211 lines
6.5 KiB
C
211 lines
6.5 KiB
C
/*
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* linux/kernel/traps.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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/*
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* 'Traps.c' handles hardware traps and faults after we have saved some
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* state in 'asm.s'. Currently mostly a debugging-aid, will be extended
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* to mainly kill the offending process (probably by giving it a signal,
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* but possibly by killing it outright if necessary).
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*/
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#include <linux/head.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/segment.h>
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#include <linux/ptrace.h>
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#include <asm/system.h>
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#include <asm/segment.h>
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#include <asm/io.h>
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static inline void console_verbose(void)
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{
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extern int console_loglevel;
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console_loglevel = 15;
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}
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#define DO_ERROR(trapnr, signr, str, name, tsk) \
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asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
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{ \
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tsk->tss.error_code = error_code; \
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tsk->tss.trap_no = trapnr; \
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if (signr == SIGTRAP && current->flags & PF_PTRACED) \
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current->blocked &= ~(1 << (SIGTRAP-1)); \
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send_sig(signr, tsk, 1); \
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die_if_kernel(str,regs,error_code); \
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}
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#define get_seg_byte(seg,addr) ({ \
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register char __res; \
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__asm__("push %%fs;mov %%ax,%%fs;movb %%fs:%2,%%al;pop %%fs" \
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:"=a" (__res):"0" (seg),"m" (*(addr))); \
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__res;})
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#define get_seg_long(seg,addr) ({ \
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register unsigned long __res; \
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__asm__("push %%fs;mov %%ax,%%fs;movl %%fs:%2,%%eax;pop %%fs" \
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:"=a" (__res):"0" (seg),"m" (*(addr))); \
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__res;})
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#define _fs() ({ \
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register unsigned short __res; \
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__asm__("mov %%fs,%%ax":"=a" (__res):); \
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__res;})
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void page_exception(void);
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asmlinkage void divide_error(void);
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asmlinkage void debug(void);
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asmlinkage void nmi(void);
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asmlinkage void int3(void);
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asmlinkage void overflow(void);
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asmlinkage void bounds(void);
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asmlinkage void invalid_op(void);
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asmlinkage void device_not_available(void);
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asmlinkage void double_fault(void);
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asmlinkage void coprocessor_segment_overrun(void);
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asmlinkage void invalid_TSS(void);
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asmlinkage void segment_not_present(void);
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asmlinkage void stack_segment(void);
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asmlinkage void general_protection(void);
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asmlinkage void page_fault(void);
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asmlinkage void coprocessor_error(void);
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asmlinkage void reserved(void);
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asmlinkage void alignment_check(void);
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/*static*/ void die_if_kernel(char * str, struct pt_regs * regs, long err)
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{
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int i;
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if ((regs->eflags & VM_MASK) || (3 & regs->cs) == 3)
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return;
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console_verbose();
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printk("%s: %04lx\n", str, err & 0xffff);
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printk("EIP: %04x:%08lx\nEFLAGS: %08lx\n", 0xffff & regs->cs,regs->eip,regs->eflags);
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printk("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
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regs->eax, regs->ebx, regs->ecx, regs->edx);
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printk("esi: %08lx edi: %08lx ebp: %08lx\n",
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regs->esi, regs->edi, regs->ebp);
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printk("ds: %04x es: %04x fs: %04x gs: %04x\n",
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regs->ds, regs->es, regs->fs, regs->gs);
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store_TR(i);
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printk("Pid: %d, process nr: %d (%s)\n", current->pid, 0xffff & i, current->comm);
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for(i=0;i<20;i++)
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printk("%02x ",0xff & get_seg_byte(regs->cs,(i+(char *)regs->eip)));
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printk("\n");
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do_exit(SIGSEGV);
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}
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DO_ERROR( 0, SIGFPE, "divide error", divide_error, current)
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DO_ERROR( 3, SIGTRAP, "int3", int3, current)
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DO_ERROR( 4, SIGSEGV, "overflow", overflow, current)
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DO_ERROR( 5, SIGSEGV, "bounds", bounds, current)
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DO_ERROR( 6, SIGILL, "invalid operand", invalid_op, current)
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DO_ERROR( 7, SIGSEGV, "device not available", device_not_available, current)
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DO_ERROR( 8, SIGSEGV, "double fault", double_fault, current)
