1257 lines
31 KiB
C
1257 lines
31 KiB
C
/*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* Pentium III FXSR, SSE support
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* Gareth Hughes <gareth@valinux.com>, May 2000
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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'.
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*/
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#include <linux/interrupt.h>
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#include <linux/kallsyms.h>
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#include <linux/spinlock.h>
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#include <linux/highmem.h>
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#include <linux/kprobes.h>
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#include <linux/uaccess.h>
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#include <linux/utsname.h>
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#include <linux/kdebug.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/ptrace.h>
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#include <linux/string.h>
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#include <linux/unwind.h>
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#include <linux/delay.h>
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#include <linux/errno.h>
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#include <linux/kexec.h>
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#include <linux/sched.h>
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#include <linux/timer.h>
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#include <linux/init.h>
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#include <linux/bug.h>
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#include <linux/nmi.h>
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#include <linux/mm.h>
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#ifdef CONFIG_EISA
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#include <linux/ioport.h>
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#include <linux/eisa.h>
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#endif
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#ifdef CONFIG_MCA
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#include <linux/mca.h>
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#endif
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#if defined(CONFIG_EDAC)
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#include <linux/edac.h>
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#endif
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#include <asm/arch_hooks.h>
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#include <asm/stacktrace.h>
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#include <asm/processor.h>
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#include <asm/debugreg.h>
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#include <asm/atomic.h>
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#include <asm/system.h>
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#include <asm/unwind.h>
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#include <asm/desc.h>
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#include <asm/i387.h>
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#include <asm/nmi.h>
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#include <asm/smp.h>
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#include <asm/io.h>
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#include "mach_traps.h"
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int panic_on_unrecovered_nmi;
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DECLARE_BITMAP(used_vectors, NR_VECTORS);
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EXPORT_SYMBOL_GPL(used_vectors);
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asmlinkage int system_call(void);
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/* Do we ignore FPU interrupts ? */
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char ignore_fpu_irq;
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/*
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* The IDT has to be page-aligned to simplify the Pentium
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* F0 0F bug workaround.. We have a special link segment
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* for this.
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*/
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gate_desc idt_table[256]
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__attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };
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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 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 simd_coprocessor_error(void);
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asmlinkage void alignment_check(void);
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asmlinkage void spurious_interrupt_bug(void);
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asmlinkage void machine_check(void);
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int kstack_depth_to_print = 24;
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static unsigned int code_bytes = 64;
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void printk_address(unsigned long address, int reliable)
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{
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#ifdef CONFIG_KALLSYMS
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char namebuf[KSYM_NAME_LEN];
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unsigned long offset = 0;
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unsigned long symsize;
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const char *symname;
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char reliab[4] = "";
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char *delim = ":";
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char *modname;
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symname = kallsyms_lookup(address, &symsize, &offset,
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&modname, namebuf);
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if (!symname) {
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printk(" [<%08lx>]\n", address);
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return;
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}
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if (!reliable)
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strcpy(reliab, "? ");
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if (!modname)
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modname = delim = "";
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printk(" [<%08lx>] %s%s%s%s%s+0x%lx/0x%lx\n",
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address, reliab, delim, modname, delim, symname, offset, symsize);
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#else
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printk(" [<%08lx>]\n", address);
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#endif
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}
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static inline int valid_stack_ptr(struct thread_info *tinfo, void *p, unsigned size)
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{
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return p > (void *)tinfo &&
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p <= (void *)tinfo + THREAD_SIZE - size;
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}
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/* The form of the top of the frame on the stack */
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struct stack_frame {
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struct stack_frame *next_frame;
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unsigned long return_address;
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};
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static inline unsigned long
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print_context_stack(struct thread_info *tinfo,
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unsigned long *stack, unsigned long bp,
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const struct stacktrace_ops *ops, void *data)
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{
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struct stack_frame *frame = (struct stack_frame *)bp;
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while (valid_stack_ptr(tinfo, stack, sizeof(*stack))) {
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unsigned long addr;
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addr = *stack;
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if (__kernel_text_address(addr)) {
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if ((unsigned long) stack == bp + 4) {
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ops->address(data, addr, 1);
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frame = frame->next_frame;
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bp = (unsigned long) frame;
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} else {
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ops->address(data, addr, bp == 0);
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}
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}
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stack++;
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}
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return bp;
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}
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#define MSG(msg) ops->warning(data, msg)
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void dump_trace(struct task_struct *task, struct pt_regs *regs,
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unsigned long *stack, unsigned long bp,
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const struct stacktrace_ops *ops, void *data)
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{
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if (!task)
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task = current;
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if (!stack) {
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unsigned long dummy;
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stack = &dummy;
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if (task != current)
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stack = (unsigned long *)task->thread.sp;
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}
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#ifdef CONFIG_FRAME_POINTER
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if (!bp) {
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if (task == current) {
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/* Grab bp right from our regs */
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asm("movl %%ebp, %0" : "=r" (bp) :);
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} else {
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/* bp is the last reg pushed by switch_to */
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bp = *(unsigned long *) task->thread.sp;
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}
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}
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#endif
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while (1) {
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struct thread_info *context;
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context = (struct thread_info *)
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((unsigned long)stack & (~(THREAD_SIZE - 1)));
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bp = print_context_stack(context, stack, bp, ops, data);
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/*
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* Should be after the line below, but somewhere
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* in early boot context comes out corrupted and we
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* can't reference it:
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*/
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if (ops->stack(data, "IRQ") < 0)
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break;
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stack = (unsigned long *)context->previous_esp;
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if (!stack)
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break;
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touch_nmi_watchdog();
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}
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}
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EXPORT_SYMBOL(dump_trace);
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static void
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print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
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{
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printk(data);
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print_symbol(msg, symbol);
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printk("\n");
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}
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static void print_trace_warning(void *data, char *msg)
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{
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printk("%s%s\n", (char *)data, msg);
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}
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static int print_trace_stack(void *data, char *name)
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{
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return 0;
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}
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/*
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* Print one address/symbol entries per line.
