gdb/gdb-pie-rerun.patch

128 lines
4.1 KiB
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http://sourceware.org/ml/gdb-patches/2010-03/msg00868.html
Subject: [patch] PIE: Fix back re-run [Re: [patch] svr4_exec_displacement success indicator]
Hi,
currently:
$ echo 'main(){}'|gcc -o 1 -fPIE -pie -x c -; ./gdb -nx -ex 'set disable-randomization off' -ex 'b main' -ex r -ex c -ex r ./1
Breakpoint 1 at 0x6b0
Starting program: /home/jkratoch/redhat/gdb-clean/gdb/testsuite/1
Breakpoint 1, 0x00007fbf73e8c6b0 in main ()
Continuing.
Program exited with code 0140.
Starting program: /home/jkratoch/redhat/gdb-clean/gdb/testsuite/1
Error in re-setting breakpoint 1: Cannot access memory at address 0x7fbf73e8c6ac
It is since:
[patch] svr4_exec_displacement success indicator [Re: PIE question]
http://sourceware.org/ml/gdb-patches/2010-03/msg00336.html
On Mon, 08 Mar 2010 22:53:58 +0100, Jan Kratochvil wrote:
> Attached these changes:
>
> * svr4_exec_displacement calling convention should have success indicator.
>
> * Preserving now section_offsets if they are already set, inspired by
> init_objfile_sect_indices.
>
> I believe either of parts would be sufficient for this problem.
The first part has caused the regression for PIE on native x86* GNU/Linux host.
As I believe for Daniel J.'s seen regression of `qOffsets' the second already
checked-in part is sufficient - I would like to remove the first part.
OK to check it in?
No regressions on {x86_64,x86_64-m32,i686}-fedora12-linux-gnu.
(I do not think one needs to think about 7.1-branch as it is not a regression
against any FSF GDB release.)
Thanks,
Jan
gdb/
2010-03-25 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix re-run of PIE executable.
* solib-svr4.c (svr4_relocate_main_executable) <symfile_objfile>: Remove
the part of pre-set SYMFILE_OBJFILE->SECTION_OFFSETS.
gdb/testsuite/
2010-03-25 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix re-run of PIE executable.
* gdb.base/break-interp.exp (test_ld): Turn off "disable-randomization".
Remove $displacement_main to match the solib-svr4.c change. New "kill"
and re-"run" of the inferior.
--- a/gdb/solib-svr4.c
+++ b/gdb/solib-svr4.c
@@ -1791,17 +1791,10 @@ svr4_relocate_main_executable (void)
{
CORE_ADDR displacement;
- if (symfile_objfile)
- {
- int i;
-
- /* Remote target may have already set specific offsets by `qOffsets'
- which should be preferred. */
-
- for (i = 0; i < symfile_objfile->num_sections; i++)
- if (ANOFFSET (symfile_objfile->section_offsets, i) != 0)
- return;
- }
+ /* SYMFILE_OBJFILE->SECTION_OFFSETS may now contain displacement from the
+ previous run of the inferior. Re-set it according to the current value,
+ if we can find it out. But otherwise keep it as for remote target it may
+ have been pre-set by the `qOffsets' packet. */
if (! svr4_exec_displacement (&displacement))
return;
--- a/gdb/testsuite/gdb.base/break-interp.exp
+++ b/gdb/testsuite/gdb.base/break-interp.exp
@@ -416,25 +416,28 @@ proc test_ld {file ifmain trynosym displacement} {
# Print the "PIE (Position Independent Executable) displacement" message.
gdb_test "set verbose on"
+ # A bit better test coverage.
+ gdb_test "set disable-randomization off"
+
reach "dl_main" "run segv" $displacement
gdb_test "bt" "#0 +\[^\r\n\]*\\mdl_main\\M.*" "dl bt"
if $ifmain {
# Displacement message will be printed the second time on initializing
- # the linker from svr4_special_symbol_handling. If any ANOFFSET has
- # been already set as non-zero the detection will no longer be run.
- if {$displacement == "NONZERO"} {
- set displacement_main "NONE"
- } else {
- set displacement_main $displacement
- }
- reach "main" continue $displacement_main
+ # the linker from svr4_special_symbol_handling.
+ reach "main" continue $displacement
reach "libfunc" continue "NONE"
gdb_test "bt" "#0 +\[^\r\n\]*\\mlibfunc\\M\[^\r\n\]*\r\n#1 +\[^\r\n\]*\\mmain\\M.*" "main bt"
+ }
+ # Try re-run if the new PIE displacement takes effect.
+ gdb_test "kill" "" "kill" {Kill the program being debugged\? \(y or n\) } "y"
+ reach "dl_main" "run segv" $displacement
+
+ if $ifmain {
test_core $file $displacement
test_attach $file $displacement