1// SPDX-License-Identifier: GPL-2.0
2
3#include <stdio.h>
4#include <stdlib.h>
5#include <unistd.h>
6#include <stdint.h>
7#include <sys/prctl.h>
8#include <sys/utsname.h>
9
10#define SHIFT_TAG(tag)		((uint64_t)(tag) << 56)
11#define SET_TAG(ptr, tag)	(((uint64_t)(ptr) & ~SHIFT_TAG(0xff)) | \
12					SHIFT_TAG(tag))
13
14int main(void)
15{
16	static int tbi_enabled = 0;
17	unsigned long tag = 0;
18	struct utsname *ptr;
19	int err;
20
21	if (prctl(PR_SET_TAGGED_ADDR_CTRL, PR_TAGGED_ADDR_ENABLE, 0, 0, 0) == 0)
22		tbi_enabled = 1;
23	ptr = (struct utsname *)malloc(sizeof(*ptr));
24	if (tbi_enabled)
25		tag = 0x42;
26	ptr = (struct utsname *)SET_TAG(ptr, tag);
27	err = uname(ptr);
28	free(ptr);
29
30	return err;
31}
32