/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_STACKTRACE_H
#define __ASM_STACKTRACE_H
#include <linux/percpu.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <asm/memory.h>
#include <asm/ptrace.h>
#include <asm/sdei.h>
struct stackframe {
unsigned long fp;
unsigned long pc;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
int graph;
#endif
};
enum stack_type {
STACK_TYPE_UNKNOWN,
STACK_TYPE_TASK,
STACK_TYPE_IRQ,
STACK_TYPE_OVERFLOW,
STACK_TYPE_SDEI_NORMAL,
STACK_TYPE_SDEI_CRITICAL,
};
struct stack_info {
unsigned long low;
unsigned long high;
enum stack_type type;
};
extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
int (*fn)(struct stackframe *, void *), void *data);
extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk);
DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
static inline bool on_irq_stack(unsigned long sp,
struct stack_info *info)
{
unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
unsigned long high = low + IRQ_STACK_SIZE;
if (!low)
return false;
if (sp < low || sp >= high)
return false;
if (info) {
info->low = low;
info->high = high;
info->type = STACK_TYPE_IRQ;
}
return true;
}
static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp,
struct stack_info *info)
{
unsigned long low = (unsigned long)task_stack_page(tsk);
unsigned long high = low + THREAD_SIZE;
if (sp < low || sp >= high)
return false;
if (info) {
info->low = low;
info->high = high;
info->type = STACK_TYPE_TASK;
}
return true;
}
#ifdef CONFIG_VMAP_STACK
DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
static inline bool on_overflow_stack(unsigned long sp,
struct stack_info *info)
{
unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack);
unsigned long high = low + OVERFLOW_STACK_SIZE;
if (sp < low || sp >= high)
return false;
if (info) {
info->low = low;
info->high = high;
info->type = STACK_TYPE_OVERFLOW;
}
return true;
}
#else
static inline bool on_overflow_stack(unsigned long sp,
struct stack_info *info) { return false; }
#endif
/*
* We can only safely access per-cpu stacks from current in a non-preemptible
* context.
*/
static inline bool on_accessible_stack(struct task_struct *tsk,
unsigned long sp,
struct stack_info *info)
{
if (on_task_stack(tsk, sp, info))
return true;
if (tsk != current || preemptible())
return false;
if (on_irq_stack(sp, info))
return true;
if (on_overflow_stack(sp, info))
return true;
if (on_sdei_stack(sp, info))
return true;
return false;
}
#endif /* __ASM_STACKTRACE_H */
