Messages in this thread |  | | Subject | Re: [patch 00/11] x86/vdso: Cleanups, simmplifications and CLOCK_TAI support | From | Florian Weimer <> | Date | Fri, 14 Sep 2018 15:06:46 +0200 |
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On 09/14/2018 03:05 PM, Thomas Gleixner wrote: > On Fri, 14 Sep 2018, Florian Weimer wrote: > >> On 09/14/2018 02:50 PM, Thomas Gleixner wrote: >>> Matt attempted to add CLOCK_TAI support to the VDSO clock_gettime() >>> implementation, which extended the clockid switch case and added yet >>> another slightly different copy of the same code. >>> >>> Especially the extended switch case is problematic as the compiler tends to >>> generate a jump table which then requires to use retpolines. >> >> Does vDSO code really have to use retpolines? It's in userspace, after all. > > Unless you have IBRS/STIPB enabled, you need user space ratpoutine as well.
I don't think this is a consensus position, and it obviously depends on the (sub)architecture.
Thanks, Florian
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