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[PATCH] Trace memalign and posix_memalign in mtrace


Hi!

Without this patch, *memalign doesn't show up in MALLOC_TRACE= output
and free() of memalign alloced memory appears as freeing invalid memory
(and of course any leaks caused by memalign don't show up).
The malloc.c change is there so that *.mtrace don't contain posix_memalign
as caller, but the actual function which called posix_memalign.

2003-12-17  Jakub Jelinek  <jakub@redhat.com>

	* malloc/mtrace.c (tr_old_memalign_hook): New variable.
	(tr_memalignhook): New function.
	(mtrace): Register tr_memalignhook.
	(muntrace): Deregister tr_memalignhook.
	* malloc/malloc.c (__posix_memalign): If __memalign_hook != NULL,
	call it directly instead of memalign_internal.

--- libc/malloc/mtrace.c.jj	2003-09-14 20:13:40.000000000 +0200
+++ libc/malloc/mtrace.c	2003-12-17 11:17:56.000000000 +0100
@@ -71,6 +71,9 @@ static __ptr_t (*tr_old_malloc_hook) __P
 static __ptr_t (*tr_old_realloc_hook) __P ((__ptr_t ptr,
 					    __malloc_size_t size,
 					    const __ptr_t));
+static __ptr_t (*tr_old_memalign_hook) __P ((__malloc_size_t __alignment,
+					     __malloc_size_t __size,
+					     __const __ptr_t));
 
 /* This function is called when the block being alloc'd, realloc'd, or
    freed has an address matching the variable "mallwatch".  In a debugger,
@@ -233,6 +236,39 @@ tr_reallochook (ptr, size, caller)
   return hdr;
 }
 
+static __ptr_t tr_memalignhook __P ((__malloc_size_t, __malloc_size_t,
+				     const __ptr_t));
+static __ptr_t
+tr_memalignhook (alignment, size, caller)
+     __malloc_size_t alignment, size;
+     const __ptr_t caller;
+{
+  __ptr_t hdr;
+
+  __libc_lock_lock (lock);
+
+  __memalign_hook = tr_old_memalign_hook;
+  __malloc_hook = tr_old_malloc_hook;
+  if (tr_old_memalign_hook != NULL)
+    hdr = (__ptr_t) (*tr_old_memalign_hook) (alignment, size, caller);
+  else
+    hdr = (__ptr_t) memalign (alignment, size);
+  __memalign_hook = tr_memalignhook;
+  __malloc_hook = tr_mallochook;
+
+  tr_where (caller);
+  /* We could be printing a NULL here; that's OK.  */
+  fprintf (mallstream, "+ %p %#lx\n", hdr, (unsigned long int) size);
+
+  __libc_lock_unlock (lock);
+
+  if (hdr == mallwatch)
+    tr_break ();
+
+  return hdr;
+}
+
+
 
 #ifdef _LIBC
 
@@ -300,6 +336,8 @@ mtrace ()
 	  __malloc_hook = tr_mallochook;
 	  tr_old_realloc_hook = __realloc_hook;
 	  __realloc_hook = tr_reallochook;
+	  tr_old_memalign_hook = __memalign_hook;
+	  __memalign_hook = tr_memalignhook;
 #ifdef _LIBC
 	  if (!added_atexit_handler)
 	    {
@@ -327,4 +365,5 @@ muntrace ()
   __free_hook = tr_old_free_hook;
   __malloc_hook = tr_old_malloc_hook;
   __realloc_hook = tr_old_realloc_hook;
+  __memalign_hook = tr_old_memalign_hook;
 }
--- libc/malloc/malloc.c.jj	2003-10-02 21:51:07.000000000 +0200
+++ libc/malloc/malloc.c	2003-12-17 11:58:48.000000000 +0100
@@ -5389,13 +5389,21 @@ 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 *).  */
   if (alignment % sizeof (void *) != 0 || !powerof2 (alignment) != 0)
     return EINVAL;
 
-  mem = __memalign_internal (alignment, size);
+  /* Call the hook here, so that caller is posix_memalign's caller
+     and not posix_memalign itself.  */
+  if (hook != NULL)
+    mem = (*hook)(alignment, size, RETURN_ADDRESS (0));
+  else
+    mem = __memalign_internal (alignment, size);
 
   if (mem != NULL) {
     *memptr = mem;

	Jakub


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