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head/sys/amd64/amd64/support.S

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* protection violation occurs inside the functions, the trap handler * protection violation occurs inside the functions, the trap handler
* returns to *curpcb->pcb_onfault instead of the function. * returns to *curpcb->pcb_onfault instead of the function.
*/ */
/* /*
* copyout(from_kernel, to_user, len) * copyout(from_kernel, to_user, len)
* %rdi, %rsi, %rdx * %rdi, %rsi, %rdx
*/ */
ENTRY(copyout) ENTRY(copyout_nosmap)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rax movq PCPU(CURPCB),%rax
movq $copyout_fault,PCB_ONFAULT(%rax) movq $copyout_fault,PCB_ONFAULT(%rax)
testq %rdx,%rdx /* anything to do? */ testq %rdx,%rdx /* anything to do? */
jz done_copyout jz done_copyout
/* /*
* Check explicitly for non-user addresses. This check is essential * Check explicitly for non-user addresses. This check is essential
Show All 25 Lines */
rep rep
movsq movsq
movb %dl,%cl movb %dl,%cl
andb $7,%cl andb $7,%cl
je done_copyout je done_copyout
rep rep
movsb movsb
jmp done_copyout
END(copyout_nosmap)
ENTRY(copyout_smap)
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rax
/* Trap entry clears PSL.AC */
movq $copyout_fault,PCB_ONFAULT(%rax)
testq %rdx,%rdx /* anything to do? */
jz done_copyout
/*
* Check explicitly for non-user addresses. If 486 write protection
* is being used, this check is essential because we are in kernel
* mode so the h/w does not provide any protection against writing
* kernel addresses.
*/
/*
* First, prevent address wrapping.
*/
movq %rsi,%rax
addq %rdx,%rax
jc copyout_fault
/*
* XXX STOP USING VM_MAXUSER_ADDRESS.
* It is an end address, not a max, so every time it is used correctly it
* looks like there is an off by one error, and of course it caused an off
* by one error in several places.
*/
movq $VM_MAXUSER_ADDRESS,%rcx
cmpq %rcx,%rax
ja copyout_fault
xchgq %rdi,%rsi
/* bcopy(%rsi, %rdi, %rdx) */
movq %rdx,%rcx
shrq $3,%rcx
cld
stac
rep
movsq
movb %dl,%cl
andb $7,%cl
rep
movsb
clac
done_copyout: done_copyout:
xorl %eax,%eax xorl %eax,%eax
movq PCPU(CURPCB),%rdx movq PCPU(CURPCB),%rdx
movq %rax,PCB_ONFAULT(%rdx) movq %rax,PCB_ONFAULT(%rdx)
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
ALIGN_TEXT ALIGN_TEXT
copyout_fault: copyout_fault:
movq PCPU(CURPCB),%rdx movq PCPU(CURPCB),%rdx
movq $0,PCB_ONFAULT(%rdx) movq $0,PCB_ONFAULT(%rdx)
movq $EFAULT,%rax movq $EFAULT,%rax
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(copyout) END(copyout)
/* /*
* copyin(from_user, to_kernel, len) * copyin(from_user, to_kernel, len)
* %rdi, %rsi, %rdx * %rdi, %rsi, %rdx
*/ */
ENTRY(copyin) ENTRY(copyin_nosmap)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rax movq PCPU(CURPCB),%rax
movq $copyin_fault,PCB_ONFAULT(%rax) movq $copyin_fault,PCB_ONFAULT(%rax)
testq %rdx,%rdx /* anything to do? */ testq %rdx,%rdx /* anything to do? */
jz done_copyin jz done_copyin
/* /*
* make sure address is valid * make sure address is valid
