/* * linux/kernel/traps.c * * Copyright (C) 1991, 1992 Linus Torvalds */ /* * 'Traps.c' handles hardware traps and faults after we have saved some * state in 'asm.s'. Currently mostly a debugging-aid, will be extended * to mainly kill the offending process (probably by giving it a signal, * but possibly by killing it outright if necessary). */ #include <linux/head.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/segment.h> #include <linux/ptrace.h> #include <asm/system.h> #include <asm/segment.h> #include <asm/io.h> #define get_seg_byte(seg,addr) ({ \ register char __res; \ __asm__("push %%fs;mov %%ax,%%fs;movb %%fs:%2,%%al;pop %%fs" \ :"=a" (__res):"0" (seg),"m" (*(addr))); \ __res;}) #define get_seg_long(seg,addr) ({ \ register unsigned long __res; \ __asm__("push %%fs;mov %%ax,%%fs;movl %%fs:%2,%%eax;pop %%fs" \ :"=a" (__res):"0" (seg),"m" (*(addr))); \ __res;}) #define _fs() ({ \ register unsigned short __res; \ __asm__("mov %%fs,%%ax":"=a" (__res):); \ __res;}) void page_exception(void); extern "C" void divide_error(void); extern "C" void debug(void); extern "C" void nmi(void); extern "C" void int3(void); extern "C" void overflow(void); extern "C" void bounds(void); extern "C" void invalid_op(void); extern "C" void device_not_available(void); extern "C" void double_fault(void); extern "C" void coprocessor_segment_overrun(void); extern "C" void invalid_TSS(void); extern "C" void segment_not_present(void); extern "C" void stack_segment(void); extern "C" void general_protection(void); extern "C" void page_fault(void); extern "C" void coprocessor_error(void); extern "C" void reserved(void); extern "C" void alignment_check(void); /*static*/ void die_if_kernel(char * str, struct pt_regs * regs, long err) { int i; if ((regs->eflags & VM_MASK) || ((0xffff & regs->cs) == USER_CS)) return; printk("%s: %04x\n", str, err & 0xffff); printk("EIP: %04x:%p\nEFLAGS: %p\n", 0xffff & regs->cs,regs->eip,regs->eflags); printk("eax: %08x ebx: %08x ecx: %08x edx: %08x\n", regs->eax, regs->ebx, regs->ecx, regs->edx); printk("esi: %08x edi: %08x ebp: %08x\n", regs->esi, regs->edi, regs->ebp); printk("ds: %04x es: %04x fs: %04x gs: %04x\n", regs->ds, regs->es, regs->fs, regs->gs); store_TR(i); printk("Pid: %d, process nr: %d\n", current->pid, 0xffff & i); for(i=0;i<10;i++) printk("%02x ",0xff & get_seg_byte(regs->cs,(i+(char *)regs->eip))); printk("\n"); do_exit(SIGSEGV); } extern "C" void do_double_fault(struct pt_regs * regs, long error_code) { send_sig(SIGSEGV, current, 1); die_if_kernel("double fault",regs,error_code); } extern "C" void do_general_protection(struct pt_regs * regs, long error_code) { send_sig(SIGSEGV, current, 1); die_if_kernel("general protection",regs,error_code); } extern "C" void do_alignment_check(struct pt_regs * regs, long error_code) { send_sig(SIGSEGV, current, 1); die_if_kernel("alignment check",regs,error_code); } extern "C" void do_divide_error(struct pt_regs * regs, long error_code) { send_sig(SIGFPE, current, 1); die_if_kernel("divide error",regs,error_code); } extern "C" void do_int3(struct pt_regs * regs, long error_code) { if (current->flags & PF_PTRACED) current->blocked &= ~(1 << (SIGTRAP-1)); send_sig(SIGTRAP, current, 1); die_if_kernel("int3",regs,error_code); } extern "C" void do_nmi(struct pt_regs * regs, long error_code) { printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n"); } extern "C" void do_debug(struct pt_regs * regs, long error_code) { if (current->flags & PF_PTRACED) current->blocked &= ~(1 << (SIGTRAP-1)); send_sig(SIGTRAP, current, 1); die_if_kernel("debug",regs,error_code); } extern "C" void do_overflow(struct pt_regs * regs, long error_code) { send_sig(SIGSEGV, current, 1); die_if_kernel("overflow",regs,error_code); } extern "C" void do_bounds(struct pt_regs * regs, long error_code) { send_sig(SIGSEGV, current, 1); die_if_kernel("bounds",regs,error_code); } extern "C" void do_invalid_op(struct pt_regs * regs, long error_code) { send_sig(SIGILL, current, 1); die_if_kernel("invalid operand",regs,error_code); } extern "C" void do_device_not_available(struct pt_regs * regs, long error_code) { send_sig(SIGSEGV, current, 1); die_if_kernel("device not available",regs,error_code); } extern "C" void do_coprocessor_segment_overrun(struct pt_regs * regs, long error_code) { send_sig(SIGFPE, last_task_used_math, 1); die_if_kernel("coprocessor segment overrun",regs,error_code); } extern "C" void do_invalid_TSS(struct pt_regs * regs,long error_code) { send_sig(SIGSEGV, current, 1); die_if_kernel("invalid TSS",regs,error_code); } extern "C" void do_segment_not_present(struct pt_regs * regs,long error_code) { send_sig(SIGSEGV, current, 1); die_if_kernel("segment not present",regs,error_code); } extern "C" void do_stack_segment(struct pt_regs * regs,long error_code) { send_sig(SIGSEGV, current, 1); die_if_kernel("stack segment",regs,error_code); } /* * Allow the process which triggered the interrupt to recover the error * condition. * - the status word is saved in the cs selector. * - the tag word is saved in the operand selector. * - the status word is then cleared and the tags all set to Empty. * * This will give sufficient information for complete recovery provided that * the affected process knows or can deduce the code and data segments * which were in force when the exception condition arose. * * Note that we play around with the 'TS' bit to hopefully get * the correct behaviour even in the presense of the asynchronous * IRQ13 behaviour */ void math_error(void) { struct i387_hard_struct * env; clts(); if (!last_task_used_math) { __asm__("fnclex"); return; } env = &last_task_used_math->tss.i387.hard; send_sig(SIGFPE, last_task_used_math, 1); __asm__ __volatile__("fnsave %0":"=m" (*env)); last_task_used_math = NULL; stts(); env->fcs = (env->swd & 0x0000ffff) | (env->fcs & 0xffff0000); env->fos = env->twd; env->swd &= 0xffff0000; env->twd = 0xffffffff; } extern "C" void do_coprocessor_error(struct pt_regs * regs, long error_code) { ignore_irq13 = 1; math_error(); } extern "C" void do_reserved(struct pt_regs * regs, long error_code) { send_sig(SIGSEGV, current, 1); die_if_kernel("reserved (15,17-47) error",regs,error_code); } void trap_init(void) { int i; set_trap_gate(0,÷_error); set_trap_gate(1,&debug); set_trap_gate(2,&nmi); set_system_gate(3,&int3); /* int3-5 can be called from all */ set_system_gate(4,&overflow); set_system_gate(5,&bounds); set_trap_gate(6,&invalid_op); set_trap_gate(7,&device_not_available); set_trap_gate(8,&double_fault); set_trap_gate(9,&coprocessor_segment_overrun); set_trap_gate(10,&invalid_TSS); set_trap_gate(11,&segment_not_present); set_trap_gate(12,&stack_segment); set_trap_gate(13,&general_protection); set_trap_gate(14,&page_fault); set_trap_gate(15,&reserved); set_trap_gate(16,&coprocessor_error); set_trap_gate(17,&alignment_check); for (i=18;i<48;i++) set_trap_gate(i,&reserved); }