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DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun, last_task_used_math)
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DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS, current)
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DO_ERROR(11, SIGSEGV, "segment not present", segment_not_present, current)
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DO_ERROR(12, SIGSEGV, "stack segment", stack_segment, current)
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DO_ERROR(13, SIGSEGV, "general protection", general_protection, current)
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DO_ERROR(15, SIGSEGV, "reserved", reserved, current)
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DO_ERROR(17, SIGSEGV, "alignment check", alignment_check, current)
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asmlinkage void do_nmi(struct pt_regs * regs, long error_code)
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{
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printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
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printk("You probably have a hardware problem with your RAM chips\n");
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}
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asmlinkage void do_debug(struct pt_regs * regs, long error_code)
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{
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if (current->flags & PF_PTRACED)
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current->blocked &= ~(1 << (SIGTRAP-1));
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send_sig(SIGTRAP, current, 1);
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current->tss.trap_no = 1;
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current->tss.error_code = error_code;
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if((regs->cs & 3) == 0) {
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/* If this is a kernel mode trap, then reset db7 and allow us to continue */
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__asm__("movl $0,%%edx\n\t" \
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"movl %%edx,%%db7\n\t" \
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: /* no output */ \
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: /* no input */ :"dx");
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return;
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};
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die_if_kernel("debug",regs,error_code);
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}
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/*
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* Allow the process which triggered the interrupt to recover the error
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* condition.
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* - the status word is saved in the cs selector.
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* - the tag word is saved in the operand selector.
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* - the status word is then cleared and the tags all set to Empty.
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*
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* This will give sufficient information for complete recovery provided that
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* the affected process knows or can deduce the code and data segments
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* which were in force when the exception condition arose.
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*
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* Note that we play around with the 'TS' bit to hopefully get
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* the correct behaviour even in the presense of the asynchronous
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* IRQ13 behaviour
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*/
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void math_error(void)
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{
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struct i387_hard_struct * env;
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clts();
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if (!last_task_used_math) {
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__asm__("fnclex");
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return;
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}
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env = &last_task_used_math->tss.i387.hard;
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send_sig(SIGFPE, last_task_used_math, 1);
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last_task_used_math->tss.trap_no = 16;
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last_task_used_math->tss.error_code = 0;
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__asm__ __volatile__("fnsave %0":"=m" (*env));
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last_task_used_math = NULL;
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stts();
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env->fcs = (env->swd & 0x0000ffff) | (env->fcs & 0xffff0000);
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env->fos = env->twd;
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env->swd &= 0xffff3800;
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env->twd = 0xffffffff;
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}
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asmlinkage void do_coprocessor_error(struct pt_regs * regs, long error_code)
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{
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ignore_irq13 = 1;
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math_error();
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}
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void trap_init(void)
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{
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int i;
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set_trap_gate(0,÷_error);
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set_trap_gate(1,&debug);
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set_trap_gate(2,&nmi);
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set_system_gate(3,&int3); /* int3-5 can be called from all */
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set_system_gate(4,&overflow);
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set_system_gate(5,&bounds);
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set_trap_gate(6,&invalid_op);
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set_trap_gate(7,&device_not_available);
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set_trap_gate(8,&double_fault);
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set_trap_gate(9,&coprocessor_segment_overrun);
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set_trap_gate(10,&invalid_TSS);
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set_trap_gate(11,&segment_not_present);
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set_trap_gate(12,&stack_segment);
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set_trap_gate(13,&general_protection);
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set_trap_gate(14,&page_fault);
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set_trap_gate(15,&reserved);
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set_trap_gate(16,&coprocessor_error);
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set_trap_gate(17,&alignment_check);
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for (i=18;i<48;i++)
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set_trap_gate(i,&reserved);
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}
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