xref: /openbmc/linux/arch/x86/include/asm/unwind.h (revision 28efb0046512e8a13ed9f9bdf0d68d10bbfbe9cf)
1 #ifndef _ASM_X86_UNWIND_H
2 #define _ASM_X86_UNWIND_H
3 
4 #include <linux/sched.h>
5 #include <linux/ftrace.h>
6 #include <asm/ptrace.h>
7 #include <asm/stacktrace.h>
8 
9 struct unwind_state {
10 	struct stack_info stack_info;
11 	unsigned long stack_mask;
12 	struct task_struct *task;
13 	int graph_idx;
14 	bool error;
15 #if defined(CONFIG_ORC_UNWINDER)
16 	bool signal, full_regs;
17 	unsigned long sp, bp, ip;
18 	struct pt_regs *regs;
19 #elif defined(CONFIG_FRAME_POINTER_UNWINDER)
20 	bool got_irq;
21 	unsigned long *bp, *orig_sp, ip;
22 	struct pt_regs *regs;
23 #else
24 	unsigned long *sp;
25 #endif
26 };
27 
28 void __unwind_start(struct unwind_state *state, struct task_struct *task,
29 		    struct pt_regs *regs, unsigned long *first_frame);
30 bool unwind_next_frame(struct unwind_state *state);
31 unsigned long unwind_get_return_address(struct unwind_state *state);
32 unsigned long *unwind_get_return_address_ptr(struct unwind_state *state);
33 
34 static inline bool unwind_done(struct unwind_state *state)
35 {
36 	return state->stack_info.type == STACK_TYPE_UNKNOWN;
37 }
38 
39 static inline bool unwind_error(struct unwind_state *state)
40 {
41 	return state->error;
42 }
43 
44 static inline
45 void unwind_start(struct unwind_state *state, struct task_struct *task,
46 		  struct pt_regs *regs, unsigned long *first_frame)
47 {
48 	first_frame = first_frame ? : get_stack_pointer(task, regs);
49 
50 	__unwind_start(state, task, regs, first_frame);
51 }
52 
53 #if defined(CONFIG_ORC_UNWINDER) || defined(CONFIG_FRAME_POINTER_UNWINDER)
54 static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state)
55 {
56 	if (unwind_done(state))
57 		return NULL;
58 
59 	return state->regs;
60 }
61 #else
62 static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state)
63 {
64 	return NULL;
65 }
66 #endif
67 
68 #ifdef CONFIG_ORC_UNWINDER
69 void unwind_init(void);
70 void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
71 			void *orc, size_t orc_size);
72 #else
73 static inline void unwind_init(void) {}
74 static inline
75 void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
76 			void *orc, size_t orc_size) {}
77 #endif
78 
79 /*
80  * This disables KASAN checking when reading a value from another task's stack,
81  * since the other task could be running on another CPU and could have poisoned
82  * the stack in the meantime.
83  */
84 #define READ_ONCE_TASK_STACK(task, x)			\
85 ({							\
86 	unsigned long val;				\
87 	if (task == current)				\
88 		val = READ_ONCE(x);			\
89 	else						\
90 		val = READ_ONCE_NOCHECK(x);		\
91 	val;						\
92 })
93 
94 static inline bool task_on_another_cpu(struct task_struct *task)
95 {
96 #ifdef CONFIG_SMP
97 	return task != current && task->on_cpu;
98 #else
99 	return false;
100 #endif
101 }
102 
103 #endif /* _ASM_X86_UNWIND_H */
104