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*/
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static void print_trace_address(void *data, unsigned long addr, int reliable)
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{
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printk("%s [<%08lx>] ", (char *)data, addr);
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if (!reliable)
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printk("? ");
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print_symbol("%s\n", addr);
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touch_nmi_watchdog();
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}
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static const struct stacktrace_ops print_trace_ops = {
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.warning = print_trace_warning,
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.warning_symbol = print_trace_warning_symbol,
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.stack = print_trace_stack,
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.address = print_trace_address,
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};
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static void
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show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
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unsigned long *stack, unsigned long bp, char *log_lvl)
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{
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dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
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printk("%s =======================\n", log_lvl);
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}
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void show_trace(struct task_struct *task, struct pt_regs *regs,
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unsigned long *stack, unsigned long bp)
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{
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show_trace_log_lvl(task, regs, stack, bp, "");
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}
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static void
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show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
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unsigned long *sp, unsigned long bp, char *log_lvl)
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{
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unsigned long *stack;
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int i;
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if (sp == NULL) {
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if (task)
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sp = (unsigned long *)task->thread.sp;
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else
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sp = (unsigned long *)&sp;
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}
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stack = sp;
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for (i = 0; i < kstack_depth_to_print; i++) {
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if (kstack_end(stack))
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break;
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if (i && ((i % 8) == 0))
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printk("\n%s ", log_lvl);
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printk("%08lx ", *stack++);
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}
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printk("\n%sCall Trace:\n", log_lvl);
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show_trace_log_lvl(task, regs, sp, bp, log_lvl);
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}
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void show_stack(struct task_struct *task, unsigned long *sp)
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{
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printk(" ");
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show_stack_log_lvl(task, NULL, sp, 0, "");
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}
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/*
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* The architecture-independent dump_stack generator
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*/
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void dump_stack(void)
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{
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unsigned long bp = 0;
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unsigned long stack;
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#ifdef CONFIG_FRAME_POINTER
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if (!bp)
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asm("movl %%ebp, %0" : "=r" (bp):);
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#endif
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printk("Pid: %d, comm: %.20s %s %s %.*s\n",
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current->pid, current->comm, print_tainted(),
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init_utsname()->release,
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(int)strcspn(init_utsname()->version, " "),
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init_utsname()->version);
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show_trace(current, NULL, &stack, bp);
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}
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EXPORT_SYMBOL(dump_stack);
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void show_registers(struct pt_regs *regs)
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{
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int i;
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print_modules();
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__show_registers(regs, 0);
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printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)",
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TASK_COMM_LEN, current->comm, task_pid_nr(current),
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current_thread_info(), current, task_thread_info(current));
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/*
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* When in-kernel, we also print out the stack and code at the
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* time of the fault..
