1 /*
2 * Copyright (C) 2012 ARM Ltd.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16 #ifndef __ASM_STACKTRACE_H
17 #define __ASM_STACKTRACE_H
18
19 #include <linux/percpu.h>
20 #include <linux/sched.h>
21 #include <linux/sched/task_stack.h>
22
23 #include <asm/memory.h>
24 #include <asm/ptrace.h>
25
26 struct stackframe {
27 unsigned long fp;
28 unsigned long pc;
29 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
30 int graph;
31 #endif
32 };
33
34 extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
35 extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
36 int (*fn)(struct stackframe *, void *), void *data);
37 extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk);
38
39 DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
40
on_irq_stack(unsigned long sp)41 static inline bool on_irq_stack(unsigned long sp)
42 {
43 unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
44 unsigned long high = low + IRQ_STACK_SIZE;
45
46 if (!low)
47 return false;
48
49 return (low <= sp && sp < high);
50 }
51
on_task_stack(struct task_struct * tsk,unsigned long sp)52 static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp)
53 {
54 unsigned long low = (unsigned long)task_stack_page(tsk);
55 unsigned long high = low + THREAD_SIZE;
56
57 return (low <= sp && sp < high);
58 }
59
60 #ifdef CONFIG_VMAP_STACK
61 DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
62
on_overflow_stack(unsigned long sp)63 static inline bool on_overflow_stack(unsigned long sp)
64 {
65 unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack);
66 unsigned long high = low + OVERFLOW_STACK_SIZE;
67
68 return (low <= sp && sp < high);
69 }
70 #else
on_overflow_stack(unsigned long sp)71 static inline bool on_overflow_stack(unsigned long sp) { return false; }
72 #endif
73
74 /*
75 * We can only safely access per-cpu stacks from current in a non-preemptible
76 * context.
77 */
on_accessible_stack(struct task_struct * tsk,unsigned long sp)78 static inline bool on_accessible_stack(struct task_struct *tsk, unsigned long sp)
79 {
80 if (on_task_stack(tsk, sp))
81 return true;
82 if (tsk != current || preemptible())
83 return false;
84 if (on_irq_stack(sp))
85 return true;
86 if (on_overflow_stack(sp))
87 return true;
88
89 return false;
90 }
91
92 #endif /* __ASM_STACKTRACE_H */
93