// 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;
}