*/ */
movq %rdi,%rax movq %rdi,%rax
addq %rdx,%rax addq %rdx,%rax
jc copyin_fault jc copyin_fault
movq $VM_MAXUSER_ADDRESS,%rcx movq $VM_MAXUSER_ADDRESS,%rcx
cmpq %rcx,%rax cmpq %rcx,%rax
ja copyin_fault ja copyin_fault
xchgq %rdi,%rsi xchgq %rdi,%rsi
movq %rdx,%rcx movq %rdx,%rcx
movb %cl,%al movb %cl,%al
shrq $3,%rcx /* copy longword-wise */ shrq $3,%rcx /* copy longword-wise */
cld
rep rep
movsq movsq
movb %al,%cl movb %al,%cl
andb $7,%cl /* copy remaining bytes */ andb $7,%cl /* copy remaining bytes */
rep
movsb
jmp done_copyin
END(copyin_nosmap)
ENTRY(copyin_smap)
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rax
movq $copyin_fault,PCB_ONFAULT(%rax)
testq %rdx,%rdx /* anything to do? */
jz done_copyin
/*
* make sure address is valid
*/
movq %rdi,%rax
addq %rdx,%rax
jc copyin_fault
movq $VM_MAXUSER_ADDRESS,%rcx
cmpq %rcx,%rax
ja copyin_fault
xchgq %rdi,%rsi
movq %rdx,%rcx
movb %cl,%al
shrq $3,%rcx /* copy longword-wise */
stac
rep
movsq
movb %al,%cl
andb $7,%cl /* copy remaining bytes */
je done_copyin je done_copyin
rep rep
movsb movsb
clac
done_copyin: done_copyin:
xorl %eax,%eax xorl %eax,%eax
movq PCPU(CURPCB),%rdx movq PCPU(CURPCB),%rdx
movq %rax,PCB_ONFAULT(%rdx) movq %rax,PCB_ONFAULT(%rdx)
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(copyin_smap)
ALIGN_TEXT ALIGN_TEXT
copyin_fault: copyin_fault:
movq PCPU(CURPCB),%rdx movq PCPU(CURPCB),%rdx
movq $0,PCB_ONFAULT(%rdx) movq $0,PCB_ONFAULT(%rdx)
movq $EFAULT,%rax movq $EFAULT,%rax
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(copyin)
/* /*
* 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
*/ */
ENTRY(casueword32) ENTRY(casueword32_nosmap)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%r8 movq PCPU(CURPCB),%r8
movq $fusufault,PCB_ONFAULT(%r8) movq $fusufault,PCB_ONFAULT(%r8)
movq $VM_MAXUSER_ADDRESS-4,%rax movq $VM_MAXUSER_ADDRESS-4,%rax
cmpq %rax,%rdi /* verify address is valid */ cmpq %rax,%rdi /* verify address is valid */
ja fusufault ja fusufault
Show All 15 Lines#endif
/* /*
* Access the oldp after the pcb_onfault is cleared, to correctly * Access the oldp after the pcb_onfault is cleared, to correctly
* catch corrupted pointer. * catch corrupted pointer.
*/ */
movl %esi,(%rdx) /* oldp = %rdx */ movl %esi,(%rdx) /* oldp = %rdx */
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(casueword32) END(casueword32_nosmap)
ENTRY(casueword32_smap)
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%r8
movq $fusufault,PCB_ONFAULT(%r8)
movq $VM_MAXUSER_ADDRESS-4,%rax
cmpq %rax,%rdi /* verify address is valid */
ja fusufault
movl %esi,%eax /* old */
stac
#ifdef SMP
lock
#endif
cmpxchgl %ecx,(%rdi) /* new = %ecx */
clac
/* /*
* The old value is in %eax. If the store succeeded it will be the
* value we expected (old) from before the store, otherwise it will
* be the current value. Save %eax into %esi to prepare the return
* value.
*/
movl %eax,%esi
xorl %eax,%eax
movq %rax,PCB_ONFAULT(%r8)
/*
* Access the oldp after the pcb_onfault is cleared, to correctly
* catch corrupted pointer.
