From 767215030150d9d01ff65fbc1c5dff515ffdcfe3 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Wed, 14 Jul 2021 15:38:43 +0100 Subject: arm64: kasan: mte: remove redundant mte_report_once logic We have special logic to suppress MTE tag check fault reporting, based on a global `mte_report_once` and `reported` variables. These can be used to suppress calling kasan_report() when taking a tag check fault, but do not prevent taking the fault in the first place, nor does they affect the way we disable tag checks upon taking a fault. The core KASAN code already defaults to reporting a single fault, and has a `multi_shot` control to permit reporting multiple faults. The only place we transiently alter `mte_report_once` is in lib/test_kasan.c, where we also the `multi_shot` state as the same time. Thus `mte_report_once` and `reported` are redundant, and can be removed. When a tag check fault is taken, tag checking will be disabled by `do_tag_recovery` and must be explicitly re-enabled if desired. The test code does this by calling kasan_enable_tagging_sync(). This patch removes the redundant mte_report_once() logic and associated variables. Signed-off-by: Mark Rutland Cc: Alexander Potapenko Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Will Deacon Cc: Vincenzo Frascino Reviewed-by: Catalin Marinas Reviewed-by: Andrey Konovalov Tested-by: Andrey Konovalov Link: https://lore.kernel.org/r/20210714143843.56537-4-mark.rutland@arm.com Signed-off-by: Catalin Marinas --- mm/kasan/hw_tags.c | 6 ------ mm/kasan/kasan.h | 7 ------- 2 files changed, 13 deletions(-) (limited to 'mm/kasan') diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c index 2c6c6c6ddfa2..e4c16f6b6680 100644 --- a/mm/kasan/hw_tags.c +++ b/mm/kasan/hw_tags.c @@ -248,12 +248,6 @@ void kasan_free_pages(struct page *page, unsigned int order) #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) -void kasan_set_tagging_report_once(bool state) -{ - hw_set_tagging_report_once(state); -} -EXPORT_SYMBOL_GPL(kasan_set_tagging_report_once); - void kasan_enable_tagging_sync(void) { hw_enable_tagging_sync(); diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 28a16b80bbef..fff93b0bcb08 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -290,9 +290,6 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag) #ifndef arch_enable_tagging_async #define arch_enable_tagging_async() #endif -#ifndef arch_set_tagging_report_once -#define arch_set_tagging_report_once(state) -#endif #ifndef arch_force_async_tag_fault #define arch_force_async_tag_fault() #endif @@ -308,7 +305,6 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag) #define hw_enable_tagging_sync() arch_enable_tagging_sync() #define hw_enable_tagging_async() arch_enable_tagging_async() -#define hw_set_tagging_report_once(state) arch_set_tagging_report_once(state) #define hw_force_async_tag_fault() arch_force_async_tag_fault() #define hw_get_random_tag() arch_get_random_tag() #define hw_get_mem_tag(addr) arch_get_mem_tag(addr) @@ -319,19 +315,16 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag) #define hw_enable_tagging_sync() #define hw_enable_tagging_async() -#define hw_set_tagging_report_once(state) #endif /* CONFIG_KASAN_HW_TAGS */ #if defined(CONFIG_KASAN_HW_TAGS) && IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) -void kasan_set_tagging_report_once(bool state); void kasan_enable_tagging_sync(void); void kasan_force_async_fault(void); #else /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */ -static inline void kasan_set_tagging_report_once(bool state) { } static inline void kasan_enable_tagging_sync(void) { } static inline void kasan_force_async_fault(void) { } -- cgit v1.2.3