2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
5 #include <linux/sched/debug.h>
6 #include <linux/kallsyms.h>
7 #include <linux/kprobes.h>
8 #include <linux/uaccess.h>
9 #include <linux/hardirq.h>
10 #include <linux/kdebug.h>
11 #include <linux/export.h>
12 #include <linux/ptrace.h>
13 #include <linux/kexec.h>
14 #include <linux/sysfs.h>
15 #include <linux/bug.h>
16 #include <linux/nmi.h>
18 #include <asm/stacktrace.h>
20 static char *exception_stack_names
[N_EXCEPTION_STACKS
] = {
21 [ DOUBLEFAULT_STACK
-1 ] = "#DF",
22 [ NMI_STACK
-1 ] = "NMI",
23 [ DEBUG_STACK
-1 ] = "#DB",
24 [ MCE_STACK
-1 ] = "#MC",
27 static unsigned long exception_stack_sizes
[N_EXCEPTION_STACKS
] = {
28 [0 ... N_EXCEPTION_STACKS
- 1] = EXCEPTION_STKSZ
,
29 [DEBUG_STACK
- 1] = DEBUG_STKSZ
32 const char *stack_type_name(enum stack_type type
)
34 BUILD_BUG_ON(N_EXCEPTION_STACKS
!= 4);
36 if (type
== STACK_TYPE_IRQ
)
39 if (type
>= STACK_TYPE_EXCEPTION
&& type
<= STACK_TYPE_EXCEPTION_LAST
)
40 return exception_stack_names
[type
- STACK_TYPE_EXCEPTION
];
45 static bool in_exception_stack(unsigned long *stack
, struct stack_info
*info
)
47 unsigned long *begin
, *end
;
51 BUILD_BUG_ON(N_EXCEPTION_STACKS
!= 4);
53 for (k
= 0; k
< N_EXCEPTION_STACKS
; k
++) {
54 end
= (unsigned long *)raw_cpu_ptr(&orig_ist
)->ist
[k
];
55 begin
= end
- (exception_stack_sizes
[k
] / sizeof(long));
56 regs
= (struct pt_regs
*)end
- 1;
58 if (stack
< begin
|| stack
>= end
)
61 info
->type
= STACK_TYPE_EXCEPTION
+ k
;
64 info
->next_sp
= (unsigned long *)regs
->sp
;
72 static bool in_irq_stack(unsigned long *stack
, struct stack_info
*info
)
74 unsigned long *end
= (unsigned long *)this_cpu_read(irq_stack_ptr
);
75 unsigned long *begin
= end
- (IRQ_STACK_SIZE
/ sizeof(long));
78 * This is a software stack, so 'end' can be a valid stack pointer.
79 * It just means the stack is empty.
81 if (stack
< begin
|| stack
> end
)
84 info
->type
= STACK_TYPE_IRQ
;
89 * The next stack pointer is the first thing pushed by the entry code
90 * after switching to the irq stack.
92 info
->next_sp
= (unsigned long *)*(end
- 1);
97 int get_stack_info(unsigned long *stack
, struct task_struct
*task
,
98 struct stack_info
*info
, unsigned long *visit_mask
)
103 task
= task
? : current
;
105 if (in_task_stack(stack
, task
, info
))
106 goto recursion_check
;
111 if (in_exception_stack(stack
, info
))
112 goto recursion_check
;
114 if (in_irq_stack(stack
, info
))
115 goto recursion_check
;
121 * Make sure we don't iterate through any given stack more than once.
122 * If it comes up a second time then there's something wrong going on:
123 * just break out and report an unknown stack type.
126 if (*visit_mask
& (1UL << info
->type
)) {
127 printk_deferred_once(KERN_WARNING
"WARNING: stack recursion on stack type %d\n", info
->type
);
130 *visit_mask
|= 1UL << info
->type
;
136 info
->type
= STACK_TYPE_UNKNOWN
;
140 void show_regs(struct pt_regs
*regs
)
144 show_regs_print_info(KERN_DEFAULT
);
145 __show_regs(regs
, 1);
148 * When in-kernel, we also print out the stack and code at the
149 * time of the fault..
151 if (!user_mode(regs
)) {
152 unsigned int code_prologue
= code_bytes
* 43 / 64;
153 unsigned int code_len
= code_bytes
;
157 show_trace_log_lvl(current
, regs
, NULL
, KERN_DEFAULT
);
159 printk(KERN_DEFAULT
"Code: ");
161 ip
= (u8
*)regs
->ip
- code_prologue
;
162 if (ip
< (u8
*)PAGE_OFFSET
|| probe_kernel_address(ip
, c
)) {
163 /* try starting at IP */
165 code_len
= code_len
- code_prologue
+ 1;
167 for (i
= 0; i
< code_len
; i
++, ip
++) {
168 if (ip
< (u8
*)PAGE_OFFSET
||
169 probe_kernel_address(ip
, c
)) {
170 pr_cont(" Bad RIP value.");
173 if (ip
== (u8
*)regs
->ip
)
174 pr_cont("<%02x> ", c
);
182 int is_valid_bugaddr(unsigned long ip
)
186 if (__copy_from_user(&ud2
, (const void __user
*) ip
, sizeof(ud2
)))
189 return ud2
== 0x0b0f;