dumpstack_32.c

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/*
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
 */
#include <linux/kallsyms.h>
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
#include <linux/kdebug.h>
#include <linux/module.h>
#include <linux/ptrace.h>
#include <linux/kexec.h>
#include <linux/sysfs.h>
#include <linux/bug.h>
#include <linux/nmi.h>

#include <asm/stacktrace.h>


void dump_trace(struct task_struct *task, struct pt_regs *regs,
        unsigned long *stack, unsigned long bp,
        const struct stacktrace_ops *ops, void *data)
{
    int graph = 0;

    if (!task)
        task = current;

    if (!stack) {
        unsigned long dummy;

        stack = &dummy;
        if (task && task != current)
            stack = (unsigned long *)task->thread.sp;
    }

    if (!bp)
        bp = stack_frame(task, regs);

    for (;;) {
        struct thread_info *context;

        context = (struct thread_info *)
            ((unsigned long)stack & (~(THREAD_SIZE - 1)));
        bp = ops->walk_stack(context, stack, bp, ops, data, NULL, &graph);

        stack = (unsigned long *)context->previous_esp;
        if (!stack)
            break;
        if (ops->stack(data, "IRQ") < 0)
            break;
        touch_nmi_watchdog();
    }
}
EXPORT_SYMBOL(dump_trace);

void
show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
           unsigned long *sp, unsigned long bp, char *log_lvl)
{
    unsigned long *stack;
    int i;

    if (sp == NULL) {
        if (task)
            sp = (unsigned long *)task->thread.sp;
        else
            sp = (unsigned long *)&sp;
    }

    stack = sp;
    for (i = 0; i < kstack_depth_to_print; i++) {
        if (kstack_end(stack))
            break;
        if (i && ((i % STACKSLOTS_PER_LINE) == 0))
            pr_cont("\n");
        pr_cont(" %08lx", *stack++);
        touch_nmi_watchdog();
    }
    pr_cont("\n");
    show_trace_log_lvl(task, regs, sp, bp, log_lvl);
}


void show_regs(struct pt_regs *regs)
{
    int i;

    __show_regs(regs, !user_mode_vm(regs));

    pr_emerg("Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
         TASK_COMM_LEN, current->comm, task_pid_nr(current),
         current_thread_info(), current, task_thread_info(current));
    /*
     * When in-kernel, we also print out the stack and code at the
     * time of the fault..
     */
    if (!user_mode_vm(regs)) {
        unsigned int code_prologue = code_bytes * 43 / 64;
        unsigned int code_len = code_bytes;
        unsigned char c;
        u8 *ip;

        pr_emerg("Stack:\n");
        show_stack_log_lvl(NULL, regs, &regs->sp, 0, KERN_EMERG);

        pr_emerg("Code:");

        ip = (u8 *)regs->ip - code_prologue;
        if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
            /* try starting at IP */
            ip = (u8 *)regs->ip;
            code_len = code_len - code_prologue + 1;
        }
        for (i = 0; i < code_len; i++, ip++) {
            if (ip < (u8 *)PAGE_OFFSET ||
                    probe_kernel_address(ip, c)) {
                pr_cont("  Bad EIP value.");
                break;
            }
            if (ip == (u8 *)regs->ip)
                pr_cont(" <%02x>", c);
            else
                pr_cont(" %02x", c);
        }
    }
    pr_cont("\n");
}

int is_valid_bugaddr(unsigned long ip)
{
    unsigned short ud2;

    if (ip < PAGE_OFFSET)
        return 0;
    if (probe_kernel_address((unsigned short *)ip, ud2))
        return 0;

    return ud2 == 0x0b0f;
}