2009-01-29  Ulrich Drepper  <drepper@redhat.com>

	* sysdeps/i386/stackinfo.h (stackinfo_get_sp): Define.
	(stackinfo_sub_sp): Define.

2009-01-28  Ulrich Drepper  <drepper@redhat.com>

	[BZ #9750]
	* nscd/mem.c (gc): Use alloca_count to get the real stack usage.
	* include/alloca.h (alloca_account): Define.
	* sysdeps/x86_64/stackinfo.h (stackinfo_get_sp): Define.
	(stackinfo_sub_sp): Define.

	[BZ #9741]
	* nscd/mem.c (gc): Fix assignment of he_data in case malloc is used.
	Reported by Jun'ichi Nomura <j-nomura@ce.jp.nec.com>.

--- libc/nscd/mem.c	12 Jun 2008 04:52:27 -0000	1.19
+++ libc/nscd/mem.c	29 Jan 2009 00:17:27 -0000	1.21
@@ -134,12 +134,11 @@ gc (struct database_dyn *db)
     stack_used = 0;
   size_t nmark = (db->head->first_free / BLOCK_ALIGN + BITS - 1) / BITS;
   size_t memory_needed = nmark * sizeof (BITMAP_T);
-  if (stack_used + memory_needed <= MAX_STACK_USE)
+  if (__builtin_expect (stack_used + memory_needed <= MAX_STACK_USE, 1))
     {
-      mark = (BITMAP_T *) alloca (memory_needed);
+      mark = (BITMAP_T *) alloca_account (memory_needed, stack_used);
       mark_use_malloc = false;
       memset (mark, '\0', memory_needed);
-      stack_used += memory_needed;
     }
   else
     {
@@ -153,19 +152,17 @@ gc (struct database_dyn *db)
   struct hashentry **he;
   struct hashentry **he_data;
   bool he_use_malloc;
-  if (stack_used + memory_needed <= MAX_STACK_USE)
+  if (__builtin_expect (stack_used + memory_needed <= MAX_STACK_USE, 1))
     {
-      he = alloca (db->head->nentries * sizeof (struct hashentry *));
-      he_data = alloca (db->head->nentries * sizeof (struct hashentry *));
+      he = alloca_account (memory_needed, stack_used);
       he_use_malloc = false;
-      stack_used += memory_needed;
     }
   else
     {
       he = xmalloc (memory_needed);
-      he_data = &he[db->head->nentries * sizeof (struct hashentry *)];
       he_use_malloc = true;
     }
+  he_data = &he[db->head->nentries];
 
   size_t cnt = 0;
   for (size_t idx = 0; idx < db->head->module; ++idx)
@@ -373,11 +370,9 @@ gc (struct database_dyn *db)
       ref_t disp = off_alloc - off_free;
 
       struct moveinfo *new_move;
-      if (stack_used + sizeof (*new_move) <= MAX_STACK_USE)
-	{
-	  new_move = alloca (sizeof (*new_move));
-	  stack_used += sizeof (*new_move);
-	}
+      if (__builtin_expect (stack_used + sizeof (*new_move) <= MAX_STACK_USE,
+			    1))
+	new_move = alloca_account (sizeof (*new_move), stack_used);
       else
 	new_move = obstack_alloc (&ob, sizeof (*new_move));
       new_move->from = db->data + off_alloc;
--- libc/include/alloca.h	6 Jan 2006 09:55:30 -0000	1.8
+++ libc/include/alloca.h	29 Jan 2009 04:38:49 -0000	1.10
@@ -46,4 +46,17 @@ extern int __libc_alloca_cutoff (size_t 
   __alloca (((len) = (newlen)))
 #endif
 
+#if defined stackinfo_get_sp && defined stackinfo_sub_sp
+# define alloca_account(size, avar) \
+  ({ void *old__ = stackinfo_get_sp ();			\
+     void *m__ = __alloca (size);			\
+     avar += stackinfo_sub_sp (old__);			\
+     m__; })
+#else
+# define alloca_account(size, avar) \
+  ({ size_t s__ = (size);		    \
+     avar += s__;			    \
+     __alloca (s__); })
+#endif
+
 #endif
--- libc/sysdeps/i386/stackinfo.h	6 Jul 2001 04:55:52 -0000	1.2
+++ libc/sysdeps/i386/stackinfo.h	29 Jan 2009 15:36:13 -0000	1.3
@@ -1,4 +1,4 @@
-/* Copyright (C) 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1999, 2009 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
@@ -25,4 +25,14 @@
 /* On x86 the stack grows down.  */
 #define _STACK_GROWS_DOWN	1
 
+/* Access to the stack pointer.  The macros are used in alloca_account
+   for which they need to act as barriers as well, hence the additional
+   (unnecessary) parameters.  */
+#define stackinfo_get_sp() \
+  ({ void *p__; asm volatile ("mov %%esp, %0" : "=r" (p__)); p__; })
+#define stackinfo_sub_sp(ptr) \
+  ({ ptrdiff_t d__;                                             \
+     asm volatile ("sub %%esp, %0" : "=r" (d__) : "0" (ptr));   \
+     d__; })
+
 #endif	/* stackinfo.h */
--- libc/sysdeps/x86_64/stackinfo.h	19 Sep 2001 10:12:08 -0000	1.1
+++ libc/sysdeps/x86_64/stackinfo.h	29 Jan 2009 00:16:59 -0000	1.2
@@ -25,4 +25,14 @@
 /* On x86_64 the stack grows down.  */
 #define _STACK_GROWS_DOWN	1
 
+/* Access to the stack pointer.  The macros are used in alloca_account
+   for which they need to act as barriers as well, hence the additional
+   (unnecessary) parameters.  */
+#define stackinfo_get_sp() \
+  ({ void *p__; asm volatile ("mov %%rsp, %0" : "=r" (p__)); p__; })
+#define stackinfo_sub_sp(ptr) \
+  ({ ptrdiff_t d__;						\
+     asm volatile ("sub %%rsp, %0" : "=r" (d__) : "0" (ptr));	\
+     d__; })
+
 #endif	/* stackinfo.h */