hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8M74H CVE: NA
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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 machine check safe framework, we introduce copy_mc_to_kernel() implementation.
Signed-off-by: Tong Tiangen tongtiangen@huawei.com --- arch/arm64/include/asm/string.h | 5 + arch/arm64/include/asm/uaccess.h | 21 +++ arch/arm64/lib/Makefile | 2 +- arch/arm64/lib/memcpy_mc.S | 257 +++++++++++++++++++++++++++++++ mm/kasan/shadow.c | 12 ++ 5 files changed, 296 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..995b63c26e99 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_mcs(void *, const void *, __kernel_size_t); +extern int __memcpy_mcs(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_mcs(dst, src, len) __memcpy_mcs(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..61e28ef2112a 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -425,4 +425,25 @@ 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 + * + * @dst: destination address + * @src: source address + * @len: number of bytes to copy + * + * Return 0 for success, or #size if there was an exception. + */ +static inline unsigned long __must_check +copy_mc_to_kernel(void *to, const void *from, unsigned long size) +{ + int ret; + + ret = memcpy_mcs(to, from, size); + return (ret == -EFAULT) ? size : 0; +} +#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..899d6ae9698c 100644 --- a/arch/arm64/lib/Makefile +++ b/arch/arm64/lib/Makefile @@ -3,7 +3,7 @@ lib-y := clear_user.o delay.o copy_from_user.o \ copy_to_user.o copy_page.o \ clear_page.o csum.o insn.o memchr.o memcpy.o \ memset.o memcmp.o strcmp.o strncmp.o strlen.o \ - strnlen.o strchr.o strrchr.o tishift.o + strnlen.o strchr.o strrchr.o tishift.o memcpy_mc.o
ifeq ($(CONFIG_KERNEL_MODE_NEON), y) obj-$(CONFIG_XOR_BLOCKS) += xor-neon.o diff --git a/arch/arm64/lib/memcpy_mc.S b/arch/arm64/lib/memcpy_mc.S new file mode 100644 index 000000000000..7076b500d154 --- /dev/null +++ b/arch/arm64/lib/memcpy_mc.S @@ -0,0 +1,257 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2012-2021, Arm Limited. + * + * Adapted from the original at: + * https://github.com/ARM-software/optimized-routines/blob/afd6244a1f8d9229/str... + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> + +/* Assumptions: + * + * ARMv8-a, AArch64, unaligned accesses. + * + */ + +#define L(label) .L ## label + +#define dstin x0 +#define src x1 +#define count x2 +#define dst x3 +#define srcend x4 +#define dstend x5 +#define A_l x6 +#define A_lw w6 +#define A_h x7 +#define B_l x8 +#define B_lw w8 +#define B_h x9 +#define C_l x10 +#define C_lw w10 +#define C_h x11 +#define D_l x12 +#define D_h x13 +#define E_l x14 +#define E_h x15 +#define F_l x16 +#define F_h x17 +#define G_l count +#define G_h dst +#define H_l src +#define H_h srcend +#define tmp1 x14 + +/* This implementation handles overlaps and supports both memcpy and memmove + from a single entry point. It uses unaligned accesses and branchless + sequences to keep the code small, simple and improve performance. + + Copies are split into 3 main cases: small copies of up to 32 bytes, medium + copies of up to 128 bytes, and large copies. The overhead of the overlap + check is negligible since it is only required for large copies. + + Large copies use a software pipelined