On Wed, 1 Jul 2026 15:29:28 +0800, Tiezhu Yang <[email protected]> wrote: > On 2026/7/1 ä¸å3:02, Leon Hwang wrote: >> On 1/7/26 14:49, Tiezhu Yang wrote: >> [...] >>>> >>>> It is a real issue. >>>> >>>> Instead of fixing up helper calls, it seems better to prevent >>>> interpreter fallback if the prog has any JIT-inlineable helper call. >>> >>> Hi Alexei and Leon, >>> >>> What about the following: (not tested yet, if it is good, I can test it) >>> >>> [...] >>> >>> If you are OK with the above changes, I will test it again and send >>> a new version later. >>> >> >> If you don't mind, I think I can disallow the interpreter fallback by >> the below diff in the next revision of this series. >> >> The 'aux->jit_required' is introduced by following Alexei's suggestion. > > I am not sure if introducing a new aux->jit_required member is necessary, > as we already have a local jit_needed flag in the current logic.
A 'must_jit'-like member was suggested by Alexei [1]. Probably, the commits in [2] could help to understand 'aux->jit_required'. [1] https://lore.kernel.org/bpf/[email protected]/ [2] https://github.com/Asphaltt/bpf/commits/bpf/fix-interpreter-fallback/v2/ > > Additionally, the issue reported in my patch [1] is fundamentally tied > to bpf_jit_inlines_helper_call(). Maybe we can simply reuse jit_needed > by checking bpf_prog_has_inline_helpers() right before JITing, and then > reject fallback with -ENOTSUPP if JIT compilation fails. Correct. Reusing jit_needed is preferred. Thanks, Leon > > Let us wait for Alexei's comments on the overall direction before > respinning. > > [1] bpf: Fix unaligned interpreter panic on JIT fallback path > https://lore.kernel.org/bpf/[email protected]/ > > Thanks, > Tiezhu
