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
  27 struct stackframe {
  28         unsigned long fp;
  29         unsigned long pc;
  30 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  31         unsigned int graph;
  32 #endif
  33 };
  34
  35 extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
  36 extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
  37                             int (*fn)(struct stackframe *, void *), void *data);
  38 extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk);
  39
  40 DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
  41
  42 static inline bool on_irq_stack(unsigned long sp)
  43 {
  44         unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
  45         unsigned long high = low + IRQ_STACK_SIZE;
  46
  47         if (!low)
  48                 return false;
  49
  50         return (low <= sp && sp < high);
  51 }
  52
  53 static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp)
  54 {
  55         unsigned long low = (unsigned long)task_stack_page(tsk);
  56         unsigned long high = low + THREAD_SIZE;
  57
  58         return (low <= sp && sp < high);
  59 }
  60
  61 #ifdef CONFIG_VMAP_STACK
  62 DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
  63
  64 static inline bool on_overflow_stack(unsigned long sp)
  65 {
  66         unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack);
  67         unsigned long high = low + OVERFLOW_STACK_SIZE;
  68
  69         return (low <= sp && sp < high);
  70 }
  71 #else
  72 static inline bool on_overflow_stack(unsigned long sp) { return false; }
  73 #endif
  74
  75 /*
  76  * We can only safely access per-cpu stacks from current in a non-preemptible
  77  * context.
  78  */
  79 static inline bool on_accessible_stack(struct task_struct *tsk, unsigned long sp)
  80 {
  81         if (on_task_stack(tsk, sp))
  82                 return true;
  83         if (tsk != current || preemptible())
  84                 return false;
  85         if (on_irq_stack(sp))
  86                 return true;
  87         if (on_overflow_stack(sp))
  88                 return true;
  89         if (on_sdei_stack(sp))
  90                 return true;
  91
  92         return false;
  93 }
  94
  95 #endif  /* __ASM_STACKTRACE_H */