diff options
| -rw-r--r-- | arch/x86/include/asm/string_64.h | 8 | ||||
| -rw-r--r-- | arch/x86/lib/memcpy_64.S | 20 | ||||
| -rw-r--r-- | drivers/nvdimm/claim.c | 3 | ||||
| -rw-r--r-- | drivers/nvdimm/pmem.c | 6 | ||||
| -rw-r--r-- | include/linux/string.h | 4 |
5 files changed, 26 insertions, 15 deletions
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h index 4752f8984923..d33f92b9fa22 100644 --- a/arch/x86/include/asm/string_64.h +++ b/arch/x86/include/asm/string_64.h @@ -116,7 +116,8 @@ int strcmp(const char *cs, const char *ct); #endif #define __HAVE_ARCH_MEMCPY_MCSAFE 1 -__must_check int __memcpy_mcsafe(void *dst, const void *src, size_t cnt); +__must_check unsigned long __memcpy_mcsafe(void *dst, const void *src, + size_t cnt); DECLARE_STATIC_KEY_FALSE(mcsafe_key); /** @@ -131,9 +132,10 @@ DECLARE_STATIC_KEY_FALSE(mcsafe_key); * actually do machine check recovery. Everyone else can just * use memcpy(). * - * Return 0 for success, -EFAULT for fail + * Return 0 for success, or number of bytes not copied if there was an + * exception. */ -static __always_inline __must_check int +static __always_inline __must_check unsigned long memcpy_mcsafe(void *dst, const void *src, size_t cnt) { #ifdef CONFIG_X86_MCE diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S index 5709f3ec22a4..f01a88391c98 100644 --- a/arch/x86/lib/memcpy_64.S +++ b/arch/x86/lib/memcpy_64.S @@ -252,14 +252,22 @@ ENDPROC(__memcpy_mcsafe) EXPORT_SYMBOL_GPL(__memcpy_mcsafe) .section .fixup, "ax" - /* Return -EFAULT for any failure */ -.L_memcpy_mcsafe_fail: - mov $-EFAULT, %rax + /* + * Return number of bytes not copied for any failure. Note that + * there is no "tail" handling since the source buffer is 8-byte + * aligned and poison is cacheline aligned. + */ +.E_read_words: + shll $3, %ecx +.E_leading_bytes: + addl %edx, %ecx +.E_trailing_bytes: + mov %ecx, %eax ret .previous - _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .L_memcpy_mcsafe_fail) - _ASM_EXTABLE_FAULT(.L_read_words, .L_memcpy_mcsafe_fail) - _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .L_memcpy_mcsafe_fail) + _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes) + _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words) + _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes) #endif diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c index 30852270484f..2e96b34bc936 100644 --- a/drivers/nvdimm/claim.c +++ b/drivers/nvdimm/claim.c @@ -276,7 +276,8 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns, if (rw == READ) { if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) return -EIO; - return memcpy_mcsafe(buf, nsio->addr + offset, size); + if (memcpy_mcsafe(buf, nsio->addr + offset, size) != 0) + return -EIO; } if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) { diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 9d714926ecf5..e023d6aa22b5 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -101,15 +101,15 @@ static blk_status_t read_pmem(struct page *page, unsigned int off, void *pmem_addr, unsigned int len) { unsigned int chunk; - int rc; + unsigned long rem; void *mem; while (len) { mem = kmap_atomic(page); chunk = min_t(unsigned int, len, PAGE_SIZE); - rc = memcpy_mcsafe(mem + off, pmem_addr, chunk); + rem = memcpy_mcsafe(mem + off, pmem_addr, chunk); kunmap_atomic(mem); - if (rc) + if (rem) return BLK_STS_IOERR; len -= chunk; off = 0; diff --git a/include/linux/string.h b/include/linux/string.h index dd39a690c841..4a5a0eb7df51 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -147,8 +147,8 @@ extern int memcmp(const void *,const void *,__kernel_size_t); extern void * memchr(const void *,int,__kernel_size_t); #endif #ifndef __HAVE_ARCH_MEMCPY_MCSAFE -static inline __must_check int memcpy_mcsafe(void *dst, const void *src, - size_t cnt) +static inline __must_check unsigned long memcpy_mcsafe(void *dst, + const void *src, size_t cnt) { memcpy(dst, src, cnt); return 0; |