[PATCH] Re: Multiple apparent leaks in dwarf2.c

[John Levon <levon at movementarian dot org>]

On Thu, Apr 21, 2005 at 07:03:40AM +0100, John Levon wrote:

> These appear to indeed be valid leaks: the code is using the
> non-objalloc'd bfd_realloc/bfd_malloc routines, but there's nothing to
> clear up the debug info stash that I can see (binutils 2.15).

Here's a patch that fixes up the issues I found in dwarf2.c. With this
patch applied to CVS, our application is valgrind-clean.

thanks,
john

Index: binutils-cvs/bfd/dwarf2.c
===================================================================
RCS file: /cvs/src/src/bfd/dwarf2.c,v
retrieving revision 1.65
diff -u -a -p -r1.65 dwarf2.c
--- binutils-cvs/bfd/dwarf2.c	3 Apr 2005 20:36:37 -0000	1.65
+++ binutils-cvs/bfd/dwarf2.c	23 Apr 2005 20:45:22 -0000
@@ -447,11 +447,26 @@ read_abbrevs (bfd *abfd, bfd_uint64_t of
 	{
 	  if ((cur_abbrev->num_attrs % ATTR_ALLOC_CHUNK) == 0)
 	    {
+	      struct attr_abbrev *tmp;
 	      amt = cur_abbrev->num_attrs + ATTR_ALLOC_CHUNK;
 	      amt *= sizeof (struct attr_abbrev);
-	      cur_abbrev->attrs = bfd_realloc (cur_abbrev->attrs, amt);
-	      if (! cur_abbrev->attrs)
-		return 0;
+	      tmp = bfd_realloc (cur_abbrev->attrs, amt);
+	      if (! tmp)
+	        {
+	          size_t i;
+
+	          for (i = 0; i < ABBREV_HASH_SIZE; i++)
+	            {
+	            struct abbrev_info *abbrev = abbrevs[i];
+	            while (abbrev)
+	              {
+	                free (abbrev->attrs);
+	                abbrev = abbrev->next;
+	              }
+	            }
+	          return 0;
+	        }
+	      cur_abbrev->attrs = tmp;
 	    }
 
 	  cur_abbrev->attrs[cur_abbrev->num_attrs].name
@@ -963,11 +978,16 @@ decode_line_info (struct comp_unit *unit
 
       if ((table->num_dirs % DIR_ALLOC_CHUNK) == 0)
 	{
+	  char **tmp;
 	  amt = table->num_dirs + DIR_ALLOC_CHUNK;
 	  amt *= sizeof (char *);
-	  table->dirs = bfd_realloc (table->dirs, amt);
-	  if (! table->dirs)
-	    return 0;
+	  tmp = bfd_realloc (table->dirs, amt);
+	  if (! tmp)
+	    {
+	      free (table->dirs);
+	      return 0;
+	    }
+	  table->dirs = tmp;
 	}
 
       table->dirs[table->num_dirs++] = cur_dir;
@@ -982,11 +1002,17 @@ decode_line_info (struct comp_unit *unit
 
       if ((table->num_files % FILE_ALLOC_CHUNK) == 0)
 	{
+	  struct fileinfo *tmp;
 	  amt = table->num_files + FILE_ALLOC_CHUNK;
 	  amt *= sizeof (struct fileinfo);
-	  table->files = bfd_realloc (table->files, amt);
-	  if (! table->files)
-	    return 0;
+	  tmp = bfd_realloc (table->files, amt);
+	  if (! tmp)
+	    {
+	      free (table->files);
+	      free (table->dirs);
+	      return 0;
+	    }
+	  table->files = tmp;
 	}
 
