On Fri, Apr 17, 2020 at 09:28:14AM +0200, Geert Uytterhoeven wrote: > On Fri, Apr 17, 2020 at 12:01 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > v3: > > - Added implementations of clear_bit_unlock_is_negative_byte() > > to architectures which need it > > I have two questions here? > 1. Why not implement arch_clear_bit_unlock_is_negative_byte() > instead, so the kasan check in asm-generic is used everywhere? That would be a larger change. As I understand it (and I may misunderstand it), I would need to rename all the clear_bit(), __clear_bit(), change_bit(), ... functions to have an 'arch_' prefix and then include instrumented-lock.h > 2. Why not add the default implementation to > include/asm-generic/bitops/instrumented-lock.h, in case an arch_*() > variant is not provided yet? > > Note that you did 1 for s390. Well, s390 already uses instrumented-lock.h so I followed along with what they're doing. I don't think instrumented-lock.h is used at all on these other architectures, but the whole bitops header files are such a mess that I could easily have built a completely wrong mental model of what's going on.