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*/
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if (!user_mode_vm(regs)) {
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unsigned int code_prologue = code_bytes * 43 / 64;
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unsigned int code_len = code_bytes;
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unsigned char c;
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u8 *ip;
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printk("\n" KERN_EMERG "Stack: ");
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show_stack_log_lvl(NULL, regs, ®s->sp, 0, KERN_EMERG);
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printk(KERN_EMERG "Code: ");
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ip = (u8 *)regs->ip - code_prologue;
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if (ip < (u8 *)PAGE_OFFSET ||
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probe_kernel_address(ip, c)) {
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/* try starting at EIP */
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ip = (u8 *)regs->ip;
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code_len = code_len - code_prologue + 1;
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}
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for (i = 0; i < code_len; i++, ip++) {
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if (ip < (u8 *)PAGE_OFFSET ||
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probe_kernel_address(ip, c)) {
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printk(" Bad EIP value.");
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break;
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}
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if (ip == (u8 *)regs->ip)
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printk("<%02x> ", c);
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else
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printk("%02x ", c);
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}
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}
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printk("\n");
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}
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int is_valid_bugaddr(unsigned long ip)
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{
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unsigned short ud2;
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if (ip < PAGE_OFFSET)
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return 0;
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if (probe_kernel_address((unsigned short *)ip, ud2))
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return 0;
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return ud2 == 0x0b0f;
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}
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static int die_counter;
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int __kprobes __die(const char *str, struct pt_regs *regs, long err)
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{
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unsigned short ss;
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unsigned long sp;
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printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
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#ifdef CONFIG_PREEMPT
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printk("PREEMPT ");
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#endif
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#ifdef CONFIG_SMP
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printk("SMP ");
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#endif
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#ifdef CONFIG_DEBUG_PAGEALLOC
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printk("DEBUG_PAGEALLOC");
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#endif
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printk("\n");
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if (notify_die(DIE_OOPS, str, regs, err,
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current->thread.trap_no, SIGSEGV) != NOTIFY_STOP) {
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show_registers(regs);
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/* Executive summary in case the oops scrolled away */
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sp = (unsigned long) (®s->sp);
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savesegment(ss, ss);
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if (user_mode(regs)) {
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sp = regs->sp;
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ss = regs->ss & 0xffff;
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}
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printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
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print_symbol("%s", regs->ip);
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printk(" SS:ESP %04x:%08lx\n", ss, sp);
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return 0;
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}
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return 1;
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}
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|
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/*
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* This is gone through when something in the kernel has done something bad
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* and is about to be terminated:
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*/
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void die(const char *str, struct pt_regs *regs, long err)
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{
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static struct {
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raw_spinlock_t lock;
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u32 lock_owner;
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int lock_owner_depth;
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} die = {
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.lock = __RAW_SPIN_LOCK_UNLOCKED,
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.lock_owner = -1,
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.lock_owner_depth = 0
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};
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unsigned long flags;
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oops_enter();
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if (die.lock_owner != raw_smp_processor_id()) {
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console_verbose();
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raw_local_irq_save(flags);
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__raw_spin_lock(&die.lock);
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die.lock_owner = smp_processor_id();
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die.lock_owner_depth = 0;
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bust_spinlocks(1);
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} else {
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raw_local_irq_save(flags);
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}
|
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|
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if (++die.lock_owner_depth < 3) {
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report_bug(regs->ip, regs);
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if (__die(str, regs, err))
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regs = NULL;
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} else {
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printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
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}
|
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|
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bust_spinlocks(0);
|
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die.lock_owner = -1;
|
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add_taint(TAINT_DIE);
|
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__raw_spin_unlock(&die.lock);
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raw_local_irq_restore(flags);
|
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|
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if (!regs)
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return;
|
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|
|
if (kexec_should_crash(current))
|
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crash_kexec(regs);
|
|
|
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if (in_interrupt())
|
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panic("Fatal exception in interrupt");
|
|
|
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if (panic_on_oops)
|
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panic("Fatal exception");
|
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|
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oops_exit();
|
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do_exit(SIGSEGV);
|
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}
|
|
|
|
static inline void
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die_if_kernel(const char *str, struct pt_regs *regs, long err)
|
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{
|
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if (!user_mode_vm(regs))
|
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die(str, regs, err);
|
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}
|
|
|
|
static void __kprobes
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do_trap(int trapnr, int signr, char *str, int vm86, struct pt_regs *regs,
|
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long error_code, siginfo_t *info)
|
|
{
|
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struct task_struct *tsk = current;
|
|
|
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if (regs->flags & X86_VM_MASK) {
|
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if (vm86)
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goto vm86_trap;
|
|
goto trap_signal;
|
|
}
|
|
|
|
if (!user_mode(regs))
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goto kernel_trap;
|
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|
|
trap_signal:
|
|
/*
|
|
* We want error_code and trap_no set for userspace faults and
|
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* kernelspace faults which result in die(), but not
|
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* kernelspace faults which are fixed up. die() gives the
|
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* process no chance to handle the signal and notice the
|
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* kernel fault information, so that won't result in polluting
|
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* the information about previously queued, but not yet
|
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* delivered, faults. See also do_general_protection below.