       table->files[table->num_files].name = cur_file;
@@ -1073,11 +1099,18 @@ decode_line_info (struct comp_unit *unit
 		  line_ptr += bytes_read;
 		  if ((table->num_files % FILE_ALLOC_CHUNK) == 0)
 		    {
+		      struct fileinfo *tmp;
 		      amt = table->num_files + FILE_ALLOC_CHUNK;
 		      amt *= sizeof (struct fileinfo);
-		      table->files = bfd_realloc (table->files, amt);
-		      if (! table->files)
-			return 0;
+		      tmp = bfd_realloc (table->files, amt);
+		      if (! tmp)
+		        {
+			  free (table->files);
+			  free (table->dirs);
+			  free (filename);
+			  return 0;
+		        }
+		      table->files = tmp;
 		    }
 		  table->files[table->num_files].name = cur_file;
 		  table->files[table->num_files].dir =
@@ -1094,6 +1127,9 @@ decode_line_info (struct comp_unit *unit
 		default:
 		  (*_bfd_error_handler) (_("Dwarf Error: mangled line number section."));
 		  bfd_set_error (bfd_error_bad_value);
+		  free (filename);
+		  free (table->files);
+		  free (table->dirs);
 		  return 0;
 		}
 	      break;
@@ -2003,3 +2039,39 @@ _bfd_dwarf2_find_nearest_line (bfd *abfd
 
   return FALSE;
 }
+
+void
+_bfd_dwarf2_cleanup_debug_info(bfd *abfd)
+{
+  struct comp_unit *each;
+  struct dwarf2_debug *stash = elf_tdata (abfd)->dwarf2_find_line_info;
+
+  if (! stash)
+    return;
+
+  for (each = stash->all_comp_units; each; each = each->next_unit)
+    {
+      struct abbrev_info **abbrevs = each->abbrevs;
+      size_t i;
+
+      for (i = 0; i < ABBREV_HASH_SIZE; i++)
+        {
+          struct abbrev_info *abbrev = abbrevs[i];
+          while (abbrev)
+            {
+              free (abbrev->attrs);
+              abbrev = abbrev->next;
+            }
+        }
+
+      if (each->line_table)
+        {
+          free (each->line_table->dirs);
+          free (each->line_table->files);
+        }
+    }
+
+  free (stash->dwarf_abbrev_buffer);
+  free (stash->dwarf_line_buffer);
+  free (stash->dwarf_ranges_buffer);
+}
Index: binutils-cvs/bfd/elf-bfd.h
===================================================================
RCS file: /cvs/src/src/bfd/elf-bfd.h,v
retrieving revision 1.179
diff -u -a -p -r1.179 elf-bfd.h
--- binutils-cvs/bfd/elf-bfd.h	4 Apr 2005 16:11:02 -0000	1.179
+++ binutils-cvs/bfd/elf-bfd.h	23 Apr 2005 20:45:25 -0000
@@ -1728,6 +1728,8 @@ extern int bfd_elf_link_record_local_dyn
 
 extern bfd_boolean _bfd_elf_close_and_cleanup
   (bfd *);
+extern void _bfd_dwarf2_cleanup_debug_info
+  (bfd *);
 extern bfd_reloc_status_type _bfd_elf_rel_vtable_reloc_fn
   (bfd *, arelent *, struct bfd_symbol *, void *,
    asection *, bfd *, char **);
Index: binutils-cvs/bfd/elf.c
===================================================================
RCS file: /cvs/src/src/bfd/elf.c,v
retrieving revision 1.280
diff -u -a -p -r1.280 elf.c
--- binutils-cvs/bfd/elf.c	21 Apr 2005 12:13:37 -0000	1.280
+++ binutils-cvs/bfd/elf.c	23 Apr 2005 20:45:36 -0000
@@ -6676,6 +6676,8 @@ _bfd_elf_close_and_cleanup (bfd *abfd)
 	_bfd_elf_strtab_free (elf_shstrtab (abfd));
     }
 
+  _bfd_dwarf2_cleanup_debug_info (abfd);
+
   return _bfd_generic_close_and_cleanup (abfd);
 }