344 lines
8.3 KiB
C
344 lines
8.3 KiB
C
/*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
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*/
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#include <linux/kallsyms.h>
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#include <linux/kprobes.h>
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#include <linux/uaccess.h>
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#include <linux/hardirq.h>
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#include <linux/kdebug.h>
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#include <linux/module.h>
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#include <linux/ptrace.h>
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#include <linux/kexec.h>
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#include <linux/sysfs.h>
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#include <linux/bug.h>
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#include <linux/nmi.h>
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#include <asm/stacktrace.h>
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#include "dumpstack.h"
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#define N_EXCEPTION_STACKS_END \
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(N_EXCEPTION_STACKS + DEBUG_STKSZ/EXCEPTION_STKSZ - 2)
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static char x86_stack_ids[][8] = {
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[ DEBUG_STACK-1 ] = "#DB",
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[ NMI_STACK-1 ] = "NMI",
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[ DOUBLEFAULT_STACK-1 ] = "#DF",
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[ STACKFAULT_STACK-1 ] = "#SS",
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[ MCE_STACK-1 ] = "#MC",
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#if DEBUG_STKSZ > EXCEPTION_STKSZ
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[ N_EXCEPTION_STACKS ...
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N_EXCEPTION_STACKS_END ] = "#DB[?]"
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#endif
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};
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int x86_is_stack_id(int id, char *name)
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{
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return x86_stack_ids[id - 1] == name;
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}
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static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
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unsigned *usedp, char **idp)
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{
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unsigned k;
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/*
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* Iterate over all exception stacks, and figure out whether
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* 'stack' is in one of them:
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*/
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for (k = 0; k < N_EXCEPTION_STACKS; k++) {
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unsigned long end = per_cpu(orig_ist, cpu).ist[k];
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/*
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* Is 'stack' above this exception frame's end?
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* If yes then skip to the next frame.
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*/
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if (stack >= end)
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continue;
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/*
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* Is 'stack' above this exception frame's start address?
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* If yes then we found the right frame.
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*/
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if (stack >= end - EXCEPTION_STKSZ) {
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/*
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* Make sure we only iterate through an exception
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* stack once. If it comes up for the second time
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* then there's something wrong going on - just
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* break out and return NULL:
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*/
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if (*usedp & (1U << k))
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break;
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*usedp |= 1U << k;
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*idp = x86_stack_ids[k];
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return (unsigned long *)end;
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}
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/*
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* If this is a debug stack, and if it has a larger size than
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* the usual exception stacks, then 'stack' might still
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* be within the lower portion of the debug stack:
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*/
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#if DEBUG_STKSZ > EXCEPTION_STKSZ
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if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
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unsigned j = N_EXCEPTION_STACKS - 1;
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/*
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* Black magic. A large debug stack is composed of
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* multiple exception stack entries, which we
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* iterate through now. Dont look:
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*/
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do {
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++j;
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end -= EXCEPTION_STKSZ;
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x86_stack_ids[j][4] = '1' +
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(j - N_EXCEPTION_STACKS);
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} while (stack < end - EXCEPTION_STKSZ);
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if (*usedp & (1U << j))
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break;
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*usedp |= 1U << j;
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*idp = x86_stack_ids[j];
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return (unsigned long *)end;
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}
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#endif
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}
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return NULL;
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}
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static inline int
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in_irq_stack(unsigned long *stack, unsigned long *irq_stack,
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unsigned long *irq_stack_end)
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{
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return (stack >= irq_stack && stack < irq_stack_end);
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}
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/*
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* We are returning from the irq stack and go to the previous one.
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* If the previous stack is also in the irq stack, then bp in the first
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* frame of the irq stack points to the previous, interrupted one.
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* Otherwise we have another level of indirection: We first save
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* the bp of the previous stack, then we switch the stack to the irq one
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* and save a new bp that links to the previous one.