|
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*/
|
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tsk->thread.error_code = error_code;
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tsk->thread.trap_no = trapnr;
|
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|
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if (info)
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force_sig_info(signr, info, tsk);
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else
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force_sig(signr, tsk);
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return;
|
|
|
|
kernel_trap:
|
|
if (!fixup_exception(regs)) {
|
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tsk->thread.error_code = error_code;
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tsk->thread.trap_no = trapnr;
|
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die(str, regs, error_code);
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}
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return;
|
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|
|
vm86_trap:
|
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if (handle_vm86_trap((struct kernel_vm86_regs *) regs,
|
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error_code, trapnr))
|
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goto trap_signal;
|
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return;
|
|
}
|
|
|
|
#define DO_ERROR(trapnr, signr, str, name) \
|
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void do_##name(struct pt_regs *regs, long error_code) \
|
|
{ \
|
|
if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
|
|
== NOTIFY_STOP) \
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return; \
|
|
do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
|
|
}
|
|
|
|
#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr, irq) \
|
|
void do_##name(struct pt_regs *regs, long error_code) \
|
|
{ \
|
|
siginfo_t info; \
|
|
if (irq) \
|
|
local_irq_enable(); \
|
|
info.si_signo = signr; \
|
|
info.si_errno = 0; \
|
|
info.si_code = sicode; \
|
|
info.si_addr = (void __user *)siaddr; \
|
|
if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
|
|
== NOTIFY_STOP) \
|
|
return; \
|
|
do_trap(trapnr, signr, str, 0, regs, error_code, &info); \
|
|
}
|
|
|
|
#define DO_VM86_ERROR(trapnr, signr, str, name) \
|
|
void do_##name(struct pt_regs *regs, long error_code) \
|
|
{ \
|
|
if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
|
|
== NOTIFY_STOP) \
|
|
return; \
|
|
do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
|
|
}
|
|
|
|
#define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
|
|
void do_##name(struct pt_regs *regs, long error_code) \
|
|
{ \
|
|
siginfo_t info; \
|
|
info.si_signo = signr; \
|
|
info.si_errno = 0; \
|
|
info.si_code = sicode; \
|
|
info.si_addr = (void __user *)siaddr; \
|
|
trace_hardirqs_fixup(); \
|
|
if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
|
|
== NOTIFY_STOP) \
|
|
return; \
|
|
do_trap(trapnr, signr, str, 1, regs, error_code, &info); \
|
|
}
|
|
|
|
DO_VM86_ERROR_INFO(0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->ip)
|
|
#ifndef CONFIG_KPROBES
|
|
DO_VM86_ERROR(3, SIGTRAP, "int3", int3)
|
|
#endif
|
|
DO_VM86_ERROR(4, SIGSEGV, "overflow", overflow)
|
|
DO_VM86_ERROR(5, SIGSEGV, "bounds", bounds)
|
|
DO_ERROR_INFO(6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip, 0)
|
|
DO_ERROR(9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
|
|
DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
|
|
DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
|
|
DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
|
|
DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0, 0)
|
|
DO_ERROR_INFO(32, SIGSEGV, "iret exception", iret_error, ILL_BADSTK, 0, 1)
|
|
|
|
void __kprobes do_general_protection(struct pt_regs *regs, long error_code)
|
|
{
|
|
struct thread_struct *thread;
|
|
struct tss_struct *tss;
|
|
int cpu;
|
|
|
|
cpu = get_cpu();
|
|
tss = &per_cpu(init_tss, cpu);
|
|
thread = ¤t->thread;
|
|
|
|
/*
|
|
* Perform the lazy TSS's I/O bitmap copy. If the TSS has an
|
|
* invalid offset set (the LAZY one) and the faulting thread has
|
|
* a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS
|
|
* and we set the offset field correctly. Then we let the CPU to
|
|
* restart the faulting instruction.
|
|
*/
|
|
if (tss->x86_tss.io_bitmap_base == INVALID_IO_BITMAP_OFFSET_LAZY &&
|
|
thread->io_bitmap_ptr) {
|
|
memcpy(tss->io_bitmap, thread->io_bitmap_ptr,
|
|
thread->io_bitmap_max);
|
|
/*
|
|
* If the previously set map was extending to higher ports
|
|
* than the current one, pad extra space with 0xff (no access).
|
|
*/
|
|
if (thread->io_bitmap_max < tss->io_bitmap_max) {
|
|
memset((char *) tss->io_bitmap +
|
|
thread->io_bitmap_max, 0xff,
|
|
tss->io_bitmap_max - thread->io_bitmap_max);
|
|
}
|
|
tss->io_bitmap_max = thread->io_bitmap_max;
|
|
tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
|
|
tss->io_bitmap_owner = thread;
|
|
put_cpu();
|
|
|
|
return;
|
|
}
|
|
put_cpu();
|
|
|
|
if (regs->flags & X86_VM_MASK)
|
|
goto gp_in_vm86;
|
|
|
|
if (!user_mode(regs))
|
|
goto gp_in_kernel;
|
|
|
|
current->thread.error_code = error_code;
|
|
current->thread.trap_no = 13;
