1 #include "types.h" 2 #include "param.h" 3 #include "mmu.h" 4 #include "proc.h" 5 #include "defs.h" 6 #include "x86.h" 7 #include "traps.h" 8 #include "syscall.h" 9 10 struct Gatedesc idt[256]; 11 struct Pseudodesc idt_pd = { 0, sizeof(idt) - 1, (unsigned) &idt }; 12 extern unsigned vectors[]; /* vectors.S, array of 256 entry point addresses */ 13 14 extern void trapenter(); 15 extern void trapenter1(); 16 17 void 18 tvinit() 19 { 20 int i; 21 22 for(i = 0; i < 256; i++){ 23 SETGATE(idt[i], 1, SEG_KCODE << 3, vectors[i], 0); 24 } 25 SETGATE(idt[T_SYSCALL], T_SYSCALL, SEG_KCODE << 3, vectors[48], 3); 26 } 27 28 void 29 idtinit() 30 { 31 asm volatile("lidt %0" : : "g" (idt_pd.pd_lim)); 32 } 33 34 void 35 trap(struct Trapframe *tf) 36 { 37 int v = tf->tf_trapno; 38 39 if(cpus[cpu()].clis){ 40 cprintf("cpu %d v %d eip %x\n", cpu(), v, tf->tf_eip); 41 panic("interrupt while interrupts are off"); 42 } 43 44 if(v == T_SYSCALL){ 45 struct proc *cp = curproc[cpu()]; 46 int num = cp->tf->tf_regs.reg_eax; 47 if(cp == 0) 48 panic("syscall with no proc"); 49 if(cp->killed) 50 proc_exit(); 51 cp->tf = tf; 52 syscall(); 53 if(cp != curproc[cpu()]) 54 panic("trap ret wrong curproc"); 55 if(cp->state != RUNNING) 56 panic("trap ret but not RUNNING"); 57 if(tf != cp->tf) 58 panic("trap ret wrong tf"); 59 if(cp->locks){ 60 cprintf("num=%d\n", num); 61 panic("syscall returning locks held"); 62 } 63 if(cpus[cpu()].clis) 64 panic("syscall returning but clis != 0"); 65 if((read_eflags() & FL_IF) == 0) 66 panic("syscall returning but FL_IF clear"); 67 if(read_esp() < (unsigned)cp->kstack || 68 read_esp() >= (unsigned)cp->kstack + KSTACKSIZE) 69 panic("trap ret esp wrong"); 70 if(cp->killed) 71 proc_exit(); 72 return; 73 } 74 75 if(v == (IRQ_OFFSET + IRQ_TIMER)){ 76 struct proc *cp = curproc[cpu()]; 77 lapic_timerintr(); 78 if(cp && cp->locks) 79 panic("timer interrupt while holding a lock"); 80 if(cp){ 81 #if 1 82 if((read_eflags() & FL_IF) == 0) 83 panic("timer interrupt but interrupts now disabled"); 84 #else 85 cpus[cpu()].clis += 1; 86 sti(); 87 #endif 88 if(cp->killed) 89 proc_exit(); 90 if(cp->state == RUNNING) 91 yield(); 92 } 93 return; 94 } 95 96 if(v == (IRQ_OFFSET + IRQ_IDE)){ 97 ide_intr(); 98 return; 99 } 100 101 102 // XXX probably ought to lgdt on trap return 103 104 return; 105 } 106