Cregit: Linux 6.18: list

Contributors: 4
Author	Tokens	Token Proportion	Commits	Commit Proportion
Keir Fraser	134	83.75%	1	20.00%
Quentin Perret	21	13.12%	1	20.00%
Marco Elver	4	2.50%	2	40.00%
Arnd Bergmann	1	0.62%	1	20.00%
Total	160		5

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2022 - Google LLC
 * Author: Keir Fraser <keirf@google.com>
 */

#include <linux/list.h>
#include <linux/bug.h>

static inline __must_check bool nvhe_check_data_corruption(bool v)
{
	return v;
}

#define NVHE_CHECK_DATA_CORRUPTION(condition)				 \
	nvhe_check_data_corruption(({					 \
		bool corruption = unlikely(condition);			 \
		if (corruption) {					 \
			if (IS_ENABLED(CONFIG_BUG_ON_DATA_CORRUPTION)) { \
				BUG();				 	 \
			} else						 \
				WARN_ON(1);				 \
		}							 \
		corruption;						 \
	}))

/* The predicates checked here are taken from lib/list_debug.c. */

__list_valid_slowpath
bool __list_add_valid_or_report(struct list_head *new, struct list_head *prev,
				struct list_head *next)
{
	if (NVHE_CHECK_DATA_CORRUPTION(next->prev != prev) ||
	    NVHE_CHECK_DATA_CORRUPTION(prev->next != next) ||
	    NVHE_CHECK_DATA_CORRUPTION(new == prev || new == next))
		return false;

	return true;
}

__list_valid_slowpath
bool __list_del_entry_valid_or_report(struct list_head *entry)
{
	struct list_head *prev, *next;

	prev = entry->prev;
	next = entry->next;

	if (NVHE_CHECK_DATA_CORRUPTION(next == LIST_POISON1) ||
	    NVHE_CHECK_DATA_CORRUPTION(prev == LIST_POISON2) ||
	    NVHE_CHECK_DATA_CORRUPTION(prev->next != entry) ||
	    NVHE_CHECK_DATA_CORRUPTION(next->prev != entry))
		return false;

	return true;
}