LXR linux/tools/testing/selftests/arm64/tags/tags

   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