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author | Tom de Vries <tdevries@suse.de> | 2021-01-08 11:11:16 +0100 |
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committer | Tom de Vries <tdevries@suse.de> | 2021-01-08 11:11:16 +0100 |
commit | 1940319c0ef6271cc42a5d4c359be90063948710 (patch) | |
tree | 318ea63963a6b6cb6b6726487e9e4fc31150c637 /opcodes | |
parent | e343681375c1e5a27ea92486649f6a58163c0e61 (diff) | |
download | gdb-1940319c0ef6271cc42a5d4c359be90063948710.zip gdb-1940319c0ef6271cc42a5d4c359be90063948710.tar.gz gdb-1940319c0ef6271cc42a5d4c359be90063948710.tar.bz2 |
[gdb] Fix internal-error in process_event_stop_test
The function create_exception_master_breakpoint in gdb/breakpoint.c attempts
to set a master exception breakpoint in each objfile. It tries this using
a libgcc/unwind probe, and if that fails then using the
_Unwind_DebugHook symbol:
...
for (objfile *objfile : current_program_space->objfiles ())
{
/* Try using probes. */
if (/* successful */)
continue;
/* Try using _Unwind_DebugHook */
}
...
The preference scheme works ok both if the objfile has debug info, and if it's
stripped.
But it doesn't work when the objfile has a .gnu_debuglink to a .debug file
(and the .debug file is present). What happens is that:
- we first encounter objfile libgcc.debug
- we try using probes, and this fails
- so we try _Unwind_DebugHook, which succeeds
- next we encounter objfile libgcc
- we try using probes, and this succeeds.
So, we end up with a master exception breakpoint in both libgcc (using probes)
and libgcc.debug (using _Unwind_DebugHook).
This eventually causes:
...
(gdb) PASS: gdb.cp/nextoverthrow.exp: post-check - next over a throw 3
next^M
src/gdb/infrun.c:6384: internal-error: \
void process_event_stop_test(execution_control_state*): \
Assertion `ecs->event_thread->control.exception_resume_breakpoint != NULL' \
failed.^M
A problem internal to GDB has been detected,^M
further debugging may prove unreliable.^M
Quit this debugging session? (y or n) FAIL: gdb.cp/nextoverthrow.exp: next
past catch (GDB internal error)
...
To trigger this internal-error, we need to use gcc-10 or later to compile the
test-case, such that it contains the fix for gcc PR97774 - "Incorrect line
info for try/catch".
Fix this by only trying to install the master exception breakpoint in
libgcc.debug using the _Unwind_DebugHook method, if the install using probes
in libgcc failed.
Tested on x86_64-linux.
gdb/ChangeLog:
2021-01-08 Tom de Vries <tdevries@suse.de>
PR gdb/26881
* breakpoint.c (create_exception_master_breakpoint_probe)
(create_exception_master_breakpoint_hook): Factor out
of ...
(create_exception_master_breakpoint): ... here. Only try to install
the master exception breakpoint in objfile.debug using the
_Unwind_DebugHook method, if the install using probes in objfile
failed.
Diffstat (limited to 'opcodes')
0 files changed, 0 insertions, 0 deletions