1  /*
       2   * Check decoding of getgroups/getgroups32 syscalls.
       3   *
       4   * Copyright (c) 2016 Dmitry V. Levin <ldv@strace.io>
       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  #ifdef __NR_getgroups32
      12  
      13  # define SYSCALL_NR	__NR_getgroups32
      14  # define SYSCALL_NAME	"getgroups32"
      15  # define GID_TYPE	unsigned int
      16  
      17  #else /* __NR_getgroups */
      18  
      19  # include "tests.h"
      20  # include "scno.h"
      21  
      22  # define SYSCALL_NR	__NR_getgroups
      23  # define SYSCALL_NAME	"getgroups"
      24  # if defined __NR_getgroups32 && __NR_getgroups != __NR_getgroups32
      25  #  define GID_TYPE	unsigned short
      26  # else
      27  #  define GID_TYPE	unsigned int
      28  # endif
      29  
      30  #endif
      31  
      32  #include <stdio.h>
      33  #include <unistd.h>
      34  
      35  #define MAX_STRLEN 32
      36  static long ngroups;
      37  
      38  static void
      39  get_groups(const long size, GID_TYPE *const g)
      40  {
      41  	long i = syscall(SYSCALL_NR, size, g);
      42  	if (i != ngroups)
      43  		perror_msg_and_fail("%s(%#lx, %p)", SYSCALL_NAME, size, g);
      44  
      45  	printf("%s(%d, [", SYSCALL_NAME, (int) size);
      46  	for (i = 0; i < ngroups; ++i) {
      47  		if (i)
      48  			printf(", ");
      49  		if (i >= MAX_STRLEN) {
      50  			printf("...");
      51  			break;
      52  		}
      53  		printf("%u", (unsigned int) g[i]);
      54  	}
      55  	printf("]) = %ld\n", ngroups);
      56  }
      57  
      58  int
      59  main(void)
      60  {
      61  	long rc;
      62  
      63  	/* check how the first argument is decoded */
      64  	ngroups = syscall(SYSCALL_NR, 0, 0);
      65  	printf("%s(0, NULL) = %ld\n", SYSCALL_NAME, ngroups);
      66  	if (ngroups < 0)
      67  		perror_msg_and_fail(SYSCALL_NAME);
      68  
      69  	rc = syscall(SYSCALL_NR, F8ILL_KULONG_MASK, 0);
      70  	printf("%s(0, NULL) = %ld\n", SYSCALL_NAME, rc);
      71  
      72  	rc = syscall(SYSCALL_NR, -1U, 0);
      73  	printf("%s(%d, NULL) = %s\n", SYSCALL_NAME, -1, sprintrc(rc));
      74  
      75  	rc = syscall(SYSCALL_NR, -1L, 0);
      76  	printf("%s(%d, NULL) = %s\n", SYSCALL_NAME, -1, sprintrc(rc));
      77  
      78  	const unsigned int ngroups_max = sysconf(_SC_NGROUPS_MAX);
      79  
      80  	rc = syscall(SYSCALL_NR, ngroups_max, 0);
      81  	printf("%s(%d, NULL) = %s\n", SYSCALL_NAME, ngroups_max, sprintrc(rc));
      82  
      83  	rc = syscall(SYSCALL_NR, F8ILL_KULONG_MASK | ngroups_max, 0);
      84  	printf("%s(%d, NULL) = %s\n", SYSCALL_NAME, ngroups_max, sprintrc(rc));
      85  
      86  	/* check how the second argument is decoded */
      87  	GID_TYPE *const g1 =
      88  		tail_alloc(ngroups ? sizeof(*g1) * ngroups : 1);
      89  	GID_TYPE *const g2 = tail_alloc(sizeof(*g2) * (ngroups + 1));
      90  	void *efault = g2 + ngroups + 1;
      91  
      92  	get_groups(ngroups, g1);
      93  	get_groups(ngroups + 1, g1);
      94  	get_groups(ngroups + 1, g2);
      95  
      96  	if (ngroups) {
      97  		rc = syscall(SYSCALL_NR, ngroups, efault);
      98  		printf("%s(%d, %p) = %s\n",
      99  		       SYSCALL_NAME, (unsigned) ngroups, efault, sprintrc(rc));
     100  	}
     101  
     102  	puts("+++ exited with 0 +++");
     103  	return 0;
     104  }