+// Copyright (C) 2013 Jann Horn <jann@thejh.net>
+// This file is licensed under the GNU GPL v2 (see
+// the LICENSE file).
+
#undef __KERNEL__
#define __KERNEL__
#undef MODULE
#include <linux/ioctl.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
+#include <linux/kallsyms.h>
+#include <linux/blkdev.h>
struct fetch_fops_args {
int fd;
return 0;
}
-static const struct file_operations dummy_fops = {};
-
static long ioctl_ioctl(struct file *filp_, unsigned int cmd, unsigned long arg) {
struct fetch_fops_args args;
struct file *filp;
- const struct file_operations *fops;
+ void *ioctl_method = NULL;
+ char ioctl_method_name[KSYM_NAME_LEN];
+ int (*lookup_symbol_name_)(unsigned long addr, char *symname);
+
+ lookup_symbol_name_ = (void*)kallsyms_lookup_name("lookup_symbol_name");
if (cmd != MOCTEL_FETCH_FOPS) return -EINVAL;
+ memset(ioctl_method_name, 0, sizeof(ioctl_method_name));
if (copy_from_user(&args, (struct fetch_fops_args __user *)arg, sizeof(args))) return -EINVAL;
filp = fget(args.fd);
if (!filp) return -EBADF;
- fops = filp->f_op;
- if (!fops) fops = &dummy_fops;
+ if (filp->f_op) ioctl_method = filp->f_op->unlocked_ioctl;
+ lookup_symbol_name_((unsigned long)ioctl_method, ioctl_method_name);
+ if (strcmp(ioctl_method_name, "block_ioctl") == 0) {
+ struct block_device *bdev = I_BDEV(filp->f_mapping->host);
+ ioctl_method = bdev->bd_disk->fops->ioctl;
+ lookup_symbol_name_((unsigned long)ioctl_method, ioctl_method_name);
+ }
fput(filp);
- if (copy_to_user((struct file_operations __user *)args.retp, fops, sizeof(*fops))) return -EINVAL;
+ if (copy_to_user((struct file_operations __user *)args.retp, ioctl_method_name, KSYM_NAME_LEN)) return -EINVAL;
return 0;
}
module_init(init_ioctl);
module_exit(cleanup_ioctl);
+
+MODULE_LICENSE("GPL v2");