140 lines
3.4 KiB
C
140 lines
3.4 KiB
C
/*
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* linux/fs/proc/proc_avc.c
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*
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*/
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/time.h>
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#include <linux/kernel.h>
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#include <linux/poll.h>
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#include <linux/proc_fs.h>
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#include <linux/fs.h>
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#include <linux/syslog.h>
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#include <linux/bootmem.h>
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#include <linux/export.h>
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#include <linux/uaccess.h>
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#include <linux/io.h>
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#include <linux/slab.h>
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#ifdef CONFIG_PROC_AVC
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#include <linux/proc_avc.h>
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#endif
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#define LOG_MAGIC 0x4d474f4c /* "LOGM" */
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static unsigned int *sec_avc_log_ptr;
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static char *sec_avc_log_buf;
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static unsigned int sec_avc_log_size;
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int __init sec_avc_log_init(void)
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{
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unsigned int size = SZ_256K;
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unsigned int *sec_avc_log_mag;
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sec_avc_log_size = size;
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sec_avc_log_mag = kzalloc(sec_avc_log_size, GFP_NOWAIT);
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pr_info("allocating %u bytes at %p (%llx physical) for avc log\n",
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sec_avc_log_size, sec_avc_log_mag, __pa(sec_avc_log_buf));
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sec_avc_log_ptr = sec_avc_log_mag + 4;
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sec_avc_log_buf = (char *)(sec_avc_log_mag + 8);
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if (*sec_avc_log_mag != LOG_MAGIC) {
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pr_info("%s: no old log found\n", __func__);
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*sec_avc_log_ptr = 0;
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*sec_avc_log_mag = LOG_MAGIC;
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}
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return 1;
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}
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#define BUF_SIZE 512
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void sec_avc_log(char *fmt, ...)
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{
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va_list args;
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char buf[BUF_SIZE];
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int len = 0;
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unsigned int idx;
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unsigned int size;
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/* In case of sec_avc_log_setup is failed */
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if (!sec_avc_log_size)
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return;
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va_start(args, fmt);
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vsnprintf(buf, sizeof(buf), fmt, args);
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va_end(args);
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idx = *sec_avc_log_ptr;
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size = strlen(buf);
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if (idx + (size * 2) > sec_avc_log_size - 1) {
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len = scnprintf(&sec_avc_log_buf[0], size + 1, "%s\n", buf);
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*sec_avc_log_ptr = len;
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} else {
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len = scnprintf(&sec_avc_log_buf[idx], size + 1, "%s\n", buf);
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*sec_avc_log_ptr += len;
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}
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}
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static ssize_t sec_avc_log_write(struct file *file,
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const char __user *buf,
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size_t count, loff_t *ppos)
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{
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char *page = NULL;
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ssize_t ret;
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int new_value;
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if (!sec_avc_log_buf)
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return 0;
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ret = -ENOMEM;
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if (count >= PAGE_SIZE)
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return ret;
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ret = -ENOMEM;
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page = (char *)get_zeroed_page(GFP_KERNEL);
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if (!page)
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return ret;
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ret = -EFAULT;
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if (copy_from_user(page, buf, count))
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goto out;
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ret = -EINVAL;
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if (sscanf(page, "%u", &new_value) != 1) {
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pr_info("%s\n", page);
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/* print avc_log to sec_avc_log_buf */
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sec_avc_log("%s", page);
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}
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ret = count;
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out:
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free_page((unsigned long)page);
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return ret;
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}
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static ssize_t sec_avc_log_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 >= (*sec_avc_log_ptr & (sec_avc_log_size - 1)))
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return 0;
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count = min(len,
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(size_t)((*sec_avc_log_ptr & (sec_avc_log_size - 1)) - pos));
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if (copy_to_user(buf, sec_avc_log_buf + 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 avc_msg_file_ops = {
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.owner = THIS_MODULE,
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.read = sec_avc_log_read,
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.write = sec_avc_log_write,
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.llseek = generic_file_llseek,
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};
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static int __init sec_avc_log_late_init(void)
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{
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struct proc_dir_entry *entry;
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if (sec_avc_log_buf == NULL) {
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pr_err("%s: sec_avc_log_buf not initialized.\n", __func__);
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return 0;
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}
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entry = proc_create_data("avc_msg", S_IFREG | 0x444, NULL, &avc_msg_file_ops, NULL);
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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, sec_avc_log_size);
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return 0;
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}
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late_initcall(sec_avc_log_late_init);
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int __init sec_log_init(void)
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{
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#ifdef CONFIG_PROC_AVC
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sec_avc_log_init();
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#endif
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return 0;
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}
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fs_initcall(sec_log_init);
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