*/
movl %esi,(%rdx) /* oldp = %rdx */
POP_FRAME_POINTER
ret
END(casueword32_smap)
/*
* casueword. Compare and set user long. Returns -1 on fault, * casueword. Compare and set user long. 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 = %rsi, oldp = %rdx, new = %rcx * dst = %rdi, old = %rsi, oldp = %rdx, new = %rcx
*/ */
ENTRY(casueword) ENTRY(casueword_nosmap)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%r8 movq PCPU(CURPCB),%r8
movq $fusufault,PCB_ONFAULT(%r8) movq $fusufault,PCB_ONFAULT(%r8)
movq $VM_MAXUSER_ADDRESS-4,%rax movq $VM_MAXUSER_ADDRESS-4,%rax
cmpq %rax,%rdi /* verify address is valid */ cmpq %rax,%rdi /* verify address is valid */
ja fusufault ja fusufault
Show All 9 Lines#endif
* be the current value. * be the current value.
*/ */
movq %rax,%rsi movq %rax,%rsi
xorl %eax,%eax xorl %eax,%eax
movq %rax,PCB_ONFAULT(%r8) movq %rax,PCB_ONFAULT(%r8)
movq %rsi,(%rdx) movq %rsi,(%rdx)
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(casueword) END(casueword_nosmap)
ENTRY(casueword_smap)
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%r8
movq $fusufault,PCB_ONFAULT(%r8)
movq $VM_MAXUSER_ADDRESS-4,%rax
cmpq %rax,%rdi /* verify address is valid */
ja fusufault
movq %rsi,%rax /* old */
stac
#ifdef SMP
lock
#endif
cmpxchgq %rcx,(%rdi) /* new = %rcx */
clac
/* /*
* The old value is in %rax. If the store succeeded it will be the
* value we expected (old) from before the store, otherwise it will
* be the current value.
*/
movq %rax,%rsi
xorl %eax,%eax
movq %rax,PCB_ONFAULT(%r8)
movq %rsi,(%rdx)
POP_FRAME_POINTER
ret
END(casueword_smap)
/*
* Fetch (load) a 64-bit word, a 32-bit word, a 16-bit word, or an 8-bit * Fetch (load) a 64-bit word, a 32-bit word, a 16-bit word, or an 8-bit
* byte from user memory. * byte from user memory.
* addr = %rdi, valp = %rsi * addr = %rdi, valp = %rsi
*/ */
ALTENTRY(fueword64) ENTRY(fueword_nosmap)
ENTRY(fueword)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx) movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-8,%rax movq $VM_MAXUSER_ADDRESS-8,%rax
cmpq %rax,%rdi /* verify address is valid */ cmpq %rax,%rdi /* verify address is valid */
ja fusufault ja fusufault
xorl %eax,%eax xorl %eax,%eax
movq (%rdi),%r11 movq (%rdi),%r11
movq %rax,PCB_ONFAULT(%rcx) movq %rax,PCB_ONFAULT(%rcx)
movq %r11,(%rsi) movq %r11,(%rsi)
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(fueword64) END(fueword64_nosmap)
END(fueword)
ENTRY(fueword32) ENTRY(fueword_smap)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx) movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-8,%rax
cmpq %rax,%rdi /* verify address is valid */
ja fusufault
xorl %eax,%eax
stac
movq (%rdi),%r11
clac
movq %rax,PCB_ONFAULT(%rcx)
movq %r11,(%rsi)
POP_FRAME_POINTER
ret
END(fueword64_smap)
ENTRY(fueword32_nosmap)
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-4,%rax movq $VM_MAXUSER_ADDRESS-4,%rax
cmpq %rax,%rdi /* verify address is valid */ cmpq %rax,%rdi /* verify address is valid */
ja fusufault ja fusufault
xorl %eax,%eax xorl %eax,%eax
movl (%rdi),%r11d movl (%rdi),%r11d
movq %rax,PCB_ONFAULT(%rcx) movq %rax,PCB_ONFAULT(%rcx)
movl %r11d,(%rsi) movl %r11d,(%rsi)
