Re: [PATCH] gdb/jit: fix jit-reader linetable integrity

[Simon Marchi <simon.marchi@polymtl.ca>]

On 2024-12-22 06:46, liuyang22 wrote:
> On Dec 22, 2024 10:12, Simon Marchi<simon.marchi@polymtl.ca> wrote:
>> On 2024-12-21 03:30, Yang Liu wrote:
>> > The custom linetable functionality in GDB's JIT Interface has been broken
>> > since commit 1acc9dca423f78e44553928f0de839b618c13766.
>> > 
>> > In that commit, linetables were made independent from the objfile, which
>> > requires objfile->section_offsets to be initialized. However, section_offsets
>> > were never initialized in objfiles generated by GDB's JIT Interface
>> > with custom jit-readers, leading to GDB crashes when stepping into JITed code
>> > blocks with the following command already executed:
>> >
>> > jit-reader-load libmygdbjitreader.so
>> >
>> > This patch fixes the issue by initializing the minimum section_offsets required
>> > for linetable parsing procedures.
>>
>> I can imagine how the problem can manifest, but do you have a
>> reproducer? I tried stepping with the binary of test
>> gdb.base/jit-reader.exp, but I couldn't get it to crash. Ideally, this
>> fix should come with a test to demonstrate the problem and the fix.
>> 
> 
> Hi Simon,
> 
> Thanks for the review!
> 
> Below is a reproducer, but I have no idea how GDB testsuite works, is it possible
> to put this in?

Thanks for the quick response.  It should be fairly easy to turn this
into a test.  I'll give it a shot if I find a bit of free time during
the holidays.

Simon