/*
* 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/export.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>
static char *exception_stack_names[N_EXCEPTION_STACKS] = {
[ DOUBLEFAULT_STACK-1 ] = "#DF",
[ NMI_STACK-1 ] = "NMI",
[ DEBUG_STACK-1 ] = "#DB",
[ MCE_STACK-1 ] = "#MC",
};
static unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = {
[0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ,
[DEBUG_STACK - 1] = DEBUG_STKSZ
};
static unsigned long *in_exception_stack(unsigned long stack, unsigned *usedp,
char **idp)
{
unsigned long begin, end;
unsigned k;
BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
for (k = 0; k < N_EXCEPTION_STACKS; k++) {
end = raw_cpu_ptr(&orig_ist)->ist[k];
begin = end - exception_stack_sizes[k];
if (stack < begin || stack >= end)
continue;
/*
* Make sure we only iterate through an exception stack once.
* If it comes up for the second time then there's something
* wrong going on - just break and return NULL:
*/
if (*usedp & (1U << k))
break;
*usedp |= 1U << k;
*idp = exception_stack_names[k];
return (unsigned long *)end;
}
return NULL;
}
static inline int
in_irq_stack(unsigned long *stack, unsigned long *irq_stack,
unsigned long *irq_stack_end)
{
return (stack >= irq_stack && stack < irq_stack_end);
}
enum stack_type {
STACK_IS_UNKNOWN,
STACK_IS_NORMAL,
STACK_IS_EXCEPTION,
STACK_IS_IRQ,
};
static enum stack_type
analyze_stack(struct task_struct *task, unsigned long *stack,
unsigned long **stack_end, unsigned long *irq_stack,
unsigned *used, char **id)
{
unsigned long addr;
addr = ((unsigned long)stack & (~(THREAD_SIZE - 1)));
if ((unsigned long)task_stack_page(task) == addr)
return STACK_IS_NORMAL;
*stack_end = in_exception_stack((unsigned long)stack, used, id);
if (*stack_end)
return STACK_IS_EXCEPTION;
if (!irq_stack)
return STACK_IS_NORMAL;
*stack_end = irq_stack;
irq_stack -= (IRQ_STACK_SIZE / sizeof(long));
if (in_irq_stack(stack, irq_stack, *stack_end))
return STACK_IS_IRQ;
return STACK_IS_UNKNOWN;
}
/*
* x86-64 can have up to three kernel stacks:
* process stack
* interrupt stack
* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
*/
void dump_trace(struct task_struct *task, struct pt_regs *regs,
unsigned long *stack, unsigned long bp,
const struct stacktrace_ops *ops, void *data)
{
unsigned long *irq_stack = (unsigned long *)this_cpu_read(irq_stack_ptr);
unsigned used = 0;
int graph = 0;
int done = 0;
task = task ? : current;
stack = stack ? : get_stack_pointer(task, regs);
bp = bp ? : (unsigned long)get_frame_pointer(task, regs);
/*
* Print function call entries in all stacks, starting at the
* current stack address. If the stacks consist of nested
* exceptions
*/
while (!done) {
unsigned long *stack_end;
enum stack_type stype;
char *id;
stype = analyze_stack(task, stack, &stack_end, irq_stack, &used,
&id);
/* Default finish unless specified to continue */
done = 1;
switch (stype) {
/* Break out early if we are on the thread stack */
case STACK_IS_NORMAL:
break;
case STACK_IS_EXCEPTION:
if (ops->stack(data, id) < 0)
break;
bp = ops->walk_stack(task, stack, bp, ops,
data, stack_end, &graph);
ops->stack(data, "EOE");
/*
* We link to the next stack via the
* second-to-last pointer (index -2 to end) in the
* exception stack:
*/
stack = (unsigned long *) stack_end[-2];
done = 0;
break;
case STACK_IS_IRQ:
if (ops->stack(data, "IRQ") < 0)
break;
bp = ops->walk_stack(task, stack, bp,
ops, data, stack_end, &graph);
/*
* We link to the next stack (which would be
* the process stack normally) the last
* pointer (index -1 to end) in the IRQ stack:
*/
stack = (unsigned long *) (stack_end[-1]);
irq_stack = NULL;
ops->stack(data, "EOI");
done = 0;
break;
case STACK_IS_UNKNOWN:
ops->stack(data, "UNK");
break;
}
}
/*
* This handles the process stack:
*/
bp = ops->walk_stack(task, stack, bp, ops, data, NULL, &graph);
}
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 *irq_stack_end;
unsigned long *irq_stack;
unsigned long *stack;
int i;
irq_stack_end = (unsigned long *)this_cpu_read(irq_stack_ptr);
irq_stack = irq_stack_end - (IRQ_STACK_SIZE / sizeof(long));
sp = sp ? : get_stack_pointer(task, regs);
stack = sp;
for (i = 0; i < kstack_depth_to_print; i++) {
unsigned long word;
if (stack >= irq_stack && stack <= irq_stack_end) {
if (stack == irq_stack_end) {
stack = (unsigned long *) (irq_stack_end[-1]);
pr_cont(" <EOI> ");
}
} else {
if (kstack_end(stack))
break;
}
if (probe_kernel_address(stack, word))
break;
if ((i % STACKSLOTS_PER_LINE) == 0) {
if (i != 0)
pr_cont("\n");
printk("%s %016lx", log_lvl, word);
} else
pr_cont(" %016lx", word);
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_print_info(KERN_DEFAULT);
__show_regs(regs, 1);
/*
* When in-kernel, we also print out the stack and code at the
* time of the fault..
*/
if (!user_mode(regs)) {
unsigned int code_prologue = code_bytes * 43 / 64;
unsigned int code_len = code_bytes;
unsigned char c;
u8 *ip;
printk(KERN_DEFAULT "Stack:\n");
show_stack_log_lvl(NULL, regs, NULL, 0, KERN_DEFAULT);
printk(KERN_DEFAULT "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 RIP 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 (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
return 0;
return ud2 == 0x0b0f;
}
