Re: [PATCH] Remove gdb_bfd_stash_filename to fix crash with fix of binutils/11983

[Hui Zhu <hui_zhu at mentor dot com>]

On 01/06/14 16:25, Tom Tromey wrote:
> > > > > > "Hui" == Hui Zhu <hui_zhu@mentor.com> writes:
>
> Hui> Thanks.  Post a new version.
>
> Thanks Hui.  This is definitely the direction I think the code should
> go.
>
> Hui>  --- a/gdb/symfile-mem.c
> Hui> +++ b/gdb/symfile-mem.c
> Hui> @@ -104,11 +104,7 @@ symbol_file_add_from_memory (struct bfd
> Hui>    if (name == NULL)
> Hui>  nbfd-> filename = "shared object read from target memory";
> Hui>    else
> Hui> -    {
> Hui> -      nbfd->filename = name;
> Hui> -      gdb_bfd_stash_filename (nbfd);
> Hui> -      xfree (name);
> Hui> -    }
> Hui> +    nbfd->filename = name;
> Hui>   cleanup = make_cleanup_bfd_unref (nbfd);
>
> In this hunk there are two things to note.
>
> First, there is an earlier assignment to filename (in the context above)
> that should use xstrdup.
>
> Second, the new assignment really ought to free the old nbfd->filename
> first.

I changed this part to:
  xfree (bfd_get_filename (nbfd));
  if (name == NULL)
    nbfd->filename = xstrdup ("shared object read from target memory");
  else
    nbfd->filename = name;

> There are also some assignments that must be fixed that do not use
> gdb_bfd_stash_filename:
>
>      solib-aix.c:solib_aix_bfd_open
>      solib-darwin.c:darwin_bfd_open

I fixed them.

>      solib-spu.c:spu_bfd_open
>      spu-linux-nat.c:spu_bfd_open

These two functions have used xstrdup, for example:
      if (sect_size > 20)
	{
	  char *buf = alloca (sect_size - 20 + strlen (original_name) + 1);

	  bfd_get_section_contents (abfd, spu_name, buf, 20, sect_size - 20);
	  buf[sect_size - 20] = '\0';

	  strcat (buf, original_name);

	  xfree ((char *)abfd->filename);
	  abfd->filename = xstrdup (buf);
	}

So I didn't update them.


> If you don't get to this soon, no worries, I will add these to your
> patch tomorrow morning and check it in.
>
> Tom

Thunderbird and maybe some others will see some empty lines because this patch include page identifier.

Thanks,
Hui

2014-01-06  Hui Zhu  <hui@codesourcery.com>

	* gdb_bfd.c (gdb_bfd_stash_filename): Removed.
	(gdb_bfd_open): Removed gdb_bfd_stash_filename.
	(gdb_bfd_fopen): Ditto.
	(gdb_bfd_openr): Ditto.
	(gdb_bfd_openw): Ditto.
	(gdb_bfd_openr_iovec): Ditto.
	(gdb_bfd_fdopenr): Ditto.
	* gdb_bfd.h (gdb_bfd_stash_filename): Removed.
	* solib-aix.c (solib_aix_bfd_open): Alloc object_bfd->filename
	with xstrdup.
	* solib-darwin.c (darwin_bfd_open): Alloc res->filename
	with xstrdup.
	* symfile-mem.c (symbol_file_add_from_memory): Removed
	gdb_bfd_stash_filename.

--- a/gdb/gdb_bfd.c
+++ b/gdb/gdb_bfd.c
@@ -57,21 +57,6 @@ struct gdb_bfd_section_data
 
 static htab_t all_bfds;
 
-/* See gdb_bfd.h.  */
-
-void
-gdb_bfd_stash_filename (struct bfd *abfd)
-{
-  char *name = bfd_get_filename (abfd);
-  char *data;
-
-  data = bfd_alloc (abfd, strlen (name) + 1);
-  strcpy (data, name);
-
-  /* Unwarranted chumminess with BFD.  */
-  abfd->filename = data;
-}
-
 /* An object of this type is stored in each BFD's user data.  */
 
 struct gdb_bfd_data
@@ -204,7 +189,6 @@ gdb_bfd_open (const char *name, const ch
   gdb_assert (!*slot);
   *slot = abfd;
 
-  gdb_bfd_stash_filename (abfd);
   gdb_bfd_ref (abfd);
   return abfd;
 }
@@ -490,10 +474,7 @@ gdb_bfd_fopen (const char *filename, con
   bfd *result = bfd_fopen (filename, target, mode, fd);
 
   if (result)
-    {
-      gdb_bfd_stash_filename (result);
-      gdb_bfd_ref (result);
-    }
+    gdb_bfd_ref (result);
 
   return result;
 }
@@ -506,10 +487,7 @@ gdb_bfd_openr (const char *filename, con
   bfd *result = bfd_openr (filename, target);
 
   if (result)
-    {
-      gdb_bfd_stash_filename (result);
-      gdb_bfd_ref (result);
-    }
+    gdb_bfd_ref (result);
 
   return result;
 }
@@ -522,10 +500,7 @@ gdb_bfd_openw (const char *filename, con
   bfd *result = bfd_openw (filename, target);
 
