kernel_samsung_a34x-permissive/drivers/uh/uh_debug_log.c
2024-04-28 15:49:01 +02:00

63 lines
1.3 KiB
C
Executable file

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/highmem.h>
#include <linux/uh.h>
ssize_t uh_log_read(struct file *filep, char __user *buf, size_t size, loff_t *offset)
{
static size_t log_buf_size;
unsigned long *log_addr = 0;
if (!strcmp(filep->f_path.dentry->d_iname, "uh_log"))
log_addr = (unsigned long *)phys_to_virt(UH_LOG_START);
else
return -EINVAL;
if (!*offset) {
log_buf_size = 0;
while (log_buf_size < UH_LOG_SIZE && ((char *)log_addr)[log_buf_size] != 0)
log_buf_size++;
}
if (*offset >= log_buf_size)
return 0;
if (*offset + size > log_buf_size)
size = log_buf_size - *offset;
if (copy_to_user(buf, (const char *)log_addr + (*offset), size))
return -EFAULT;
*offset += size;
return size;
}
static const struct file_operations uh_proc_fops = {
.owner = THIS_MODULE,
.read = uh_log_read,
};
static int __init uh_log_init(void)
{
struct proc_dir_entry *entry;
entry = proc_create("uh_log", 0644, NULL, &uh_proc_fops);
if (!entry) {
pr_err("uh_log: Error creating proc entry\n");
return -ENOMEM;
}
pr_info("uh_log : create /proc/uh_log\n");
return 0;
}
static void __exit uh_log_exit(void)
{
remove_proc_entry("uh_log", NULL);
}
module_init(uh_log_init);
module_exit(uh_log_exit);