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[RFC] problem in solib-svr4/enable_break
- From: Michael Snyder <msnyder at vmware dot com>
- To: "gdb-patches at sourceware dot org" <gdb-patches at sourceware dot org>
- Date: Thu, 14 Jan 2010 14:08:03 -0800
- Subject: [RFC] problem in solib-svr4/enable_break
The attached patch isn't for submission, but just to help
illustrate the problem. It fixes a symptom but seems kludgy
to me (and not well understood).
Here's the problem. I have a kernel image which is statically
linked and PIE. When it gets to enable_break, it succeeds in
finding "debug_base", but "debug_base" is in the text section
of the main executable (ie. not in the dynamic loader, which is
not actually present).
Therefore we compute info->interp_text_sect_low and
info->interp_text_sect_high as the start and end of the text
section of the main executable. And therefore whenever we
call in_solib_dynsym_resolve_code(), it returns TRUE, and
therefore source level stepping won't work.
This simple patch just checks to see whether "tmp_bfd" (which
is supposed to be the dynamic loader) matches exec_bfd, and
if so, lets interp_text_sect_low and interp_text_sect_high
remain zero.
Anybody got a better suggestion?
Index: solib-svr4.c
===================================================================
RCS file: /cvs/src/src/gdb/solib-svr4.c,v
retrieving revision 1.110
diff -u -p -r1.110 solib-svr4.c
--- solib-svr4.c 8 Jan 2010 22:52:03 -0000 1.110
+++ solib-svr4.c 14 Jan 2010 21:57:37 -0000
@@ -1312,7 +1312,10 @@ enable_break (struct svr4_info *info, in
os->objfile->sect_index_text);
interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
- if (interp_sect)
+
+ /* Skip if tmp_bfd points to main executable. */
+ if (interp_sect
+ && strcmp (tmp_bfd->filename, exec_bfd->filename) != 0)
{
info->interp_text_sect_low =
bfd_section_vma (tmp_bfd, interp_sect) + load_addr;