instead of setting pcb_onfault on every calls of copyin and friends,
make the fault handler investigate program counter of faulting code. inspired from linux.
This commit is contained in:
yamt
parent
5155a3ee9b
commit
d0f12a6ad9
@ -1,4 +1,4 @@
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/* $NetBSD: copy.S,v 1.11 2007/11/21 00:15:08 dsl Exp $ */
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/* $NetBSD: copy.S,v 1.12 2007/11/29 09:53:33 yamt Exp $ */
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/* NetBSD: locore.S,v 1.34 2005/04/01 11:59:31 yamt Exp $ */
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/*-
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@ -124,30 +124,25 @@ ENTRY(fillw)
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ENTRY(kcopy)
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pushl %esi
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pushl %edi
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GET_CURPCB(%eax) # load curpcb into eax and set on-fault
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pushl PCB_ONFAULT(%eax)
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movl $_C_LABEL(kcopy_fault), PCB_ONFAULT(%eax)
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movl 16(%esp),%esi
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movl 20(%esp),%edi
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movl 24(%esp),%ecx
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.Lkcopy_start:
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movl 12(%esp),%esi
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movl 16(%esp),%edi
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movl 20(%esp),%ecx
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movl %edi,%eax
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subl %esi,%eax
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cmpl %ecx,%eax # overlapping?
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movl %ecx,%edx
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jb 1f
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# nope, copy forward
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shrl $2,%ecx # copy by 32-bit words
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rep
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movsl
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movl 24(%esp),%ecx
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movl %edx,%ecx
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andl $3,%ecx # any bytes left?
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jz 0f
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rep
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movsb
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0:
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GET_CURPCB(%edx) # XXX save curpcb?
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popl PCB_ONFAULT(%edx)
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popl %edi
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popl %esi
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xorl %eax,%eax
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@ -162,7 +157,7 @@ ENTRY(kcopy)
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decl %esi
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rep
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movsb
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movl 24(%esp),%ecx # copy remainder by 32-bit words
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movl %edx,%ecx # copy remainder by 32-bit words
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shrl $2,%ecx
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subl $3,%esi
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subl $3,%edi
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@ -170,8 +165,7 @@ ENTRY(kcopy)
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movsl
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cld
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GET_CURPCB(%edx)
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popl PCB_ONFAULT(%edx)
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.Lkcopy_end:
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popl %edi
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popl %esi
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xorl %eax,%eax
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@ -192,17 +186,14 @@ ENTRY(kcopy)
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/* LINTSTUB: Func: int copyout(const void *kaddr, void *uaddr, size_t len) */
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ENTRY(copyout)
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DO_DEFERRED_SWITCH
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GET_CURPCB(%edx)
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pushl %esi
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pushl %edi
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pushl $0 /* PCB_ONFAULT(%edx) */
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.Lcopyout_start:
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DO_DEFERRED_SWITCH_RETRY
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movl 16(%esp),%esi
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movl 20(%esp),%edi
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movl 24(%esp),%eax
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movl $_C_LABEL(copy_fault),PCB_ONFAULT(%edx)
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movl 12(%esp),%esi
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movl 16(%esp),%edi
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movl 20(%esp),%eax
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/*
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* We check that the end of the destination buffer is not past the end
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@ -223,8 +214,7 @@ ENTRY(copyout)
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rep
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movsb
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1:
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GET_CURPCB(%edx)
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popl PCB_ONFAULT(%edx)
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.Lcopyout_end:
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popl %edi
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popl %esi
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xorl %eax,%eax
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@ -238,17 +228,14 @@ ENTRY(copyout)
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/* LINTSTUB: Func: int copyin(const void *uaddr, void *kaddr, size_t len) */
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ENTRY(copyin)
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DO_DEFERRED_SWITCH
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GET_CURPCB(%edx)
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pushl %esi
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pushl %edi
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pushl $0 /* PCB_ONFAULT(%edx) */
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.Lcopyin_start:
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DO_DEFERRED_SWITCH_RETRY
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movl 16(%esp),%esi
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movl 20(%esp),%edi
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movl 24(%esp),%eax
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movl $_C_LABEL(copy_fault),PCB_ONFAULT(%edx)
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movl 12(%esp),%esi
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movl 16(%esp),%edi
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movl 20(%esp),%eax
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/*
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* We check that the end of the destination buffer is not past the end
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@ -270,8 +257,7 @@ ENTRY(copyin)
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rep
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movsb
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1:
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GET_CURPCB(%edx)
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popl PCB_ONFAULT(%edx)
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.Lcopyin_end:
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popl %edi
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popl %esi
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xorl %eax,%eax
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@ -288,16 +274,12 @@ NENTRY(copy_efault)
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*/
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/* LINTSTUB: Ignore */
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NENTRY(kcopy_fault)
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GET_CURPCB(%edx)
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popl PCB_ONFAULT(%edx)
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popl %edi
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popl %esi
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ret
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/* LINTSTUB: Ignore */
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NENTRY(copy_fault)
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GET_CURPCB(%edx)
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popl PCB_ONFAULT(%edx)
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popl %edi
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popl %esi
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ret
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@ -315,14 +297,14 @@ ENTRY(copyoutstr)
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pushl %esi
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pushl %edi
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DO_DEFERRED_SWITCH
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.Lcopyoutstr_start:
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DO_DEFERRED_SWITCH_RETRY
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movl 12(%esp),%esi # esi = from
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movl 16(%esp),%edi # edi = to
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movl 20(%esp),%edx # edx = maxlen
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5: GET_CURPCB(%eax)
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movl $_C_LABEL(copystr_fault),PCB_ONFAULT(%eax)
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5:
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/*
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* Get min(%edx, VM_MAXUSER_ADDRESS-%edi).
