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Commit ad2fc2cd authored by Vitaly Mayatskikh's avatar Vitaly Mayatskikh Committed by Ingo Molnar
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x86: fix copy_user on x86 

Switch copy_user_generic_string(), copy_user_generic_unrolled() and
__copy_user_nocache() from custom tail handlers to generic
copy_user_tail_handle().
Signed-off-by: default avatarVitaly Mayatskikh <v.mayatskih@gmail.com>
Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 1129585a
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Showing with 275 additions and 435 deletions
arch/x86/lib/copy_user_64.S
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arch/x86/lib/copy_user_nocache_64.S
View file @ ad2fc2cd
/* Copyright 2002 Andi Kleen, SuSE Labs.
/*
* Copyright 2008 Vitaly Mayatskikh <vmayatsk@redhat.com>
* Copyright 2002 Andi Kleen, SuSE Labs.
* Subject to the GNU Public License v2.
*
* Functions to copy from and to user space.
......@@ -12,204 +14,125 @@
#include <asm/current.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#include <asm/cpufeature.h>
/*
* copy_user_nocache - Uncached memory copy with exception handling
* This will force destination/source out of cache for more performance.
*
* Input:
* rdi destination
* rsi source
* rdx count
* rcx zero flag when 1 zero on exception
*
* Output:
* eax uncopied bytes or 0 if successful.
*/
ENTRY(__copy_user_nocache)
CFI_STARTPROC
pushq %rbx
CFI_ADJUST_CFA_OFFSET 8
CFI_REL_OFFSET rbx, 0
pushq %rcx /* save zero flag */
CFI_ADJUST_CFA_OFFSET 8
CFI_REL_OFFSET rcx, 0
xorl %eax,%eax /* zero for the exception handler */
.macro ALIGN_DESTINATION
#ifdef FIX_ALIGNMENT
/* check for bad alignment of destination */
movl %edi,%ecx
andl $7,%ecx
jnz .Lbad_alignment
.Lafter_bad_alignment:
#endif
movq %rdx,%rcx
movl $64,%ebx
shrq $6,%rdx
decq %rdx
js .Lhandle_tail
.p2align 4
.Lloop:
.Ls1: movq (%rsi),%r11
.Ls2: movq 1*8(%rsi),%r8
.Ls3: movq 2*8(%rsi),%r9
.Ls4: movq 3*8(%rsi),%r10
.Ld1: movnti %r11,(%rdi)
.Ld2: movnti %r8,1*8(%rdi)
.Ld3: movnti %r9,2*8(%rdi)
.Ld4: movnti %r10,3*8(%rdi)
.Ls5: movq 4*8(%rsi),%r11
.Ls6: movq 5*8(%rsi),%r8
.Ls7: movq 6*8(%rsi),%r9
.Ls8: movq 7*8(%rsi),%r10
.Ld5: movnti %r11,4*8(%rdi)
.Ld6: movnti %r8,5*8(%rdi)
.Ld7: movnti %r9,6*8(%rdi)
.Ld8: movnti %r10,7*8(%rdi)
jz 102f /* already aligned */
subl $8,%ecx
negl %ecx
subl %ecx,%edx
100: movb (%rsi),%al
101: movb %al,(%rdi)
incq %rsi
incq %rdi
decl %ecx
jnz 100b
102:
.section .fixup,"ax"
103: addl %r8d,%edx /* ecx is zerorest also */
jmp copy_user_handle_tail
.previous
dec %rdx
.section __ex_table,"a"
.align 8
.quad 100b,103b
.quad 101b,103b
.previous
#endif
.endm
/*
* copy_user_nocache - Uncached memory copy with exception handling
* This will force destination/source out of cache for more performance.
