Re: RFC: Verify AT_ENTRY before using it

Jan Kratochvil
2010-03-12T15:28:49Z

On Wed, 10 Mar 2010 22:11:38 +0100, Jan Kratochvil wrote:
> It has been checked-in without the warning() calls.
[...]
> http://sourceware.org/ml/gdb-cvs/2010-03/msg00096.html
>
> --- src/gdb/ChangeLog 2010/03/10 18:41:37 1.11466
> +++ src/gdb/ChangeLog 2010/03/10 20:50:48 1.11467
> @@ -1,3 +1,16 @@
> +2010-03-10 Jan Kratochvil <jan.kratochvil@redhat.com>
> + Daniel Jacobowitz <dan@codesourcery.com>
> +
> + * solib-svr4.c (read_program_header): Support type == -1 to read
> + all program headers.
> + (read_program_headers_from_bfd): New function.
> + (svr4_static_exec_displacement): Remove and move the comment ...
> + (svr4_exec_displacement): ... here. Remove variable found. New
> + variable displacement. Check also DYNAMIC. Verify DISPLACEMENT
> + alignment for ELF targets. Compare target vs. exec_bfd PHDRs for ELF
> + targets using read_program_headers_from_bfd. Remove the call of
> + svr4_static_exec_displacement.

Is it OK also for gdb_7_1-branch?

Otherwise the minimized attached patch also works for me. Still I would
prefer the full patch from the master branch.

No regressions on {x86_64,x86_64-m32,i686}-fedora13-linux-gnu.

Thanks,
Jan

gdb/
2010-03-12 Jan Kratochvil <jan.kratochvil@redhat.com>

* solib-svr4.c (svr4_relocate_main_executable): Delay the
svr4_exec_displacement call. Return on non-DYNAMIC exec_bfd.

--- a/gdb/solib-svr4.c
+++ b/gdb/solib-svr4.c
@@ -1719,7 +1719,15 @@ svr4_exec_displacement (void)
static void
svr4_relocate_main_executable (void)
{
- CORE_ADDR displacement = svr4_exec_displacement ();
+ CORE_ADDR displacement;
+
+ /* Therefore for ELF it is ET_EXEC and not ET_DYN. Both shared libraries
+ being executed themselves and PIE (Position Independent Executable)
+ executables are ET_DYN. */
+ if (exec_bfd && (bfd_get_file_flags (exec_bfd) & DYNAMIC) == 0)
+ return;
+
+ displacement = svr4_exec_displacement ();

/* Even if DISPLACEMENT is 0 still try to relocate it as this is a new
difference of in-memory vs. in-file addresses and we could already