mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-15 06:55:13 +08:00
26a37ab319
Back in commit:92b0729c34("x86/mm, x86/mce: Add memcpy_mcsafe()") ... I made a copy/paste error setting up the exception table entries and ended up with two for label .L_cache_w3 and none for .L_cache_w2. This means that if we take a machine check on: .L_cache_w2: movq 2*8(%rsi), %r10 then we don't have an exception table entry for this instruction and we can't recover. Fix: s/3/2/ Signed-off-by: Tony Luck <tony.luck@intel.com> Cc: <stable@vger.kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes:92b0729c34("x86/mm, x86/mce: Add memcpy_mcsafe()") Link: http://lkml.kernel.org/r/1490046030-25862-1-git-send-email-tony.luck@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
302 lines
6.2 KiB
ArmAsm
302 lines
6.2 KiB
ArmAsm
/* Copyright 2002 Andi Kleen */
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/errno.h>
|
|
#include <asm/cpufeatures.h>
|
|
#include <asm/alternative-asm.h>
|
|
#include <asm/export.h>
|
|
|
|
/*
|
|
* We build a jump to memcpy_orig by default which gets NOPped out on
|
|
* the majority of x86 CPUs which set REP_GOOD. In addition, CPUs which
|
|
* have the enhanced REP MOVSB/STOSB feature (ERMS), change those NOPs
|
|
* to a jmp to memcpy_erms which does the REP; MOVSB mem copy.
|
|
*/
|
|
|
|
.weak memcpy
|
|
|
|
/*
|
|
* memcpy - Copy a memory block.
|
|
*
|
|
* Input:
|
|
* rdi destination
|
|
* rsi source
|
|
* rdx count
|
|
*
|
|
* Output:
|
|
* rax original destination
|
|
*/
|
|
ENTRY(__memcpy)
|
|
ENTRY(memcpy)
|
|
ALTERNATIVE_2 "jmp memcpy_orig", "", X86_FEATURE_REP_GOOD, \
|
|
"jmp memcpy_erms", X86_FEATURE_ERMS
|
|
|
|
movq %rdi, %rax
|
|
movq %rdx, %rcx
|
|
shrq $3, %rcx
|
|
andl $7, %edx
|
|
rep movsq
|
|
movl %edx, %ecx
|
|
rep movsb
|
|
ret
|
|
ENDPROC(memcpy)
|
|
ENDPROC(__memcpy)
|
|
EXPORT_SYMBOL(memcpy)
|
|
EXPORT_SYMBOL(__memcpy)
|
|
|
|
/*
|
|
* memcpy_erms() - enhanced fast string memcpy. This is faster and
|
|
* simpler than memcpy. Use memcpy_erms when possible.
|
|
*/
|
|
ENTRY(memcpy_erms)
|
|
movq %rdi, %rax
|
|
movq %rdx, %rcx
|
|
rep movsb
|
|
ret
|
|
ENDPROC(memcpy_erms)
|
|
|
|
ENTRY(memcpy_orig)
|
|
movq %rdi, %rax
|
|
|
|
cmpq $0x20, %rdx
|
|
jb .Lhandle_tail
|
|
|
|
/*
|
|
* We check whether memory false dependence could occur,
|
|
* then jump to corresponding copy mode.
|
|
*/
|
|
cmp %dil, %sil
|
|
jl .Lcopy_backward
|
|
subq $0x20, %rdx
|
|
.Lcopy_forward_loop:
|
|
subq $0x20, %rdx
|
|
|
|
/*
|
|
* Move in blocks of 4x8 bytes:
|
|
*/
|
|
movq 0*8(%rsi), %r8
|
|
movq 1*8(%rsi), %r9
|
|
movq 2*8(%rsi), %r10
|
|
movq 3*8(%rsi), %r11
|
|
leaq 4*8(%rsi), %rsi
|
|
|
|
movq %r8, 0*8(%rdi)
|
|
movq %r9, 1*8(%rdi)
|
|
movq %r10, 2*8(%rdi)
|
|
movq %r11, 3*8(%rdi)
|
|
leaq 4*8(%rdi), %rdi
|
|
jae .Lcopy_forward_loop
|
|
addl $0x20, %edx
|
|
jmp .Lhandle_tail
|
|
|
|
.Lcopy_backward:
|
|
/*
|
|
* Calculate copy position to tail.
|
|
*/
|
|
addq %rdx, %rsi
|
|
addq %rdx, %rdi
|
|
subq $0x20, %rdx
|
|
/*
|
|
* At most 3 ALU operations in one cycle,
|
|
* so append NOPS in the same 16 bytes trunk.
