1 /*
2  * Check decoding of getgroups/getgroups32 syscalls.
3  *
4  * Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
5  * Copyright (c) 2016-2017 The strace developers.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #ifdef __NR_getgroups32
32 
33 # define SYSCALL_NR	__NR_getgroups32
34 # define SYSCALL_NAME	"getgroups32"
35 # define GID_TYPE	unsigned int
36 
37 #else
38 
39 # include "tests.h"
40 # include <asm/unistd.h>
41 
42 # ifdef __NR_getgroups
43 
44 #  define SYSCALL_NR	__NR_getgroups
45 #  define SYSCALL_NAME	"getgroups"
46 #  if defined __NR_getgroups32 && __NR_getgroups != __NR_getgroups32
47 #   define GID_TYPE	unsigned short
48 #  else
49 #   define GID_TYPE	unsigned int
50 #  endif
51 
52 # endif
53 
54 #endif
55 
56 #ifdef GID_TYPE
57 
58 # include <stdio.h>
59 # include <unistd.h>
60 
61 #define MAX_STRLEN 32
62 static long ngroups;
63 
64 static void
get_groups(const long size,GID_TYPE * const g)65 get_groups(const long size, GID_TYPE *const g)
66 {
67 	long i = syscall(SYSCALL_NR, size, g);
68 	if (i != ngroups)
69 		perror_msg_and_fail("%s(%#lx, %p)", SYSCALL_NAME, size, g);
70 
71 	printf("%s(%d, [", SYSCALL_NAME, (int) size);
72 	for (i = 0; i < ngroups; ++i) {
73 		if (i)
74 			printf(", ");
75 		if (i >= MAX_STRLEN) {
76 			printf("...");
77 			break;
78 		}
79 		printf("%u", (unsigned int) g[i]);
80 	}
81 	printf("]) = %ld\n", ngroups);
82 }
83 
84 int
main(void)85 main(void)
86 {
87 	long rc;
88 
89 	/* check how the first argument is decoded */
90 	ngroups = syscall(SYSCALL_NR, 0, 0);
91 	printf("%s(0, NULL) = %ld\n", SYSCALL_NAME, ngroups);
92 	if (ngroups < 0)
93 		perror_msg_and_fail(SYSCALL_NAME);
94 
95 	rc = syscall(SYSCALL_NR, F8ILL_KULONG_MASK, 0);
96 	printf("%s(0, NULL) = %ld\n", SYSCALL_NAME, rc);
97 
98 	rc = syscall(SYSCALL_NR, -1U, 0);
99 	printf("%s(%d, NULL) = %s\n", SYSCALL_NAME, -1, sprintrc(rc));
100 
101 	rc = syscall(SYSCALL_NR, -1L, 0);
102 	printf("%s(%d, NULL) = %s\n", SYSCALL_NAME, -1, sprintrc(rc));
103 
104 	const unsigned int ngroups_max = sysconf(_SC_NGROUPS_MAX);
105 
106 	rc = syscall(SYSCALL_NR, ngroups_max, 0);
107 	printf("%s(%d, NULL) = %s\n", SYSCALL_NAME, ngroups_max, sprintrc(rc));
108 
109 	rc = syscall(SYSCALL_NR, F8ILL_KULONG_MASK | ngroups_max, 0);
110 	printf("%s(%d, NULL) = %s\n", SYSCALL_NAME, ngroups_max, sprintrc(rc));
111 
112 	/* check how the second argument is decoded */
113 	GID_TYPE *const g1 =
114 		tail_alloc(ngroups ? sizeof(*g1) * ngroups : 1);
115 	GID_TYPE *const g2 = tail_alloc(sizeof(*g2) * (ngroups + 1));
116 	void *efault = g2 + ngroups + 1;
117 
118 	get_groups(ngroups, g1);
119 	get_groups(ngroups + 1, g1);
120 	get_groups(ngroups + 1, g2);
121 
122 	if (ngroups) {
123 		rc = syscall(SYSCALL_NR, ngroups, efault);
124 		printf("%s(%d, %p) = %s\n",
125 		       SYSCALL_NAME, (unsigned) ngroups, efault, sprintrc(rc));
126 	}
127 
128 	puts("+++ exited with 0 +++");
129 	return 0;
130 }
131 
132 #else
133 
134 SKIP_MAIN_UNDEFINED("__NR_getgroups")
135 
136 #endif
137