[BZ #9957]

2009-04-16  Ulrich Drepper  <drepper@redhat.com>
	[BZ #9957]
	* malloc/malloc.c (force_reg): Define.
	(sYSMALLOc): Load hook variable into variable
	before test and force into register.
	(sYSTRIm): Likewise.
	(public_mALLOc): Force hook value into register.
	(public_fREe): Likewise.
	(public_rEALLOc): Likewise.
	(public_mEMALIGn): Likewise.
	(public_vALLOc): Likewise.
	(public_pVALLOc): Likewise.
	(public_cALLOc): Likewise.
	(__posix_memalign): Likewise.
	* malloc/arena.c (ptmalloc_init): Load hook variable into variable
	before test and force into register.
	* malloc/hooks.c (top_check): Likewise.
	(public_s_ET_STATe): Pretty printing.

	* resolv/res_send.c (send_dg): Don't just ignore the result we got
	in case we only receive one reply in single-request mode.

3 files changed, 41 insertions, 26 deletions

diff --git a/malloc/arena.c b/malloc/arena.c
index f280d38..4d0deef 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -624,8 +624,9 @@ ptmalloc_init (void)
     if (check_action != 0)
       __malloc_check_init();
   }
-  if(__malloc_initialize_hook != NULL)
-    (*__malloc_initialize_hook)();
+  void (*hook) (void) = force_reg (__malloc_initialize_hook);
+  if (hook != NULL)
+    (*hook)();
   __malloc_initialized = 1;
 }
 
diff --git a/malloc/hooks.c b/malloc/hooks.c
index 72c2929..5360037 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -235,8 +235,9 @@ top_check()
       return -1;
     }
   /* Call the `morecore' hook if necessary.  */
-  if (__after_morecore_hook)
-    (*__after_morecore_hook) ();
+  void (*hook) (void) = __after_morecore_hook;
+  if (hook)
+    (*hook) ();
   main_arena.system_mem = (new_brk - mp_.sbrk_base) + sbrk_size;
 
   top(&main_arena) = (mchunkptr)(brk + front_misalign);
@@ -669,10 +670,10 @@ public_sET_STATe(Void_t* msptr)
         !disallow_malloc_check)
       __malloc_check_init ();
     else if (!ms->using_malloc_checking && using_malloc_checking) {
-      __malloc_hook = 0;
-      __free_hook = 0;
-      __realloc_hook = 0;
-      __memalign_hook = 0;
+      __malloc_hook = NULL;
+      __free_hook = NULL;
+      __realloc_hook = NULL;
+      __memalign_hook = NULL;
       using_malloc_checking = 0;
     }
   }
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 17e4e03..3bd19b0 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -564,6 +564,13 @@ Void_t* memcpy();
 #endif
 #endif
 
+
+/* Force a value to be in a register and stop the compiler referring
+   to the source (mostly memory location) again.  */
+#define force_reg(val) \
+  ({ __typeof (val) _v; asm ("" : "=r" (_v) : "0" (val)); _v; })
+
+
 /*
   MALLOC_FAILURE_ACTION is the action to take before "return 0" when
   malloc fails to be able to return memory, either because memory is
@@ -3165,8 +3172,9 @@ static Void_t* sYSMALLOc(nb, av) INTERNAL_SIZE_T nb; mstate av;
 
   if (brk != (char*)(MORECORE_FAILURE)) {
     /* Call the `morecore' hook if necessary.  */
-    if (__builtin_expect (__after_morecore_hook != NULL, 0))
-      (*__after_morecore_hook) ();
+    void (*hook) (void) = force_reg (__after_morecore_hook);
+    if (__builtin_expect (hook != NULL, 0))
+      (*hook) ();
   } else {
   /*
     If have mmap, try using it as a backup when MORECORE fails or
@@ -3302,10 +3310,12 @@ static Void_t* sYSMALLOc(nb, av) INTERNAL_SIZE_T nb; mstate av;
         if (snd_brk == (char*)(MORECORE_FAILURE)) {
           correction = 0;
           snd_brk = (char*)(MORECORE(0));
-        } else
+        } else {
 	  /* Call the `morecore' hook if necessary.  */
-	  if (__builtin_expect (__after_morecore_hook != NULL, 0))
-	    (*__after_morecore_hook) ();
+	  void (*hook) (void) = force_reg (__after_morecore_hook);
+	  if (__builtin_expect (hook != NULL, 0))
+	    (*hook) ();
+	}
       }
 
       /* handle non-contiguous cases */
@@ -3453,8 +3463,9 @@ static int sYSTRIm(pad, av) size_t pad; mstate av;
 
