On Thu, Dec 7, 2023 at 1:58 PM Andrei Matei <andreimatei1@xxxxxxxxx> wrote: > > If Eduard's patch cannot be backported, I had a random thought that perhaps > dead-code elimination could be partially disabled (perhaps only for loop > callbacks, ignoring the functions that the callbacks call). imo the dead code elimination issue is a minor pain point compared to the safety issue that patches addressed. The barrier_var() and asm volatile can workaround "wrong dead code" issue. Pls use it while the fixes are slowly getting into older kernels. Eduard's patches are the only feasible path to backport. We cannot support franken kernels with different verifier logic. The patches were designed to be backportable. We didn't start backport activities to make sure the fixes are not causing regressions in bpf progs. The backports don't have to be done in order either. If there is a particular kernel version you care about please prepare a backport and cc bpf list, Greg KH and Sasha Levin. It could happen that your favorite kernel is not on their list though.
