1 /* Check DTAUDIT and vDSO interaction.
2 Copyright (C) 2021-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <errno.h>
20 #include <getopt.h>
21 #include <limits.h>
22 #include <inttypes.h>
23 #include <string.h>
24 #include <stdlib.h>
25 #include <support/capture_subprocess.h>
26 #include <support/check.h>
27 #include <support/xstdio.h>
28 #include <support/support.h>
29 #include <sys/auxv.h>
30
31 static int restart;
32 #define CMDLINE_OPTIONS \
33 { "restart", no_argument, &restart, 1 },
34
35 static uintptr_t vdso_addr;
36
37 static int
handle_restart(void)38 handle_restart (void)
39 {
40 fprintf (stderr, "vdso: %p\n", (void*) vdso_addr);
41 return 0;
42 }
43
44 static uintptr_t
parse_address(const char * str)45 parse_address (const char *str)
46 {
47 void *r;
48 TEST_COMPARE (sscanf (str, "%p\n", &r), 1);
49 return (uintptr_t) r;
50 }
51
52 static inline bool
startswith(const char * str,const char * pre)53 startswith (const char *str, const char *pre)
54 {
55 size_t lenpre = strlen (pre);
56 size_t lenstr = strlen (str);
57 return lenstr >= lenpre && memcmp (pre, str, lenpre) == 0;
58 }
59
60 static int
do_test(int argc,char * argv[])61 do_test (int argc, char *argv[])
62 {
63 vdso_addr = getauxval (AT_SYSINFO_EHDR);
64 if (vdso_addr == 0)
65 FAIL_UNSUPPORTED ("getauxval (AT_SYSINFO_EHDR) returned 0");
66
67 /* We must have either:
68 - One our fource parameters left if called initially:
69 + path to ld.so optional
70 + "--library-path" optional
71 + the library path optional
72 + the application name */
73 if (restart)
74 return handle_restart ();
75
76 char *spargv[9];
77 int i = 0;
78 for (; i < argc - 1; i++)
79 spargv[i] = argv[i + 1];
80 spargv[i++] = (char *) "--direct";
81 spargv[i++] = (char *) "--restart";
82 spargv[i] = NULL;
83
84 setenv ("LD_AUDIT", "tst-auditmod22.so", 0);
85 struct support_capture_subprocess result
86 = support_capture_subprogram (spargv[0], spargv);
87 support_capture_subprocess_check (&result, "tst-audit22", 0, sc_allow_stderr);
88
89 /* The respawned process should always print the vDSO address (otherwise it
90 will fails as unsupported). However, on some architectures the audit
91 module might see the vDSO with l_addr being 0, meaning a fixed mapping
92 (linux-gate.so). In this case we don't check its value against
93 AT_SYSINFO_EHDR one. */
94 uintptr_t vdso_process = 0;
95 bool vdso_audit_found = false;
96 uintptr_t vdso_audit = 0;
97
98 FILE *out = fmemopen (result.err.buffer, result.err.length, "r");
99 TEST_VERIFY (out != NULL);
100 char *buffer = NULL;
101 size_t buffer_length = 0;
102 while (xgetline (&buffer, &buffer_length, out))
103 {
104 if (startswith (buffer, "vdso: "))
105 vdso_process = parse_address (buffer + strlen ("vdso: "));
106 else if (startswith (buffer, "vdso found: "))
107 {
108 vdso_audit = parse_address (buffer + strlen ("vdso found: "));
109 vdso_audit_found = true;
110 }
111 }
112
113 TEST_COMPARE (vdso_audit_found, true);
114 if (vdso_audit != 0)
115 TEST_COMPARE (vdso_process, vdso_audit);
116
117 free (buffer);
118 xfclose (out);
119
120 return 0;
121 }
122
123 #define TEST_FUNCTION_ARGV do_test
124 #include <support/test-driver.c>
125