On Sun, Sep 10, 2017 at 2:11 PM, Ian Lance Taylor <iant@google.com> wrote:
> On Sat, Jul 29, 2017 at 1:42 PM, Denis Khalikov
> <d.khalikov@partner.samsung.com> wrote:
>>
>> Hello Ian,
>> thanks for review.
>> I've updated the patch, can you please take a look.
>
> Apologies again for the length of time it took to reply.  I've had a
> hard time understanding the patch.  It's quite likely that I don't
> understand how it works, but it seems to pass the same file descriptor
> to process_elf_header twice.  It seems to look for debug files with
> the buildid in places where they will not be found.  It seems to work
> out the file name a second time, even though the file name must
> already be known.  I eventually just wrote my own implementation.
>
> Could you try this patch and see if it works for your cases?  The
> patch is against current mainline.  Thanks.

I have committed this patch as appended.  Bootstrapped and tested on
x86_64-pc-linux-gnu.

Ian

2017-09-20  Ian Lance Taylor  <iant@golang.org>
    Denis Khalikov  <d.khalikov@partner.samsung.com>

PR sanitizer/77631
Support for external debug info.
* elf.c: Include <errno.h>, <sys/stat.h>, <unistd.h>.
(S_ISLNK): Define if not defined.
(xstrnlen): Define if strnlen is not available.
(b_elf_note): Define type.
(NT_GNU_BUILD_ID): Define macro.
(elf_crc32, elf_crc32_file): New static functions.
(elf_is_symlink, elf_readlink): New static functions.
(elf_open_debugfile_by_buildid): New static function.
(elf_try_debugfile): New static function.
(elf_find_debugfile_by_debuglink): New static function.
(elf_open_debugfile_by_debuglink): New static function.
(elf_add): Add filename and debuginfo parameters.  Adjust all
callers.  Look for external debug info notes, and try to fetch
debug info from external file.
(struct phdr_data): Add exe_filename field.
(phdr_callback): Pass filename to elf_add.
(backtrace_initialize): Add filename parameter.
* internal.h (backtrace_initialize): Add filename parameter.
* fileline.c (fileline_initialize): Pass filename to
backtrace_initialize.
* pecoff.c (fileline_initialize): Add unused filename parameter.
* unknown.c (fileline_initialize): Likewise.
* xcoff.c (fileline_initialize): Likewise.
* configure.ac: Check for objcopy --add-gnu-debuglink.
* Makefile.am (dtest): New test target.
* configure, Makefile.in: Rebuild.