495 lines
13 KiB
ArmAsm
495 lines
13 KiB
ArmAsm
/*-
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* Copyright (c) 1989, 1990 William F. Jolitz.
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include "opt_apic.h"
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#include "opt_npx.h"
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#include <machine/asmacros.h>
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#include <machine/psl.h>
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#include <machine/trap.h>
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#include "assym.s"
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#define SEL_RPL_MASK 0x0002
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#define __HYPERVISOR_iret 23
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/* Offsets into shared_info_t. */
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#define evtchn_upcall_pending /* 0 */
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#define evtchn_upcall_mask 1
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#define sizeof_vcpu_shift 6
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#ifdef SMP
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#define GET_VCPU_INFO(reg) movl PCPU(CPUID),reg ; \
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shl $sizeof_vcpu_shift,reg ; \
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addl HYPERVISOR_shared_info,reg
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#else
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#define GET_VCPU_INFO(reg) movl HYPERVISOR_shared_info,reg
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#endif
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#define __DISABLE_INTERRUPTS(reg) movb $1,evtchn_upcall_mask(reg)
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#define __ENABLE_INTERRUPTS(reg) movb $0,evtchn_upcall_mask(reg)
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#define DISABLE_INTERRUPTS(reg) GET_VCPU_INFO(reg) ; \
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__DISABLE_INTERRUPTS(reg)
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#define ENABLE_INTERRUPTS(reg) GET_VCPU_INFO(reg) ; \
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__ENABLE_INTERRUPTS(reg)
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#define __TEST_PENDING(reg) testb $0xFF,evtchn_upcall_pending(reg)
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#define POPA \
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popl %edi; \
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popl %esi; \
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popl %ebp; \
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popl %ebx; \
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popl %ebx; \
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popl %edx; \
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popl %ecx; \
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popl %eax;
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.text
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/*****************************************************************************/
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/* Trap handling */
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/*****************************************************************************/
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/*
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* Trap and fault vector routines.
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*
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* Most traps are 'trap gates', SDT_SYS386TGT. A trap gate pushes state on
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* the stack that mostly looks like an interrupt, but does not disable
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* interrupts. A few of the traps we are use are interrupt gates,
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* SDT_SYS386IGT, which are nearly the same thing except interrupts are
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* disabled on entry.
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*
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* The cpu will push a certain amount of state onto the kernel stack for
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* the current process. The amount of state depends on the type of trap
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* and whether the trap crossed rings or not. See i386/include/frame.h.
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* At the very least the current EFLAGS (status register, which includes
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* the interrupt disable state prior to the trap), the code segment register,
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* and the return instruction pointer are pushed by the cpu. The cpu
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* will also push an 'error' code for certain traps. We push a dummy
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* error code for those traps where the cpu doesn't in order to maintain
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* a consistent frame. We also push a contrived 'trap number'.
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*
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* The cpu does not push the general registers, we must do that, and we
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* must restore them prior to calling 'iret'. The cpu adjusts the %cs and
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* %ss segment registers, but does not mess with %ds, %es, or %fs. Thus we
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* must load them with appropriate values for supervisor mode operation.
