| /* |
| * 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> |
| |
| static inline void console_verbose(void) |
| { |
| extern int console_loglevel; |
| console_loglevel = 15; |
| } |
| |
| #define DO_ERROR(trapnr, signr, str, name, tsk) \ |
| asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ |
| { \ |
| tsk->tss.error_code = error_code; \ |
| tsk->tss.trap_no = trapnr; \ |
| if (signr == SIGTRAP && current->flags & PF_PTRACED) \ |
| current->blocked &= ~(1 << (SIGTRAP-1)); \ |
| send_sig(signr, tsk, 1); \ |
| die_if_kernel(str,regs,error_code); \ |
| } |
| |
| #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); |
| |
| asmlinkage void divide_error(void); |
| asmlinkage void debug(void); |
| asmlinkage void nmi(void); |
| asmlinkage void int3(void); |
| asmlinkage void overflow(void); |
| asmlinkage void bounds(void); |
| asmlinkage void invalid_op(void); |
| asmlinkage void device_not_available(void); |
| asmlinkage void double_fault(void); |
| asmlinkage void coprocessor_segment_overrun(void); |
| asmlinkage void invalid_TSS(void); |
| asmlinkage void segment_not_present(void); |
| asmlinkage void stack_segment(void); |
| asmlinkage void general_protection(void); |
| asmlinkage void page_fault(void); |
| asmlinkage void coprocessor_error(void); |
| asmlinkage void reserved(void); |
| asmlinkage void alignment_check(void); |
| |
| /*static*/ void die_if_kernel(char * str, struct pt_regs * regs, long err) |
| { |
| int i; |
| |
| if ((regs->eflags & VM_MASK) || (3 & regs->cs) == 3) |
| return; |
| |
| console_verbose(); |
| printk("%s: %04lx\n", str, err & 0xffff); |
| printk("EIP: %04x:%08lx\nEFLAGS: %08lx\n", 0xffff & regs->cs,regs->eip,regs->eflags); |
| printk("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n", |
| regs->eax, regs->ebx, regs->ecx, regs->edx); |
| printk("esi: %08lx edi: %08lx ebp: %08lx\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 (%s)\n", current->pid, 0xffff & i, current->comm); |
| for(i=0;i<20;i++) |
| printk("%02x ",0xff & get_seg_byte(regs->cs,(i+(char *)regs->eip))); |
| printk("\n"); |
| do_exit(SIGSEGV); |
| } |
| |
| DO_ERROR( 0, SIGFPE, "divide error", divide_error, current) |
| DO_ERROR( 3, SIGTRAP, "int3", int3, current) |
| DO_ERROR( 4, SIGSEGV, "overflow", overflow, current) |
| DO_ERROR( 5, SIGSEGV, "bounds", bounds, current) |
| DO_ERROR( 6, SIGILL, "invalid operand", invalid_op, current) |
| DO_ERROR( 7, SIGSEGV, "device not available", device_not_available, current) |
| DO_ERROR( 8, SIGSEGV, "double fault", double_fault, current) |
| DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun, last_task_used_math) |
| DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS, current) |
| DO_ERROR(11, SIGSEGV, "segment not present", segment_not_present, current) |
| DO_ERROR(12, SIGSEGV, "stack segment", stack_segment, current) |
| DO_ERROR(13, SIGSEGV, "general protection", general_protection, current) |
| DO_ERROR(15, SIGSEGV, "reserved", reserved, current) |
| DO_ERROR(17, SIGSEGV, "alignment check", alignment_check, current) |
| |
| asmlinkage void do_nmi(struct pt_regs * regs, long error_code) |
| { |
| printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n"); |
| printk("You probably have a hardware problem with your RAM chips\n"); |
| } |
| |
| asmlinkage 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); |
| current->tss.trap_no = 1; |
| current->tss.error_code = error_code; |
| if((regs->cs & 3) == 0) { |
| /* If this is a kernel mode trap, then reset db7 and allow us to continue */ |
| __asm__("movl $0,%%edx\n\t" \ |
| "movl %%edx,%%db7\n\t" \ |
| : /* no output */ \ |
| : /* no input */ :"dx"); |
| |
| return; |
| }; |
| die_if_kernel("debug",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); |
| last_task_used_math->tss.trap_no = 16; |
| last_task_used_math->tss.error_code = 0; |
| __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 &= 0xffff3800; |
| env->twd = 0xffffffff; |
| } |
| |
| asmlinkage void do_coprocessor_error(struct pt_regs * regs, long error_code) |
| { |
| ignore_irq13 = 1; |
| math_error(); |
| } |
| |
| 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); |
| } |