loop processing 64 bytes per iteration. + The destination pointer is 16-byte aligned to minimize unaligned accesses. + The loop tail is handled by always copying 64 bytes from the end. +*/ + +SYM_FUNC_START(__pi_memcpy_mcs) + add srcend, src, count + add dstend, dstin, count + cmp count, 128 + b.hi L(copy_long) + cmp count, 32 + b.hi L(copy32_128) + + /* Small copies: 0..32 bytes. */ + cmp count, 16 + b.lo L(copy16) + CPY_MC(9998f, ldp A_l, A_h, [src]) + CPY_MC(9998f, ldp D_l, D_h, [srcend, -16]) + CPY_MC(9998f, stp A_l, A_h, [dstin]) + CPY_MC(9998f, stp D_l, D_h, [dstend, -16]) + mov x0, #0 + ret + + /* Copy 8-15 bytes. */ +L(copy16): + tbz count, 3, L(copy8) + CPY_MC(9998f, ldr A_l, [src]) + CPY_MC(9998f, ldr A_h, [srcend, -8]) + CPY_MC(9998f, str A_l, [dstin]) + CPY_MC(9998f, str A_h, [dstend, -8]) + mov x0, #0 + ret + + .p2align 3 + /* Copy 4-7 bytes. */ +L(copy8): + tbz count, 2, L(copy4) + CPY_MC(9998f, ldr A_lw, [src]) + CPY_MC(9998f, ldr B_lw, [srcend, -4]) + CPY_MC(9998f, str A_lw, [dstin]) + CPY_MC(9998f, str B_lw, [dstend, -4]) + mov x0, #0 + ret + + /* Copy 0..3 bytes using a branchless sequence. */ +L(copy4): + cbz count, L(copy0) + lsr tmp1, count, 1 + CPY_MC(9998f, ldrb A_lw, [src]) + CPY_MC(9998f, ldrb C_lw, [srcend, -1]) + CPY_MC(9998f, ldrb B_lw, [src, tmp1]) + CPY_MC(9998f, strb A_lw, [dstin]) + CPY_MC(9998f, strb B_lw, [dstin, tmp1]) + CPY_MC(9998f, strb C_lw, [dstend, -1]) +L(copy0): + mov x0, #0 + ret + + .p2align 4 + /* Medium copies: 33..128 bytes. */ +L(copy32_128): + CPY_MC(9998f, ldp A_l, A_h, [src]) + CPY_MC(9998f, ldp B_l, B_h, [src, 16]) + CPY_MC(9998f, ldp C_l, C_h, [srcend, -32]) + CPY_MC(9998f, ldp D_l, D_h, [srcend, -16]) + cmp count, 64 + b.hi L(copy128) + CPY_MC(9998f, stp A_l, A_h, [dstin]) + CPY_MC(9998f, stp B_l, B_h, [dstin, 16]) + CPY_MC(9998f, stp C_l, C_h, [dstend, -32]) + CPY_MC(9998f, stp D_l, D_h, [dstend, -16]) + mov x0, #0 + ret + + .p2align 4 + /* Copy 65..128 bytes. */ +L(copy128): + CPY_MC(9998f, ldp E_l, E_h, [src, 32]) + CPY_MC(9998f, ldp F_l, F_h, [src, 48]) + cmp count, 96 + b.ls L(copy96) + CPY_MC(9998f, ldp G_l, G_h, [srcend, -64]) + CPY_MC(9998f, ldp H_l, H_h, [srcend, -48]) + CPY_MC(9998f, stp G_l, G_h, [dstend, -64]) + CPY_MC(9998f, stp H_l, H_h, [dstend, -48]) +L(copy96): + CPY_MC(9998f, stp A_l, A_h, [dstin]) + CPY_MC(9998f, stp B_l, B_h, [dstin, 16]) + CPY_MC(9998f, stp E_l, E_h, [dstin, 32]) + CPY_MC(9998f, stp F_l, F_h, [dstin, 48]) + CPY_MC(9998f, stp C_l, C_h, [dstend, -32]) + CPY_MC(9998f, stp D_l, D_h, [dstend, -16]) + mov x0, #0 + ret + + .p2align 4 + /* Copy more than 128 bytes. */ +L(copy_long): + /* Use backwards copy if there is an overlap. */ + sub tmp1, dstin, src + cbz tmp1, L(copy0) + cmp tmp1, count + b.lo L(copy_long_backwards) + + /* Copy 16 bytes and then align dst to 16-byte alignment. */ + + CPY_MC(9998f, ldp D_l, D_h, [src]) + and tmp1, dstin, 15 + bic dst, dstin, 15 + sub src, src, tmp1 + add count, count, tmp1 /* Count is now 16 too large. */ + CPY_MC(9998f, ldp A_l, A_h, [src, 16]) + CPY_MC(9998f, stp D_l, D_h, [dstin]) + CPY_MC(9998f, ldp B_l, B_h, [src, 32]) + CPY_MC(9998f, ldp C_l, C_h, [src, 48]) + CPY_MC(9998f, ldp D_l, D_h, [src, 64]!) + subs count, count, 128 + 16 /* Test and readjust count. */ + b.ls L(copy64_from_end) + +L(loop64): + CPY_MC(9998f, stp A_l, A_h, [dst, 