+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <linux/ioctl.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+struct fetch_fops_args {
+ int fd;
+ uint64_t retp;
+};
+
+#define MOCTEL_FETCH_FOPS _IOR('m', 1, struct fetch_fops_args)
+
+struct file_operations {
+ void *owner;
+ void *llseek;
+ void *read;
+ void *write;
+ void *aio_read;
+ void *aio_write;
+ void *readdir;
+ void *poll;
+ void *unlocked_ioctl;
+ void *compat_ioctl;
+ void *mmap;
+ void *open;
+ void *flush;
+ void *release;
+ void *fsync;
+ void *aio_fsync;
+ void *fasync;
+ void *lock;
+ void *sendpage;
+ void *get_unmapped_area;
+ void *check_flags;
+ void *flock;
+ void *splice_write;
+ void *splice_read;
+ void *setlease;
+ void *fallocate;
+};
+
+
+
+int main(int argc, char **argv) {
+ if (argc != 2) fputs("Usage: show_ioctl <device>\n", stderr), exit(1);
+
+ char *devname = argv[1];
+ int devfd = open(devname, O_RDONLY);
+ if (devfd == -1) fprintf(stderr, "Can't open %s: %m\n", devname), exit(1);
+
+ int ioctlfd = open("/dev/ioctl_info", O_RDONLY);
+ if (ioctlfd == -1) fprintf(stderr, "Can't open /dev/ioctl_info: %m\n"), exit(1);
+
+ struct file_operations fops;
+ struct fetch_fops_args ioctl_args = {
+ .fd = devfd,
+ .retp = (uint64_t)&fops
+ };
+ int ret = ioctl(ioctlfd, MOCTEL_FETCH_FOPS, &ioctl_args);
+ if (ret) fprintf(stderr, "can't perform MOCTEL_FETCH_FOPS: %m\n"), exit(1);
+
+ close(ioctlfd);
+ close(devfd);
+
+ printf("unlocked_ioctl: %llx\n", (unsigned long long)fops.unlocked_ioctl);
+
+ return 0;
+}