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(fueword32) END(fueword32_nosmap)
ENTRY(fuword16) ENTRY(fueword32_smap)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx) movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-4,%rax
cmpq %rax,%rdi /* verify address is valid */
ja fusufault
xorl %eax,%eax
stac
movl (%rdi),%r11d
clac
movq %rax,PCB_ONFAULT(%rcx)
movl %r11d,(%rsi)
POP_FRAME_POINTER
ret
END(fueword32_smap)
ENTRY(fuword16_nosmap)
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-2,%rax movq $VM_MAXUSER_ADDRESS-2,%rax
cmpq %rax,%rdi cmpq %rax,%rdi
ja fusufault ja fusufault
movzwl (%rdi),%eax movzwl (%rdi),%eax
movq $0,PCB_ONFAULT(%rcx) movq $0,PCB_ONFAULT(%rcx)
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(fuword16) END(fuword16_nosmap)
ENTRY(fubyte) ENTRY(fuword16_smap)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx) movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-2,%rax
cmpq %rax,%rdi
ja fusufault
stac
movzwl (%rdi),%eax
clac
movq $0,PCB_ONFAULT(%rcx)
POP_FRAME_POINTER
ret
END(fuword16_smap)
ENTRY(fubyte_nosmap)
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-1,%rax movq $VM_MAXUSER_ADDRESS-1,%rax
cmpq %rax,%rdi cmpq %rax,%rdi
ja fusufault ja fusufault
movzbl (%rdi),%eax movzbl (%rdi),%eax
movq $0,PCB_ONFAULT(%rcx) movq $0,PCB_ONFAULT(%rcx)
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(fubyte) END(fubyte_nosmap)
ENTRY(fubyte_smap)
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-1,%rax
cmpq %rax,%rdi
ja fusufault
stac
movzbl (%rdi),%eax
clac
movq $0,PCB_ONFAULT(%rcx)
POP_FRAME_POINTER
ret
END(fubyte_smap)
ALIGN_TEXT ALIGN_TEXT
/* Fault entry clears PSL.AC */
fusufault: fusufault:
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
xorl %eax,%eax xorl %eax,%eax
movq %rax,PCB_ONFAULT(%rcx) movq %rax,PCB_ONFAULT(%rcx)
decq %rax decq %rax
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
/* /*
* Store a 64-bit word, a 32-bit word, a 16-bit word, or an 8-bit byte to * Store a 64-bit word, a 32-bit word, a 16-bit word, or an 8-bit byte to
* user memory. * user memory.
* addr = %rdi, value = %rsi * addr = %rdi, value = %rsi
*/ */
ALTENTRY(suword64) ENTRY(suword_nosmap)
ENTRY(suword)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx) movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-8,%rax movq $VM_MAXUSER_ADDRESS-8,%rax
cmpq %rax,%rdi /* verify address validity */ cmpq %rax,%rdi /* verify address validity */
ja fusufault ja fusufault
movq %rsi,(%rdi) movq %rsi,(%rdi)
xorl %eax,%eax xorl %eax,%eax
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
movq %rax,PCB_ONFAULT(%rcx) movq %rax,PCB_ONFAULT(%rcx)
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(suword64) END(suword_nosmap)
END(suword)
ENTRY(suword32) ENTRY(suword_smap)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx) movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-8,%rax
cmpq %rax,%rdi /* verify address validity */
ja fusufault
stac
movq %rsi,(%rdi)
clac
xorl %eax,%eax
movq PCPU(CURPCB),%rcx
movq %rax,PCB_ONFAULT(%rcx)
POP_FRAME_POINTER
ret
END(suword_smap)
ENTRY(suword32_nosmap)
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-4,%rax movq $VM_MAXUSER_ADDRESS-4,%rax
