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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
*/
#include <linux/sched/debug.h>
#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>
const char *stack_type_name(enum stack_type type)
{
if (type == STACK_TYPE_IRQ)
return "IRQ";
if (type == STACK_TYPE_SOFTIRQ)
return "SOFTIRQ";
return NULL;
}
static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info)
{
unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack);
unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
/*
* This is a software stack, so 'end' can be a valid stack pointer.
* It just means the stack is empty.
*/
if (stack <= begin || stack > end)
return false;
info->type = STACK_TYPE_IRQ;
info->begin = begin;
info->end = end;
/*
* See irq_32.c -- the next stack pointer is stored at the beginning of
* the stack.
*/
info->next_sp = (unsigned long *)*begin;
return true;
}
static bool in_softirq_stack(unsigned long *stack, struct stack_info *info)
{
unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack);
unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
/*
* This is a software stack, so 'end' can be a valid stack pointer.
* It just means the stack is empty.
*/
if (stack <= begin || stack > end)
return false;
info->type = STACK_TYPE_SOFTIRQ;
info->begin = begin;
info->end = end;
/*
* The next stack pointer is stored at the beginning of the stack.
* See irq_32.c.
*/
info->next_sp = (unsigned long *)*begin;
return true;
}
int get_stack_info(unsigned long *stack, struct task_struct *task,
struct stack_info *info, unsigned long *visit_mask)
{
if (!stack)
goto unknown;
task = task ? : current;
if (in_task_stack(stack, task, info))
goto recursion_check;
if (task != current)
goto unknown;
if (in_hardirq_stack(stack, info))
goto recursion_check;
if (in_softirq_stack(stack, info))
goto recursion_check;
goto unknown;
recursion_check:
/*
* Make sure we don't iterate through any given stack more than once.
* If it comes up a second time then there's something wrong going on:
* just break out and report an unknown stack type.
*/
if (visit_mask) {
if (*visit_mask & (1UL << info->type)) {
printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
goto unknown;
}
*visit_mask |= 1UL << info->type;
}
return 0;
unknown:
info->type = STACK_TYPE_UNKNOWN;
return -EINVAL;
}
void show_regs(struct pt_regs *regs)
{
int i;
show_regs_print_info(KERN_EMERG);
__show_regs(regs, !user_mode(regs));
/*
* 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;
show_trace_log_lvl(current, regs, NULL, 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");
}
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