hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9GCZS CVE: NA
-------------------------------
The copy_mc_to_kernel() helper is memory copy implementation that handles source exceptions. It can be used in memory copy scenarios that tolerate hardware memory errors(e.g: pmem_read/dax_copy_to_iter).
Currnently, only x86 and ppc suuport this helper, after arm64 support ARCH_HAS_COPY_MC , we introduce copy_mc_to_kernel() implementation.
Also add memcpy_mc() for memory copy that handles source exceptions. Because there is no GPR is available for saving "bytes not copied" in memcpy(), the mempcy_mc() is referenced to the implementation of copy_from_user().
Signed-off-by: Tong Tiangen tongtiangen@huawei.com --- arch/arm64/include/asm/string.h | 5 +++ arch/arm64/include/asm/uaccess.h | 18 ++++++++ arch/arm64/lib/Makefile | 2 +- arch/arm64/lib/memcpy_mc.S | 73 ++++++++++++++++++++++++++++++++ mm/kasan/shadow.c | 12 ++++++ 5 files changed, 109 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/lib/memcpy_mc.S
diff --git a/arch/arm64/include/asm/string.h b/arch/arm64/include/asm/string.h index 3a3264ff47b9..23eca4fb24fa 100644 --- a/arch/arm64/include/asm/string.h +++ b/arch/arm64/include/asm/string.h @@ -35,6 +35,10 @@ extern void *memchr(const void *, int, __kernel_size_t); extern void *memcpy(void *, const void *, __kernel_size_t); extern void *__memcpy(void *, const void *, __kernel_size_t);
+#define __HAVE_ARCH_MEMCPY_MC +extern int memcpy_mc(void *, const void *, __kernel_size_t); +extern int __memcpy_mc(void *, const void *, __kernel_size_t); + #define __HAVE_ARCH_MEMMOVE extern void *memmove(void *, const void *, __kernel_size_t); extern void *__memmove(void *, const void *, __kernel_size_t); @@ -57,6 +61,7 @@ void memcpy_flushcache(void *dst, const void *src, size_t cnt); */
#define memcpy(dst, src, len) __memcpy(dst, src, len) +#define memcpy_mc(dst, src, len) __memcpy_mc(dst, src, len) #define memmove(dst, src, len) __memmove(dst, src, len) #define memset(s, c, n) __memset(s, c, n)
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 14be5000c5a0..07c1aeaeb094 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -425,4 +425,22 @@ static inline size_t probe_subpage_writeable(const char __user *uaddr,
#endif /* CONFIG_ARCH_HAS_SUBPAGE_FAULTS */
+#ifdef CONFIG_ARCH_HAS_COPY_MC +/** + * copy_mc_to_kernel - memory copy that handles source exceptions + * + * @to: destination address + * @from: source address + * @size: number of bytes to copy + * + * Return 0 for success, or bytes not copied. + */ +static inline unsigned long __must_check +copy_mc_to_kernel(void *to, const void *from, unsigned long size) +{ + return memcpy_mc(to, from, size); +} +#define copy_mc_to_kernel copy_mc_to_kernel +#endif + #endif /* __ASM_UACCESS_H */ diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile index a2fd865b816d..3b6914bb8ec7 100644 --- a/arch/arm64/lib/Makefile +++ b/arch/arm64/lib/Makefile @@ -15,7 +15,7 @@ endif
lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o
-lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_mc_page.o +lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_mc_page.o memcpy_mc.o
obj-$(CONFIG_CRC32) += crc32.o
diff --git a/arch/arm64/lib/memcpy_mc.S b/arch/arm64/lib/memcpy_mc.S new file mode 100644 index 000000000000..1798090eba06 --- /dev/null +++ b/arch/arm64/lib/memcpy_mc.S @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2013 ARM Ltd. + * Copyright (C) 2013 Linaro. + * + * This code is based on glibc cortex strings work originally authored by Linaro + * be found @ + * + * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/ + * files/head:/src/aarch64/ + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/cache.h> +#include <asm/asm-uaccess.h> + +/* + * Copy a buffer from src to dest (alignment handled by the hardware) + * + * Parameters: + * x0 - dest + * x1 - src + * x2 - n + * Returns: + * x0 - dest + */ + .macro ldrb1 reg, ptr, val + KERNEL_ME_SAFE(9997f, ldrb \reg, [\ptr], \val) + .endm + + .macro strb1 reg, ptr, val + strb \reg, [\ptr], \val + .endm + + .macro ldrh1 reg, ptr, val + KERNEL_ME_SAFE(9997f, ldrh \reg, [\ptr], \val) + .endm + + .macro strh1 reg, ptr, val + strh \reg, [\ptr], \val + .endm + + .macro ldr1 reg, ptr, val + KERNEL_ME_SAFE(9997f, ldr \reg, [\ptr], \val) + .endm + + .macro str1 reg, ptr, val + str \reg, [\ptr], \val + .endm + + .macro ldp1 reg1, reg2, ptr, val + KERNEL_ME_SAFE(9997f, ldp \reg1, \reg2, [\ptr], \val) + .endm + + .macro stp1 reg1, reg2, ptr, val + stp \reg1, \reg2, [\ptr], \val + .endm + +end .req x5 +SYM_FUNC_START(__memcpy_mc) + add end, x0, x2 +#include "copy_template.S" + mov x0, #0 // Nothing to copy + ret + + // Exception fixups +9997: sub x0, end, dst // bytes not copied + ret +SYM_FUNC_END(__memcpy_mc) +EXPORT_SYMBOL(__memcpy_mc) +SYM_FUNC_ALIAS_WEAK(memcpy_mc, __memcpy_mc) +EXPORT_SYMBOL(memcpy_mc) diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c index dd772f9d0f08..ac8d19bdcc95 100644 --- a/mm/kasan/shadow.c +++ b/mm/kasan/shadow.c @@ -79,6 +79,18 @@ void *memcpy(void *dest, const void *src, size_t len) } #endif
+#ifdef __HAVE_ARCH_MEMCPY_MC +#undef memcpy_mc +int memcpy_mc(void *dest, const void *src, size_t len) +{ + if (!kasan_check_range(src, len, false, _RET_IP_) || + !kasan_check_range(dest, len, true, _RET_IP_)) + return (int)len; + + return __memcpy_mc(dest, src, len); +} +#endif + void *__asan_memset(void *addr, int c, ssize_t len) { if (!kasan_check_range(addr, len, true, _RET_IP_))