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amd64: employ MEMMOVE in copyin/copyout

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See r339205 for justification.

Reviewed by:	kib
Approved by:	re (gjb)
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D17526
This commit is contained in:
mjg 2018-10-12 21:59:09 +00:00
parent 94097c608e
commit 0e8914d763
1 changed files with 37 additions and 57 deletions
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94
sys/amd64/amd64/support.S
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@ -576,14 +576,27 @@ END(fillw)
.endif
.endm
.macro COPYINOUT_BEGIN
.endm
.macro COPYINOUT_END
movq %rax,PCB_ONFAULT(%r11)
POP_FRAME_POINTER
.endm
.macro COPYINOUT_SMAP_END
SMAP_ENABLE smap=1
COPYINOUT_END
.endm
/*
* copyout(from_kernel, to_user, len)
* %rdi, %rsi, %rdx
*/
.macro COPYOUT smap erms
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%r9
movq $copy_fault,PCB_ONFAULT(%r9)
movq PCPU(CURPCB),%r11
movq $copy_fault,PCB_ONFAULT(%r11)
/*
* Check explicitly for non-user addresses. If 486 write protection
@ -609,43 +622,27 @@ END(fillw)
ja copy_fault
/*
* Set up arguments for rep movs*.
* Set return value to zero. Remaining failure mode goes through
* copy_fault.
*/
xorl %eax,%eax
/*
* Set up arguments for MEMMOVE.
*/
movq %rdi,%r8
movq %rsi,%rdi
movq %r8,%rsi
movq %rdx,%rcx
/*
* Set return value to zero. Remaining failure mode goes through
* copy_fault.
*/
xorl %eax,%eax
SMAP_DISABLE \smap
.if \erms == 0
cmpq $15,%rcx
jbe 1f
shrq $3,%rcx
rep
movsq
movb %dl,%cl
andb $7,%cl
jne 1f
SMAP_ENABLE \smap
movq %rax,PCB_ONFAULT(%r9)
POP_FRAME_POINTER
ret
ALIGN_TEXT
1:
.if \smap == 1
MEMMOVE erms=\erms overlap=0 begin=COPYINOUT_BEGIN end=COPYINOUT_SMAP_END
.else
MEMMOVE erms=\erms overlap=0 begin=COPYINOUT_BEGIN end=COPYINOUT_END
.endif
rep
movsb
SMAP_ENABLE \smap
movq %rax,PCB_ONFAULT(%r9)
POP_FRAME_POINTER
ret
/* NOTREACHED */
.endm
ENTRY(copyout_nosmap_std)
@ -670,8 +667,8 @@ END(copyout_smap_erms)
*/
.macro COPYIN smap erms
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%r9
movq $copy_fault,PCB_ONFAULT(%r9)
movq PCPU(CURPCB),%r11
movq $copy_fault,PCB_ONFAULT(%r11)
/*
* make sure address is valid
@ -683,37 +680,20 @@ END(copyout_smap_erms)
cmpq %rcx,%rax
ja copy_fault
xorl %eax,%eax
movq %rdi,%r8
movq %rsi,%rdi
movq %r8,%rsi
movq %rdx,%rcx
xorl %eax,%eax
SMAP_DISABLE \smap
.if \erms == 0
cmpq $15,%rcx
jbe 1f
shrq $3,%rcx /* copy longword-wise */
rep
movsq
movb %dl,%cl
andb $7,%cl /* copy remaining bytes */
jne 1f
SMAP_ENABLE \smap
movq %rax,PCB_ONFAULT(%r9)
POP_FRAME_POINTER
ret
ALIGN_TEXT
1:
.if \smap == 1
MEMMOVE erms=\erms overlap=0 begin=COPYINOUT_BEGIN end=COPYINOUT_SMAP_END
.else
MEMMOVE erms=\erms overlap=0 begin=COPYINOUT_BEGIN end=COPYINOUT_END
.endif
rep
movsb
SMAP_ENABLE \smap
movq %rax,PCB_ONFAULT(%r9)
POP_FRAME_POINTER
ret
/* NOTREACHED */
.endm
ENTRY(copyin_nosmap_std)
@ -735,7 +715,7 @@ END(copyin_smap_erms)
ALIGN_TEXT
/* Trap entry clears PSL.AC */
copy_fault:
movq $0,PCB_ONFAULT(%r9)
movq $0,PCB_ONFAULT(%r11)
movl $EFAULT,%eax
POP_FRAME_POINTER
ret