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* (See save_args())
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*/
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static inline unsigned long
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fixup_bp_irq_link(unsigned long bp, unsigned long *stack,
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unsigned long *irq_stack, unsigned long *irq_stack_end)
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{
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#ifdef CONFIG_FRAME_POINTER
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struct stack_frame *frame = (struct stack_frame *)bp;
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if (!in_irq_stack(stack, irq_stack, irq_stack_end))
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return (unsigned long)frame->next_frame;
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#endif
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return bp;
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}
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/*
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* x86-64 can have up to three kernel stacks:
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* process stack
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* interrupt stack
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* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
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*/
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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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const unsigned cpu = get_cpu();
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unsigned long *irq_stack_end =
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(unsigned long *)per_cpu(irq_stack_ptr, cpu);
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unsigned used = 0;
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struct thread_info *tinfo;
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int graph = 0;
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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 && 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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get_bp(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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/*
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* Print function call entries in all stacks, starting at the
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* current stack address. If the stacks consist of nested
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* exceptions
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*/
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tinfo = task_thread_info(task);
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for (;;) {
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char *id;
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unsigned long *estack_end;
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estack_end = in_exception_stack(cpu, (unsigned long)stack,
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&used, &id);
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if (estack_end) {
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if (ops->stack(data, id) < 0)
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break;
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bp = ops->walk_stack(tinfo, stack, bp, ops,
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data, estack_end, &graph);
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ops->stack(data, "<EOE>");
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/*
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* We link to the next stack via the
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* second-to-last pointer (index -2 to end) in the
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* exception stack:
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*/
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stack = (unsigned long *) estack_end[-2];
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continue;
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}
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if (irq_stack_end) {
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unsigned long *irq_stack;
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irq_stack = irq_stack_end -
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(IRQ_STACK_SIZE - 64) / sizeof(*irq_stack);
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if (in_irq_stack(stack, irq_stack, irq_stack_end)) {
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if (ops->stack(data, "IRQ") < 0)
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break;
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bp = print_context_stack(tinfo, stack, bp,
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ops, data, irq_stack_end, &graph);
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/*
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* We link to the next stack (which would be
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* the process stack normally) the last
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* pointer (index -1 to end) in the IRQ stack:
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*/
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stack = (unsigned long *) (irq_stack_end[-1]);
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bp = fixup_bp_irq_link(bp, stack, irq_stack,
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irq_stack_end);
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irq_stack_end = NULL;
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ops->stack(data, "EOI");
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continue;
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}
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}
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break;
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}
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/*
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* This handles the process stack:
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*/
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bp = print_context_stack(tinfo, stack, bp, ops, data, NULL, &graph);
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put_cpu();
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}
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EXPORT_SYMBOL(dump_trace);
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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 *irq_stack_end;
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unsigned long *irq_stack;
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unsigned long *stack;
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int cpu;
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int i;
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preempt_disable();
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cpu = smp_processor_id();
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irq_stack_end = (unsigned long *)(per_cpu(irq_stack_ptr, cpu));
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irq_stack = (unsigned long *)(per_cpu(irq_stack_ptr, cpu) - IRQ_STACK_SIZE);
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/*
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* Debugging aid: "show_stack(NULL, NULL);" prints the
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* back trace for this cpu:
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*/
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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 (stack >= irq_stack && stack <= irq_stack_end) {
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if (stack == irq_stack_end) {
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stack = (unsigned long *) (irq_stack_end[-1]);
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printk(" <EOI> ");
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}
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} else {
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if (((long) stack & (THREAD_SIZE-1)) == 0)
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break;
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}
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if (i && ((i % STACKSLOTS_PER_LINE) == 0))
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printk("\n%s", log_lvl);
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printk(" %016lx", *stack++);
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touch_nmi_watchdog();
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}
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preempt_enable();
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printk("\n");
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show_trace_log_lvl(task, regs, sp, bp, log_lvl);
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}
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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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unsigned long sp;
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const int cpu = smp_processor_id();
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struct task_struct *cur = current;
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sp = regs->sp;
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printk("CPU %d ", cpu);
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__show_regs(regs, 1);
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printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
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cur->comm, cur->pid, task_thread_info(cur), cur);
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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(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(KERN_EMERG "Stack:\n");
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show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
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regs->bp, 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 || probe_kernel_address(ip, c)) {
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/* try starting at IP */
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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 RIP 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 (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
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return 0;
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return ud2 == 0x0b0f;
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}
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