|
|
|
|
if (show_unhandled_signals && unhandled_signal(current, SIGSEGV) &&
|
|
printk_ratelimit()) {
|
|
printk(KERN_INFO
|
|
"%s[%d] general protection ip:%lx sp:%lx error:%lx",
|
|
current->comm, task_pid_nr(current),
|
|
regs->ip, regs->sp, error_code);
|
|
print_vma_addr(" in ", regs->ip);
|
|
printk("\n");
|
|
}
|
|
|
|
force_sig(SIGSEGV, current);
|
|
return;
|
|
|
|
gp_in_vm86:
|
|
local_irq_enable();
|
|
handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
|
|
return;
|
|
|
|
gp_in_kernel:
|
|
if (!fixup_exception(regs)) {
|
|
current->thread.error_code = error_code;
|
|
current->thread.trap_no = 13;
|
|
if (notify_die(DIE_GPF, "general protection fault", regs,
|
|
error_code, 13, SIGSEGV) == NOTIFY_STOP)
|
|
return;
|
|
die("general protection fault", regs, error_code);
|
|
}
|
|
}
|
|
|
|
static notrace __kprobes void
|
|
mem_parity_error(unsigned char reason, struct pt_regs *regs)
|
|
{
|
|
printk(KERN_EMERG
|
|
"Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
|
|
reason, smp_processor_id());
|
|
|
|
printk(KERN_EMERG
|
|
"You have some hardware problem, likely on the PCI bus.\n");
|
|
|
|
#if defined(CONFIG_EDAC)
|
|
if (edac_handler_set()) {
|
|
edac_atomic_assert_error();
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
if (panic_on_unrecovered_nmi)
|
|
panic("NMI: Not continuing");
|
|
|
|
printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
|
|
|
|
/* Clear and disable the memory parity error line. */
|
|
clear_mem_error(reason);
|
|
}
|
|
|
|
static notrace __kprobes void
|
|
io_check_error(unsigned char reason, struct pt_regs *regs)
|
|
{
|
|
unsigned long i;
|
|
|
|
printk(KERN_EMERG "NMI: IOCK error (debug interrupt?)\n");
|
|
show_registers(regs);
|
|
|
|
/* Re-enable the IOCK line, wait for a few seconds */
|
|
reason = (reason & 0xf) | 8;
|
|
outb(reason, 0x61);
|
|
|
|
i = 2000;
|
|
while (--i)
|
|
udelay(1000);
|
|
|
|
reason &= ~8;
|
|
outb(reason, 0x61);
|
|
}
|
|
|
|
static notrace __kprobes void
|
|
unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
|
|
{
|
|
if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
|
|
return;
|
|
#ifdef CONFIG_MCA
|
|
/*
|
|
* Might actually be able to figure out what the guilty party
|
|
* is:
|
|
*/
|
|
if (MCA_bus) {
|
|
mca_handle_nmi();
|
|
return;
|
|
}
|
|
#endif
|
|
printk(KERN_EMERG
|
|
"Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
|
|
reason, smp_processor_id());
|
|
|
|
printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
|
|
if (panic_on_unrecovered_nmi)
|
|
panic("NMI: Not continuing");
|
|
|
|
printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
|
|
}
|
|
|
|
static DEFINE_SPINLOCK(nmi_print_lock);
|
|
|
|
void notrace __kprobes die_nmi(struct pt_regs *regs, const char *msg)
|
|
{
|
|
if (notify_die(DIE_NMIWATCHDOG, msg, regs, 0, 2, SIGINT) == NOTIFY_STOP)
|
|
return;
|
|
|
|
spin_lock(&nmi_print_lock);
|
|
/*
|
|
* We are in trouble anyway, lets at least try
|
|
* to get a message out:
|
|
*/
|
|
bust_spinlocks(1);
|
|
printk(KERN_EMERG "%s", msg);
|
|
printk(" on CPU%d, ip %08lx, registers:\n",
|
|
smp_processor_id(), regs->ip);
|
|
show_registers(regs);
|
|
console_silent();
|
|
spin_unlock(&nmi_print_lock);
|
|
bust_spinlocks(0);
|
|
|
|
/*
|
|
* If we are in kernel we are probably nested up pretty bad
|
|
* and might aswell get out now while we still can:
|
|
*/
|
|
if (!user_mode_vm(regs)) {
|
|
current->thread.trap_no = 2;
|
|
crash_kexec(regs);
|
|
}
|
|
|
|
do_exit(SIGSEGV);
|
|
}
|
|
|
|
static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
|
|
{
|
|
unsigned char reason = 0;
|
|
|
|
/* Only the BSP gets external NMIs from the system: */
|
|
if (!smp_processor_id())
|
|
reason = get_nmi_reason();
|
|
|
|
if (!(reason & 0xc0)) {
|
|
if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
|
|
== NOTIFY_STOP)
|
|
return;
|
|
#ifdef CONFIG_X86_LOCAL_APIC
|
|
/*
|
|
* Ok, so this is none of the documented NMI sources,
|
|
* so it must be the NMI watchdog.
|
|
*/
|
|
if (nmi_watchdog_tick(regs, reason))
|
|
return;
|
|
if (!do_nmi_callback(regs, smp_processor_id()))
|
|
unknown_nmi_error(reason, regs);
|
|
#else
|
|
unknown_nmi_error(reason, regs);
|
|
#endif
|
|
|
|
return;
|
|
}
|
|
if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
|
|
return;
|
|
if (reason & 0x80)
|
|
mem_parity_error(reason, regs);
|
|
if (reason & 0x40)
|
|
io_check_error(reason, regs);
|
|
/*
|
|
* Reassert NMI in case it became active meanwhile
|
|
* as it's edge-triggered:
|
|
*/
|
|
reassert_nmi();
|
|
}
|
|
|
|
static int ignore_nmis;
|
|
|
|
notrace __kprobes void do_nmi(struct pt_regs *regs, long error_code)
|
|
{
|
|
int cpu;
|
|
|
|
nmi_enter();
|
|
|
|
cpu = smp_processor_id();
|
|
|
|
++nmi_count(cpu);
|
|
|
|
if (!ignore_nmis)
|
|
default_do_nmi(regs);
|
|
|
|
nmi_exit();
|
|
}
|
|
|
|
void stop_nmi(void)
|
|
{
|
|
acpi_nmi_disable();
|
|
ignore_nmis++;
|
|
}
|
|
|
|
void restart_nmi(void)
|
|
{
|
|
ignore_nmis--;
|
|
acpi_nmi_enable();
|
|
}
|
|
|
|
#ifdef CONFIG_KPROBES
|
|
void __kprobes do_int3(struct pt_regs *regs, long error_code)
|
|
{
|
|
trace_hardirqs_fixup();
|
|
|
|
if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
|
|
== NOTIFY_STOP)
|
|
return;
|
|
/*
|
|
* This is an interrupt gate, because kprobes wants interrupts
|
|
* disabled. Normal trap handlers don't.
