/* 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 <linux/types.h> #include <asm/memory.h>#include <asm/ptrace.h>#include <asm/sdei.h> enum stack_type {	STACK_TYPE_UNKNOWN,	STACK_TYPE_TASK,	STACK_TYPE_IRQ,	STACK_TYPE_OVERFLOW,	STACK_TYPE_SDEI_NORMAL,	STACK_TYPE_SDEI_CRITICAL,	__NR_STACK_TYPES}; struct stack_info {	unsigned long low;	unsigned long high;	enum stack_type type;}; /* * A snapshot of a frame record or fp/lr register values, along with some * accounting information necessary for robust unwinding. * * @fp:          The fp value in the frame record (or the real fp) * @pc:          The fp value in the frame record (or the real lr) * * @stacks_done: Stacks which have been entirely unwound, for which it is no *               longer valid to unwind to. * * @prev_fp:     The fp that pointed to this frame record, or a synthetic value *               of 0. This is used to ensure that within a stack, each *               subsequent frame record is at an increasing address. * @prev_type:   The type of stack this frame record was on, or a synthetic *               value of STACK_TYPE_UNKNOWN. This is used to detect a *               transition from one stack to another. * * @graph:       When FUNCTION_GRAPH_TRACER is selected, holds the index of a *               replacement lr value in the ftrace graph stack. */struct stackframe {	unsigned long fp;	unsigned long pc;	DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES);	unsigned long prev_fp;	enum stack_type prev_type;#ifdef CONFIG_FUNCTION_GRAPH_TRACER	int graph;#endif}; 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,			   const char *loglvl); DECLARE_PER_CPU(unsigned long *, irq_stack_ptr); static inline bool on_stack(unsigned long sp, unsigned long low,				unsigned long high, enum stack_type type,				struct stack_info *info){	if (!low)		return false; 	if (sp < low || sp >= high)		return false; 	if (info) {		info->low = low;		info->high = high;		info->type = type;	}	return true;} 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; 	return on_stack(sp, low, high, STACK_TYPE_IRQ, info);} static inline bool on_task_stack(const 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; 	return on_stack(sp, low, high, STACK_TYPE_TASK, info);} #ifdef CONFIG_VMAP_STACKDECLARE_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; 	return on_stack(sp, low, high, STACK_TYPE_OVERFLOW, info);}#elsestatic 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(const struct task_struct *tsk,				       unsigned long sp,				       struct stack_info *info){	if (info)		info->type = STACK_TYPE_UNKNOWN; 	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;} static inline void start_backtrace(struct stackframe *frame,				   unsigned long fp, unsigned long pc){	frame->fp = fp;	frame->pc = pc;#ifdef CONFIG_FUNCTION_GRAPH_TRACER	frame->graph = 0;#endif 	/*	 * Prime the first unwind.	 *	 * In unwind_frame() we'll check that the FP points to a valid stack,	 * which can't be STACK_TYPE_UNKNOWN, and the first unwind will be	 * treated as a transition to whichever stack that happens to be. The	 * prev_fp value won't be used, but we set it to 0 such that it is	 * definitely not an accessible stack address.	 */	bitmap_zero(frame->stacks_done, __NR_STACK_TYPES);	frame->prev_fp = 0;	frame->prev_type = STACK_TYPE_UNKNOWN;} #endif	/* __ASM_STACKTRACE_H */