Messages in this thread | | | Date | Thu, 30 May 2019 14:05:31 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH] ptrace: restore smp_rmb() in __ptrace_may_access() |
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On 05/29, Jann Horn wrote: > > > (I am wondering if smp_acquire__after_ctrl_dep() could be used instead, just to > > make this code look more confusing) > > Uuh, I had no idea that that barrier type exists. The helper isn't > even explicitly mentioned in Documentation/memory-barriers.rst. I > don't really want to use dark magic in the middle of ptrace access > logic...
Yes. and if it was not clear I didn't try to seriously suggest to use this barrier. I was just curious if it can be used or not in this particular case.
> Anyway, looking at it, I think smp_acquire__after_ctrl_dep() doesn't > make sense here;
Well I still _think_ it should work, it provides the LOAD-LOAD ordering and this is what we need.
But I can be easily wrong, and again, I wasn't serious.
Oleg.
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