134 lines
3.6 KiB
C
134 lines
3.6 KiB
C
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/*
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* Copyright (c) 2017, GlobalLogic Ukraine LLC
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the GlobalLogic.
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* 4. Neither the name of the GlobalLogic nor the
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* names of its contributors may be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY GLOBALLOGIC UKRAINE LLC ``AS IS`` AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL GLOBALLOGIC UKRAINE LLC BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/printk.h>
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#include <linux/slab.h>
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#define DEBUG
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MODULE_AUTHOR("Serhii Popovych <serhii.popovych@globallogic.com>");
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MODULE_DESCRIPTION("Hello, world in Linux Kernel Training");
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MODULE_LICENSE("Dual BSD/GPL");
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struct TimingList {
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struct TimingList *next;
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ktime_t time_before, time_after;
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};
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static struct TimingList *list_head;
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static unsigned int bug_generator;
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static struct TimingList *write_first_node(void)
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{
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list_head = kmalloc(sizeof(struct TimingList), GFP_KERNEL);
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list_head->next = NULL;
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return list_head;
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}
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static struct TimingList *insert_next_node(struct TimingList *tail)
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{
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struct TimingList *new_node = kmalloc(sizeof(struct TimingList),
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GFP_KERNEL);
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if (bug_generator == 5) {
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new_node = NULL;
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} else {
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tail->next = new_node;
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new_node->next = NULL;
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}
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return new_node;
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}
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static struct TimingList *add_new_node(struct TimingList *tail)
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{
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if (tail == NULL)
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return write_first_node();
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else
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return insert_next_node(tail);
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}
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static void print_time_diff(struct TimingList *node)
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{
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pr_debug("%lld\n", node->time_after - node->time_before);
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}
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void destroy_list(void)
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{
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struct TimingList *current_node = list_head;
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struct TimingList *next_node = NULL;
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list_head = NULL;
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while (current_node != NULL) {
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print_time_diff(current_node);
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next_node = current_node->next;
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kfree(current_node);
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current_node = next_node;
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}
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}
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EXPORT_SYMBOL(destroy_list);
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static int __init hello_init(void)
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{
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return 0;
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}
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void print_hello(int message_count)
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{
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int i;
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struct TimingList *current_tail = list_head;
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for (i = 0; i < message_count; i++) {
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bug_generator = i;
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current_tail = add_new_node(current_tail);
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current_tail->time_before = ktime_get();
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pr_info("Hello, world!\n");
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current_tail->time_after = ktime_get();
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}
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}
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EXPORT_SYMBOL(print_hello);
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static void __exit hello_exit(void)
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{
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destroy_list();
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}
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module_init(hello_init);
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module_exit(hello_exit);
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