|
|
*/
|
|
restore_interrupts(regs);
|
|
|
|
do_trap(3, SIGTRAP, "int3", 1, regs, error_code, NULL);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Our handling of the processor debug registers is non-trivial.
|
|
* We do not clear them on entry and exit from the kernel. Therefore
|
|
* it is possible to get a watchpoint trap here from inside the kernel.
|
|
* However, the code in ./ptrace.c has ensured that the user can
|
|
* only set watchpoints on userspace addresses. Therefore the in-kernel
|
|
* watchpoint trap can only occur in code which is reading/writing
|
|
* from user space. Such code must not hold kernel locks (since it
|
|
* can equally take a page fault), therefore it is safe to call
|
|
* force_sig_info even though that claims and releases locks.
|
|
*
|
|
* Code in ./signal.c ensures that the debug control register
|
|
* is restored before we deliver any signal, and therefore that
|
|
* user code runs with the correct debug control register even though
|
|
* we clear it here.
|
|
*
|
|
* Being careful here means that we don't have to be as careful in a
|
|
* lot of more complicated places (task switching can be a bit lazy
|
|
* about restoring all the debug state, and ptrace doesn't have to
|
|
* find every occurrence of the TF bit that could be saved away even
|
|
* by user code)
|
|
*/
|
|
void __kprobes do_debug(struct pt_regs *regs, long error_code)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
unsigned int condition;
|
|
|
|
trace_hardirqs_fixup();
|
|
|
|
get_debugreg(condition, 6);
|
|
|
|
/*
|
|
* The processor cleared BTF, so don't mark that we need it set.
|
|
*/
|
|
clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR);
|
|
tsk->thread.debugctlmsr = 0;
|
|
|
|
if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
|
|
SIGTRAP) == NOTIFY_STOP)
|
|
return;
|
|
/* It's safe to allow irq's after DR6 has been saved */
|
|
if (regs->flags & X86_EFLAGS_IF)
|
|
local_irq_enable();
|
|
|
|
/* Mask out spurious debug traps due to lazy DR7 setting */
|
|
if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
|
|
if (!tsk->thread.debugreg7)
|
|
goto clear_dr7;
|
|
}
|
|
|
|
if (regs->flags & X86_VM_MASK)
|
|
goto debug_vm86;
|
|
|
|
/* Save debug status register where ptrace can see it */
|
|
tsk->thread.debugreg6 = condition;
|
|
|
|
/*
|
|
* Single-stepping through TF: make sure we ignore any events in
|
|
* kernel space (but re-enable TF when returning to user mode).
|
|
*/
|
|
if (condition & DR_STEP) {
|
|
/*
|
|
* We already checked v86 mode above, so we can
|
|
* check for kernel mode by just checking the CPL
|
|
* of CS.
|
|
*/
|
|
if (!user_mode(regs))
|
|
goto clear_TF_reenable;
|
|
}
|
|
|
|
/* Ok, finally something we can handle */
|
|
send_sigtrap(tsk, regs, error_code);
|
|
|
|
/*
|
|
* Disable additional traps. They'll be re-enabled when
|
|
* the signal is delivered.
|
|
*/
|
|
clear_dr7:
|
|
set_debugreg(0, 7);
|
|
return;
|
|
|
|
debug_vm86:
|
|
handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1);
|
|
return;
|
|
|
|
clear_TF_reenable:
|
|
set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
|
|
regs->flags &= ~X86_EFLAGS_TF;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Note that we play around with the 'TS' bit in an attempt to get
|
|
* the correct behaviour even in the presence of the asynchronous
|
|
* IRQ13 behaviour
|
|
*/
|
|
void math_error(void __user *ip)
|
|
{
|
|
struct task_struct *task;
|
|
unsigned short cwd;
|
|
unsigned short swd;
|
|
siginfo_t info;
|
|
|
|
/*
|
|
* Save the info for the exception handler and clear the error.