   if (result)
-    {
-      gdb_bfd_stash_filename (result);
-      gdb_bfd_ref (result);
-    }
+    gdb_bfd_ref (result);
 
   return result;
 }
@@ -553,10 +528,7 @@ gdb_bfd_openr_iovec (const char *filenam
 				 pread_func, close_func, stat_func);
 
   if (result)
-    {
-      gdb_bfd_ref (result);
-      gdb_bfd_stash_filename (result);
-    }
+    gdb_bfd_ref (result);
 
   return result;
 }
@@ -603,10 +575,7 @@ gdb_bfd_fdopenr (const char *filename, c
   bfd *result = bfd_fdopenr (filename, target, fd);
 
   if (result)
-    {
-      gdb_bfd_ref (result);
-      gdb_bfd_stash_filename (result);
-    }
+    gdb_bfd_ref (result);
 
   return result;
 }
--- a/gdb/gdb_bfd.h
+++ b/gdb/gdb_bfd.h
@@ -24,12 +24,6 @@
 
 DECLARE_REGISTRY (bfd);
 
-/* Make a copy ABFD's filename using bfd_alloc, and reassign it to the
-   BFD.  This ensures that the BFD's filename has the same lifetime as
-   the BFD itself.  */
-
-void gdb_bfd_stash_filename (struct bfd *abfd);
-
 /* Open a read-only (FOPEN_RB) BFD given arguments like bfd_fopen.
    Returns NULL on error.  On success, returns a new reference to the
    BFD, which must be freed with gdb_bfd_unref.  BFDs returned by this
@@ -79,22 +73,22 @@ int gdb_bfd_crc (struct bfd *abfd, unsig
 
 
 /* A wrapper for bfd_fopen that initializes the gdb-specific reference
-   count and calls gdb_bfd_stash_filename.  */
+   count.  */
 
 bfd *gdb_bfd_fopen (const char *, const char *, const char *, int);
 
 /* A wrapper for bfd_openr that initializes the gdb-specific reference
-   count and calls gdb_bfd_stash_filename.  */
+   count.  */
 
 bfd *gdb_bfd_openr (const char *, const char *);
 
 /* A wrapper for bfd_openw that initializes the gdb-specific reference
-   count and calls gdb_bfd_stash_filename.  */
+   count.  */
 
 bfd *gdb_bfd_openw (const char *, const char *);
 
 /* A wrapper for bfd_openr_iovec that initializes the gdb-specific
-   reference count and calls gdb_bfd_stash_filename.  */
+   reference count.  */
 
 bfd *gdb_bfd_openr_iovec (const char *filename, const char *target,
 			  void *(*open_func) (struct bfd *nbfd,
@@ -112,12 +106,12 @@ bfd *gdb_bfd_openr_iovec (const char *fi
 					    struct stat *sb));
 
 /* A wrapper for bfd_openr_next_archived_file that initializes the
-   gdb-specific reference count and calls gdb_bfd_stash_filename.  */
+   gdb-specific reference count.  */
 
 bfd *gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous);
 
 /* A wrapper for bfd_fdopenr that initializes the gdb-specific
-   reference count and calls gdb_bfd_stash_filename.  */
+   reference count.  */
 
 bfd *gdb_bfd_fdopenr (const char *filename, const char *target, int fd);
 
--- a/gdb/solib-aix.c
+++ b/gdb/solib-aix.c
@@ -728,12 +728,8 @@ solib_aix_bfd_open (char *pathname)
      to allow commands listing all shared libraries to display that
      synthetic name.  Otherwise, we would only be displaying the name
      of the archive member object.  */
-    {
-      char *data = bfd_alloc (object_bfd, path_len + 1);
-
-      strcpy (data, pathname);
-      object_bfd->filename = data;
-    }
+  xfree (bfd_get_filename (object_bfd));
+  object_bfd->filename = xstrdup (pathname);
 
   gdb_bfd_unref (archive_bfd);
   do_cleanups (cleanup);
--- a/gdb/solib-darwin.c
+++ b/gdb/solib-darwin.c
@@ -621,12 +621,8 @@ darwin_bfd_open (char *pathname)
   /* The current filename for fat-binary BFDs is a name generated
      by BFD, usually a string containing the name of the architecture.
      Reset its value to the actual filename.  */
-    {
-      char *data = bfd_alloc (res, strlen (pathname) + 1);
-
-      strcpy (data, pathname);
-      res->filename = data;
-    }
+  xfree (bfd_get_filename (res));
+  res->filename = xstrdup (pathname);
 
   gdb_bfd_unref (abfd);
   return res;
--- a/gdb/symfile-mem.c
+++ b/gdb/symfile-mem.c
@@ -101,14 +101,11 @@ symbol_file_add_from_memory (struct bfd
     error (_("Failed to read a valid object file image from memory."));
 
   gdb_bfd_ref (nbfd);
+  xfree (bfd_get_filename (nbfd));
   if (name == NULL)
-    nbfd->filename = "shared object read from target memory";
+    nbfd->filename = xstrdup ("shared object read from target memory");
   else
-    {
-      nbfd->filename = name;
-      gdb_bfd_stash_filename (nbfd);
-      xfree (name);
-    }
+    nbfd->filename = name;
 
   cleanup = make_cleanup_bfd_unref (nbfd);