16]) + CPY_MC(9998f, ldp A_l, A_h, [src, 16]) + CPY_MC(9998f, stp B_l, B_h, [dst, 32]) + CPY_MC(9998f, ldp B_l, B_h, [src, 32]) + CPY_MC(9998f, stp C_l, C_h, [dst, 48]) + CPY_MC(9998f, ldp C_l, C_h, [src, 48]) + CPY_MC(9998f, stp D_l, D_h, [dst, 64]!) + CPY_MC(9998f, ldp D_l, D_h, [src, 64]!) + subs count, count, 64 + b.hi L(loop64) + + /* Write the last iteration and copy 64 bytes from the end. */ +L(copy64_from_end): + CPY_MC(9998f, ldp E_l, E_h, [srcend, -64]) + CPY_MC(9998f, stp A_l, A_h, [dst, 16]) + CPY_MC(9998f, ldp A_l, A_h, [srcend, -48]) + CPY_MC(9998f, stp B_l, B_h, [dst, 32]) + CPY_MC(9998f, ldp B_l, B_h, [srcend, -32]) + CPY_MC(9998f, stp C_l, C_h, [dst, 48]) + CPY_MC(9998f, ldp C_l, C_h, [srcend, -16]) + CPY_MC(9998f, stp D_l, D_h, [dst, 64]) + CPY_MC(9998f, stp E_l, E_h, [dstend, -64]) + CPY_MC(9998f, stp A_l, A_h, [dstend, -48]) + CPY_MC(9998f, stp B_l, B_h, [dstend, -32]) + CPY_MC(9998f, stp C_l, C_h, [dstend, -16]) + mov x0, #0 + ret + + .p2align 4 + + /* Large backwards copy for overlapping copies. + Copy 16 bytes and then align dst to 16-byte alignment. */ +L(copy_long_backwards): + CPY_MC(9998f, ldp D_l, D_h, [srcend, -16]) + and tmp1, dstend, 15 + sub srcend, srcend, tmp1 + sub count, count, tmp1 + CPY_MC(9998f, ldp A_l, A_h, [srcend, -16]) + CPY_MC(9998f, stp D_l, D_h, [dstend, -16]) + CPY_MC(9998f, ldp B_l, B_h, [srcend, -32]) + CPY_MC(9998f, ldp C_l, C_h, [srcend, -48]) + CPY_MC(9998f, ldp D_l, D_h, [srcend, -64]!) + sub dstend, dstend, tmp1 + subs count, count, 128 + b.ls L(copy64_from_start) + +L(loop64_backwards): + CPY_MC(9998f, stp A_l, A_h, [dstend, -16]) + CPY_MC(9998f, ldp A_l, A_h, [srcend, -16]) + CPY_MC(9998f, stp B_l, B_h, [dstend, -32]) + CPY_MC(9998f, ldp B_l, B_h, [srcend, -32]) + CPY_MC(9998f, stp C_l, C_h, [dstend, -48]) + CPY_MC(9998f, ldp C_l, C_h, [srcend, -48]) + CPY_MC(9998f, stp D_l, D_h, [dstend, -64]!) + CPY_MC(9998f, ldp D_l, D_h, [srcend, -64]!) + subs count, count, 64 + b.hi L(loop64_backwards) + + /* Write the last iteration and copy 64 bytes from the start. */ +L(copy64_from_start): + CPY_MC(9998f, ldp G_l, G_h, [src, 48]) + CPY_MC(9998f, stp A_l, A_h, [dstend, -16]) + CPY_MC(9998f, ldp A_l, A_h, [src, 32]) + CPY_MC(9998f, stp B_l, B_h, [dstend, -32]) + CPY_MC(9998f, ldp B_l, B_h, [src, 16]) + CPY_MC(9998f, stp C_l, C_h, [dstend, -48]) + CPY_MC(9998f, ldp C_l, C_h, [src]) + CPY_MC(9998f, stp D_l, D_h, [dstend, -64]) + CPY_MC(9998f, stp G_l, G_h, [dstin, 48]) + CPY_MC(9998f, stp A_l, A_h, [dstin, 32]) + CPY_MC(9998f, stp B_l, B_h, [dstin, 16]) + CPY_MC(9998f, stp C_l, C_h, [dstin]) + mov x0, #0 + ret + +9998: mov x0, #-EFAULT + ret +SYM_FUNC_END(__pi_memcpy_mcs) + +SYM_FUNC_ALIAS(__memcpy_mcs, __pi_memcpy_mcs) +EXPORT_SYMBOL(__memcpy_mcs) +SYM_FUNC_ALIAS_WEAK(memcpy_mcs, __memcpy_mcs) +EXPORT_SYMBOL(memcpy_mcs) diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c index dd772f9d0f08..ffaf2df1ed6e 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_mcs +int memcpy_mcs(void *dest, const void *src, size_t len) +{ + if (!check_memory_region((unsigned long)src, len, false, _RET_IP_) || + !check_memory_region((unsigned long)dest, len, true, _RET_IP_)) + return (unsigned long)len; + + return __memcpy_mcs(dest, src, len); +} +#endif + void *__asan_memset(void *addr, int c, ssize_t len) { if (!kasan_check_range(addr, len, true, _RET_IP_))