105 lines
2.6 KiB
C
Executable File
105 lines
2.6 KiB
C
Executable File
/*
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* Copyright (c) 2016 Samsung Electronics Co., Ltd.
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* http://www.samsung.com
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*
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* Samsung TN debugging code
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/uaccess.h>
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#include <linux/slab.h>
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#include <linux/proc_fs.h>
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#include <linux/sec_debug.h>
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static char *last_kmsg_buffer;
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static size_t last_kmsg_size;
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void sec_debug_save_last_kmsg(unsigned char *head_ptr, unsigned char *curr_ptr, size_t buf_size)
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{
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size_t size;
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unsigned char *magickey_addr;
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if (!head_ptr || !curr_ptr || head_ptr == curr_ptr) {
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pr_err("%s: no data\n", __func__);
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return;
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}
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if ((curr_ptr - head_ptr) <= 0) {
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pr_err("%s: invalid args\n", __func__);
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return;
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}
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size = (size_t)(curr_ptr - head_ptr);
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magickey_addr = head_ptr + buf_size - (size_t)0x08;
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/* provide previous log as last_kmsg */
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if (*((unsigned long long *)magickey_addr) == SEC_LKMSG_MAGICKEY) {
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pr_info("%s: sec_log buffer is full\n", __func__);
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last_kmsg_size = (size_t)SZ_2M;
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last_kmsg_buffer = kzalloc(last_kmsg_size, GFP_NOWAIT);
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if (last_kmsg_size && last_kmsg_buffer) {
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memcpy(last_kmsg_buffer, curr_ptr, last_kmsg_size - size);
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memcpy(last_kmsg_buffer + (last_kmsg_size - size), head_ptr, size);
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pr_info("%s: succeeded\n", __func__);
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} else {
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pr_err("%s: failed\n", __func__);
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}
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} else {
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pr_info("%s: sec_log buffer is not full\n", __func__);
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last_kmsg_size = size;
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last_kmsg_buffer = kzalloc(last_kmsg_size, GFP_NOWAIT);
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if (last_kmsg_size && last_kmsg_buffer) {
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memcpy(last_kmsg_buffer, head_ptr, last_kmsg_size);
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pr_info("%s: succeeded\n", __func__);
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} else {
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pr_err("%s: failed\n", __func__);
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}
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}
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}
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static ssize_t sec_last_kmsg_read(struct file *file, char __user *buf,
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size_t len, loff_t *offset)
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{
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loff_t pos = *offset;
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ssize_t count;
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if (pos >= last_kmsg_size)
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return 0;
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count = min(len, (size_t)(last_kmsg_size - pos));
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if (copy_to_user(buf, last_kmsg_buffer + pos, count))
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return -EFAULT;
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*offset += count;
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return count;
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}
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static const struct file_operations last_kmsg_file_ops = {
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.owner = THIS_MODULE,
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.read = sec_last_kmsg_read,
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};
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static int __init sec_last_kmsg_late_init(void)
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{
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struct proc_dir_entry *entry;
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if (!last_kmsg_buffer)
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return 0;
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entry = proc_create("last_kmsg", S_IFREG | 0444,
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NULL, &last_kmsg_file_ops);
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if (!entry) {
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pr_err("%s: failed to create proc entry\n", __func__);
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return 0;
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}
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proc_set_size(entry, last_kmsg_size);
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return 0;
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}
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late_initcall(sec_last_kmsg_late_init);
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