1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) Wipro Technologies Ltd, 2002.  All Rights Reserved.
4 * Copyright (c) 2018 Xiao Yang <yangx.jy@cn.fujitsu.com>
5 */
6
7/*
8 * AUTHOR: Madhu T L <madhu.tarikere@wipro.com>
9 *
10 * DESCRIPTION
11 * Verify that,
12 * 1. delete_module(2) returns -1 and sets errno to ENOENT for nonexistent
13 *    module entry.
14 * 2. delete_module(2) returns -1 and sets errno to EFAULT, if
15 *    module name parameter is outside program's accessible address space.
16 * 3. delete_module(2) returns -1 and sets errno to EPERM, if effective
17 *    user id of the caller is not superuser.
18 */
19
20#include <errno.h>
21#include <pwd.h>
22#include <stdio.h>
23#include <string.h>
24
25#include "tst_test.h"
26#include "lapi/syscalls.h"
27
28#define BASEMODNAME	"dummy"
29#define LONGMODNAMECHAR	'm'
30
31/*
32 * From kernel internal headers: include/linux/module.h
33 * include/linux/moduleparam.h
34 */
35#define MODULE_NAME_LEN	(64 - sizeof(unsigned long))
36
37static struct passwd *ltpuser;
38static char longmodname[MODULE_NAME_LEN];
39static char modname[20];
40
41static struct test_case_t {
42	char *modname;
43	int experrno;
44	char *desc;
45	/* 1: nobody_user 0: root_user */
46	int nobody_user;
47} tdat[] = {
48	{ modname, ENOENT, "nonexistent module", 0},
49	{ "", ENOENT, "null terminated module name", 0},
50	{ NULL, EFAULT, "module name outside program's accessible address space", 0},
51	{ longmodname, ENOENT, "long module name", 0},
52	{ modname, EPERM, "non-superuser", 1},
53};
54
55static void do_delete_module(unsigned int n)
56{
57	struct test_case_t *tc = &tdat[n];
58
59	if (!tc->modname)
60		tc->modname = tst_get_bad_addr(NULL);
61
62	if (tc->nobody_user)
63		SAFE_SETEUID(ltpuser->pw_uid);
64
65	tst_res(TINFO, "test %s", tc->desc);
66	TEST(tst_syscall(__NR_delete_module, tc->modname, 0));
67	if (TST_RET != -1) {
68		tst_res(TFAIL, "delete_module() succeeded unexpectedly");
69	} else if (TST_ERR == tc->experrno) {
70		tst_res(TPASS | TTERRNO, "delete_module() failed as expected");
71	} else {
72		tst_res(TFAIL | TTERRNO, "delete_module() failed unexpectedly;"
73			" expected: %s", tst_strerrno(tc->experrno));
74	}
75
76	if (tc->nobody_user)
77		SAFE_SETEUID(0);
78}
79
80static void setup(void)
81{
82	ltpuser = SAFE_GETPWNAM("nobody");
83
84	/* Initialize longmodname to LONGMODNAMECHAR character */
85	memset(longmodname, LONGMODNAMECHAR, MODULE_NAME_LEN - 1);
86
87	/* Get unique module name for each child process */
88	sprintf(modname, "%s_%d", BASEMODNAME, getpid());
89}
90
91static struct tst_test test = {
92	.tcnt = ARRAY_SIZE(tdat),
93	.needs_root = 1,
94	.setup = setup,
95	.test = do_delete_module,
96};
97