Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
/*
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
 */
#include <linux/sched/debug.h>
#include <linux/kallsyms.h>
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
#include <linux/kdebug.h>
#include <linux/export.h>
#include <linux/ptrace.h>
#include <linux/kexec.h>
#include <linux/sysfs.h>
#include <linux/bug.h>
#include <linux/nmi.h>
 
#include <asm/cpu_entry_area.h>
#include <asm/stacktrace.h>
 
static const char * const exception_stack_names[] = {
<------><------>[ ESTACK_DF	]	= "#DF",
<------><------>[ ESTACK_NMI	]	= "NMI",
<------><------>[ ESTACK_DB	]	= "#DB",
<------><------>[ ESTACK_MCE	]	= "#MC",
<------><------>[ ESTACK_VC	]	= "#VC",
<------><------>[ ESTACK_VC2	]	= "#VC2",
};
 
const char *stack_type_name(enum stack_type type)
{
<------>BUILD_BUG_ON(N_EXCEPTION_STACKS != 6);
 
<------>if (type == STACK_TYPE_IRQ)
<------><------>return "IRQ";
 
<------>if (type == STACK_TYPE_ENTRY) {
<------><------>/*
<------><------> * On 64-bit, we have a generic entry stack that we
<------><------> * use for all the kernel entry points, including
<------><------> * SYSENTER.
<------><------> */
<------><------>return "ENTRY_TRAMPOLINE";
<------>}
 
<------>if (type >= STACK_TYPE_EXCEPTION && type <= STACK_TYPE_EXCEPTION_LAST)
<------><------>return exception_stack_names[type - STACK_TYPE_EXCEPTION];
 
<------>return NULL;
}
 
/**
 * struct estack_pages - Page descriptor for exception stacks
 * @offs:	Offset from the start of the exception stack area
 * @size:	Size of the exception stack
 * @type:	Type to store in the stack_info struct
 */
struct estack_pages {
<------>u32	offs;
<------>u16	size;
<------>u16	type;
};
 
#define EPAGERANGE(st)							\
<------>[PFN_DOWN(CEA_ESTACK_OFFS(st)) ...				\
<------> PFN_DOWN(CEA_ESTACK_OFFS(st) + CEA_ESTACK_SIZE(st) - 1)] = {	\
<------><------>.offs	= CEA_ESTACK_OFFS(st),				\
<------><------>.size	= CEA_ESTACK_SIZE(st),				\
<------><------>.type	= STACK_TYPE_EXCEPTION + ESTACK_ ##st, }
 
/*
 * Array of exception stack page descriptors. If the stack is larger than
 * PAGE_SIZE, all pages covering a particular stack will have the same
 * info. The guard pages including the not mapped DB2 stack are zeroed
 * out.
 */
static const
struct estack_pages estack_pages[CEA_ESTACK_PAGES] ____cacheline_aligned = {
<------>EPAGERANGE(DF),
<------>EPAGERANGE(NMI),
<------>EPAGERANGE(DB),
<------>EPAGERANGE(MCE),
<------>EPAGERANGE(VC),
<------>EPAGERANGE(VC2),
};
 
static __always_inline bool in_exception_stack(unsigned long *stack, struct stack_info *info)
{
<------>unsigned long begin, end, stk = (unsigned long)stack;
<------>const struct estack_pages *ep;
<------>struct pt_regs *regs;
<------>unsigned int k;
 
<------>BUILD_BUG_ON(N_EXCEPTION_STACKS != 6);
 
<------>begin = (unsigned long)__this_cpu_read(cea_exception_stacks);
<------>/*
<------> * Handle the case where stack trace is collected _before_
<------> * cea_exception_stacks had been initialized.
<------> */
<------>if (!begin)
<------><------>return false;
 
<------>end = begin + sizeof(struct cea_exception_stacks);
<------>/* Bail if @stack is outside the exception stack area. */
<------>if (stk < begin || stk >= end)
<------><------>return false;
 
<------>/* Calc page offset from start of exception stacks */
<------>k = (stk - begin) >> PAGE_SHIFT;
<------>/* Lookup the page descriptor */
<------>ep = &estack_pages[k];
<------>/* Guard page? */
<------>if (!ep->size)
<------><------>return false;
 
<------>begin += (unsigned long)ep->offs;
<------>end = begin + (unsigned long)ep->size;
<------>regs = (struct pt_regs *)end - 1;
 
<------>info->type	= ep->type;
<------>info->begin	= (unsigned long *)begin;
<------>info->end	= (unsigned long *)end;
<------>info->next_sp	= (unsigned long *)regs->sp;
<------>return true;
}
 
static __always_inline bool in_irq_stack(unsigned long *stack, struct stack_info *info)
{
<------>unsigned long *end   = (unsigned long *)this_cpu_read(hardirq_stack_ptr);
<------>unsigned long *begin = end - (IRQ_STACK_SIZE / sizeof(long));
 
<------>/*
<------> * This is a software stack, so 'end' can be a valid stack pointer.
<------> * It just means the stack is empty.
<------> */
<------>if (stack < begin || stack >= end)
<------><------>return false;
 
<------>info->type	= STACK_TYPE_IRQ;
<------>info->begin	= begin;
<------>info->end	= end;
 
<------>/*
<------> * The next stack pointer is the first thing pushed by the entry code
<------> * after switching to the irq stack.
<------> */
<------>info->next_sp = (unsigned long *)*(end - 1);
 
<------>return true;
}
 
bool noinstr get_stack_info_noinstr(unsigned long *stack, struct task_struct *task,
<------><------><------><------>    struct stack_info *info)
{
<------>if (in_task_stack(stack, task, info))
<------><------>return true;
 
<------>if (task != current)
<------><------>return false;
 
<------>if (in_exception_stack(stack, info))
<------><------>return true;
 
<------>if (in_irq_stack(stack, info))
<------><------>return true;
 
<------>if (in_entry_stack(stack, info))
<------><------>return true;
 
<------>return false;
}
 
int get_stack_info(unsigned long *stack, struct task_struct *task,
<------><------>   struct stack_info *info, unsigned long *visit_mask)
{
<------>task = task ? : current;
 
<------>if (!stack)
<------><------>goto unknown;
 
<------>if (!get_stack_info_noinstr(stack, task, info))
<------><------>goto unknown;
 
<------>/*
<------> * Make sure we don't iterate through any given stack more than once.
<------> * If it comes up a second time then there's something wrong going on:
<------> * just break out and report an unknown stack type.
<------> */
<------>if (visit_mask) {
<------><------>if (*visit_mask & (1UL << info->type)) {
<------><------><------>if (task == current)
<------><------><------><------>printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
<------><------><------>goto unknown;
<------><------>}
<------><------>*visit_mask |= 1UL << info->type;
<------>}
 
<------>return 0;
 
unknown:
<------>info->type = STACK_TYPE_UNKNOWN;
<------>return -EINVAL;
}