Update.

* malloc/hooks.c (DEFAULT_CHECK_ACTION): Moved to malloc.c.
	(check_action): Likewise.
	When printing error messages, use malloc_printf_nc now instead of
	fiddling with the streams cancellation flag in every place.
	* malloc/malloc.c (DEFAULT_CHECK_ACTION): New definition.  Change
	default to 3.
	(check_action): New variable.
	(unlink): Print error message and eventually terminate in case list
	is corrupted.
	(malloc_printf_nc): New function.  Use it in _int_free.
	Change proposed by Arjan van de Ven.

ChangeLog

@@ -1,5 +1,17 @@
 2004-08-21  Ulrich Drepper  <drepper@redhat.com>
 
+	* malloc/hooks.c (DEFAULT_CHECK_ACTION): Moved to malloc.c.
+	(check_action): Likewise.
+	When printing error messages, use malloc_printf_nc now instead of
+	fiddling with the streams cancellation flag in every place.
+	* malloc/malloc.c (DEFAULT_CHECK_ACTION): New definition.  Change
+	default to 3.
+	(check_action): New variable.
+	(unlink): Print error message and eventually terminate in case list
+	is corrupted.
+	(malloc_printf_nc): New function.  Use it in _int_free.
+	Change proposed by Arjan van de Ven.
+
 	* dlfcn/Makefile: Don't build eval.c anymore.
 
 2004-08-20  Roland McGrath  <roland@frob.com>

malloc/hooks.c

@@ -1,5 +1,5 @@
 /* Malloc implementation for multiple threads without lock contention.
-   Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
+   Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Wolfram Gloger <wg@malloc.de>, 2001.
 
@@ -20,10 +20,6 @@
 
 /* $Id$ */
 
-#ifndef DEFAULT_CHECK_ACTION
-#define DEFAULT_CHECK_ACTION 1
-#endif
-
 /* What to do if the standard debugging hooks are in place and a
    corrupt pointer is detected: do nothing (0), print an error message
    (1), or call abort() (2). */
@@ -71,9 +67,6 @@ memalign_hook_ini(alignment, sz, caller)
   return public_mEMALIGn(alignment, sz);
 }
 
-
-static int check_action = DEFAULT_CHECK_ACTION;
-
 /* Whether we are using malloc checking.  */
 static int using_malloc_checking;
 
@@ -106,18 +99,7 @@ __malloc_check_init()
   __realloc_hook = realloc_check;
   __memalign_hook = memalign_check;
   if(check_action & 1)
-    {
+    malloc_printf_nc (1, "malloc: using debugging hooks\n");
-#ifdef _LIBC
-      _IO_flockfile (stderr);
-      int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
-      ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL;
-#endif
-      fprintf(stderr, "malloc: using debugging hooks\n");
-#ifdef _LIBC
-      ((_IO_FILE *) stderr)->_flags2 |= old_flags2;
-      _IO_funlockfile (stderr);
-#endif
-    }
 }
 
 /* A simple, standard set of debugging hooks.  Overhead is `only' one
@@ -234,21 +216,7 @@ top_check()
   if((char*)t + chunksize(t) == mp_.sbrk_base + main_arena.system_mem ||
      t == initial_top(&main_arena)) return 0;
 
-  if(check_action & 1)
+  malloc_printf_nc (check_action, "malloc: top chunk is corrupt\n");
-    {
-#ifdef _LIBC
-      _IO_flockfile (stderr);
-      int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
-      ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL;
-#endif
-      fprintf(stderr, "malloc: top chunk is corrupt\n");
-#ifdef _LIBC
-      ((_IO_FILE *) stderr)->_flags2 |= old_flags2;
-      _IO_funlockfile (stderr);
-#endif
-    }
-  if(check_action & 2)
-    abort();
 
