LXR linux/arch/arm64/include/asm/stacktrace.h

   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#include <asm/sdei.h>
  26
  27struct stackframe {
  28        unsigned long fp;
  29        unsigned long pc;
  30#ifdef CONFIG_FUNCTION_GRAPH_TRACER
  31        int graph;
  32#endif
  33};
  34
  35enum stack_type {
  36        STACK_TYPE_UNKNOWN,
  37        STACK_TYPE_TASK,
  38        STACK_TYPE_IRQ,
  39        STACK_TYPE_OVERFLOW,
  40        STACK_TYPE_SDEI_NORMAL,
  41        STACK_TYPE_SDEI_CRITICAL,
  42};
  43
  44struct stack_info {
  45        unsigned long low;
  46        unsigned long high;
  47        enum stack_type type;
  48};
  49
  50extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
  51extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
  52                            int (*fn)(struct stackframe *, void *), void *data);
  53extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk);
  54
  55DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
  56
  57static inline bool on_irq_stack(unsigned long sp,
  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        if (!low)
  64                return false;
  65
  66        if (sp < low || sp >= high)
  67                return false;
  68
  69        if (info) {
  70                info->low = low;
  71                info->high = high;
  72                info->type = STACK_TYPE_IRQ;
  73        }
  74
  75        return true;
  76}
  77
  78static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp,
  79                                struct stack_info *info)
  80{
  81        unsigned long low = (unsigned long)task_stack_page(tsk);
  82        unsigned long high = low + THREAD_SIZE;
  83
  84        if (sp < low || sp >= high)
  85                return false;
  86
  87        if (info) {
  88                info->low = low;
  89                info->high = high;
  90                info->type = STACK_TYPE_TASK;
  91        }
  92
  93        return true;
  94}
  95
  96#ifdef CONFIG_VMAP_STACK
  97DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
  98
  99static inline bool on_overflow_stack(unsigned long sp,
 100                                struct stack_info *info)
 101{
 102        unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack);
 103        unsigned long high = low + OVERFLOW_STACK_SIZE;
 104
 105        if (sp < low || sp >= high)
 106                return false;
 107
 108        if (info) {
 109                info->low = low;
 110                info->high = high;
 111                info->type = STACK_TYPE_OVERFLOW;
 112        }
 113
 114        return true;
 115}
 116#else
 117static inline bool on_overflow_stack(unsigned long sp,
 118                        struct stack_info *info) { return false; }
 119#endif
 120
 121
 122/*
 123 * We can only safely access per-cpu stacks from current in a non-preemptible
 124 * context.
 125 */
 126static inline bool on_accessible_stack(struct task_struct *tsk,
 127                                        unsigned long sp,
 128                                        struct stack_info *info)
 129{
 130        if (on_task_stack(tsk, sp, info))
 131                return true;
 132        if (tsk != current || preemptible())
 133                return false;
 134        if (on_irq_stack(sp, info))
 135                return true;
 136        if (on_overflow_stack(sp, info))
 137                return true;
 138        if (on_sdei_stack(sp, info))
 139                return true;
 140
 141        return false;
 142}
 143
 144#endif  /* __ASM_STACKTRACE_H */
 145