On Sat, Jun 28, 2025 at 3:57 PM Andrey Konovalov <andreyk...@gmail.com> wrote: > > On Thu, Jun 26, 2025 at 5:32 PM Sabyrzhan Tasbolatov > <snovit...@gmail.com> wrote: > > > > This patch series unifies the kasan_arch_is_ready() and kasan_enabled() > > interfaces by extending the existing kasan_enabled() infrastructure to > > work consistently across all KASAN modes (Generic, SW_TAGS, HW_TAGS). > > > > Currently, kasan_enabled() only works for HW_TAGS mode using a static key, > > while other modes either return IS_ENABLED(CONFIG_KASAN) (compile-time > > constant) or rely on architecture-specific kasan_arch_is_ready() > > implementations with custom static keys and global variables. > > > > This leads to: > > - Code duplication across architectures > > - Inconsistent runtime behavior between KASAN modes > > - Architecture-specific readiness tracking > > > > After this series: > > - All KASAN modes use the same kasan_flag_enabled static key > > - Consistent runtime enable/disable behavior across modes > > - Simplified architecture code with unified kasan_init_generic() calls > > - Elimination of arch specific kasan_arch_is_ready() implementations > > - Unified vmalloc integration using kasan_enabled() checks > > > > This addresses the bugzilla issue [1] about making > > kasan_flag_enabled and kasan_enabled() work for Generic mode, > > and extends it to provide true unification across all modes. > > > > [1] https://bugzilla.kernel.org/show_bug.cgi?id=217049 > > Hi Sabyrzhan, > > Thank you for working on this! > > One aspect that is missing from the patches is moving the > kasan_arch_is_ready() calls into the include/linux/kasan.h (this is > not explicitly mentioned in the issue, but this is what the "adding > __wrappers" part is about). > > Another thing that needs careful consideration is whether it's > possible to combine kasan_arch_is_ready() and kasan_enabled() into the > same check logically at all. There's one issue mentioned in [1]:
Hello, I've removed kasan_arch_is_ready() at all in this series: [PATCH v2 11/11] kasan: replace kasan_arch_is_ready with kasan_enabled Is it not what's expected by unification? > > > In kasan_cache_create() we unconditionally allocate a metadata buffer, > > but the kasan_init_slab_obj() call to initialise it is guarded by > > kasan_enabled(). But later parts of the code only check the presence of > > the buffer before using it, so bad things happen if kasan_enabled() > > later turns on (I was getting some error about invalid lock state). > > And there might be other callbacks that should be executed even before > kasan_init_...() completes. But then for the HW_TAGS mode, if > kasan_enabled() is off, then we don't want to execute any callbacks. > > So maybe we do actually need a separate static key for > kasan_arch_is_ready(). But even if so, it still makes sense to move > kasan_arch_is_ready() into the __wrappers for the affected callbacks. > > Thanks! > > [1] > https://lore.kernel.org/linux-mm/ca+fcnzf7jqth46c7og2wk9nnlu7hgivdek0ea8ratyr-kgk...@mail.gmail.com/