cmpq %rax,%rdi /* verify address validity */ cmpq %rax,%rdi /* verify address validity */
ja fusufault ja fusufault
movl %esi,(%rdi) movl %esi,(%rdi)
xorl %eax,%eax xorl %eax,%eax
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
movq %rax,PCB_ONFAULT(%rcx) movq %rax,PCB_ONFAULT(%rcx)
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(suword32) END(suword32_nosmap)
ENTRY(suword16) ENTRY(suword32_smap)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx) movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-4,%rax
cmpq %rax,%rdi /* verify address validity */
ja fusufault
stac
movl %esi,(%rdi)
clac
xorl %eax,%eax
movq PCPU(CURPCB),%rcx
movq %rax,PCB_ONFAULT(%rcx)
POP_FRAME_POINTER
ret
END(suword32_smap)
ENTRY(suword16_nosmap)
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-2,%rax movq $VM_MAXUSER_ADDRESS-2,%rax
cmpq %rax,%rdi /* verify address validity */ cmpq %rax,%rdi /* verify address validity */
ja fusufault ja fusufault
movw %si,(%rdi) movw %si,(%rdi)
xorl %eax,%eax xorl %eax,%eax
movq PCPU(CURPCB),%rcx /* restore trashed register */ movq PCPU(CURPCB),%rcx /* restore trashed register */
movq %rax,PCB_ONFAULT(%rcx) movq %rax,PCB_ONFAULT(%rcx)
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(suword16) END(suword16_nosmap)
ENTRY(subyte) ENTRY(suword16_smap)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx) movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-2,%rax
cmpq %rax,%rdi /* verify address validity */
ja fusufault
stac
movw %si,(%rdi)
clac
xorl %eax,%eax
movq PCPU(CURPCB),%rcx /* restore trashed register */
movq %rax,PCB_ONFAULT(%rcx)
POP_FRAME_POINTER
ret
END(suword16_smap)
ENTRY(subyte_nosmap)
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-1,%rax movq $VM_MAXUSER_ADDRESS-1,%rax
cmpq %rax,%rdi /* verify address validity */ cmpq %rax,%rdi /* verify address validity */
ja fusufault ja fusufault
movl %esi,%eax movl %esi,%eax
movb %al,(%rdi) movb %al,(%rdi)
xorl %eax,%eax xorl %eax,%eax
movq PCPU(CURPCB),%rcx /* restore trashed register */ movq PCPU(CURPCB),%rcx /* restore trashed register */
movq %rax,PCB_ONFAULT(%rcx) movq %rax,PCB_ONFAULT(%rcx)
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(subyte) END(subyte_nosmap)
ENTRY(subyte_smap)
PUSH_FRAME_POINTER
movq PCPU(CURPCB),%rcx
movq $fusufault,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS-1,%rax
cmpq %rax,%rdi /* verify address validity */
ja fusufault
movl %esi,%eax
stac
movb %al,(%rdi)
clac
xorl %eax,%eax
movq PCPU(CURPCB),%rcx /* restore trashed register */
movq %rax,PCB_ONFAULT(%rcx)
POP_FRAME_POINTER
ret
END(subyte_smap)
/* /*
* copyinstr(from, to, maxlen, int *lencopied) * copyinstr(from, to, maxlen, int *lencopied)
* %rdi, %rsi, %rdx, %rcx * %rdi, %rsi, %rdx, %rcx
* *
* copy a string from 'from' to 'to', stop when a 0 character is reached. * copy a string from 'from' to 'to', stop when a 0 character is reached.
* return ENAMETOOLONG if string is longer than maxlen, and * return ENAMETOOLONG if string is longer than maxlen, and
* EFAULT on protection violations. If lencopied is non-zero, * EFAULT on protection violations. If lencopied is non-zero,
* return the actual length in *lencopied. * return the actual length in *lencopied.
