From 90db9dbedd26ce029f3a0f8d2cbd3a142f452408 Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Mon, 27 Feb 2023 10:47:27 +0100 Subject: [PATCH] kasan, powerpc: don't rename memintrinsics if compiler adds prefixes With appropriate compiler support [1], KASAN builds use __asan prefixed meminstrinsics, and KASAN no longer overrides memcpy/memset/memmove. If compiler support is detected (CC_HAS_KASAN_MEMINTRINSIC_PREFIX), define memintrinsics normally (do not prefix '__'). On powerpc, KASAN is the only user of __mem functions, which are used to define instrumented memintrinsics. Alias the normal versions for KASAN to use in its implementation. Link: https://lore.kernel.org/all/20230224085942.1791837-1-elver@google.com/ [1] Link: https://lore.kernel.org/oe-kbuild-all/202302271348.U5lvmo0S-lkp@intel.com/ Link: https://lkml.kernel.org/r/20230227094726.3833247-1-elver@google.com Signed-off-by: Marco Elver Reported-by: kernel test robot Acked-by: Michael Ellerman [powerpc] Cc: Alexander Potapenko Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Christophe Leroy Cc: Daniel Axtens Cc: Dmitry Vyukov Cc: Liam R. Howlett Cc: Nicholas Piggin Cc: Vincenzo Frascino Signed-off-by: Andrew Morton --- arch/powerpc/include/asm/kasan.h | 2 +- arch/powerpc/include/asm/string.h | 15 +++++++++++---- arch/powerpc/kernel/prom_init_check.sh | 9 +++++++-- 3 files changed, 19 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/include/asm/kasan.h b/arch/powerpc/include/asm/kasan.h index 92a968202ba7..365d2720097c 100644 --- a/arch/powerpc/include/asm/kasan.h +++ b/arch/powerpc/include/asm/kasan.h @@ -2,7 +2,7 @@ #ifndef __ASM_KASAN_H #define __ASM_KASAN_H -#ifdef CONFIG_KASAN +#if defined(CONFIG_KASAN) && !defined(CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX) #define _GLOBAL_KASAN(fn) _GLOBAL(__##fn) #define _GLOBAL_TOC_KASAN(fn) _GLOBAL_TOC(__##fn) #define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(__##fn) diff --git a/arch/powerpc/include/asm/string.h b/arch/powerpc/include/asm/string.h index 2aa0e31e6884..60ba22770f51 100644 --- a/arch/powerpc/include/asm/string.h +++ b/arch/powerpc/include/asm/string.h @@ -30,11 +30,17 @@ extern int memcmp(const void *,const void *,__kernel_size_t); extern void * memchr(const void *,int,__kernel_size_t); void memcpy_flushcache(void *dest, const void *src, size_t size); +#ifdef CONFIG_KASAN +/* __mem variants are used by KASAN to implement instrumented meminstrinsics. */ +#ifdef CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX +#define __memset memset +#define __memcpy memcpy +#define __memmove memmove +#else /* CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX */ void *__memset(void *s, int c, __kernel_size_t count); void *__memcpy(void *to, const void *from, __kernel_size_t n); void *__memmove(void *to, const void *from, __kernel_size_t n); - -#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__) +#ifndef __SANITIZE_ADDRESS__ /* * For files that are not instrumented (e.g. mm/slub.c) we * should use not instrumented version of mem* functions. @@ -46,8 +52,9 @@ void *__memmove(void *to, const void *from, __kernel_size_t n); #ifndef __NO_FORTIFY #define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */ #endif - -#endif +#endif /* !__SANITIZE_ADDRESS__ */ +#endif /* CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX */ +#endif /* CONFIG_KASAN */ #ifdef CONFIG_PPC64 #ifndef CONFIG_KASAN diff --git a/arch/powerpc/kernel/prom_init_check.sh b/arch/powerpc/kernel/prom_init_check.sh index 5a319863f289..69623b9045d5 100644 --- a/arch/powerpc/kernel/prom_init_check.sh +++ b/arch/powerpc/kernel/prom_init_check.sh @@ -13,8 +13,13 @@ # If you really need to reference something from prom_init.o add # it to the list below: -grep "^CONFIG_KASAN=y$" ${KCONFIG_CONFIG} >/dev/null -if [ $? -eq 0 ] +has_renamed_memintrinsics() +{ + grep -q "^CONFIG_KASAN=y$" ${KCONFIG_CONFIG} && \ + ! grep -q "^CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX=y" ${KCONFIG_CONFIG} +} + +if has_renamed_memintrinsics then MEM_FUNCS="__memcpy __memset" else