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head/sys/amd64/amd64/support.S

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.macro SMAP_ENABLE smap .macro SMAP_ENABLE smap
.if \smap .if \smap
clac clac
.endif .endif
.endm .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) * copyout(from_kernel, to_user, len)
* %rdi, %rsi, %rdx * %rdi, %rsi, %rdx
*/ */
.macro COPYOUT smap erms .macro COPYOUT smap erms
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%r9 movq PCPU(CURPCB),%r11
movq $copy_fault,PCB_ONFAULT(%r9) movq $copy_fault,PCB_ONFAULT(%r11)
/* /*
* Check explicitly for non-user addresses. If 486 write protection * Check explicitly for non-user addresses. If 486 write protection
* is being used, this check is essential because we are in kernel * is being used, this check is essential because we are in kernel
* mode so the h/w does not provide any protection against writing * mode so the h/w does not provide any protection against writing
* kernel addresses. * kernel addresses.
*/ */
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* looks like there is an off by one error, and of course it caused an off * looks like there is an off by one error, and of course it caused an off
* by one error in several places. * by one error in several places.
*/ */
movq $VM_MAXUSER_ADDRESS,%rcx movq $VM_MAXUSER_ADDRESS,%rcx
cmpq %rcx,%rax cmpq %rcx,%rax
ja copy_fault 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 %rdi,%r8
movq %rsi,%rdi movq %rsi,%rdi
movq %r8,%rsi movq %r8,%rsi
movq %rdx,%rcx movq %rdx,%rcx
/*
* Set return value to zero. Remaining failure mode goes through
* copy_fault.
*/
xorl %eax,%eax
SMAP_DISABLE \smap SMAP_DISABLE \smap
.if \erms == 0 .if \smap == 1
cmpq $15,%rcx MEMMOVE erms=\erms overlap=0 begin=COPYINOUT_BEGIN end=COPYINOUT_SMAP_END
jbe 1f .else
shrq $3,%rcx MEMMOVE erms=\erms overlap=0 begin=COPYINOUT_BEGIN end=COPYINOUT_END
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:
.endif .endif
rep /* NOTREACHED */
movsb
SMAP_ENABLE \smap
movq %rax,PCB_ONFAULT(%r9)
POP_FRAME_POINTER
ret
.endm .endm
ENTRY(copyout_nosmap_std) ENTRY(copyout_nosmap_std)
COPYOUT smap=0 erms=0 COPYOUT smap=0 erms=0
END(copyout_nosmap_std) END(copyout_nosmap_std)
ENTRY(copyout_smap_std) ENTRY(copyout_smap_std)
COPYOUT smap=1 erms=0 COPYOUT smap=1 erms=0
END(copyout_smap_std) END(copyout_smap_std)
ENTRY(copyout_nosmap_erms) ENTRY(copyout_nosmap_erms)
COPYOUT smap=0 erms=1 COPYOUT smap=0 erms=1
END(copyout_nosmap_erms) END(copyout_nosmap_erms)
ENTRY(copyout_smap_erms) ENTRY(copyout_smap_erms)
COPYOUT smap=1 erms=1 COPYOUT smap=1 erms=1
END(copyout_smap_erms) END(copyout_smap_erms)
/* /*
* copyin(from_user, to_kernel, len) * copyin(from_user, to_kernel, len)
* %rdi, %rsi, %rdx * %rdi, %rsi, %rdx
*/ */
.macro COPYIN smap erms .macro COPYIN smap erms
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%r9 movq PCPU(CURPCB),%r11
movq $copy_fault,PCB_ONFAULT(%r9) movq $copy_fault,PCB_ONFAULT(%r11)
/* /*
* make sure address is valid * make sure address is valid
*/ */
movq %rdi,%rax movq %rdi,%rax
addq %rdx,%rax addq %rdx,%rax
jc copy_fault jc copy_fault
movq $VM_MAXUSER_ADDRESS,%rcx movq $VM_MAXUSER_ADDRESS,%rcx
cmpq %rcx,%rax cmpq %rcx,%rax
ja copy_fault ja copy_fault
xorl %eax,%eax
movq %rdi,%r8 movq %rdi,%r8
movq %rsi,%rdi movq %rsi,%rdi
movq %r8,%rsi movq %r8,%rsi
movq %rdx,%rcx movq %rdx,%rcx
xorl %eax,%eax
SMAP_DISABLE \smap SMAP_DISABLE \smap
.if \erms == 0 .if \smap == 1
cmpq $15,%rcx MEMMOVE erms=\erms overlap=0 begin=COPYINOUT_BEGIN end=COPYINOUT_SMAP_END
jbe 1f .else
shrq $3,%rcx /* copy longword-wise */ MEMMOVE erms=\erms overlap=0 begin=COPYINOUT_BEGIN end=COPYINOUT_END
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:
.endif .endif
rep /* NOTREACHED */
movsb
SMAP_ENABLE \smap
movq %rax,PCB_ONFAULT(%r9)
POP_FRAME_POINTER
ret
.endm .endm
ENTRY(copyin_nosmap_std) ENTRY(copyin_nosmap_std)
COPYIN smap=0 erms=0 COPYIN smap=0 erms=0
END(copyin_nosmap_std) END(copyin_nosmap_std)
ENTRY(copyin_smap_std) ENTRY(copyin_smap_std)
COPYIN smap=1 erms=0 COPYIN smap=1 erms=0
END(copyin_smap_std) END(copyin_smap_std)
ENTRY(copyin_nosmap_erms) ENTRY(copyin_nosmap_erms)
COPYIN smap=0 erms=1 COPYIN smap=0 erms=1
END(copyin_nosmap_erms) END(copyin_nosmap_erms)
ENTRY(copyin_smap_erms) ENTRY(copyin_smap_erms)
COPYIN smap=1 erms=1 COPYIN smap=1 erms=1
END(copyin_smap_erms) END(copyin_smap_erms)
ALIGN_TEXT ALIGN_TEXT
/* Trap entry clears PSL.AC */ /* Trap entry clears PSL.AC */
copy_fault: copy_fault:
movq $0,PCB_ONFAULT(%r9) movq $0,PCB_ONFAULT(%r11)
movl $EFAULT,%eax movl $EFAULT,%eax
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
/* /*
* casueword32. Compare and set user integer. Returns -1 on fault, * casueword32. Compare and set user integer. Returns -1 on fault,
* 0 if access was successful. Old value is written to *oldp. * 0 if access was successful. Old value is written to *oldp.
* dst = %rdi, old = %esi, oldp = %rdx, new = %ecx * dst = %rdi, old = %esi, oldp = %rdx, new = %ecx
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