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*/
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MCOUNT_LABEL(user)
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MCOUNT_LABEL(btrap)
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#define TRAP(a) pushl $(a) ; jmp alltraps
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IDTVEC(div)
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pushl $0; TRAP(T_DIVIDE)
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IDTVEC(dbg)
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pushl $0; TRAP(T_TRCTRAP)
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IDTVEC(nmi)
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pushl $0; TRAP(T_NMI)
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IDTVEC(bpt)
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pushl $0; TRAP(T_BPTFLT)
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IDTVEC(ofl)
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pushl $0; TRAP(T_OFLOW)
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IDTVEC(bnd)
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pushl $0; TRAP(T_BOUND)
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IDTVEC(ill)
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pushl $0; TRAP(T_PRIVINFLT)
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IDTVEC(dna)
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pushl $0; TRAP(T_DNA)
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IDTVEC(fpusegm)
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pushl $0; TRAP(T_FPOPFLT)
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IDTVEC(tss)
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TRAP(T_TSSFLT)
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IDTVEC(missing)
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TRAP(T_SEGNPFLT)
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IDTVEC(stk)
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TRAP(T_STKFLT)
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IDTVEC(prot)
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TRAP(T_PROTFLT)
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IDTVEC(page)
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TRAP(T_PAGEFLT)
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IDTVEC(mchk)
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pushl $0; TRAP(T_MCHK)
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IDTVEC(rsvd)
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pushl $0; TRAP(T_RESERVED)
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IDTVEC(fpu)
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pushl $0; TRAP(T_ARITHTRAP)
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IDTVEC(align)
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TRAP(T_ALIGNFLT)
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IDTVEC(xmm)
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pushl $0; TRAP(T_XMMFLT)
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IDTVEC(hypervisor_callback)
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pushl $0;
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pushl $0;
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pushal
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pushl %ds
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pushl %es
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pushl %fs
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upcall_with_regs_pushed:
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SET_KERNEL_SREGS
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FAKE_MCOUNT(TF_EIP(%esp))
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call_evtchn_upcall:
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movl TF_EIP(%esp),%eax
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cmpl $scrit,%eax
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jb 10f
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cmpl $ecrit,%eax
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jb critical_region_fixup
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10: pushl %esp
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call evtchn_do_upcall
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addl $4,%esp
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/*
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* Return via doreti to handle ASTs.
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*/
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MEXITCOUNT
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jmp doreti
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hypervisor_callback_pending:
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DISABLE_INTERRUPTS(%esi) /* cli */
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jmp 10b
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/*
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* alltraps entry point. Interrupts are enabled if this was a trap
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* gate (TGT), else disabled if this was an interrupt gate (IGT).
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* Note that int0x80_syscall is a trap gate. Only page faults
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* use an interrupt gate.
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*/
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SUPERALIGN_TEXT
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.globl alltraps
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.type alltraps,@function
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alltraps:
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pushal
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pushl %ds
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pushl %es
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pushl %fs
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alltraps_with_regs_pushed:
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SET_KERNEL_SREGS
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FAKE_MCOUNT(TF_EIP(%esp))
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calltrap:
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push %esp
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call trap
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add $4, %esp
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/*
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* Return via doreti to handle ASTs.
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*/
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MEXITCOUNT
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jmp doreti
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/*
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* SYSCALL CALL GATE (old entry point for a.out binaries)
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*
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* The intersegment call has been set up to specify one dummy parameter.
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*
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* This leaves a place to put eflags so that the call frame can be
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* converted to a trap frame. Note that the eflags is (semi-)bogusly
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* pushed into (what will be) tf_err and then copied later into the
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* final spot. It has to be done this way because esp can't be just
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* temporarily altered for the pushfl - an interrupt might come in
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* and clobber the saved cs/eip.
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*/
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SUPERALIGN_TEXT
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IDTVEC(lcall_syscall)
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pushfl /* save eflags */
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popl 8(%esp) /* shuffle into tf_eflags */
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pushl $7 /* sizeof "lcall 7,0" */
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subl $4,%esp /* skip over tf_trapno */
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pushal
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pushl %ds
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pushl %es
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pushl %fs
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SET_KERNEL_SREGS
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FAKE_MCOUNT(TF_EIP(%esp))
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pushl %esp
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call syscall
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add $4, %esp
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MEXITCOUNT
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jmp doreti
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/*
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* Call gate entry for FreeBSD ELF and Linux/NetBSD syscall (int 0x80)
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*
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* Even though the name says 'int0x80', this is actually a TGT (trap gate)
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* rather then an IGT (interrupt gate). Thus interrupts are enabled on
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* entry just as they are for a normal syscall.