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*/
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@ -341,6 +323,7 @@ ENTRY(copyoutstr)
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lodsb
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stosb
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testb %al,%al
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.Lcopyoutstr_end:
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jnz 1b
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/* Success -- 0 byte reached. */
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@ -367,10 +350,8 @@ ENTRY(copyinstr)
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pushl %esi
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pushl %edi
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DO_DEFERRED_SWITCH
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GET_CURPCB(%ecx)
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movl $_C_LABEL(copystr_fault),PCB_ONFAULT(%ecx)
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.Lcopyinstr_start:
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DO_DEFERRED_SWITCH_RETRY
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movl 12(%esp),%esi # %esi = from
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movl 16(%esp),%edi # %edi = to
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@ -394,6 +375,7 @@ ENTRY(copyinstr)
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lodsb
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stosb
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testb %al,%al
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.Lcopyinstr_end:
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jnz 1b
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/* Success -- 0 byte reached. */
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@ -415,8 +397,6 @@ NENTRY(copystr_efault)
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NENTRY(copystr_fault)
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copystr_return:
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/* Set *lencopied and return %eax. */
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GET_CURPCB(%ecx)
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movl $0,PCB_ONFAULT(%ecx)
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movl 20(%esp),%ecx
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subl %edx,%ecx
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movl 24(%esp),%edx
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@ -655,14 +635,13 @@ ENTRY(subyte)
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*/
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ENTRY(x86_copyargs)
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pushl %esi
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GET_CURPCB(%eax)
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pushl $0
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movl $_C_LABEL(x86_copyargs_fault),PCB_ONFAULT(%eax)
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movl 12(%esp),%esi
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movl 16(%esp),%edx
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movl 20(%esp),%ecx
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movl 8(%esp),%esi
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movl 12(%esp),%edx
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movl 16(%esp),%ecx
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.Lx86_copyargs_start:
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DO_DEFERRED_SWITCH_RETRY
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/*
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* We check that the end of the destination buffer is not past the end
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* of the user's address space. If it's not, then we only need to
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@ -685,8 +664,6 @@ ENTRY(x86_copyargs)
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movl %ecx,12(%edx)
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ja 2f /* Optimise since most sycalls have <= 4 args */
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1:
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GET_CURPCB(%edx)
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popl PCB_ONFAULT(%edx)
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popl %esi
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xorl %eax,%eax
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ret
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@ -703,6 +680,7 @@ ENTRY(x86_copyargs)
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movl 36(%esi),%ecx
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movl %eax,32(%edx)
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movl %ecx,36(%edx)
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.Lx86_copyargs_end:
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jmp 1b
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/* LINTSTUB: Ignore */
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@ -711,7 +689,36 @@ NENTRY(x86_copyargs_efault)
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/* LINTSTUB: Ignore */
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NENTRY(x86_copyargs_fault)
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GET_CURPCB(%edx)
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popl PCB_ONFAULT(%edx)
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popl %esi
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ret
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.section ".rodata"
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.globl _C_LABEL(onfault_table)
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_C_LABEL(onfault_table):
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.long .Lcopyin_start
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.long .Lcopyin_end
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.long _C_LABEL(copy_fault)
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.long .Lcopyout_start
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.long .Lcopyout_end
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.long _C_LABEL(copy_fault)
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.long .Lkcopy_start
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.long .Lkcopy_end
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.long _C_LABEL(kcopy_fault)
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.long .Lcopyoutstr_start
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.long .Lcopyoutstr_end
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.long _C_LABEL(copystr_fault)
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.long .Lcopyinstr_start
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.long .Lcopyinstr_end
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.long _C_LABEL(copystr_fault)
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.long .Lx86_copyargs_start
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.long .Lx86_copyargs_end
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.long _C_LABEL(x86_copyargs_fault)
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.long 0 /* terminate */
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.text
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@ -1,4 +1,4 @@
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/* $NetBSD: trap.c,v 1.225 2007/11/28 14:02:30 yamt Exp $ */
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/* $NetBSD: trap.c,v 1.226 2007/11/29 09:53:33 yamt Exp $ */
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/*-
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* Copyright (c) 1998, 2000, 2005 The NetBSD Foundation, Inc.
