1  /*
       2   * Check decoding of lookup_dcookie syscall.
       3   *
       4   * Copyright (c) 2016 Eugene Syromyatnikov <evgsyr@gmail.com>
       5   * Copyright (c) 2016-2021 The strace developers.
       6   * All rights reserved.
       7   *
       8   * SPDX-License-Identifier: GPL-2.0-or-later
       9   */
      10  
      11  #include "tests.h"
      12  #include "scno.h"
      13  
      14  #include <inttypes.h>
      15  #include <limits.h>
      16  #include <stdio.h>
      17  #include <unistd.h>
      18  
      19  static void
      20  do_lookup_cookie(uint64_t cookie, char *buf, kernel_ulong_t len)
      21  {
      22  	long rc;
      23  	const char *errstr;
      24  
      25  #if (LONG_MAX > INT_MAX) \
      26    || (defined __x86_64__ && defined __ILP32__) \
      27    || defined LINUX_MIPSN32
      28  	rc = syscall(__NR_lookup_dcookie, cookie, buf, len);
      29  #else
      30  	rc = syscall(__NR_lookup_dcookie, LL_VAL_TO_PAIR(cookie), buf, len);
      31  #endif
      32  
      33  	errstr = sprintrc(rc);
      34  	printf("lookup_dcookie(%" PRIu64 ", ", cookie);
      35  
      36  	/* Here, we trust successful return code */
      37  	if ((rc >= 0) && (rc < (long) INT_MAX)) {
      38  		printf("%.*s, ", (int) rc, buf);
      39  	} else {
      40  		if (buf != NULL)
      41  			printf("%p, ", buf);
      42  		else
      43  			printf("NULL, ");
      44  	}
      45  
      46  	printf("%" PRIu64 ") = %s\n", (uint64_t) len, errstr);
      47  }
      48  
      49  int
      50  main(void)
      51  {
      52  	enum { BUF_SIZE = 4096 };
      53  
      54  	static const uint64_t bogus_cookie =
      55  		(uint64_t) 0xf157feeddeadfaceULL;
      56  	static const kernel_ulong_t bogus_len =
      57  		(kernel_ulong_t) 0xbadc0dedda7a1057ULL;
      58  
      59  	char *buf = tail_alloc(BUF_SIZE);
      60  
      61  	do_lookup_cookie(0, NULL, 0);
      62  	do_lookup_cookie(bogus_cookie, buf + BUF_SIZE, bogus_len);
      63  	do_lookup_cookie(bogus_cookie, buf, BUF_SIZE);
      64  
      65  	puts("+++ exited with 0 +++");
      66  
      67  	return 0;
      68  }