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*/
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SUPERALIGN_TEXT
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IDTVEC(int0x80_syscall)
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pushl $2 /* sizeof "int 0x80" */
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pushl $0xBEEF /* for debug */
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pushal
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pushl %ds
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pushl %es
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pushl %fs
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SET_KERNEL_SREGS
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FAKE_MCOUNT(TF_EIP(%esp))
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pushl %esp
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call syscall
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add $4, %esp
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MEXITCOUNT
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jmp doreti
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ENTRY(fork_trampoline)
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pushl %esp /* trapframe pointer */
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pushl %ebx /* arg1 */
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pushl %esi /* function */
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call fork_exit
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addl $12,%esp
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/* cut from syscall */
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/*
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* Return via doreti to handle ASTs.
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*/
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MEXITCOUNT
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jmp doreti
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/*
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* To efficiently implement classification of trap and interrupt handlers
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* for profiling, there must be only trap handlers between the labels btrap
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* and bintr, and only interrupt handlers between the labels bintr and
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* eintr. This is implemented (partly) by including files that contain
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* some of the handlers. Before including the files, set up a normal asm
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* environment so that the included files doen't need to know that they are
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* included.
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*/
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.data
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.p2align 4
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.text
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SUPERALIGN_TEXT
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MCOUNT_LABEL(bintr)
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#ifdef DEV_APIC
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.data
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.p2align 4
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.text
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SUPERALIGN_TEXT
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#include <i386/i386/apic_vector.s>
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#endif
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.data
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.p2align 4
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.text
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SUPERALIGN_TEXT
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#include <i386/i386/vm86bios.s>
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.text
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MCOUNT_LABEL(eintr)
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/*
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* void doreti(struct trapframe)
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*
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* Handle return from interrupts, traps and syscalls.
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*/
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.text
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SUPERALIGN_TEXT
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.type doreti,@function
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doreti:
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FAKE_MCOUNT($bintr) /* init "from" bintr -> doreti */
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doreti_next:
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#ifdef notyet
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/*
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* Check if ASTs can be handled now. PSL_VM must be checked first
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* since segment registers only have an RPL in non-VM86 mode.
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*/
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testl $PSL_VM,TF_EFLAGS(%esp) /* are we in vm86 mode? */
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jz doreti_notvm86
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movl PCPU(CURPCB),%ecx
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testl $PCB_VM86CALL,PCB_FLAGS(%ecx) /* are we in a vm86 call? */
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jz doreti_ast /* can handle ASTS now if not */
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jmp doreti_exit
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doreti_notvm86:
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#endif
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testb $SEL_RPL_MASK,TF_CS(%esp) /* are we returning to user mode? */
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jz doreti_exit /* can't handle ASTs now if not */
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doreti_ast:
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/*
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* Check for ASTs atomically with returning. Disabling CPU
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* interrupts provides sufficient locking even in the SMP case,
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* since we will be informed of any new ASTs by an IPI.
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*/
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DISABLE_INTERRUPTS(%esi) /* cli */
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movl PCPU(CURTHREAD),%eax
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testl $TDF_ASTPENDING | TDF_NEEDRESCHED,TD_FLAGS(%eax)
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je doreti_exit
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ENABLE_INTERRUPTS(%esi) /* sti */
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pushl %esp /* pass a pointer to the trapframe */
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call ast
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add $4,%esp
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jmp doreti_ast
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/*
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* doreti_exit: pop registers, iret.
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*
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* The segment register pop is a special case, since it may
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* fault if (for example) a sigreturn specifies bad segment
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* registers. The fault is handled in trap.c.
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*/
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doreti_exit:
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ENABLE_INTERRUPTS(%esi) # reenable event callbacks (sti)
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.globl scrit
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scrit:
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__TEST_PENDING(%esi)
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jnz hypervisor_callback_pending /* More to go */
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MEXITCOUNT
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.globl doreti_popl_fs
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doreti_popl_fs:
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popl %fs
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.globl doreti_popl_es
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doreti_popl_es:
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popl %es
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.globl doreti_popl_ds
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doreti_popl_ds:
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popl %ds
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/*
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* This is important: as nothing is atomic over here (we can get
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* interrupted any time), we use the critical_region_fixup() in
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* order to figure out where out stack is. Therefore, do NOT use
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* 'popal' here without fixing up the table!