*/ */
ENTRY(copyinstr) ENTRY(copyinstr_nosmap)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq %rdx,%r8 /* %r8 = maxlen */ movq %rdx,%r8 /* %r8 = maxlen */
movq %rcx,%r9 /* %r9 = *len */ movq %rcx,%r9 /* %r9 = *len */
xchgq %rdi,%rsi /* %rdi = from, %rsi = to */ xchgq %rdi,%rsi /* %rdi = from, %rsi = to */
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
movq $cpystrflt,PCB_ONFAULT(%rcx) movq $cpystrflt,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS,%rax movq $VM_MAXUSER_ADDRESS,%rax
/* make sure 'from' is within bounds */ /* make sure 'from' is within bounds */
subq %rsi,%rax subq %rsi,%rax
jbe cpystrflt jbe cpystrflt
/* restrict maxlen to <= VM_MAXUSER_ADDRESS-from */ /* restrict maxlen to <= VM_MAXUSER_ADDRESS-from */
cmpq %rdx,%rax cmpq %rdx,%rax
jae 1f jae 1f
movq %rax,%rdx movq %rax,%rdx
movq %rax,%r8 movq %rax,%r8
1: 1:
incq %rdx incq %rdx
cld
2: 2:
decq %rdx decq %rdx
jz 3f jz copyinstr_toolong
lodsb lodsb
stosb stosb
orb %al,%al orb %al,%al
jnz 2b jnz 2b
jmp copyinstr_succ
END(copyinstr_nosmap)
ENTRY(copyinstr_smap)
PUSH_FRAME_POINTER
movq %rdx,%r8 /* %r8 = maxlen */
movq %rcx,%r9 /* %r9 = *len */
xchgq %rdi,%rsi /* %rdi = from, %rsi = to */
movq PCPU(CURPCB),%rcx
movq $cpystrflt,PCB_ONFAULT(%rcx)
movq $VM_MAXUSER_ADDRESS,%rax
/* make sure 'from' is within bounds */
subq %rsi,%rax
jbe cpystrflt
/* restrict maxlen to <= VM_MAXUSER_ADDRESS-from */
cmpq %rdx,%rax
jae 1f
movq %rax,%rdx
movq %rax,%r8
1:
incq %rdx
2:
decq %rdx
jz copyinstr_succ
stac
lodsb
stosb
clac
orb %al,%al
jnz 2b
copyinstr_succ:
/* Success -- 0 byte reached */ /* Success -- 0 byte reached */
decq %rdx decq %rdx
xorl %eax,%eax xorl %eax,%eax
jmp cpystrflt_x jmp cpystrflt_x
3: copyinstr_toolong:
/* rdx is zero - return ENAMETOOLONG or EFAULT */ /* rdx is zero - return ENAMETOOLONG or EFAULT */
movq $VM_MAXUSER_ADDRESS,%rax movq $VM_MAXUSER_ADDRESS,%rax
cmpq %rax,%rsi cmpq %rax,%rsi
jae cpystrflt jae cpystrflt
4:
movq $ENAMETOOLONG,%rax movq $ENAMETOOLONG,%rax
jmp cpystrflt_x jmp cpystrflt_x
/* Fault entry clears PSL.AC */
cpystrflt: cpystrflt:
movq $EFAULT,%rax movq $EFAULT,%rax
cpystrflt_x: cpystrflt_x:
/* set *lencopied and return %eax */ /* set *lencopied and return %eax */
movq PCPU(CURPCB),%rcx movq PCPU(CURPCB),%rcx
movq $0,PCB_ONFAULT(%rcx) movq $0,PCB_ONFAULT(%rcx)
testq %r9,%r9 testq %r9,%r9
jz 1f jz 1f
subq %rdx,%r8 subq %rdx,%r8
movq %r8,(%r9) movq %r8,(%r9)
1: 1:
POP_FRAME_POINTER POP_FRAME_POINTER
ret ret
END(copyinstr) END(copyinstr_smap)
/* /*
* copystr(from, to, maxlen, int *lencopied) * copystr(from, to, maxlen, int *lencopied)
* %rdi, %rsi, %rdx, %rcx * %rdi, %rsi, %rdx, %rcx
*/ */
ENTRY(copystr) ENTRY(copystr)
PUSH_FRAME_POINTER PUSH_FRAME_POINTER
movq %rdx,%r8 /* %r8 = maxlen */ movq %rdx,%r8 /* %r8 = maxlen */
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