2007-11-25  Ulrich Drepper  <drepper@redhat.com>

	* nscd/nscd.h (MAX_STACK_USE): Define.
	* nscd/mem.c (MAX_STACK_USE): Remove definition here.
	(gc): Initialize stack_used based on allocation in prune_cache.
	* nscd/cache.c (prune_cache): Use heap for mark array if necessary.
	Clear array before use.

--- libc/nscd/cache.c	14 Nov 2007 15:26:02 -0000	1.33
+++ libc/nscd/cache.c	25 Nov 2007 21:47:35 -0000	1.35
@@ -36,6 +36,10 @@
 #include "dbg_log.h"
 
 
+/* Wrapper functions with error checking for standard functions.  */
+extern void *xcalloc (size_t n, size_t s);
+
+
 /* Number of times a value is reloaded without being used.  UINT_MAX
    means unlimited.  */
 unsigned int reload_count = DEFAULT_RELOAD_LIMIT;
@@ -278,7 +282,20 @@ prune_cache (struct database_dyn *table,
      we don't need to get any lock.  It is at all timed assured that the
      linked lists are set up correctly and that no second thread prunes
      the cache.  */
-  bool mark[cnt];
+  bool *mark;
+  size_t memory_needed = cnt * sizeof (bool);
+  bool mark_use_alloca;
+  if (__builtin_expect (memory_needed <= MAX_STACK_USE, 1))
+    {
+      mark = alloca (cnt * sizeof (bool));
+      memset (mark, '\0', memory_needed);
+      mark_use_alloca = true;
+    }
+  else
+    {
+      mark = xcalloc (1, memory_needed);
+      mark_use_alloca = false;
+    }
   size_t first = cnt + 1;
   size_t last = 0;
   char *const data = table->data;
@@ -471,6 +488,9 @@ prune_cache (struct database_dyn *table,
 	}
     }
 
+  if (__builtin_expect (! mark_use_alloca, 0))
+    free (mark);
+
   /* Run garbage collection if any entry has been removed or replaced.  */
   if (any)
     gc (table);
--- libc/nscd/mem.c	23 Nov 2007 06:37:12 -0000	1.11
+++ libc/nscd/mem.c	25 Nov 2007 21:07:14 -0000	1.12
@@ -74,10 +74,6 @@ sort_he_data (const void *p1, const void
 #define ALLBITS ((((BITMAP_T) 1) << BITS) - 1)
 #define HIGHBIT (((BITMAP_T) 1) << (BITS - 1))
 
-/* Maximum size of stack frames we allow the thread to use.  We use
-   80% of the thread stack size.  */
-#define MAX_STACK_USE ((8 * NSCD_THREAD_STACKSIZE) / 10)
-
 
 static void
 markrange (BITMAP_T *mark, ref_t start, size_t len)
@@ -129,7 +125,11 @@ gc (struct database_dyn *db)
 
   BITMAP_T *mark;
   bool mark_use_malloc;
-  size_t stack_used = 0;
+  /* In prune_cache we are also using a dynamically allocated array.
+     If the array in the caller is too large we have malloc'ed it.  */
+  size_t stack_used = sizeof (bool) * db->head->module;
+  if (__builtin_expect (stack_used > MAX_STACK_USE, 0))
+    stack_used = 0;
   size_t memory_needed = ((db->head->first_free / BLOCK_ALIGN + BITS - 1)
 			  / BITS) * sizeof (BITMAP_T);
   if (memory_needed <= MAX_STACK_USE)
--- libc/nscd/nscd.h	23 Nov 2007 06:28:41 -0000	1.31
+++ libc/nscd/nscd.h	25 Nov 2007 21:06:58 -0000	1.32
@@ -58,6 +58,10 @@ typedef enum
 /* Stack size for worker threads.  */
 #define NSCD_THREAD_STACKSIZE 1024 * 1024 * (sizeof (void *) / 4)
 
+/* Maximum size of stack frames we allow the thread to use.  We use
+   80% of the thread stack size.  */
+#define MAX_STACK_USE ((8 * NSCD_THREAD_STACKSIZE) / 10)
+
 
 /* Structure describing dynamic part of one database.  */
 struct database_dyn