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*/
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POPA
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addl $8,%esp
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.globl doreti_iret
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doreti_iret:
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jmp hypercall_page + (__HYPERVISOR_iret * 32)
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.globl ecrit
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ecrit:
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/*
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* doreti_iret_fault and friends. Alternative return code for
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* the case where we get a fault in the doreti_exit code
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* above. trap() (i386/i386/trap.c) catches this specific
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* case, sends the process a signal and continues in the
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* corresponding place in the code below.
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*/
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ALIGN_TEXT
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.globl doreti_iret_fault
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doreti_iret_fault:
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subl $8,%esp
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pushal
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pushl %ds
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.globl doreti_popl_ds_fault
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doreti_popl_ds_fault:
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pushl %es
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.globl doreti_popl_es_fault
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doreti_popl_es_fault:
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pushl %fs
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.globl doreti_popl_fs_fault
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doreti_popl_fs_fault:
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movl $0,TF_ERR(%esp) /* XXX should be the error code */
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movl $T_PROTFLT,TF_TRAPNO(%esp)
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jmp alltraps_with_regs_pushed
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/*
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# [How we do the fixup]. We want to merge the current stack frame with the
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# just-interrupted frame. How we do this depends on where in the critical
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# region the interrupted handler was executing, and so how many saved
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# registers are in each frame. We do this quickly using the lookup table
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# 'critical_fixup_table'. For each byte offset in the critical region, it
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# provides the number of bytes which have already been popped from the
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# interrupted stack frame.
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*/
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.globl critical_region_fixup
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critical_region_fixup:
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addl $critical_fixup_table-scrit,%eax
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movzbl (%eax),%eax # %eax contains num bytes popped
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movl %esp,%esi
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add %eax,%esi # %esi points at end of src region
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movl %esp,%edi
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add $0x40,%edi # %edi points at end of dst region
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movl %eax,%ecx
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shr $2,%ecx # convert bytes to words
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je 16f # skip loop if nothing to copy
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15: subl $4,%esi # pre-decrementing copy loop
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subl $4,%edi
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movl (%esi),%eax
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movl %eax,(%edi)
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loop 15b
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16: movl %edi,%esp # final %edi is top of merged stack
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jmp hypervisor_callback_pending
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critical_fixup_table:
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.byte 0x0,0x0,0x0 #testb $0x1,(%esi)
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.byte 0x0,0x0,0x0,0x0,0x0,0x0 #jne ea
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.byte 0x0,0x0 #pop %fs
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.byte 0x04 #pop %es
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.byte 0x08 #pop %ds
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.byte 0x0c #pop %edi
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.byte 0x10 #pop %esi
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.byte 0x14 #pop %ebp
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.byte 0x18 #pop %ebx
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.byte 0x1c #pop %ebx
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.byte 0x20 #pop %edx
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.byte 0x24 #pop %ecx
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.byte 0x28 #pop %eax
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.byte 0x2c,0x2c,0x2c #add $0x8,%esp
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#if 0
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.byte 0x34 #iret
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#endif
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.byte 0x34,0x34,0x34,0x34,0x34 #HYPERVISOR_iret
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/* # Hypervisor uses this for application faults while it executes.*/
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ENTRY(failsafe_callback)
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pushal
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call xen_failsafe_handler
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/*# call install_safe_pf_handler */
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movl 28(%esp),%ebx
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1: movl %ebx,%ds
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movl 32(%esp),%ebx
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2: movl %ebx,%es
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movl 36(%esp),%ebx
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3: movl %ebx,%fs
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movl 40(%esp),%ebx
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4: movl %ebx,%gs
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/*# call install_normal_pf_handler */
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popal
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addl $12,%esp
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iret
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