t argv_max = INITIAL_ARGV_MAX;
+  const char *initial_argv[INITIAL_ARGV_MAX];
+  const char **argv = initial_argv;
   va_list args;
 
   argv[0] = arg;
 
   va_start (args, arg);
-  i = 0;
+  unsigned int i = 0;
   while (argv[i++] != NULL)
     {
       if (i == argv_max)
        {
-         const char **nptr = alloca ((argv_max *= 2) * sizeof (const char *));
-
-#ifndef _STACK_GROWS_UP
-         if ((char *) nptr + argv_max == (char *) argv)
+         argv_max *= 2;
+         const char **nptr = realloc (argv == initial_argv ? NULL : argv,
+                                      argv_max * sizeof (const char *));
+         if (nptr == NULL)
            {
-             /* Stack grows down.  */
-             argv = (const char **) memcpy (nptr, argv,
-                                            i * sizeof (const char *));
-             argv_max += i;
+             if (argv != initial_argv)
+               free (argv);
+             return -1;
            }
-         else
-#endif
-#ifndef _STACK_GROWS_DOWN
-           if ((char *) argv + i == (char *) nptr)
-           /* Stack grows up.  */
-           argv_max += i;
-         else
-#endif
-           /* We have a hole in the stack.  */
-           argv = (const char **) memcpy (nptr, argv,
-                                          i * sizeof (const char *));
+         if (argv == initial_argv)
+           /* We have to copy the already filled-in data ourselves.  */
+           memcpy (nptr, argv, i * sizeof (const char *));
+
+         argv = nptr;
        }
 
       argv[i] = va_arg (args, const char *);
     }
   va_end (args);
 
-  return execvp (file, (char *const *) argv);
+  int ret = execvp (file, (char *const *) argv);
+  if (argv != initial_argv)
+    free (argv);
+
+  return ret;
 }
 libc_hidden_def (execlp)