322 lines
6.5 KiB
ArmAsm
322 lines
6.5 KiB
ArmAsm
/*
|
|
* 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.
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/current.h>
|
|
#include <asm/asm-offsets.h>
|
|
#include <asm/thread_info.h>
|
|
#include <asm/cpufeature.h>
|
|
#include <asm/alternative-asm.h>
|
|
#include <asm/asm.h>
|
|
#include <asm/smap.h>
|
|
|
|
/* Standard copy_to_user with segment limit checking */
|
|
ENTRY(_copy_to_user)
|
|
GET_THREAD_INFO(%rax)
|
|
movq %rdi,%rcx
|
|
addq %rdx,%rcx
|
|
jc bad_to_user
|
|
cmpq TI_addr_limit(%rax),%rcx
|
|
ja bad_to_user
|
|
ALTERNATIVE_2 "jmp copy_user_generic_unrolled", \
|
|
"jmp copy_user_generic_string", \
|
|
X86_FEATURE_REP_GOOD, \
|
|
"jmp copy_user_enhanced_fast_string", \
|
|
X86_FEATURE_ERMS
|
|
ENDPROC(_copy_to_user)
|
|
|
|
/* Standard copy_from_user with segment limit checking */
|
|
ENTRY(_copy_from_user)
|
|
GET_THREAD_INFO(%rax)
|
|
movq %rsi,%rcx
|
|
addq %rdx,%rcx
|
|
jc bad_from_user
|
|
cmpq TI_addr_limit(%rax),%rcx
|
|
ja bad_from_user
|
|
ALTERNATIVE_2 "jmp copy_user_generic_unrolled", \
|
|
"jmp copy_user_generic_string", \
|
|
X86_FEATURE_REP_GOOD, \
|
|
"jmp copy_user_enhanced_fast_string", \
|
|
X86_FEATURE_ERMS
|
|
ENDPROC(_copy_from_user)
|
|
|
|
.section .fixup,"ax"
|
|
/* must zero dest */
|
|
ENTRY(bad_from_user)
|
|
bad_from_user:
|
|
movl %edx,%ecx
|
|
xorl %eax,%eax
|
|
rep
|
|
stosb
|
|
bad_to_user:
|
|
movl %edx,%eax
|
|
ret
|
|
ENDPROC(bad_from_user)
|
|
.previous
|
|
|
|
/*
|
|
* copy_user_generic_unrolled - memory copy with exception handling.
|
|
* This version is for CPUs like P4 that don't have efficient micro
|
|
* code for rep movsq
|
|
*
|
|
* Input:
|
|
* rdi destination
|
|
* rsi source
|
|
* rdx count
|
|
*
|
|
* Output:
|
|
* eax uncopied bytes or 0 if successful.
|
|
*/
|
|
ENTRY(copy_user_generic_unrolled)
|
|
ASM_STAC
|
|
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: movq %r8,(%rdi)
|
|
6: movq %r9,1*8(%rdi)
|
|
7: movq %r10,2*8(%rdi)
|
|
8: movq %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: movq %r8,4*8(%rdi)
|
|
14: movq %r9,5*8(%rdi)
|
|
15: movq %r10,6*8(%rdi)
|
|
16: movq %r11,7*8(%rdi)
|
|
leaq 64(%rsi),%rsi
|
|
leaq 64(%rdi),%rdi
|
|
decl %ecx
|
|
jnz 1b
|
|
17: movl %edx,%ecx
|
|
andl $7,%edx
|
|
shrl $3,%ecx
|
|
jz 20f
|
|
18: movq (%rsi),%r8
|
|
19: movq %r8,(%rdi)
|
|
leaq 8(%rsi),%rsi
|
|
leaq 8(%rdi),%rdi
|
|
decl %ecx
|
|
jnz 18b
|
|
20: andl %edx,%edx
|
|
jz 23f
|
|
movl %edx,%ecx
|
|
21: movb (%rsi),%al
|
|
22: movb %al,(%rdi)
|
|
incq %rsi
|
|
incq %rdi
|
|
decl %ecx
|
|
jnz 21b
|
|
23: xor %eax,%eax
|
|
ASM_CLAC
|
|
ret
|
|
|
|
.section .fixup,"ax"
|
|
30: shll $6,%ecx
|
|
addl %ecx,%edx
|
|
jmp 60f
|
|
40: leal (%rdx,%rcx,8),%edx
|
|
jmp 60f
|
|
50: movl %ecx,%edx
|
|
60: jmp copy_user_handle_tail /* ecx is zerorest also */
|
|
.previous
|
|
|
|
_ASM_EXTABLE(1b,30b)
|
|
_ASM_EXTABLE(2b,30b)
|
|
_ASM_EXTABLE(3b,30b)
|
|
_ASM_EXTABLE(4b,30b)
|
|
_ASM_EXTABLE(5b,30b)
|
|
_ASM_EXTABLE(6b,30b)
|
|
_ASM_EXTABLE(7b,30b)
|
|
_ASM_EXTABLE(8b,30b)
|
|
_ASM_EXTABLE(9b,30b)
|
|
_ASM_EXTABLE(10b,30b)
|
|
_ASM_EXTABLE(11b,30b)
|
|
_ASM_EXTABLE(12b,30b)
|
|
_ASM_EXTABLE(13b,30b)
|
|
_ASM_EXTABLE(14b,30b)
|
|
_ASM_EXTABLE(15b,30b)
|
|
_ASM_EXTABLE(16b,30b)
|
|
_ASM_EXTABLE(18b,40b)
|
|
_ASM_EXTABLE(19b,40b)
|
|
_ASM_EXTABLE(21b,50b)
|
|
_ASM_EXTABLE(22b,50b)
|
|
ENDPROC(copy_user_generic_unrolled)
|
|
|
|
/* Some CPUs run faster using the string copy instructions.
