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, *prev_regs;
23 #elif defined(CONFIG_UNWINDER_FRAME_POINTER)
24 bool got_irq;
25 unsigned long *bp, *orig_sp, ip;
26 /*
27 * If non-NULL: The current frame is incomplete and doesn't contain a
28 * valid BP. When looking for the next frame, use this instead of the
29 * non-existent saved BP.
30 */
31 unsigned long *next_bp;
32 struct pt_regs *regs;
33 #else
34 unsigned long *sp;
35 #endif
36 };
37
38 void __unwind_start(struct unwind_state *state, struct task_struct *task,
39 struct pt_regs *regs, unsigned long *first_frame);
40 bool unwind_next_frame(struct unwind_state *state);
41 unsigned long unwind_get_return_address(struct unwind_state *state);
42 unsigned long *unwind_get_return_address_ptr(struct unwind_state *state);
43
unwind_done(struct unwind_state * state)44 static inline bool unwind_done(struct unwind_state *state)
45 {
46 return state->stack_info.type == STACK_TYPE_UNKNOWN;
47 }
48
unwind_error(struct unwind_state * state)49 static inline bool unwind_error(struct unwind_state *state)
50 {
51 return state->error;
52 }
53
54 static inline
unwind_start(struct unwind_state * state,struct task_struct * task,struct pt_regs * regs,unsigned long * first_frame)55 void unwind_start(struct unwind_state *state, struct task_struct *task,
56 struct pt_regs *regs, unsigned long *first_frame)
57 {
58 first_frame = first_frame ? : get_stack_pointer(task, regs);
59
60 __unwind_start(state, task, regs, first_frame);
61 }
62
63 #if defined(CONFIG_UNWINDER_ORC) || defined(CONFIG_UNWINDER_FRAME_POINTER)
64 /*
65 * If 'partial' returns true, only the iret frame registers are valid.
66 */
unwind_get_entry_regs(struct unwind_state * state,bool * partial)67 static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state,
68 bool *partial)
69 {
70 if (unwind_done(state))
71 return NULL;
72
73 if (partial) {
74 #ifdef CONFIG_UNWINDER_ORC
75 *partial = !state->full_regs;
76 #else
77 *partial = false;
78 #endif
79 }
80
81 return state->regs;
82 }
83 #else
unwind_get_entry_regs(struct unwind_state * state,bool * partial)84 static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state,
85 bool *partial)
86 {
87 return NULL;
88 }
89 #endif
90
91 #ifdef CONFIG_UNWINDER_ORC
92 void unwind_init(void);
93 void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
94 void *orc, size_t orc_size);
95 #else
unwind_init(void)96 static inline void unwind_init(void) {}
97 static inline
unwind_module_init(struct module * mod,void * orc_ip,size_t orc_ip_size,void * orc,size_t orc_size)98 void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
99 void *orc, size_t orc_size) {}
100 #endif
101
102 /*
103 * This disables KASAN checking when reading a value from another task's stack,
104 * since the other task could be running on another CPU and could have poisoned
105 * the stack in the meantime.
106 */
107 #define READ_ONCE_TASK_STACK(task, x) \
108 ({ \
109 unsigned long val; \
110 if (task == current) \
111 val = READ_ONCE(x); \
112 else \
113 val = READ_ONCE_NOCHECK(x); \
114 val; \
115 })
116
task_on_another_cpu(struct task_struct * task)117 static inline bool task_on_another_cpu(struct task_struct *task)
118 {
119 #ifdef CONFIG_SMP
120 return task != current && task->on_cpu;
121 #else
122 return false;
123 #endif
124 }
125
126 #endif /* _ASM_X86_UNWIND_H */
127