Re: [Libunwind-devel] Bug fixes in libunwind git = make another "release"?

[Lassi Tuura]

Hi,

>> As long as _dl_debug_state() has enough space to patch in the jump to our
>> code
> 
> A single 'ret' is a single byte, which isn't enough space to patch anything
> (which was my point).
> 
>> The dynamic linkers I looked seem to be built with enough code padding
>> that there's space to replace the ret with a jump.
> 
> You are likely saved by '-falign-functions=16', which leaves you 15 bytes
> to play with.
> 
> You can't count on it though, and I believe that I *have* seen dynamic
> loaders where there literally was only one byte available.

Yeah, exactly. I'm slightly pragmatic here, because every once in a while
we get a dead-lock. So I am looking for practical alternatives. The systems
we use are aged (RHEL5 / x86_64) with little hope of picking up fresh work
like Linux kernel or GLIBC. We still try to campaign for those for future,
but we also need a practical solution for today.

Regards,
Lassi