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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