kcookie.c

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/* -*- C -*- */
/*
 * Copyright (c) 2012-2020 Seagate Technology LLC and/or its Affiliates
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * For any questions about this software or licensing,
 * please email opensource@seagate.com or cortx-questions@seagate.com.
 *
 */


#include <linux/uaccess.h>

#define try_read(addr, dummy)                   \
({                                              \
        long rc;                                \
        mm_segment_t save_fs = get_fs();        \
                                                \
        set_fs(KERNEL_DS);                      \
        pagefault_disable();                    \
        rc = __copy_from_user_inatomic(&(dummy), \
                (__force typeof(dummy) __user *)(addr), \
                sizeof(dummy));                 \
        pagefault_enable();                     \
        set_fs(save_fs);                        \
        rc;                                     \
})

M0_INTERNAL bool m0_arch_addr_is_sane(const uint64_t * addr)
{
        uint64_t dummy;

        return try_read(addr, dummy) == 0;
}

M0_INTERNAL int m0_arch_cookie_global_init(void)
{
        return 0;
}

M0_INTERNAL void m0_arch_cookie_global_fini(void)
{
}

/*
 *  Local variables:
 *  c-indentation-style: "K&R"
 *  c-basic-offset: 8
 *  tab-width: 8
 *  fill-column: 80
 *  scroll-step: 1
 *  End:
 */