       MORECORE(-extra);
       /* Call the `morecore' hook if necessary.  */
-      if (__builtin_expect (__after_morecore_hook != NULL, 0))
-	(*__after_morecore_hook) ();
+      void (*hook) (void) = force_reg (__after_morecore_hook);
+      if (__builtin_expect (hook != NULL, 0))
+	(*hook) ();
       new_brk = (char*)(MORECORE(0));
 
       if (new_brk != (char*)MORECORE_FAILURE) {
@@ -3579,7 +3590,8 @@ public_mALLOc(size_t bytes)
   mstate ar_ptr;
   Void_t *victim;
 
-  __malloc_ptr_t (*hook) (size_t, __const __malloc_ptr_t) = __malloc_hook;
+  __malloc_ptr_t (*hook) (size_t, __const __malloc_ptr_t)
+    = force_reg (__malloc_hook);
   if (__builtin_expect (hook != NULL, 0))
     return (*hook)(bytes, RETURN_ADDRESS (0));
 
@@ -3655,7 +3667,8 @@ public_fREe(Void_t* mem)
   mstate ar_ptr;
   mchunkptr p;                          /* chunk corresponding to mem */
 
-  void (*hook) (__malloc_ptr_t, __const __malloc_ptr_t) = __free_hook;
+  void (*hook) (__malloc_ptr_t, __const __malloc_ptr_t)
+    = force_reg (__free_hook);
   if (__builtin_expect (hook != NULL, 0)) {
     (*hook)(mem, RETURN_ADDRESS (0));
     return;
@@ -3713,7 +3726,7 @@ public_rEALLOc(Void_t* oldmem, size_t bytes)
   Void_t* newp;             /* chunk to return */
 
   __malloc_ptr_t (*hook) (__malloc_ptr_t, size_t, __const __malloc_ptr_t) =
-    __realloc_hook;
+    force_reg (__realloc_hook);
   if (__builtin_expect (hook != NULL, 0))
     return (*hook)(oldmem, bytes, RETURN_ADDRESS (0));
 
@@ -3825,7 +3838,7 @@ public_mEMALIGn(size_t alignment, size_t bytes)
 
   __malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, size_t,
 					__const __malloc_ptr_t)) =
-    __memalign_hook;
+    force_reg (__memalign_hook);
   if (__builtin_expect (hook != NULL, 0))
     return (*hook)(alignment, bytes, RETURN_ADDRESS (0));
 
@@ -3882,7 +3895,7 @@ public_vALLOc(size_t bytes)
 
   __malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, size_t,
 					__const __malloc_ptr_t)) =
-    __memalign_hook;
+    force_reg (__memalign_hook);
   if (__builtin_expect (hook != NULL, 0))
     return (*hook)(pagesz, bytes, RETURN_ADDRESS (0));
 
@@ -3929,7 +3942,7 @@ public_pVALLOc(size_t bytes)
 
   __malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, size_t,
 					__const __malloc_ptr_t)) =
-    __memalign_hook;
+    force_reg (__memalign_hook);
   if (__builtin_expect (hook != NULL, 0))
     return (*hook)(pagesz, rounded_bytes, RETURN_ADDRESS (0));
 
@@ -3970,8 +3983,6 @@ public_cALLOc(size_t n, size_t elem_size)
   unsigned long clearsize;
   unsigned long nclears;
   INTERNAL_SIZE_T* d;
-  __malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, __const __malloc_ptr_t)) =
-    __malloc_hook;
 
   /* size_t is unsigned so the behavior on overflow is defined.  */
   bytes = n * elem_size;
@@ -3984,6 +3995,8 @@ public_cALLOc(size_t n, size_t elem_size)
     }
   }
 
+  __malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, __const __malloc_ptr_t)) =
+    force_reg (__malloc_hook);
   if (__builtin_expect (hook != NULL, 0)) {
     sz = bytes;
     mem = (*hook)(sz, RETURN_ADDRESS (0));
@@ -6192,9 +6205,6 @@ int
 __posix_memalign (void **memptr, size_t alignment, size_t size)
 {
   void *mem;
-  __malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, size_t,
-					__const __malloc_ptr_t)) =
-    __memalign_hook;
 
   /* Test whether the SIZE argument is valid.  It must be a power of
      two multiple of sizeof (void *).  */
@@ -6205,6 +6215,9 @@ __posix_memalign (void **memptr, size_t alignment, size_t size)
 
   /* Call the hook here, so that caller is posix_memalign's caller
      and not posix_memalign itself.  */
+  __malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, size_t,
+					__const __malloc_ptr_t)) =
+    force_reg (__memalign_hook);
   if (__builtin_expect (hook != NULL, 0))
     mem = (*hook)(alignment, size, RETURN_ADDRESS (0));
   else