*/
ENTRY(__copy_user_nocache)
CFI_STARTPROC
cmpl $8,%edx
jb 20f /* less then 8 bytes, go to byte copy loop */
ALIGN_DESTINATION
movl %edx,%ecx
andl $63,%edx
shrl $6,%ecx
jz 17f
1: movq (%rsi),%r8
2: movq 1*8(%rsi),%r9
3: movq 2*8(%rsi),%r10
4: movq 3*8(%rsi),%r11
5: movnti %r8,(%rdi)
6: movnti %r9,1*8(%rdi)
7: movnti %r10,2*8(%rdi)
8: movnti %r11,3*8(%rdi)
9: movq 4*8(%rsi),%r8
10: movq 5*8(%rsi),%r9
11: movq 6*8(%rsi),%r10
12: movq 7*8(%rsi),%r11
13: movnti %r8,4*8(%rdi)
14: movnti %r9,5*8(%rdi)
15: movnti %r10,6*8(%rdi)
16: movnti %r11,7*8(%rdi)
leaq 64(%rsi),%rsi
leaq 64(%rdi),%rdi
jns .Lloop
.p2align 4
.Lhandle_tail:
movl %ecx,%edx
andl $63,%ecx
shrl $3,%ecx
jz .Lhandle_7
movl $8,%ebx
.p2align 4
.Lloop_8:
.Ls9: movq (%rsi),%r8
.Ld9: movnti %r8,(%rdi)
decl %ecx
leaq 8(%rdi),%rdi
jnz 1b
17: movl %edx,%ecx
andl $7,%edx
shrl $3,%ecx
jz 20f
18: movq (%rsi),%r8
19: movnti %r8,(%rdi)
leaq 8(%rsi),%rsi
jnz .Lloop_8
.Lhandle_7:
leaq 8(%rdi),%rdi
decl %ecx
jnz 18b
20: andl %edx,%edx
jz 23f
movl %edx,%ecx
andl $7,%ecx
jz .Lende
.p2align 4
.Lloop_1:
.Ls10: movb (%rsi),%bl
.Ld10: movb %bl,(%rdi)
incq %rdi
21: movb (%rsi),%al
22: movb %al,(%rdi)
incq %rsi
incq %rdi
decl %ecx
jnz .Lloop_1
CFI_REMEMBER_STATE
.Lende:
popq %rcx
CFI_ADJUST_CFA_OFFSET -8
CFI_RESTORE %rcx
popq %rbx
CFI_ADJUST_CFA_OFFSET -8
CFI_RESTORE rbx
jnz 21b
23: xorl %eax,%eax
sfence
ret
CFI_RESTORE_STATE
#ifdef FIX_ALIGNMENT
/* align destination */
.p2align 4
.Lbad_alignment:
movl $8,%r9d
subl %ecx,%r9d
movl %r9d,%ecx
cmpq %r9,%rdx
jz .Lhandle_7
js .Lhandle_7
.Lalign_1:
.Ls11: movb (%rsi),%bl
.Ld11: movb %bl,(%rdi)
incq %rsi
incq %rdi
decl %ecx
jnz .Lalign_1
subq %r9,%rdx
jmp .Lafter_bad_alignment
#endif
.section .fixup,"ax"
30: shll $6,%ecx
addl %ecx,%edx
jmp 60f
40: leal (%edx,%ecx,8),%edx
jmp 60f
50: movl %ecx,%edx
60: sfence
movl %r8d,%ecx
jmp copy_user_handle_tail
.previous
/* table sorted by exception address */
.section __ex_table,"a"
.align 8
.quad .Ls1,.Ls1e /* .Ls[1-4] - 0 bytes copied */
.quad .Ls2,.Ls1e
.quad .Ls3,.Ls1e
.quad .Ls4,.Ls1e
.quad .Ld1,.Ls1e /* .Ld[1-4] - 0..24 bytes coped */
.quad .Ld2,.Ls2e
.quad .Ld3,.Ls3e
.quad .Ld4,.Ls4e
.quad .Ls5,.Ls5e /* .Ls[5-8] - 32 bytes copied */
.quad .Ls6,.Ls5e
.quad .Ls7,.Ls5e
.quad .Ls8,.Ls5e
.quad .Ld5,.Ls5e /* .Ld[5-8] - 32..56 bytes copied */
.quad .Ld6,.Ls6e
.quad .Ld7,.Ls7e
.quad .Ld8,.Ls8e
.quad .Ls9,.Le_quad
.quad .Ld9,.Le_quad
.quad .Ls10,.Le_byte
.quad .Ld10,.Le_byte
#ifdef FIX_ALIGNMENT
.quad .Ls11,.Lzero_rest
.quad .Ld11,.Lzero_rest
#endif
.quad .Le5,.Le_zero
.quad 1b,30b
.quad 2b,30b
.quad 3b,30b
.quad 4b,30b
.quad 5b,30b
.quad 6b,30b
.quad 7b,30b
.quad 8b,30b
.quad 9b,30b
.quad 10b,30b
.quad 11b,30b
.quad 12b,30b
.quad 13b,30b
.quad 14b,30b
.quad 15b,30b
.quad 16b,30b
.quad 18b,40b
.quad 19b,40b
.quad 21b,50b
.quad 22b,50b
.previous
/* eax: zero, ebx: 64 */
.Ls1e: addl $8,%eax /* eax: bytes left uncopied: Ls1e: 64 .. Ls8e: 8 */
.Ls2e: addl $8,%eax
.Ls3e: addl $8,%eax
.Ls4e: addl $8,%eax
.Ls5e: addl $8,%eax
.Ls6e: addl $8,%eax
.Ls7e: addl $8,%eax
.Ls8e: addl $8,%eax
addq %rbx,%rdi /* +64 */
subq %rax,%rdi /* correct destination with computed offset */
shlq $6,%rdx /* loop counter * 64 (stride length) */
addq %rax,%rdx /* add offset to loopcnt */
andl $63,%ecx /* remaining bytes */
addq %rcx,%rdx /* add them */
jmp .Lzero_rest
/* exception on quad word loop in tail handling */
/* ecx: loopcnt/8, %edx: length, rdi: correct */
.Le_quad:
shll $3,%ecx
andl $7,%edx
addl %ecx,%edx
/* edx: bytes to zero, rdi: dest, eax:zero */
.Lzero_rest:
cmpl $0,(%rsp) /* zero flag set? */
jz .Le_zero
movq %rdx,%rcx
.Le_byte:
xorl %eax,%eax
.Le5: rep
stosb
/* when there is another exception while zeroing the rest just return */
.Le_zero:
movq %rdx,%rax
jmp .Lende
CFI_ENDPROC
ENDPROC(__copy_user_nocache)
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