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.
