[PATCH] Test in stratcliff for zero length at the end of the cliff

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

With this patch we'd know that memchr on x86_64 has a problem, better
test it on all functions where we don't test it ATM and which have a length
argument and shouldn't dereference the pointer at all in that case.

2009-05-09  Jakub Jelinek  <jakub@redhat.com>

	* string/stratcliff.c (do_test): Test for zero length
	STRNLEN, MEMCHR, STRNCPY, STPNCPY, MEMCPY, MEMPCPY and memccpy
	at the end of the page.

--- libc/string/stratcliff.c.jj	2009-04-08 21:32:54.000000000 +0200
+++ libc/string/stratcliff.c	2009-05-09 10:06:22.000000000 +0200
@@ -129,10 +129,10 @@ do_test (void)
         }
       for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
         {
-          for (inner = MAX (outer, nchars - 64); inner < nchars; ++inner)
+	  for (inner = MAX (outer, nchars - 64); inner <= nchars; ++inner)
 	    {
-	      if (STRNLEN (&adr[outer], inner - outer + 1)
-		  != (size_t) (inner - outer + 1))
+	      if (STRNLEN (&adr[outer], inner - outer)
+		  != (size_t) (inner - outer))
 		{
 		  printf ("%s flunked bounded for outer = %d, inner = %d\n",
 			  STRINGIFY (STRNLEN), outer, inner);
@@ -225,7 +225,7 @@ do_test (void)
 	      adr[middle] = L('T');
 	    }
         }
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
         {
 	  CHAR *cp = MEMCHR (&adr[outer], L('V'), nchars - outer);
 
@@ -279,9 +279,9 @@ do_test (void)
 	    }
         }
 
-      /* strncpy tests */
+      /* strncpy/wcsncpy tests */
       adr[nchars - 1] = L('T');
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
 	{
 	  size_t len;
 
@@ -355,6 +355,24 @@ do_test (void)
         }
 
       /* stpncpy/wcpncpy test */
+      adr[nchars - 1] = L('T');
+      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
+	{
+	  size_t len;
+
+	  for (len = 0; len < nchars - outer; ++len)
+	    {
+	      if (STPNCPY (dest, &adr[outer], len) != dest + len
+		  || MEMCMP (dest, &adr[outer], len) != 0)
+		{
+		  printf ("outer %s flunked for outer = %d, len = %Zd\n",
+			  STRINGIFY (STPNCPY), outer, len);
+		  result = 1;
+		}
+	    }
+	}
+      adr[nchars - 1] = L('\0');
+
       for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
         {
           for (middle = MAX (outer, nchars - 64); middle < nchars; ++middle)
@@ -378,7 +396,7 @@ do_test (void)
         }
 
       /* memcpy/wmemcpy test */
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
 	for (inner = 0; inner < nchars - outer; ++inner)
 	  if (MEMCPY (dest, &adr[outer], inner) !=  dest)
 	    {
@@ -388,7 +406,7 @@ do_test (void)
 	    }
 
       /* mempcpy/wmempcpy test */
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
 	for (inner = 0; inner < nchars - outer; ++inner)
 	  if (MEMPCPY (dest, &adr[outer], inner) !=  dest + inner)
 	    {
@@ -401,7 +419,7 @@ do_test (void)
 #ifndef WCSTEST
       /* memccpy test */
       memset (adr, '\0', nchars);
-      for (outer = nchars - 1; outer >= MAX (0, nchars - 128); --outer)
+      for (outer = nchars; outer >= MAX (0, nchars - 128); --outer)
 	for (inner = 0; inner < nchars - outer; ++inner)
 	  if (memccpy (dest, &adr[outer], L('\1'), inner) != NULL)
 	    {

	Jakub