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 #include <linux/types.h>
  12 #include <linux/llist.h>
  13
  14 #include <asm/memory.h>
  15 #include <asm/ptrace.h>
  16 #include <asm/sdei.h>
  17
  18 enum stack_type {
  19         STACK_TYPE_UNKNOWN,
  20         STACK_TYPE_TASK,
  21         STACK_TYPE_IRQ,
  22         STACK_TYPE_OVERFLOW,
  23         STACK_TYPE_SDEI_NORMAL,
  24         STACK_TYPE_SDEI_CRITICAL,
  25         __NR_STACK_TYPES
  26 };
  27
  28 struct stack_info {
  29         unsigned long low;
  30         unsigned long high;
  31         enum stack_type type;
  32 };
  33
  34 extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
  35                            const char *loglvl);
  36
  37 DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
  38
  39 static inline bool on_stack(unsigned long sp, unsigned long size,
  40                             unsigned long low, unsigned long high,
  41                             enum stack_type type, struct stack_info *info)
  42 {
  43         if (!low)
  44                 return false;
  45
  46         if (sp < low || sp + size < sp || sp + size > high)
  47                 return false;
  48
  49         if (info) {
  50                 info->low = low;
  51                 info->high = high;
  52                 info->type = type;
  53         }
  54         return true;
  55 }
  56
  57 static inline bool on_irq_stack(unsigned long sp, unsigned long size,
  58                                 struct stack_info *info)
  59 {
  60         unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
  61         unsigned long high = low + IRQ_STACK_SIZE;
  62
  63         return on_stack(sp, size, low, high, STACK_TYPE_IRQ, info);
  64 }
  65
  66 static inline bool on_task_stack(const struct task_struct *tsk,
  67                                  unsigned long sp, unsigned long size,
  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         return on_stack(sp, size, low, high, STACK_TYPE_TASK, info);
  74 }
  75
  76 #ifdef CONFIG_VMAP_STACK
  77 DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
  78
  79 static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
  80                                 struct stack_info *info)
  81 {
  82         unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack);
  83         unsigned long high = low + OVERFLOW_STACK_SIZE;
  84
  85         return on_stack(sp, size, low, high, STACK_TYPE_OVERFLOW, info);
  86 }
  87 #else
  88 static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
  89                         struct stack_info *info) { return false; }
  90 #endif
  91
  92
  93 /*
  94  * We can only safely access per-cpu stacks from current in a non-preemptible
  95  * context.
  96  */
  97 static inline bool on_accessible_stack(const struct task_struct *tsk,
  98                                        unsigned long sp, unsigned long size,
  99                                        struct stack_info *info)
 100 {
 101         if (info)
 102                 info->type = STACK_TYPE_UNKNOWN;
 103
 104         if (on_task_stack(tsk, sp, size, info))
 105                 return true;
 106         if (tsk != current || preemptible())
 107                 return false;
 108         if (on_irq_stack(sp, size, info))
 109                 return true;
 110         if (on_overflow_stack(sp, size, info))
 111                 return true;
 112         if (on_sdei_stack(sp, size, info))
 113                 return true;
 114
 115         return false;
 116 }
 117
 118 #endif  /* __ASM_STACKTRACE_H */