Messages in this thread |  | | From | Alexei Starovoitov <> | | Date | Sun, 24 Mar 2024 15:13:08 -0700 | | Subject | Re: [PATCH bpf-next v5 2/6] bpf/verifier: add bpf_timer as a kfunc capable type |
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On Sat, Mar 23, 2024 at 9:57 PM Kumar Kartikeya Dwivedi <memxor@gmail.com> wrote:
> > > > > > > > Observation is correct. The patch is buggy, > > > > but the suggestion to follow process_dynptr_func() will lead > > > > to unnecessary complexity. > > > > dynptr-s are on stack with plenty of extra checks. > > > > > > The suggestion was to call process_timer_func, not process_dynptr_func. > > > > > > > In this case bpf_timer is in map_value. > > > > Much simpler is to follow KF_ARG_PTR_TO_MAP approach. > > > > > > What I meant by the example was that dynptr handling does the same > > > thing for kfuncs and helpers (using the same function), so timer > > > arguments should do the same (i.e. use process_timer_func), which will > > > do all checks for constant offset (ensuring var_off is tnum_is_const) > > > and match it against btf_record->timer_off. > > > > I don't follow. Please elaborate with a patch. > > The var_off and off is a part of the bug, but it's not the biggest part of it. > > Not compile tested.
I see. All makes sense to me.
Benjamin, pls incorporate it in your set.
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