powerpc: prepare string/mem functions for KASAN

CONFIG_KASAN implements wrappers for memcpy() memmove() and memset()
Those wrappers are doing the verification then call respectively
__memcpy() __memmove() and __memset(). The arches are therefore
expected to rename their optimised functions that way.

For files on which KASAN is inhibited, #defines are used to allow
them to directly call optimised versions of the functions without
going through the KASAN wrappers.

See commit 393f203f5f ("x86_64: kasan: add interceptors for
memset/memmove/memcpy functions") for details.

Other string / mem functions do not (yet) have kasan wrappers,
we therefore have to fallback to the generic versions when
KASAN is active, otherwise KASAN checks will be skipped.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Fixups to keep selftests working]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Christophe Leroy
2019-04-26 16:23:26 +00:00
committed by Michael Ellerman
parent d69ca6bab3
commit 26deb04342
10 changed files with 82 additions and 13 deletions

View File

@@ -4,14 +4,17 @@
#ifdef __KERNEL__
#ifndef CONFIG_KASAN
#define __HAVE_ARCH_STRNCPY
#define __HAVE_ARCH_STRNCMP
#define __HAVE_ARCH_MEMCHR
#define __HAVE_ARCH_MEMCMP
#define __HAVE_ARCH_MEMSET16
#endif
#define __HAVE_ARCH_MEMSET
#define __HAVE_ARCH_MEMCPY
#define __HAVE_ARCH_MEMMOVE
#define __HAVE_ARCH_MEMCMP
#define __HAVE_ARCH_MEMCHR
#define __HAVE_ARCH_MEMSET16
#define __HAVE_ARCH_MEMCPY_FLUSHCACHE
extern char * strcpy(char *,const char *);
@@ -27,7 +30,27 @@ extern int memcmp(const void *,const void *,__kernel_size_t);
extern void * memchr(const void *,int,__kernel_size_t);
extern void * memcpy_flushcache(void *,const void *,__kernel_size_t);
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__)
/*
* For files that are not instrumented (e.g. mm/slub.c) we
* should use not instrumented version of mem* functions.
*/
#define memcpy(dst, src, len) __memcpy(dst, src, len)
#define memmove(dst, src, len) __memmove(dst, src, len)
#define memset(s, c, n) __memset(s, c, n)
#ifndef __NO_FORTIFY
#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
#endif
#endif
#ifdef CONFIG_PPC64
#ifndef CONFIG_KASAN
#define __HAVE_ARCH_MEMSET32
#define __HAVE_ARCH_MEMSET64
@@ -49,8 +72,11 @@ static inline void *memset64(uint64_t *p, uint64_t v, __kernel_size_t n)
{
return __memset64(p, v, n * 8);
}
#endif
#else
#ifndef CONFIG_KASAN
#define __HAVE_ARCH_STRLEN
#endif
extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
#endif