|
|
*/
|
|
.p2align 4
|
|
.Lcopy_backward_loop:
|
|
subq $0x20, %rdx
|
|
movq -1*8(%rsi), %r8
|
|
movq -2*8(%rsi), %r9
|
|
movq -3*8(%rsi), %r10
|
|
movq -4*8(%rsi), %r11
|
|
leaq -4*8(%rsi), %rsi
|
|
movq %r8, -1*8(%rdi)
|
|
movq %r9, -2*8(%rdi)
|
|
movq %r10, -3*8(%rdi)
|
|
movq %r11, -4*8(%rdi)
|
|
leaq -4*8(%rdi), %rdi
|
|
jae .Lcopy_backward_loop
|
|
|
|
/*
|
|
* Calculate copy position to head.
|
|
*/
|
|
addl $0x20, %edx
|
|
subq %rdx, %rsi
|
|
subq %rdx, %rdi
|
|
.Lhandle_tail:
|
|
cmpl $16, %edx
|
|
jb .Lless_16bytes
|
|
|
|
/*
|
|
* Move data from 16 bytes to 31 bytes.
|
|
*/
|
|
movq 0*8(%rsi), %r8
|
|
movq 1*8(%rsi), %r9
|
|
movq -2*8(%rsi, %rdx), %r10
|
|
movq -1*8(%rsi, %rdx), %r11
|
|
movq %r8, 0*8(%rdi)
|
|
movq %r9, 1*8(%rdi)
|
|
movq %r10, -2*8(%rdi, %rdx)
|
|
movq %r11, -1*8(%rdi, %rdx)
|
|
retq
|
|
.p2align 4
|
|
.Lless_16bytes:
|
|
cmpl $8, %edx
|
|
jb .Lless_8bytes
|
|
/*
|
|
* Move data from 8 bytes to 15 bytes.
|
|
*/
|
|
movq 0*8(%rsi), %r8
|
|
movq -1*8(%rsi, %rdx), %r9
|
|
movq %r8, 0*8(%rdi)
|
|
movq %r9, -1*8(%rdi, %rdx)
|
|
retq
|
|
.p2align 4
|
|
.Lless_8bytes:
|
|
cmpl $4, %edx
|
|
jb .Lless_3bytes
|
|
|
|
/*
|
|
* Move data from 4 bytes to 7 bytes.
|
|
*/
|
|
movl (%rsi), %ecx
|
|
movl -4(%rsi, %rdx), %r8d
|
|
movl %ecx, (%rdi)
|
|
movl %r8d, -4(%rdi, %rdx)
|
|
retq
|
|
.p2align 4
|
|
.Lless_3bytes:
|
|
subl $1, %edx
|
|
jb .Lend
|
|
/*
|
|
* Move data from 1 bytes to 3 bytes.
|
|
*/
|
|
movzbl (%rsi), %ecx
|
|
jz .Lstore_1byte
|
|
movzbq 1(%rsi), %r8
|
|
movzbq (%rsi, %rdx), %r9
|
|
movb %r8b, 1(%rdi)
|
|
movb %r9b, (%rdi, %rdx)
|
|
.Lstore_1byte:
|
|
movb %cl, (%rdi)
|
|
|
|
.Lend:
|
|
retq
|
|
ENDPROC(memcpy_orig)
|
|
|
|
#ifndef CONFIG_UML
|
|
/*
|
|
* memcpy_mcsafe_unrolled - memory copy with machine check exception handling
|
|
* Note that we only catch machine checks when reading the source addresses.
|
|
* Writes to target are posted and don't generate machine checks.
