From: Andrey Ryabinin aryabinin@virtuozzo.com
[ Upstream commit 19a2ca0fb560fd7be7b5293c6b652c6d6078dcde ]
ARM64 has asm implementation of memchr(), memcmp(), str[r]chr(), str[n]cmp(), str[n]len(). KASAN don't see memory accesses in asm code, thus it can potentially miss many bugs.
Ifdef out __HAVE_ARCH_* defines of these functions when KASAN is enabled, so the generic implementations from lib/string.c will be used.
We can't just remove the asm functions because efistub uses them. And we can't have two non-weak functions either, so declare the asm functions as weak.
Link: http://lkml.kernel.org/r/20180920135631.23833-2-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin aryabinin@virtuozzo.com Reported-by: Kyeongdon Kim kyeongdon.kim@lge.com Cc: Alexander Potapenko glider@google.com Cc: Ard Biesheuvel ard.biesheuvel@linaro.org Cc: Dmitry Vyukov dvyukov@google.com Cc: Mark Rutland mark.rutland@arm.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/include/asm/string.h | 14 ++++++++------ arch/arm64/kernel/arm64ksyms.c | 7 +++++-- arch/arm64/lib/memchr.S | 2 +- arch/arm64/lib/memcmp.S | 2 +- arch/arm64/lib/strchr.S | 2 +- arch/arm64/lib/strcmp.S | 2 +- arch/arm64/lib/strlen.S | 2 +- arch/arm64/lib/strncmp.S | 2 +- arch/arm64/lib/strnlen.S | 2 +- arch/arm64/lib/strrchr.S | 2 +- 10 files changed, 21 insertions(+), 16 deletions(-)
diff --git a/arch/arm64/include/asm/string.h b/arch/arm64/include/asm/string.h index dd95d33a5bd5d..03a6c256b7ec4 100644 --- a/arch/arm64/include/asm/string.h +++ b/arch/arm64/include/asm/string.h @@ -16,6 +16,7 @@ #ifndef __ASM_STRING_H #define __ASM_STRING_H
+#ifndef CONFIG_KASAN #define __HAVE_ARCH_STRRCHR extern char *strrchr(const char *, int c);
@@ -34,6 +35,13 @@ extern __kernel_size_t strlen(const char *); #define __HAVE_ARCH_STRNLEN extern __kernel_size_t strnlen(const char *, __kernel_size_t);
+#define __HAVE_ARCH_MEMCMP +extern int memcmp(const void *, const void *, size_t); + +#define __HAVE_ARCH_MEMCHR +extern void *memchr(const void *, int, __kernel_size_t); +#endif + #define __HAVE_ARCH_MEMCPY extern void *memcpy(void *, const void *, __kernel_size_t); extern void *__memcpy(void *, const void *, __kernel_size_t); @@ -42,16 +50,10 @@ extern void *__memcpy(void *, const void *, __kernel_size_t); extern void *memmove(void *, const void *, __kernel_size_t); extern void *__memmove(void *, const void *, __kernel_size_t);
-#define __HAVE_ARCH_MEMCHR -extern void *memchr(const void *, int, __kernel_size_t); - #define __HAVE_ARCH_MEMSET extern void *memset(void *, int, __kernel_size_t); extern void *__memset(void *, int, __kernel_size_t);
-#define __HAVE_ARCH_MEMCMP -extern int memcmp(const void *, const void *, size_t); - #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE #define __HAVE_ARCH_MEMCPY_FLUSHCACHE void memcpy_flushcache(void *dst, const void *src, size_t cnt); diff --git a/arch/arm64/kernel/arm64ksyms.c b/arch/arm64/kernel/arm64ksyms.c index 66be504edb6cf..9eedf839e7393 100644 --- a/arch/arm64/kernel/arm64ksyms.c +++ b/arch/arm64/kernel/arm64ksyms.c @@ -44,20 +44,23 @@ EXPORT_SYMBOL(__arch_copy_in_user); EXPORT_SYMBOL(memstart_addr);
