On 5/23/23 09:42, Lorenzo Stoakes wrote: > On Tue, May 23, 2023 at 09:31:36AM +0200, Vlastimil Babka wrote: >> With SLOB removed, both remaining allocators support hardened usercopy, >> so remove the config and associated #ifdef. >> >> Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> >> --- >> mm/Kconfig | 2 -- >> mm/slab.h | 9 --------- >> security/Kconfig | 8 -------- >> 3 files changed, 19 deletions(-) >> >> diff --git a/mm/Kconfig b/mm/Kconfig >> index 7672a22647b4..041f0da42f2b 100644 >> --- a/mm/Kconfig >> +++ b/mm/Kconfig >> @@ -221,7 +221,6 @@ choice >> config SLAB >> bool "SLAB" >> depends on !PREEMPT_RT >> - select HAVE_HARDENED_USERCOPY_ALLOCATOR >> help >> The regular slab allocator that is established and known to work >> well in all environments. It organizes cache hot objects in >> @@ -229,7 +228,6 @@ config SLAB >> >> config SLUB >> bool "SLUB (Unqueued Allocator)" >> - select HAVE_HARDENED_USERCOPY_ALLOCATOR >> help >> SLUB is a slab allocator that minimizes cache line usage >> instead of managing queues of cached objects (SLAB approach). >> diff --git a/mm/slab.h b/mm/slab.h >> index f01ac256a8f5..695ef96b4b5b 100644 >> --- a/mm/slab.h >> +++ b/mm/slab.h >> @@ -832,17 +832,8 @@ struct kmem_obj_info { >> void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab); >> #endif >> >> -#ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR >> void __check_heap_object(const void *ptr, unsigned long n, >> const struct slab *slab, bool to_user); >> -#else >> -static inline >> -void __check_heap_object(const void *ptr, unsigned long n, >> - const struct slab *slab, bool to_user) >> -{ >> -} >> -#endif > > Hm, this is still defined in slab.c/slub.c and invoked in usercopy.c, do we > not want the prototype? Well I didn't delete the prototype, just the ifdef/else around, so now it's there unconditionally. > Perhaps replacing with #ifdef > CONFIG_HARDENED_USERCOPY instead? I may be missing something here :) Putting it under that #ifdef would work and match that the implementations of that function are under that same ifdef, but maybe it's unnecessary noise in the header?