Re: [PATCH v3] readelf: Save and dump the original section header values

On 04.07.2026 13:06, H.J. Lu wrote:
> On Sat, Jul 4, 2026 at 11:01 AM H.J. Lu <[email protected]> wrote:
>> On Sat, Jul 4, 2026 at 8:39 AM H.J. Lu <[email protected]> wrote:
>>> On Sat, Jul 4, 2026 at 7:49 AM Alan Modra <[email protected]> wrote:
>>>>
>>>> On Fri, Jul 03, 2026 at 10:30:14PM +0800, H.J. Lu wrote:
>>>>> validate_section_info clears the garbage values in the section header
>>>>> to avoid crash later.  Save and dump the original section header values
>>>>> to make the garbage values in the section header visible when dumping
>>>>> section headers.
>>>>
>>>> I think this would be better done the other way around.  ie. have a
>>>> Elf_Internal_Shdr **sane_section_headers that is initialised to point
>>>> at entries in section_headers, with sane_section_headers[i] allocated
>>>> as necessary when needing to correct a bogus header.
>>>>
>>>
>>> I have thought about something similar and decided against it
>>> since filedata->section_headers is used in many places.   However,
>>> I can change filedata->orig_section_headers to on demand.

I find this a plausible argument, so ...

>> Changes in v2:
>>
>> 1.  filedata->orig_section_headers is changed to on demand.
> 
> Changes in v3:
> 
> 1.  Clear filedata->orig_section_headers first.

... the patch is okay unless you get an objection from Alan within another
day or two. Just one thing though: calloc() + memset(, 0,) is redundant.
Please drop those memset()s.

Jan