/* string / mem functions */ +#ifndef CONFIG_KASAN EXPORT_SYMBOL(strchr); EXPORT_SYMBOL(strrchr); EXPORT_SYMBOL(strcmp); EXPORT_SYMBOL(strncmp); EXPORT_SYMBOL(strlen); EXPORT_SYMBOL(strnlen); +EXPORT_SYMBOL(memcmp); +EXPORT_SYMBOL(memchr); +#endif + EXPORT_SYMBOL(memset); EXPORT_SYMBOL(memcpy); EXPORT_SYMBOL(memmove); EXPORT_SYMBOL(__memset); EXPORT_SYMBOL(__memcpy); EXPORT_SYMBOL(__memmove); -EXPORT_SYMBOL(memchr); -EXPORT_SYMBOL(memcmp);
/* atomic bitops */ EXPORT_SYMBOL(set_bit); diff --git a/arch/arm64/lib/memchr.S b/arch/arm64/lib/memchr.S index 4444c1d25f4bb..0f164a4baf52a 100644 --- a/arch/arm64/lib/memchr.S +++ b/arch/arm64/lib/memchr.S @@ -30,7 +30,7 @@ * Returns: * x0 - address of first occurrence of 'c' or 0 */ -ENTRY(memchr) +WEAK(memchr) and w1, w1, #0xff 1: subs x2, x2, #1 b.mi 2f diff --git a/arch/arm64/lib/memcmp.S b/arch/arm64/lib/memcmp.S index 2a4e239bd17a0..fb295f52e9f87 100644 --- a/arch/arm64/lib/memcmp.S +++ b/arch/arm64/lib/memcmp.S @@ -58,7 +58,7 @@ pos .req x11 limit_wd .req x12 mask .req x13
-ENTRY(memcmp) +WEAK(memcmp) cbz limit, .Lret0 eor tmp1, src1, src2 tst tmp1, #7 diff --git a/arch/arm64/lib/strchr.S b/arch/arm64/lib/strchr.S index dae0cf5591f99..7c83091d1bcdd 100644 --- a/arch/arm64/lib/strchr.S +++ b/arch/arm64/lib/strchr.S @@ -29,7 +29,7 @@ * Returns: * x0 - address of first occurrence of 'c' or 0 */ -ENTRY(strchr) +WEAK(strchr) and w1, w1, #0xff 1: ldrb w2, [x0], #1 cmp w2, w1 diff --git a/arch/arm64/lib/strcmp.S b/arch/arm64/lib/strcmp.S index 471fe61760ef6..7d5d15398bfbc 100644 --- a/arch/arm64/lib/strcmp.S +++ b/arch/arm64/lib/strcmp.S @@ -60,7 +60,7 @@ tmp3 .req x9 zeroones .req x10 pos .req x11
-ENTRY(strcmp) +WEAK(strcmp) eor tmp1, src1, src2 mov zeroones, #REP8_01 tst tmp1, #7 diff --git a/arch/arm64/lib/strlen.S b/arch/arm64/lib/strlen.S index 55ccc8e24c084..8e0b14205dcb4 100644 --- a/arch/arm64/lib/strlen.S +++ b/arch/arm64/lib/strlen.S @@ -56,7 +56,7 @@ pos .req x12 #define REP8_7f 0x7f7f7f7f7f7f7f7f #define REP8_80 0x8080808080808080
-ENTRY(strlen) +WEAK(strlen) mov zeroones, #REP8_01 bic src, srcin, #15 ands tmp1, srcin, #15 diff --git a/arch/arm64/lib/strncmp.S b/arch/arm64/lib/strncmp.S index e267044761c6f..66bd145935d9e 100644 --- a/arch/arm64/lib/strncmp.S +++ b/arch/arm64/lib/strncmp.S @@ -64,7 +64,7 @@ limit_wd .req x13 mask .req x14 endloop .req x15
-ENTRY(strncmp) +WEAK(strncmp) cbz limit, .Lret0 eor tmp1, src1, src2 mov zeroones, #REP8_01 diff --git a/arch/arm64/lib/strnlen.S b/arch/arm64/lib/strnlen.S index eae38da6e0bb3..355be04441fe6 100644 --- a/arch/arm64/lib/strnlen.S +++ b/arch/arm64/lib/strnlen.S @@ -59,7 +59,7 @@ limit_wd .req x14 #define REP8_7f 0x7f7f7f7f7f7f7f7f #define REP8_80 0x8080808080808080
-ENTRY(strnlen) +WEAK(strnlen) cbz limit, .Lhit_limit mov zeroones, #REP8_01 bic src, srcin, #15 diff --git a/arch/arm64/lib/strrchr.S b/arch/arm64/lib/strrchr.S index 61eabd9a289a6..f3b9f8e2917c6 100644 --- a/arch/arm64/lib/strrchr.S +++ b/arch/arm64/lib/strrchr.S @@ -29,7 +29,7 @@ * Returns: * x0 - address of last occurrence of 'c' or 0 */ -ENTRY(strrchr) +WEAK(strrchr) mov x3, #0 and w1, w1, #0xff 1: ldrb w2, [x0], #1