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 #define IRET_FRAME_OFFSET (offsetof(struct pt_regs, ip))
11 #define IRET_FRAME_SIZE (sizeof(struct pt_regs) - IRET_FRAME_OFFSET)
12
13 struct unwind_state {
14 struct stack_info stack_info;
15 unsigned long stack_mask;
16 struct task_struct *task;
17 int graph_idx;
18 bool error;
19 #if defined(CONFIG_UNWINDER_ORC)
20 bool signal, full_regs;
21 unsigned long sp, bp, ip;
22 struct pt_regs *regs;
23 #elif defined(CONFIG_UNWINDER_FRAME_POINTER)
24 bool got_irq;
25 unsigned long *bp, *orig_sp, ip;
26 struct pt_regs *regs;
27 #else
28 unsigned long *sp;
29 #endif
30 };
31
32 void __unwind_start(struct unwind_state *state, struct task_struct *task,
33 struct pt_regs *regs, unsigned long *first_frame);
34 bool unwind_next_frame(struct unwind_state *state);
35 unsigned long unwind_get_return_address(struct unwind_state *state);
36 unsigned long *unwind_get_return_address_ptr(struct unwind_state *state);
37
unwind_done(struct unwind_state * state)38 static inline bool unwind_done(struct unwind_state *state)
39 {
40 return state->stack_info.type == STACK_TYPE_UNKNOWN;
41 }
42
unwind_error(struct unwind_state * state)43 static inline bool unwind_error(struct unwind_state *state)
44 {
45 return state->error;
46 }
47
48 static inline
unwind_start(struct unwind_state * state,struct task_struct * task,struct pt_regs * regs,unsigned long * first_frame)49 void unwind_start(struct unwind_state *state, struct task_struct *task,
50 struct pt_regs *regs, unsigned long *first_frame)
51 {
52 first_frame = first_frame ? : get_stack_pointer(task, regs);
53
54 __unwind_start(state, task, regs, first_frame);
55 }
56
57 #if defined(CONFIG_UNWINDER_ORC) || defined(CONFIG_UNWINDER_FRAME_POINTER)
58 /*
59 * If 'partial' returns true, only the iret frame registers are valid.
60 */
unwind_get_entry_regs(struct unwind_state * state,bool * partial)61 static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state,
62 bool *partial)
63 {
64 if (unwind_done(state))
65 return NULL;
66
67 if (partial) {
68 #ifdef CONFIG_UNWINDER_ORC
69 *partial = !state->full_regs;
70 #else
71 *partial = false;
72 #endif
73 }
74
75 return state->regs;
76 }
77 #else
unwind_get_entry_regs(struct unwind_state * state,bool * partial)78 static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state,
79 bool *partial)
80 {
81 return NULL;
82 }
83 #endif
84
85 #ifdef CONFIG_UNWINDER_ORC
86 void unwind_init(void);
87 void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
88 void *orc, size_t orc_size);
89 #else
unwind_init(void)90 static inline void unwind_init(void) {}
91 static inline
unwind_module_init(struct module * mod,void * orc_ip,size_t orc_ip_size,void * orc,size_t orc_size)92 void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
93 void *orc, size_t orc_size) {}
94 #endif
95
96 /*
97 * This disables KASAN checking when reading a value from another task's stack,
98 * since the other task could be running on another CPU and could have poisoned
99 * the stack in the meantime.
100 */
101 #define READ_ONCE_TASK_STACK(task, x) \
102 ({ \
103 unsigned long val; \
104 if (task == current) \
105 val = READ_ONCE(x); \
106 else \
107 val = READ_ONCE_NOCHECK(x); \
108 val; \
109 })
110
task_on_another_cpu(struct task_struct * task)111 static inline bool task_on_another_cpu(struct task_struct *task)
112 {
113 #ifdef CONFIG_SMP
114 return task != current && task->on_cpu;
115 #else
116 return false;
117 #endif
118 }
119
120 #endif /* _ASM_X86_UNWIND_H */
121
