* Thomas Gleixner: > On Tue, 5 Nov 2019, Florian Weimer wrote: >> * Shawn Landden: >> > If this new ABI is used, then bit 1 of the *next pointer of the >> > user-space robust_list indicates that the futex_offset2 value should >> > be used in place of the existing futex_offset. >> >> The futex interface currently has some races which can only be fixed by >> API changes. I'm concerned that we sacrifice the last bit for some >> rather obscure feature. What if we need that bit for fixing the >> correctness issues? > > That current approach is going nowhere and if we change the ABI ever then > this needs to happen with all *libc folks involved and agreeing. > > Out of curiosity, what's the race issue vs. robust list which you are > trying to solve? Sadly I'm not trying to solve them. Here's one of the issues: <https://sourceware.org/bugzilla/show_bug.cgi?id=14485> I think there are others, but I can't find a reference to them. If anyone wants to work on this, I can dig out the details and ask some folks who have looked at this in the past. Thanks, Florian
