xref: /openbmc/linux/arch/x86/include/asm/unwind.h (revision bbecb07f)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_UNWIND_H
3 #define _ASM_X86_UNWIND_H
4 
5 #include <linux/sched.h>
6 #include <linux/ftrace.h>
7 #include <asm/ptrace.h>
8 #include <asm/stacktrace.h>
9 
10 struct unwind_state {
11 	struct stack_info stack_info;
12 	unsigned long stack_mask;
13 	struct task_struct *task;
14 	int graph_idx;
15 	bool error;
16 #if defined(CONFIG_UNWINDER_ORC)
17 	bool signal, full_regs;
18 	unsigned long sp, bp, ip;
19 	struct pt_regs *regs;
20 #elif defined(CONFIG_UNWINDER_FRAME_POINTER)
21 	bool got_irq;
22 	unsigned long *bp, *orig_sp, ip;
23 	struct pt_regs *regs;
24 #else
25 	unsigned long *sp;
26 #endif
27 };
28 
29 void __unwind_start(struct unwind_state *state, struct task_struct *task,
30 		    struct pt_regs *regs, unsigned long *first_frame);
31 bool unwind_next_frame(struct unwind_state *state);
32 unsigned long unwind_get_return_address(struct unwind_state *state);
33 unsigned long *unwind_get_return_address_ptr(struct unwind_state *state);
34 
35 static inline bool unwind_done(struct unwind_state *state)
36 {
37 	return state->stack_info.type == STACK_TYPE_UNKNOWN;
38 }
39 
40 static inline bool unwind_error(struct unwind_state *state)
41 {
42 	return state->error;
43 }
44 
45 static inline
46 void unwind_start(struct unwind_state *state, struct task_struct *task,
47 		  struct pt_regs *regs, unsigned long *first_frame)
48 {
49 	first_frame = first_frame ? : get_stack_pointer(task, regs);
50 
51 	__unwind_start(state, task, regs, first_frame);
52 }
53 
54 #if defined(CONFIG_UNWINDER_ORC) || defined(CONFIG_UNWINDER_FRAME_POINTER)
55 static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state)
56 {
57 	if (unwind_done(state))
58 		return NULL;
59 
60 	return state->regs;
61 }
62 #else
63 static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state)
64 {
65 	return NULL;
66 }
67 #endif
68 
69 #ifdef CONFIG_UNWINDER_ORC
70 void unwind_init(void);
71 void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
72 			void *orc, size_t orc_size);
73 #else
74 static inline void unwind_init(void) {}
75 static inline
76 void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
77 			void *orc, size_t orc_size) {}
78 #endif
79 
80 /*
81  * This disables KASAN checking when reading a value from another task's stack,
82  * since the other task could be running on another CPU and could have poisoned
83  * the stack in the meantime.
84  */
85 #define READ_ONCE_TASK_STACK(task, x)			\
86 ({							\
87 	unsigned long val;				\
88 	if (task == current)				\
89 		val = READ_ONCE(x);			\
90 	else						\
91 		val = READ_ONCE_NOCHECK(x);		\
92 	val;						\
93 })
94 
95 static inline bool task_on_another_cpu(struct task_struct *task)
96 {
97 #ifdef CONFIG_SMP
98 	return task != current && task->on_cpu;
99 #else
100 	return false;
101 #endif
102 }
103 
104 #endif /* _ASM_X86_UNWIND_H */
105