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]: > 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/
