Re: [PING][8.3 backport] Adjust i386 registers on SystemTap probes' arguments (PR breakpoints/24541)

[Sergio Durigan Junior <sergiodj at redhat dot com>]

On Wednesday, September 04 2019, Tom de Vries wrote:

> On 21-08-19 11:11, Tom de Vries wrote:
>> [ was: Re: Updates on GDB 8.3.1 and GDB 9 releases (2019-07-14) ]
>> 
>> On 12-08-19 23:44, Sergio Durigan Junior wrote:
>>> On Tuesday, July 16 2019, Tom de Vries wrote:
>> 
>>>> The stap-probe.exp fix looks like 7d7571f0c1 "Adjust i386 registers on
>>>> SystemTap probes' arguments (PR breakpoints/24541)".
>>>>
>>>> If bisected the base/info-shared.exp fix to the same commit (which I did
>>>> not expect).
>>>
>>> This is because GDB uses SystemTap probes behind the scenes to deal with
>>> the linker-debugger interface.  I don't have the logs here, but I'd
>>> guess there's something nasty going on because of the -m32 stap bug...
>>>
>>>> So I wonder if this commit is a good candidate to backport.
>>>
>>> I'd say so.  The commit is simple enough, hasn't caused any regressions
>>> so far, and fixes a decent number of failures on -m32.
>> 
>> The patch does not apply cleanly on gdb-8.3-branch, but it does if I
>> first apply commit 677052f2a5 (Make
>> stap-probe.c:stap_parse_register_operand's "regname" an std::string).
>> 
>> I've tested the two commits on top of gdb-8.3-branch for x86_64-linux
>> with unix/-m32 target board.
>> 
>> No regression, and these progressions:
>> ...
>> -FAIL: gdb.base/catch-load.exp: plain unload: continue
>> +PASS: gdb.base/catch-load.exp: plain unload: continue
>> -FAIL: gdb.base/catch-load.exp: rx unload: continue
>> +PASS: gdb.base/catch-load.exp: rx unload: continue
>> -FAIL: gdb.base/info-shared.exp: info sharedlibrary #7
>> +PASS: gdb.base/info-shared.exp: info sharedlibrary #7
>> -FAIL: gdb.base/info-shared.exp: info sharedlibrary #8
>> +PASS: gdb.base/info-shared.exp: info sharedlibrary #8
>> -FAIL: gdb.base/stap-probe.exp: without semaphore, not optimized: check
>> $_probe_arg1 for probe m4
>> +PASS: gdb.base/stap-probe.exp: without semaphore, not optimized: check
>> $_probe_arg1 for probe m4
>> -FAIL: gdb.base/stap-probe.exp: with semaphore, not optimized: check
>> $_probe_arg1 for probe m4
>> +PASS: gdb.base/stap-probe.exp: with semaphore, not optimized: check
>> $_probe_arg1 for probe m4
>> -FAIL: gdb.base/stap-probe.exp: without semaphore, optimized: check
>> $_probe_arg1 for probe m4
>> +PASS: gdb.base/stap-probe.exp: without semaphore, optimized: check
>> $_probe_arg1 for probe m4
>> -FAIL: gdb.base/stap-probe.exp: without semaphore, optimized: print
>> $_probe_arg1 for probe ps
>> +PASS: gdb.base/stap-probe.exp: without semaphore, optimized: print
>> $_probe_arg1 for probe ps
>> -FAIL: gdb.base/stap-probe.exp: with semaphore, optimized: check
>> $_probe_arg1 for probe m4
>> +PASS: gdb.base/stap-probe.exp: with semaphore, optimized: check
>> $_probe_arg1 for probe m4
>> -FAIL: gdb.base/stap-probe.exp: with semaphore, optimized: print
>> $_probe_arg1 for probe ps
>> +PASS: gdb.base/stap-probe.exp: with semaphore, optimized: print
>> $_probe_arg1 for probe ps
>> -FAIL: gdb.base/unload.exp: continuing to unloaded libfile
>> +PASS: gdb.base/unload.exp: continuing to unloaded libfile
>> -FAIL: gdb.base/unload.exp: continuing to unloaded libfile
>> +PASS: gdb.base/unload.exp: continuing to unloaded libfile
>> -FAIL: gdb.base/unload.exp: continuing to unloaded libfile2
>> +PASS: gdb.base/unload.exp: continuing to unloaded libfile2
>> -FAIL: gdb.mi/mi-breakpoint-changed.exp: test_pending_resolved: pending
>> resolved: breakpoint on pendfunc3 pending again
>> -FAIL: gdb.mi/mi-breakpoint-changed.exp: test_pending_resolved: pending
>> resolved: (timeout)
>> +PASS: gdb.mi/mi-breakpoint-changed.exp: test_pending_resolved: pending
>> resolved: breakpoint on pendfunc3 pending again
>> +PASS: gdb.mi/mi-breakpoint-changed.exp: test_pending_resolved: pending
>> resolved:
>> -FAIL: gdb.mi/mi-catch-load.exp: catch-unload: solib-event stop
>> +PASS: gdb.mi/mi-catch-load.exp: catch-unload: solib-event stop
>> -# of expected passes           65957
>> -# of unexpected failures       235
>> +# of expected passes           65973
>> +# of unexpected failures       219
>> ...
>> 
>> OK to backport both commits to gdb-8.3-branch?
>
> Ping.

I'm the maintainer of the SystemTap/generic probe interfaces, but I'm
not sure I can give you the green light for you in this case, because
it's about backporting to a branch.  In any case, just to make sure I'm
clear: this one LGTM.

Thanks,

-- 
Sergio
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