|
|
*/
|
|
task = current;
|
|
save_init_fpu(task);
|
|
task->thread.trap_no = 16;
|
|
task->thread.error_code = 0;
|
|
info.si_signo = SIGFPE;
|
|
info.si_errno = 0;
|
|
info.si_code = __SI_FAULT;
|
|
info.si_addr = ip;
|
|
/*
|
|
* (~cwd & swd) will mask out exceptions that are not set to unmasked
|
|
* status. 0x3f is the exception bits in these regs, 0x200 is the
|
|
* C1 reg you need in case of a stack fault, 0x040 is the stack
|
|
* fault bit. We should only be taking one exception at a time,
|
|
* so if this combination doesn't produce any single exception,
|
|
* then we have a bad program that isn't syncronizing its FPU usage
|
|
* and it will suffer the consequences since we won't be able to
|
|
* fully reproduce the context of the exception
|
|
*/
|
|
cwd = get_fpu_cwd(task);
|
|
swd = get_fpu_swd(task);
|
|
switch (swd & ~cwd & 0x3f) {
|
|
case 0x000: /* No unmasked exception */
|
|
return;
|
|
default: /* Multiple exceptions */
|
|
break;
|
|
case 0x001: /* Invalid Op */
|
|
/*
|
|
* swd & 0x240 == 0x040: Stack Underflow
|
|
* swd & 0x240 == 0x240: Stack Overflow
|
|
* User must clear the SF bit (0x40) if set
|
|
*/
|
|
info.si_code = FPE_FLTINV;
|
|
break;
|
|
case 0x002: /* Denormalize */
|
|
case 0x010: /* Underflow */
|
|
info.si_code = FPE_FLTUND;
|
|
break;
|
|
case 0x004: /* Zero Divide */
|
|
info.si_code = FPE_FLTDIV;
|
|
break;
|
|
case 0x008: /* Overflow */
|
|
info.si_code = FPE_FLTOVF;
|
|
break;
|
|
case 0x020: /* Precision */
|
|
info.si_code = FPE_FLTRES;
|
|
break;
|
|
}
|
|
force_sig_info(SIGFPE, &info, task);
|
|
}
|
|
|
|
void do_coprocessor_error(struct pt_regs *regs, long error_code)
|
|
{
|
|
ignore_fpu_irq = 1;
|
|
math_error((void __user *)regs->ip);
|
|
}
|
|
|
|
static void simd_math_error(void __user *ip)
|
|
{
|
|
struct task_struct *task;
|
|
unsigned short mxcsr;
|
|
siginfo_t info;
|
|
|
|
/*
|
|
* Save the info for the exception handler and clear the error.
|
|
*/
|
|
task = current;
|
|
save_init_fpu(task);
|
|
task->thread.trap_no = 19;
|
|
task->thread.error_code = 0;
|
|
info.si_signo = SIGFPE;
|
|
info.si_errno = 0;
|
|
info.si_code = __SI_FAULT;
|
|
info.si_addr = ip;
|
|
/*
|
|
* The SIMD FPU exceptions are handled a little differently, as there
|
|
* is only a single status/control register. Thus, to determine which
|
|
* unmasked exception was caught we must mask the exception mask bits
|
|
* at 0x1f80, and then use these to mask the exception bits at 0x3f.
|
|
*/
|
|
mxcsr = get_fpu_mxcsr(task);
|
|
switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
|
|
case 0x000:
|
|
default:
|
|
break;
|
|
case 0x001: /* Invalid Op */
|
|
info.si_code = FPE_FLTINV;
|
|
break;
|
|
case 0x002: /* Denormalize */
|
|
case 0x010: /* Underflow */
|
|
info.si_code = FPE_FLTUND;
|
|
break;
|
|
case 0x004: /* Zero Divide */
|
|
info.si_code = FPE_FLTDIV;
|
|
break;
|
|
case 0x008: /* Overflow */
|
|
info.si_code = FPE_FLTOVF;
|
|
break;
|
|
case 0x020: /* Precision */
|
|
info.si_code = FPE_FLTRES;
|
|
break;
|
|
}
|
|
force_sig_info(SIGFPE, &info, task);
|
|
}
|
|
|
|
void do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
|
|
{
|
|
if (cpu_has_xmm) {
|
|
/* Handle SIMD FPU exceptions on PIII+ processors. */
|
|
ignore_fpu_irq = 1;
|
|
simd_math_error((void __user *)regs->ip);
|
|
return;
|
|
}
|
|
/*
|
|
* Handle strange cache flush from user space exception
|
|
* in all other cases. This is undocumented behaviour.
