diff options
Diffstat (limited to 'arch/i386/kernel/traps.c')
| -rw-r--r-- | arch/i386/kernel/traps.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c new file mode 100644 index 000000000..6dd7fc65b --- /dev/null +++ b/arch/i386/kernel/traps.c @@ -0,0 +1,349 @@ +/* + * linux/arch/i386/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/ptrace.h> +#include <linux/config.h> +#include <linux/timer.h> +#include <linux/mm.h> + +#include <asm/system.h> +#include <asm/segment.h> +#include <asm/io.h> + +asmlinkage int system_call(void); +asmlinkage void lcall7(void); +struct desc_struct default_ldt; + +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 unsigned 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); + +int kstack_depth_to_print = 24; + +/* + * These constants are for searching for possible module text + * segments. VMALLOC_OFFSET comes from mm/vmalloc.c; MODULE_RANGE is + * a guess of how much space is likely to be vmalloced. + */ +#define VMALLOC_OFFSET (8*1024*1024) +#define MODULE_RANGE (8*1024*1024) + +/*static*/ void die_if_kernel(char * str, struct pt_regs * regs, long err) +{ + int i; + unsigned long esp; + unsigned short ss; + unsigned long *stack, addr, module_start, module_end; + extern char start_kernel, etext; + + esp = (unsigned long) ®s->esp; + ss = KERNEL_DS; + if ((regs->eflags & VM_MASK) || (3 & regs->cs) == 3) + return; + if (regs->cs & 3) { + esp = regs->esp; + ss = regs->ss; + } + 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 esp: %08lx\n", + regs->esi, regs->edi, regs->ebp, esp); + printk("ds: %04x es: %04x fs: %04x gs: %04x ss: %04x\n", + regs->ds, regs->es, regs->fs, regs->gs, ss); + store_TR(i); + if (STACK_MAGIC != *(unsigned long *)current->kernel_stack_page) + printk("Corrupted stack page\n"); + printk("Process %s (pid: %d, process nr: %d, stackpage=%08lx)\nStack: ", + current->comm, current->pid, 0xffff & i, current->kernel_stack_page); + stack = (unsigned long *) esp; + for(i=0; i < kstack_depth_to_print; i++) { + if (((long) stack & 4095) == 0) + break; + if (i && ((i % 8) == 0)) + printk("\n "); + printk("%08lx ", get_seg_long(ss,stack++)); + } + printk("\nCall Trace: "); + stack = (unsigned long *) esp; + i = 1; + module_start = ((high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)); + module_end = module_start + MODULE_RANGE; + while (((long) stack & 4095) != 0) { + addr = get_seg_long(ss, stack++); + /* + * If the address is either in the text segment of the + * kernel, or in the region which contains vmalloc'ed + * memory, it *may* be the address of a calling + * routine; if so, print it so that someone tracing + * down the cause of the crash will be able to figure + * out the call path that was taken. + */ + if (((addr >= (unsigned long) &start_kernel) && + (addr <= (unsigned long) &etext)) || + ((addr >= module_start) && (addr <= module_end))) { + if (i && ((i % 8) == 0)) + printk("\n "); + printk("%08lx ", addr); + i++; + } + } + printk("\nCode: "); + 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, SIGBUS, "segment not present", segment_not_present, current) +DO_ERROR(12, SIGBUS, "stack segment", stack_segment, current) +DO_ERROR(15, SIGSEGV, "reserved", reserved, current) +DO_ERROR(17, SIGSEGV, "alignment check", alignment_check, current) + +asmlinkage void do_general_protection(struct pt_regs * regs, long error_code) +{ + if (regs->eflags & VM_MASK) { + handle_vm86_fault((struct vm86_regs *) regs, error_code); + return; + } + die_if_kernel("general protection",regs,error_code); + current->tss.error_code = error_code; + current->tss.trap_no = 13; + send_sig(SIGSEGV, current, 1); +} + +asmlinkage void do_nmi(struct pt_regs * regs, long error_code) +{ +#ifndef CONFIG_IGNORE_NMI + printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n"); + printk("You probably have a hardware problem with your RAM chips or a\n"); + printk("power saving mode enabled.\n"); +#endif +} + +asmlinkage void do_debug(struct pt_regs * regs, long error_code) +{ + if (regs->eflags & VM_MASK) { + handle_vm86_debug((struct vm86_regs *) regs, error_code); + return; + } + 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,%%db7" + : /* no output */ + : "r" (0)); + 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 presence 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(); +} + +/* + * 'math_state_restore()' saves the current math information in the + * old math state array, and gets the new ones from the current task + * + * Careful.. There are problems with IBM-designed IRQ13 behaviour. + * Don't touch unless you *really* know how it works. + */ +asmlinkage void math_state_restore(void) +{ + __asm__ __volatile__("clts"); + if (last_task_used_math == current) + return; + timer_table[COPRO_TIMER].expires = jiffies+50; + timer_active |= 1<<COPRO_TIMER; + if (last_task_used_math) + __asm__("fnsave %0":"=m" (last_task_used_math->tss.i387)); + else + __asm__("fnclex"); + last_task_used_math = current; + if (current->used_math) { + __asm__("frstor %0": :"m" (current->tss.i387)); + } else { + __asm__("fninit"); + current->used_math=1; + } + timer_active &= ~(1<<COPRO_TIMER); +} + +#ifndef CONFIG_MATH_EMULATION + +asmlinkage void math_emulate(long arg) +{ + printk("math-emulation not enabled and no coprocessor found.\n"); + printk("killing %s.\n",current->comm); + send_sig(SIGFPE,current,1); + schedule(); +} + +#endif /* CONFIG_MATH_EMULATION */ + +void trap_init(void) +{ + int i; + struct desc_struct * p; + + if (strncmp((char*)0x0FFFD9, "EISA", 4) == 0) + EISA_bus = 1; + set_call_gate(&default_ldt,lcall7); + 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); + set_system_gate(0x80,&system_call); +/* set up GDT task & ldt entries */ + p = gdt+FIRST_TSS_ENTRY; + set_tss_desc(p, &init_task.tss); + p++; + set_ldt_desc(p, &default_ldt, 1); + p++; + for(i=1 ; i<NR_TASKS ; i++) { + p->a=p->b=0; + p++; + p->a=p->b=0; + p++; + } +/* Clear NT, so that we won't have troubles with that later on */ + __asm__("pushfl ; andl $0xffffbfff,(%esp) ; popfl"); + load_TR(0); + load_ldt(0); +} |