   /* Try to set up a new top chunk. */
   brk = MORECORE(0);
@@ -299,21 +267,8 @@ free_check(mem, caller) Void_t* mem; const Void_t *caller;
   p = mem2chunk_check(mem);
   if(!p) {
     (void)mutex_unlock(&main_arena.mutex);
-    if(check_action & 1)
+
-      {
+    malloc_printf_nc(check_action, "free(): invalid pointer %p!\n", mem);
-#ifdef _LIBC
-	_IO_flockfile (stderr);
-	int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
-	((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL;
-#endif
-	fprintf(stderr, "free(): invalid pointer %p!\n", mem);
-#ifdef _LIBC
-	((_IO_FILE *) stderr)->_flags2 |= old_flags2;
-	_IO_funlockfile (stderr);
-#endif
-      }
-    if(check_action & 2)
-      abort();
     return;
   }
 #if HAVE_MMAP
@@ -347,21 +302,7 @@ realloc_check(oldmem, bytes, caller)
   oldp = mem2chunk_check(oldmem);
   (void)mutex_unlock(&main_arena.mutex);
   if(!oldp) {
-    if(check_action & 1)
+    malloc_printf_nc(check_action, "realloc(): invalid pointer %p!\n", oldmem);
-      {
-#ifdef _LIBC
-	_IO_flockfile (stderr);
-	int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
-	((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL;
-#endif
-	fprintf(stderr, "realloc(): invalid pointer %p!\n", oldmem);
-#ifdef _LIBC
-	((_IO_FILE *) stderr)->_flags2 |= old_flags2;
-	_IO_funlockfile (stderr);
-#endif
-      }
-    if(check_action & 2)
-      abort();
     return malloc_check(bytes, NULL);
   }
   oldsize = chunksize(oldp);

malloc/malloc.c

@@ -280,6 +280,9 @@ extern "C" {
 /* For uintptr_t.  */
 #include <stdint.h>
 
+/* For va_arg, va_start, va_end.  */
+#include <stdarg.h>
+
 /*
   Debugging:
 
@@ -1498,6 +1501,7 @@ static size_t   mUSABLe(Void_t*);
 static void     mSTATs(void);
 static int      mALLOPt(int, int);
 static struct mallinfo mALLINFo(mstate);
+static void malloc_printf_nc(int action, const char *template, ...);
 
 static Void_t* internal_function mem2mem_check(Void_t *p, size_t sz);
 static int internal_function top_check(void);
@@ -1966,6 +1970,9 @@ typedef struct malloc_chunk* mbinptr;
 #define unlink(P, BK, FD) {                                            \
   FD = P->fd;                                                          \
   BK = P->bk;                                                          \
+  if (__builtin_expect (FD->bk != P || BK->fd != P, 0))                \
+    malloc_printf_nc (check_action,                                    \
+		      "corrupted double-linked list at %p!\n", P);     \
   FD->bk = BK;                                                         \
   BK->fd = FD;                                                         \
 }
@@ -2327,6 +2334,15 @@ __malloc_ptr_t weak_variable (*__memalign_hook)
 void weak_variable (*__after_morecore_hook) __MALLOC_P ((void)) = NULL;
 
 
+/* ---------------- Error behavior ------------------------------------ */
+
+#ifndef DEFAULT_CHECK_ACTION
+#define DEFAULT_CHECK_ACTION 3
+#endif
+
+static int check_action = DEFAULT_CHECK_ACTION;
+
+
 /* ------------------- Support for multiple arenas -------------------- */
 #include "arena.c"
 
@@ -4164,21 +4180,7 @@ _int_free(mstate av, Void_t* mem)
        here by accident or by "design" from some intruder.  */
     if (__builtin_expect ((uintptr_t) p > (uintptr_t) -size, 0))
       {
-	if (check_action & 1)
+	malloc_printf_nc (check_action, "free(): invalid pointer %p!\n", mem);
-	  {
-#ifdef _LIBC
-	    _IO_flockfile (stderr);
-	    int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
-	    ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL;
-#endif
-	    fprintf (stderr, "free(): invalid pointer %p!\n", mem);
-#ifdef _LIBC
-	    ((_IO_FILE *) stderr)->_flags2 |= old_flags2;
-	    _IO_funlockfile (stderr);
-#endif
-	  }
-	if (check_action & 2)
-	  abort ();
 	return;
       }
 
@@ -5404,6 +5406,35 @@ int mALLOPt(param_number, value) int param_number; int value;
 */
 
 
+/* Helper code.  */
+
+static void
+malloc_printf_nc(int action, const char *template, ...)
+{
+  if (action & 1)
+    {
+#ifdef _LIBC
+      _IO_flockfile (stderr);
+      int old_flags2 = ((_IO_FILE *) stderr)->_flags2;
+      ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL;
+#endif
+
+      va_list ap;
+      va_start (ap, template);
+
+      vfprintf (stderr, template, ap);
+
+      va_end (ap);
+
+#ifdef _LIBC
+      ((_IO_FILE *) stderr)->_flags2 |= old_flags2;
+      _IO_funlockfile (stderr);
+#endif
+    }
+  if (action & 2)
+    abort ();
+}
+
 #ifdef _LIBC
 # include <sys/param.h>