|
|
*/
|
|
if (regs->flags & X86_VM_MASK) {
|
|
handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code);
|
|
return;
|
|
}
|
|
current->thread.trap_no = 19;
|
|
current->thread.error_code = error_code;
|
|
die_if_kernel("cache flush denied", regs, error_code);
|
|
force_sig(SIGSEGV, current);
|
|
}
|
|
|
|
void do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
|
|
{
|
|
#if 0
|
|
/* No need to warn about this any longer. */
|
|
printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
|
|
#endif
|
|
}
|
|
|
|
unsigned long patch_espfix_desc(unsigned long uesp, unsigned long kesp)
|
|
{
|
|
struct desc_struct *gdt = __get_cpu_var(gdt_page).gdt;
|
|
unsigned long base = (kesp - uesp) & -THREAD_SIZE;
|
|
unsigned long new_kesp = kesp - base;
|
|
unsigned long lim_pages = (new_kesp | (THREAD_SIZE - 1)) >> PAGE_SHIFT;
|
|
__u64 desc = *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS];
|
|
|
|
/* Set up base for espfix segment */
|
|
desc &= 0x00f0ff0000000000ULL;
|
|
desc |= ((((__u64)base) << 16) & 0x000000ffffff0000ULL) |
|
|
((((__u64)base) << 32) & 0xff00000000000000ULL) |
|
|
((((__u64)lim_pages) << 32) & 0x000f000000000000ULL) |
|
|
(lim_pages & 0xffff);
|
|
*(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS] = desc;
|
|
|
|
return new_kesp;
|
|
}
|
|
|
|
/*
|
|
* '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.
|
|
*
|
|
* Must be called with kernel preemption disabled (in this case,
|
|
* local interrupts are disabled at the call-site in entry.S).
|
|
*/
|
|
asmlinkage void math_state_restore(void)
|
|
{
|
|
struct thread_info *thread = current_thread_info();
|
|
struct task_struct *tsk = thread->task;
|
|
|
|
clts(); /* Allow maths ops (or we recurse) */
|
|
if (!tsk_used_math(tsk))
|
|
init_fpu(tsk);
|
|
restore_fpu(tsk);
|
|
thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
|
|
tsk->fpu_counter++;
|
|
}
|
|
EXPORT_SYMBOL_GPL(math_state_restore);
|
|
|
|
#ifndef CONFIG_MATH_EMULATION
|
|
|
|
asmlinkage void math_emulate(long arg)
|
|
{
|
|
printk(KERN_EMERG
|
|
"math-emulation not enabled and no coprocessor found.\n");
|
|
printk(KERN_EMERG "killing %s.\n", current->comm);
|
|
force_sig(SIGFPE, current);
|
|
schedule();
|
|
}
|
|
|
|
#endif /* CONFIG_MATH_EMULATION */
|
|
|
|
void __init trap_init(void)
|
|
{
|
|
int i;
|
|
|
|
#ifdef CONFIG_EISA
|
|
void __iomem *p = early_ioremap(0x0FFFD9, 4);
|
|
|
|
if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
|
|
EISA_bus = 1;
|
|
early_iounmap(p, 4);
|
|
#endif
|
|
|
|
#ifdef CONFIG_X86_LOCAL_APIC
|
|
init_apic_mappings();
|
|
#endif
|
|
set_trap_gate(0, ÷_error);
|
|
set_intr_gate(1, &debug);
|
|
set_intr_gate(2, &nmi);
|
|
set_system_intr_gate(3, &int3); /* int3/4 can be called from all */
|
|
set_system_gate(4, &overflow);
|
|
set_trap_gate(5, &bounds);
|
|
set_trap_gate(6, &invalid_op);
|
|
set_trap_gate(7, &device_not_available);
|
|
set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS);
|
|
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_intr_gate(14, &page_fault);
|
|
set_trap_gate(15, &spurious_interrupt_bug);
|
|
set_trap_gate(16, &coprocessor_error);
|
|
set_trap_gate(17, &alignment_check);
|
|
#ifdef CONFIG_X86_MCE
|
|
set_trap_gate(18, &machine_check);
|
|
#endif
|
|
set_trap_gate(19, &simd_coprocessor_error);
|
|
|
|
if (cpu_has_fxsr) {
|
|
printk(KERN_INFO "Enabling fast FPU save and restore... ");
|
|
set_in_cr4(X86_CR4_OSFXSR);
|
|
printk("done.\n");
|
|
}
|
|
if (cpu_has_xmm) {
|
|
printk(KERN_INFO
|
|
"Enabling unmasked SIMD FPU exception support... ");
|
|
set_in_cr4(X86_CR4_OSXMMEXCPT);
|
|
printk("done.\n");
|
|
}
|
|
|
|
set_system_gate(SYSCALL_VECTOR, &system_call);
|
|
|
|
/* Reserve all the builtin and the syscall vector: */
|
|
for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
|
|
set_bit(i, used_vectors);
|
|
|
|
set_bit(SYSCALL_VECTOR, used_vectors);
|
|
|
|
init_thread_xstate();
|
|
/*
|
|
* Should be a barrier for any external CPU state:
|
|
*/
|
|
cpu_init();
|
|
|
|
trap_init_hook();
|
|
}
|
|
|
|
static int __init kstack_setup(char *s)
|
|
{
|
|
kstack_depth_to_print = simple_strtoul(s, NULL, 0);
|
|
|
|
return 1;
|
|
}
|
|
__setup("kstack=", kstack_setup);
|
|
|
|
static int __init code_bytes_setup(char *s)
|
|
{
|
|
code_bytes = simple_strtoul(s, NULL, 0);
|
|
if (code_bytes > 8192)
|
|
code_bytes = 8192;
|
|
|
|
return 1;
|
|
}
|
|
__setup("code_bytes=", code_bytes_setup);
|