|
|
* This is also a lot simpler. Use them when possible.
|
|
*
|
|
* Only 4GB of copy is supported. This shouldn't be a problem
|
|
* because the kernel normally only writes from/to page sized chunks
|
|
* even if user space passed a longer buffer.
|
|
* And more would be dangerous because both Intel and AMD have
|
|
* errata with rep movsq > 4GB. If someone feels the need to fix
|
|
* this please consider this.
|
|
*
|
|
* Input:
|
|
* rdi destination
|
|
* rsi source
|
|
* rdx count
|
|
*
|
|
* Output:
|
|
* eax uncopied bytes or 0 if successful.
|
|
*/
|
|
ENTRY(copy_user_generic_string)
|
|
ASM_STAC
|
|
cmpl $8,%edx
|
|
jb 2f /* less than 8 bytes, go to byte copy loop */
|
|
ALIGN_DESTINATION
|
|
movl %edx,%ecx
|
|
shrl $3,%ecx
|
|
andl $7,%edx
|
|
1: rep
|
|
movsq
|
|
2: movl %edx,%ecx
|
|
3: rep
|
|
movsb
|
|
xorl %eax,%eax
|
|
ASM_CLAC
|
|
ret
|
|
|
|
.section .fixup,"ax"
|
|
11: leal (%rdx,%rcx,8),%ecx
|
|
12: movl %ecx,%edx /* ecx is zerorest also */
|
|
jmp copy_user_handle_tail
|
|
.previous
|
|
|
|
_ASM_EXTABLE(1b,11b)
|
|
_ASM_EXTABLE(3b,12b)
|
|
ENDPROC(copy_user_generic_string)
|
|
|
|
/*
|
|
* Some CPUs are adding enhanced REP MOVSB/STOSB instructions.
|
|
* It's recommended to use enhanced REP MOVSB/STOSB if it's enabled.
|
|
*
|
|
* Input:
|
|
* rdi destination
|
|
* rsi source
|
|
* rdx count
|
|
*
|
|
* Output:
|
|
* eax uncopied bytes or 0 if successful.
|
|
*/
|
|
ENTRY(copy_user_enhanced_fast_string)
|
|
ASM_STAC
|
|
movl %edx,%ecx
|
|
1: rep
|
|
movsb
|
|
xorl %eax,%eax
|
|
ASM_CLAC
|
|
ret
|
|
|
|
.section .fixup,"ax"
|
|
12: movl %ecx,%edx /* ecx is zerorest also */
|
|
jmp copy_user_handle_tail
|
|
.previous
|
|
|
|
_ASM_EXTABLE(1b,12b)
|
|
ENDPROC(copy_user_enhanced_fast_string)
|
|
|
|
/*
|
|
* copy_user_nocache - Uncached memory copy with exception handling
|
|
* This will force destination/source out of cache for more performance.
|
|
*/
|
|
ENTRY(__copy_user_nocache)
|
|
ASM_STAC
|
|
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
|
|
decl %ecx
|
|
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
|
|
leaq 8(%rdi),%rdi
|
|
decl %ecx
|
|
jnz 18b
|
|
20: andl %edx,%edx
|
|
jz 23f
|
|
movl %edx,%ecx
|
|
21: movb (%rsi),%al
|
|
22: movb %al,(%rdi)
|
|
incq %rsi
|
|
incq %rdi
|
|
decl %ecx
|
|
jnz 21b
|
|
23: xorl %eax,%eax
|
|
ASM_CLAC
|
|
sfence
|
|
ret
|
|
|
|
.section .fixup,"ax"
|
|
30: shll $6,%ecx
|
|
addl %ecx,%edx
|
|
jmp 60f
|
|
40: lea (%rdx,%rcx,8),%rdx
|
|
jmp 60f
|
|
50: movl %ecx,%edx
|
|
60: sfence
|
|
jmp copy_user_handle_tail
|
|
.previous
|
|
|
|
_ASM_EXTABLE(1b,30b)
|
|
_ASM_EXTABLE(2b,30b)
|
|
_ASM_EXTABLE(3b,30b)
|
|
_ASM_EXTABLE(4b,30b)
|
|
_ASM_EXTABLE(5b,30b)
|
|
_ASM_EXTABLE(6b,30b)
|
|
_ASM_EXTABLE(7b,30b)
|
|
_ASM_EXTABLE(8b,30b)
|
|
_ASM_EXTABLE(9b,30b)
|
|
_ASM_EXTABLE(10b,30b)
|
|
_ASM_EXTABLE(11b,30b)
|
|
_ASM_EXTABLE(12b,30b)
|
|
_ASM_EXTABLE(13b,30b)
|
|
_ASM_EXTABLE(14b,30b)
|
|
_ASM_EXTABLE(15b,30b)
|
|
_ASM_EXTABLE(16b,30b)
|
|
_ASM_EXTABLE(18b,40b)
|
|
_ASM_EXTABLE(19b,40b)
|
|
_ASM_EXTABLE(21b,50b)
|
|
_ASM_EXTABLE(22b,50b)
|
|
ENDPROC(__copy_user_nocache)
|