Re: [PATCH] Add _FORTIFY_SOURCE implementation documentation [BZ #28998]

[Siddhesh Poyarekar <siddhesh@sourceware.org>]

On 2022-12-22 08:08, Sam James wrote:
> 
> 
>> On 22 Dec 2022, at 12:56, Siddhesh Poyarekar <siddhesh@gotplt.org> wrote:
>>
>> Ping!  Any further comments other than the redundant 'See' Andreas noted?
>>
> 
> It looks good & thanks for doing it.
> 
> I wonder if it's worth noting (maybe it's obvious) that tools which
> make use of LD_PRELOAD may need to provide their own wrappers.
> 
> (umockdev being an example I'm thinking of here.)

Hi Sam, sorry I missed your response (and funnily, I got 3 of them!).

I'm not sure, there are other issues with interposing, e.g. string 
function calls where the result is already dependent on how the compiler 
treats those calls, making the result of the interposition kinda 
indeterminate across builds.  So I don't know how useful it would be to 
call it out specifically in the context of _FORTIFY_SOURCE.  However, I 
don't think it's a bad idea to do so either (i.e. I don't see it 
imposing any constraints on us as implementers), so if you like it (and 
others don't express a dislike), I'll be happy to add a note in there.

If there's a positive review for the latest version of this patch, I'll 
post it as an add-on fix or else I'll include it in the next version of 
the patch.

Thanks,
Sid