[PATCH] Remove gdb_bfd_stash_filename to fix crash with fix of binutils/11983
Hui Zhu
hui_zhu@mentor.com
Sun Jan 5 15:48:00 GMT 2014
On 01/05/14 23:05, Sergio Durigan Junior wrote:
> On Saturday, January 04 2014, Hui Zhu wrote:
>
>> Got double free or corruption with new GDB:
>> (gdb) r
>> Starting program: /home/teawater/tmp/a.out
>> *** glibc detected *** /home/teawater/gdb/git/bgdbno/gdb/gdb: double free or corruption (out): 0x00000000011ed4d0 ***
>> ======= Backtrace: =========
>> /lib/x86_64-linux-gnu/libc.so.6(+0x7eb96)[0x7ffff65f5b96]
>
> [...]
>
>> The reason is when GDB open bfd, it will call gdb_bfd_stash_filename to the memory of abfd.
>> But in binutils/11983, it add "(_bfd_delete_bfd): Free filename." So when gdb try to close the bfd, it will crash.
>>
>> I make a patch to remove all gdb_bfd_stash_filename to fix this issue.
>
> Hm, given what Tom said on
> <https://sourceware.org/bugzilla/show_bug.cgi?id=11983#c12>, I believe
> this is the right way to solve the problem.
>
> Edjunior posted a patch a few days ago that duplicated the name. I'm
> adding him on the Cc. I'm also adding Nick and Tom.
>
> BTW, Hui, your patch seems to have been mangled by your MUA.
Thanks. Post a new version.
Best,
Hui
2014-01-05 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.
* 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/symfile-mem.c
+++ b/gdb/symfile-mem.c
@@ -104,11 +104,7 @@ symbol_file_add_from_memory (struct bfd
if (name == NULL)
nbfd->filename = "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);
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