Messages in this thread | | | Subject | Re: [RFC PATCH v2 1/3] restartable sequences: user-space per-cpu critical sections | From | Johannes Berg <> | Date | Thu, 19 Nov 2015 17:38:10 +0100 |
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On Tue, 2015-10-27 at 16:56 -0700, Paul Turner wrote: > > + * flags is currently unused. > + */ > +SYSCALL_DEFINE3(restartable_sequences, > +> > > int, flags, long, event_and_cpu, long, post_commit_instr_addr)
> +{ > + return rseq_configure_current((__user u64 *)event_and_cpu, > + (__user void *)post_commit_instr_addr);
It seems that, for forward compatibility and actually usefulness of the 'flags' argument, you need to reject the syscall if it's passed non- zero right now. Otherwise applications can (inadvertedly) pass garbage and you'll not be able to use it in the future.
johannes
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