arch/arm64/include/asm/stacktrace.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2012 ARM Ltd.
   4  */
   5 #ifndef __ASM_STACKTRACE_H
   6 #define __ASM_STACKTRACE_H
   7
   8 #include <linux/percpu.h>
   9 #include <linux/sched.h>
  10 #include <linux/sched/task_stack.h>
  11
  12 #include <asm/memory.h>
  13 #include <asm/ptrace.h>
  14 #include <asm/sdei.h>
  15
  16 struct stackframe {
  17         unsigned long fp;
  18         unsigned long pc;
  19 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  20         int graph;
  21 #endif
  22 };
  23
  24 enum stack_type {
  25         STACK_TYPE_UNKNOWN,
  26         STACK_TYPE_TASK,
  27         STACK_TYPE_IRQ,
  28         STACK_TYPE_OVERFLOW,
  29         STACK_TYPE_SDEI_NORMAL,
  30         STACK_TYPE_SDEI_CRITICAL,
  31 };
  32
  33 struct stack_info {
  34         unsigned long low;
  35         unsigned long high;
  36         enum stack_type type;
  37 };
  38
  39 extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
  40 extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
  41                             int (*fn)(struct stackframe *, void *), void *data);
  42 extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk);
  43
  44 DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
  45
  46 static inline bool on_irq_stack(unsigned long sp,
  47                                 struct stack_info *info)
  48 {
  49         unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
  50         unsigned long high = low + IRQ_STACK_SIZE;
  51
  52         if (!low)
  53                 return false;
  54
  55         if (sp < low || sp >= high)
  56                 return false;
  57
  58         if (info) {
  59                 info->low = low;
  60                 info->high = high;
  61                 info->type = STACK_TYPE_IRQ;
  62         }
  63
  64         return true;
  65 }
  66
  67 static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp,
  68                                 struct stack_info *info)
  69 {
  70         unsigned long low = (unsigned long)task_stack_page(tsk);
  71         unsigned long high = low + THREAD_SIZE;
  72
  73         if (sp < low || sp >= high)
  74                 return false;
  75
  76         if (info) {
  77                 info->low = low;
  78                 info->high = high;
  79                 info->type = STACK_TYPE_TASK;
  80         }
  81
  82         return true;
  83 }
  84
  85 #ifdef CONFIG_VMAP_STACK
  86 DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
  87
  88 static inline bool on_overflow_stack(unsigned long sp,
  89                                 struct stack_info *info)
  90 {
  91         unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack);
  92         unsigned long high = low + OVERFLOW_STACK_SIZE;
  93
  94         if (sp < low || sp >= high)
  95                 return false;
  96
  97         if (info) {
  98                 info->low = low;
  99                 info->high = high;
 100                 info->type = STACK_TYPE_OVERFLOW;
 101         }
 102
 103         return true;
 104 }
 105 #else
 106 static inline bool on_overflow_stack(unsigned long sp,
 107                         struct stack_info *info) { return false; }
 108 #endif
 109
 110
 111 /*
 112  * We can only safely access per-cpu stacks from current in a non-preemptible
 113  * context.
 114  */
 115 static inline bool on_accessible_stack(struct task_struct *tsk,
 116                                         unsigned long sp,
 117                                         struct stack_info *info)
 118 {
 119         if (on_task_stack(tsk, sp, info))
 120                 return true;
 121         if (tsk != current || preemptible())
 122                 return false;
 123         if (on_irq_stack(sp, info))
 124                 return true;
 125         if (on_overflow_stack(sp, info))
 126                 return true;
 127         if (on_sdei_stack(sp, info))
 128                 return true;
 129
 130         return false;
 131 }
 132
 133 #endif  /* __ASM_STACKTRACE_H */