Re: [PATCH] Protect _dl_profile_fixup data-dependency order [BZ #23690]

[John David Anglin <dave dot anglin at bell dot net>]

On 2018-09-19 8:16 PM, Carlos O'Donell wrote:
> >    DL_FIXUP_VALUE_TYPE *resultp = &reloc_result->addr;
> > +  DL_FIXUP_VALUE_TYPE value = atomic_load_acquire(resultp);
> You are potentially requiring an atomic load of a structure whose size can be
> an arbitrary size depending on machine and ABI design (64-bit fore 32-bit hppa,
> and 128-bit for 64-bit ia64). These architectures might not have such wide
> atomic operations, and ...
We have implemented 64-bit atomic loads and stores for 32-bit hppa. They 
are not well tested but
they might work.  They use floating point loads and stores, and kernel 
helper.  The code is pretty horrific :-(

Dave

--
John David Anglin  dave.anglin@bell.net