Re: [committed][gdb/testsuite] Add gdb.base/eh_return.exp

[Tom de Vries <tdevries@suse.de>]

On 8/26/20 7:20 PM, Luis Machado wrote:
> On 8/16/20 8:31 AM, Tom de Vries wrote:
>> Hi,
>>
>> In PR25350, an internal error was reported:
>> ...
>> (gdb) break *eh2+0x7e
>> Breakpoint 1 at 0x13e2: file small.c, line 38.
>> (gdb) run
>> Starting program: a.out
>> [Thread debugging using libthread_db enabled]
>> Using host libthread_db library "/usr/lib/libthread_db.so.1".
>>
>> Breakpoint 1, 0x00005555555553e2 in eh2 (
>> frame.c:558: internal-error: frame_id get_frame_id(frame_info*): \
>>    Assertion `stashed' failed.
>> A problem internal to GDB has been detected,
>> further debugging may prove unreliable.
>> ...
>>
>> The internal error does not reproduce after recent commit 547ce8f00b
>> "[gdb/backtrace] Fix printing of fortran string args".
>>
>> Add the corresponding test-case as regression test, given that the
>> code is
>> rather atypical.
>>
>> Tested on x86_64-linux.
> 
> This doesn't work so well on aarch64-linux because the breakpoint
> location from before running the program doesn't exists after running
> it. Things get relocated.
> 

Right, I don't think that's architecture-related.

I'm running into the same issue on x86_64-linux with target board
unix/-fPIE/-pie.

> -- 
> 
> (gdb) break *0x000000000000099c^M
> Breakpoint 1 at 0x99c: file
> /home/luis.machado/work/tcwg/build/binutils-gdb-master/gdb/testsuite/../../../../repos/binutils-gdb/gdb/testsuite/gdb.base/eh_return.c,
> line 54.^M
> (gdb) PASS: gdb.base/eh_return.exp: setting breakpoint at
> *0x000000000000099c
> run ^M
> Starting program:
> /home/luis.machado/work/tcwg/build/binutils-gdb-master/gdb/testsuite/outputs/gdb.base/eh_return/eh_return
> ^M
> Warning:^M
> Cannot insert breakpoint 1.^M
> Cannot access memory at address 0x99c^M
> ^M
> (gdb) FAIL: gdb.base/eh_return.exp: hit breakpoint
> 
> -- 
> 
> Shouldn't we insert a breakpoint after the relocation has happened?

As I mentioned in the test-case:
...
# The assert did not reproduce when running to main, and continuing to
# the breakpoint, so instead, run to the breakpoint.
...
So I'm afraid that's not going to work.

> Or
> add the breakpoint to a symbolic reference?

Yeah, that might work.  If not, we'll have to restrict this to no-pie.

Thanks,
- Tom