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-rw-r--r--malloc/mtrace.c211
1 files changed, 211 insertions, 0 deletions
diff --git a/malloc/mtrace.c b/malloc/mtrace.c
new file mode 100644
index 0000000000..35380a09a1
--- /dev/null
+++ b/malloc/mtrace.c
@@ -0,0 +1,211 @@
+/* More debugging hooks for `malloc'.
+   Copyright (C) 1991, 1992, 1993, 1994, 1996 Free Software Foundation, Inc.
+		 Written April 2, 1991 by John Gilmore of Cygnus Support.
+		 Based on mcheck.c by Mike Haertel.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with this library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.
+
+   The author may be reached (Email) at the address mike@ai.mit.edu,
+   or (US mail) as Mike Haertel c/o Free Software Foundation.  */
+
+#ifndef	_MALLOC_INTERNAL
+#define	_MALLOC_INTERNAL
+#include <malloc.h>
+#include <mcheck.h>
+#include <libc-lock.h>
+#endif
+
+#include <stdio.h>
+
+#ifndef	__GNU_LIBRARY__
+extern char *getenv ();
+#else
+#include <stdlib.h>
+#endif
+
+static FILE *mallstream;
+static char mallenv[]= "MALLOC_TRACE";
+static char mallbuf[BUFSIZ];	/* Buffer for the output.  */
+
+__libc_lock_define_initialized (static, lock);
+
+/* Address to breakpoint on accesses to... */
+__ptr_t mallwatch;
+
+/* File name and line number information, for callers that had
+   the foresight to call through a macro.  */
+char *_mtrace_file;
+int _mtrace_line;
+
+/* Old hook values.  */
+static void (*tr_old_free_hook) __P ((__ptr_t ptr));
+static __ptr_t (*tr_old_malloc_hook) __P ((__malloc_size_t size));
+static __ptr_t (*tr_old_realloc_hook) __P ((__ptr_t ptr, __malloc_size_t size));
+
+/* This function is called when the block being alloc'd, realloc'd, or
+   freed has an address matching the variable "mallwatch".  In a debugger,
+   set "mallwatch" to the address of interest, then put a breakpoint on
+   tr_break.  */
+
+void tr_break __P ((void));
+void
+tr_break ()
+{
+}
+
+static void tr_where __P ((void));
+static void
+tr_where ()
+{
+  if (_mtrace_file)
+    {
+      fprintf (mallstream, "@ %s:%d ", _mtrace_file, _mtrace_line);
+      _mtrace_file = NULL;
+    }
+}
+
+static void tr_freehook __P ((__ptr_t));
+static void
+tr_freehook (ptr)
+     __ptr_t ptr;
+{
+  tr_where ();
+  fprintf (mallstream, "- %p\n", ptr);	/* Be sure to print it first.  */
+  if (ptr == mallwatch)
+    tr_break ();
+  __libc_lock_lock (lock);
+  __free_hook = tr_old_free_hook;
+  free (ptr);
+  __free_hook = tr_freehook;
+  __libc_lock_unlock (lock);
+}
+
+static __ptr_t tr_mallochook __P ((__malloc_size_t));
+static __ptr_t
+tr_mallochook (size)
+     __malloc_size_t size;
+{
+  __ptr_t hdr;
+
+  __libc_lock_lock (lock);
+
+  __malloc_hook = tr_old_malloc_hook;
+  hdr = (__ptr_t) malloc (size);
+  __malloc_hook = tr_mallochook;
+
+  __libc_lock_unlock (lock);
+
+  tr_where ();
+  /* We could be printing a NULL here; that's OK.  */
+  fprintf (mallstream, "+ %p %lx\n", hdr, (unsigned long)size);
+
+  if (hdr == mallwatch)
+    tr_break ();
+
+  return hdr;
+}
+
+static __ptr_t tr_reallochook __P ((__ptr_t, __malloc_size_t));
+static __ptr_t
+tr_reallochook (ptr, size)
+     __ptr_t ptr;
+     __malloc_size_t size;
+{
+  __ptr_t hdr;
+
+  if (ptr == mallwatch)
+    tr_break ();
+
+  __libc_lock_lock (lock);
+
+  __free_hook = tr_old_free_hook;
+  __malloc_hook = tr_old_malloc_hook;
+  __realloc_hook = tr_old_realloc_hook;
+  hdr = (__ptr_t) realloc (ptr, size);
+  __free_hook = tr_freehook;
+  __malloc_hook = tr_mallochook;
+  __realloc_hook = tr_reallochook;
+
+  __libc_lock_unlock (lock);
+
+  tr_where ();
+  if (hdr == NULL)
+    /* Failed realloc.  */
+    fprintf (mallstream, "! %p %lx\n", ptr, (unsigned long)size);
+  else if (ptr == NULL)
+    fprintf (mallstream, "+ %p %lx\n", hdr, (unsigned long)size);
+  else
+    fprintf (mallstream, "< %p\n> %p %lx\n", ptr, hdr, (unsigned long)size);
+
+  if (hdr == mallwatch)
+    tr_break ();
+
+  return hdr;
+}
+
+/* We enable tracing if either the environment variable MALLOC_TRACE
+   is set, or if the variable mallwatch has been patched to an address
+   that the debugging user wants us to stop on.  When patching mallwatch,
+   don't forget to set a breakpoint on tr_break!  */
+
+void
+mtrace ()
+{
+  char *mallfile;
+
+  /* Don't panic if we're called more than once.  */
+  if (mallstream != NULL)
+    return;
+
+#ifdef _LIBC
+  /* When compiling the GNU libc we use the secure getenv function
+     which prevents the misuse in case of SUID or SGID enabled
+     programs.  */
+  mallfile = __secure_getenv (mallenv);
+#else
+  mallfile = getenv (mallenv);
+#endif
+  if (mallfile != NULL || mallwatch != NULL)
+    {
+      mallstream = fopen (mallfile != NULL ? mallfile : "/dev/null", "w");
+      if (mallstream != NULL)
+	{
+	  /* Be sure it doesn't malloc its buffer!  */
+	  setbuf (mallstream, mallbuf);
+	  fprintf (mallstream, "= Start\n");
+	  tr_old_free_hook = __free_hook;
+	  __free_hook = tr_freehook;
+	  tr_old_malloc_hook = __malloc_hook;
+	  __malloc_hook = tr_mallochook;
+	  tr_old_realloc_hook = __realloc_hook;
+	  __realloc_hook = tr_reallochook;
+	}
+    }
+}
+
+void
+muntrace ()
+{
+  if (mallstream == NULL)
+    return;
+
+  fprintf (mallstream, "= End\n");
+  fclose (mallstream);
+  mallstream = NULL;
+  __free_hook = tr_old_free_hook;
+  __malloc_hook = tr_old_malloc_hook;
+  __realloc_hook = tr_old_realloc_hook;
+}