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@ -75,7 +75,7 @@
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.225 2007/11/28 14:02:30 yamt Exp $");
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__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.226 2007/11/29 09:53:33 yamt Exp $");
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#include "opt_ddb.h"
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#include "opt_kgdb.h"
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@ -230,6 +230,30 @@ xmm_si_code(struct lwp *l)
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}
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}
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static void *
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onfault_handler(const struct pcb *pcb, const struct trapframe *tf)
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{
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struct onfault_table {
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uintptr_t start;
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uintptr_t end;
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void *handler;
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};
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extern const struct onfault_table onfault_table[];
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const struct onfault_table *p;
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uintptr_t pc;
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if (pcb->pcb_onfault != NULL) {
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return pcb->pcb_onfault;
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}
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pc = tf->tf_eip;
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for (p = onfault_table; p->start; p++) {
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if (p->start <= pc && pc < p->end) {
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return p->handler;
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}
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}
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return NULL;
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}
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/*
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* trap(frame):
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@ -351,11 +375,12 @@ trap(frame)
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if (p == NULL)
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goto we_re_toast;
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/* Check for copyin/copyout fault. */
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if (pcb->pcb_onfault != 0) {
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onfault = onfault_handler(pcb, frame);
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if (onfault != NULL) {
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copyefault:
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error = EFAULT;
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copyfault:
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frame->tf_eip = (int)pcb->pcb_onfault;
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frame->tf_eip = (uintptr_t)onfault;
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frame->tf_eax = error;
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return;
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}
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@ -570,8 +595,9 @@ copyfault:
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* fusubail is used by [fs]uswintr() to prevent page faulting
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* from inside the profiling interrupt.
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*/
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if (pcb->pcb_onfault == fusubail)
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if ((onfault = pcb->pcb_onfault) == fusubail) {
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goto copyefault;
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}
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#if 0
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/* XXX - check only applies to 386's and 486's with WP off */
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@ -652,9 +678,13 @@ copyfault:
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* it never touch userspace.
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*/
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if (onfault != kcopy_fault &&
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curcpu()->ci_want_pmapload)
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pmap_load();
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if (curcpu()->ci_want_pmapload) {
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onfault = onfault_handler(pcb, frame);
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if (onfault != NULL &&
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onfault != kcopy_fault) {
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pmap_load();
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}
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}
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return;
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}
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KERNEL_UNLOCK_LAST(l);
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@ -671,7 +701,8 @@ copyfault:
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}
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if (type == T_PAGEFLT) {
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if (pcb->pcb_onfault != 0) {
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onfault = onfault_handler(pcb, frame);
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if (onfault != NULL) {
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KERNEL_UNLOCK_ONE(NULL);
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goto copyfault;
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}
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@ -1,4 +1,4 @@
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/* $NetBSD: frameasm.h,v 1.9 2007/11/14 11:09:49 ad Exp $ */
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/* $NetBSD: frameasm.h,v 1.10 2007/11/29 09:53:33 yamt Exp $ */
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#ifndef _I386_FRAMEASM_H_
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#define _I386_FRAMEASM_H_
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@ -90,6 +90,14 @@
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call _C_LABEL(pmap_load) ; \
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1:
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#define DO_DEFERRED_SWITCH_RETRY \
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1: ; \
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cmpl $0, CPUVAR(WANT_PMAPLOAD) ; \
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jz 1f ; \
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call _C_LABEL(pmap_load) ; \
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jmp 1b ; \
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1:
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#define CHECK_DEFERRED_SWITCH \
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cmpl $0, CPUVAR(WANT_PMAPLOAD)
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Loading…
Reference in New Issue
Block a user