|
|
*/
|
|
ENTRY(memcpy_mcsafe_unrolled)
|
|
cmpl $8, %edx
|
|
/* Less than 8 bytes? Go to byte copy loop */
|
|
jb .L_no_whole_words
|
|
|
|
/* Check for bad alignment of source */
|
|
testl $7, %esi
|
|
/* Already aligned */
|
|
jz .L_8byte_aligned
|
|
|
|
/* Copy one byte at a time until source is 8-byte aligned */
|
|
movl %esi, %ecx
|
|
andl $7, %ecx
|
|
subl $8, %ecx
|
|
negl %ecx
|
|
subl %ecx, %edx
|
|
.L_copy_leading_bytes:
|
|
movb (%rsi), %al
|
|
movb %al, (%rdi)
|
|
incq %rsi
|
|
incq %rdi
|
|
decl %ecx
|
|
jnz .L_copy_leading_bytes
|
|
|
|
.L_8byte_aligned:
|
|
/* Figure out how many whole cache lines (64-bytes) to copy */
|
|
movl %edx, %ecx
|
|
andl $63, %edx
|
|
shrl $6, %ecx
|
|
jz .L_no_whole_cache_lines
|
|
|
|
/* Loop copying whole cache lines */
|
|
.L_cache_w0: movq (%rsi), %r8
|
|
.L_cache_w1: movq 1*8(%rsi), %r9
|
|
.L_cache_w2: movq 2*8(%rsi), %r10
|
|
.L_cache_w3: movq 3*8(%rsi), %r11
|
|
movq %r8, (%rdi)
|
|
movq %r9, 1*8(%rdi)
|
|
movq %r10, 2*8(%rdi)
|
|
movq %r11, 3*8(%rdi)
|
|
.L_cache_w4: movq 4*8(%rsi), %r8
|
|
.L_cache_w5: movq 5*8(%rsi), %r9
|
|
.L_cache_w6: movq 6*8(%rsi), %r10
|
|
.L_cache_w7: movq 7*8(%rsi), %r11
|
|
movq %r8, 4*8(%rdi)
|
|
movq %r9, 5*8(%rdi)
|
|
movq %r10, 6*8(%rdi)
|
|
movq %r11, 7*8(%rdi)
|
|
leaq 64(%rsi), %rsi
|
|
leaq 64(%rdi), %rdi
|
|
decl %ecx
|
|
jnz .L_cache_w0
|
|
|
|
/* Are there any trailing 8-byte words? */
|
|
.L_no_whole_cache_lines:
|
|
movl %edx, %ecx
|
|
andl $7, %edx
|
|
shrl $3, %ecx
|
|
jz .L_no_whole_words
|
|
|
|
/* Copy trailing words */
|
|
.L_copy_trailing_words:
|
|
movq (%rsi), %r8
|
|
mov %r8, (%rdi)
|
|
leaq 8(%rsi), %rsi
|
|
leaq 8(%rdi), %rdi
|
|
decl %ecx
|
|
jnz .L_copy_trailing_words
|
|
|
|
/* Any trailing bytes? */
|
|
.L_no_whole_words:
|
|
andl %edx, %edx
|
|
jz .L_done_memcpy_trap
|
|
|
|
/* Copy trailing bytes */
|
|
movl %edx, %ecx
|
|
.L_copy_trailing_bytes:
|
|
movb (%rsi), %al
|
|
movb %al, (%rdi)
|
|
incq %rsi
|
|
incq %rdi
|
|
decl %ecx
|
|
jnz .L_copy_trailing_bytes
|
|
|
|
/* Copy successful. Return zero */
|
|
.L_done_memcpy_trap:
|
|
xorq %rax, %rax
|
|
ret
|
|
ENDPROC(memcpy_mcsafe_unrolled)
|
|
EXPORT_SYMBOL_GPL(memcpy_mcsafe_unrolled)
|
|
|
|
.section .fixup, "ax"
|
|
/* Return -EFAULT for any failure */
|
|
.L_memcpy_mcsafe_fail:
|
|
mov $-EFAULT, %rax
|
|
ret
|
|
|
|
.previous
|
|
|
|
_ASM_EXTABLE_FAULT(.L_copy_leading_bytes, .L_memcpy_mcsafe_fail)
|
|
_ASM_EXTABLE_FAULT(.L_cache_w0, .L_memcpy_mcsafe_fail)
|
|
_ASM_EXTABLE_FAULT(.L_cache_w1, .L_memcpy_mcsafe_fail)
|
|
_ASM_EXTABLE_FAULT(.L_cache_w2, .L_memcpy_mcsafe_fail)
|
|
_ASM_EXTABLE_FAULT(.L_cache_w3, .L_memcpy_mcsafe_fail)
|
|
_ASM_EXTABLE_FAULT(.L_cache_w4, .L_memcpy_mcsafe_fail)
|
|
_ASM_EXTABLE_FAULT(.L_cache_w5, .L_memcpy_mcsafe_fail)
|
|
_ASM_EXTABLE_FAULT(.L_cache_w6, .L_memcpy_mcsafe_fail)
|
|
_ASM_EXTABLE_FAULT(.L_cache_w7, .L_memcpy_mcsafe_fail)
|
|
_ASM_EXTABLE_FAULT(.L_copy_trailing_words, .L_memcpy_mcsafe_fail)
|
|
_ASM_EXTABLE_FAULT(.L_copy_trailing_bytes, .L_memcpy_mcsafe_fail)
|
|
#endif
|