1 | /* Basic tests for pldd program. |
2 | Copyright (C) 2019-2022 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 <stdio.h> |
20 | #include <string.h> |
21 | #include <stdlib.h> |
22 | #include <unistd.h> |
23 | #include <stdint.h> |
24 | #include <stdbool.h> |
25 | |
26 | #include <array_length.h> |
27 | #include <gnu/lib-names.h> |
28 | |
29 | #include <support/subprocess.h> |
30 | #include <support/capture_subprocess.h> |
31 | #include <support/check.h> |
32 | #include <support/support.h> |
33 | #include <support/xptrace.h> |
34 | #include <support/xunistd.h> |
35 | #include <sys/mman.h> |
36 | #include <errno.h> |
37 | #include <signal.h> |
38 | |
39 | static void |
40 | target_process (void *arg) |
41 | { |
42 | pause (); |
43 | } |
44 | |
45 | static void |
46 | pldd_process (void *arg) |
47 | { |
48 | pid_t *target_pid_ptr = (pid_t *) arg; |
49 | |
50 | /* Create a copy of current test to check with pldd. As the |
51 | target_process is a child of this pldd_process, pldd is also able |
52 | to attach to target_process if YAMA is configured to 1 = |
53 | "restricted ptrace". */ |
54 | struct support_subprocess target = support_subprocess (callback: target_process, NULL); |
55 | |
56 | /* Store the pid of target-process as do_test needs it in order to |
57 | e.g. terminate it at end of the test. */ |
58 | *target_pid_ptr = target.pid; |
59 | |
60 | /* Three digits per byte plus null terminator. */ |
61 | char pid[3 * sizeof (uint32_t) + 1]; |
62 | snprintf (s: pid, array_length (pid), format: "%d" , target.pid); |
63 | |
64 | char *prog = xasprintf (format: "%s/pldd" , support_bindir_prefix); |
65 | |
66 | /* Run pldd and use the pid of target_process as argument. */ |
67 | execve (path: prog, argv: (char *const []) { (char *) prog, pid, NULL }, |
68 | envp: (char *const []) { NULL }); |
69 | |
70 | FAIL_EXIT1 ("Returned from execve: errno=%d=%m\n" , errno); |
71 | } |
72 | |
73 | /* The test runs in a container because pldd does not support tracing |
74 | a binary started by the loader iself (as with testrun.sh). */ |
75 | |
76 | static bool |
77 | in_str_list (const char *libname, const char *const strlist[]) |
78 | { |
79 | for (const char *const *str = strlist; *str != NULL; str++) |
80 | if (strcmp (s1: libname, s2: *str) == 0) |
81 | return true; |
82 | return false; |
83 | } |
84 | |
85 | static int |
86 | do_test (void) |
87 | { |
88 | support_need_proc (why_msg: "needs /proc/sys/kernel/yama/ptrace_scope and /proc/$child" ); |
89 | |
90 | /* Check if our subprocess can be debugged with ptrace. */ |
91 | { |
92 | int ptrace_scope = support_ptrace_scope (); |
93 | if (ptrace_scope >= 2) |
94 | FAIL_UNSUPPORTED ("/proc/sys/kernel/yama/ptrace_scope >= 2" ); |
95 | } |
96 | |
97 | pid_t *target_pid_ptr = (pid_t *) xmmap (NULL, length: sizeof (pid_t), |
98 | PROT_READ | PROT_WRITE, |
99 | MAP_SHARED | MAP_ANONYMOUS, fd: -1); |
100 | |
101 | /* Run 'pldd' on test subprocess which will be created in pldd_process. |
102 | The pid of the subprocess will be written to target_pid_ptr. */ |
103 | struct support_capture_subprocess pldd; |
104 | pldd = support_capture_subprocess (callback: pldd_process, closure: target_pid_ptr); |
105 | support_capture_subprocess_check (&pldd, context: "pldd" , status_or_signal: 0, allowed: sc_allow_stdout); |
106 | |
107 | /* Check 'pldd' output. The test is expected to be linked against only |
108 | loader and libc. */ |
109 | { |
110 | pid_t pid; |
111 | #define BUFFERLEN 511 |
112 | char buffer[BUFFERLEN + 1]; |
113 | #define STRINPUT(size) XSTRINPUT(size) |
114 | #define XSTRINPUT(size) "%" # size "s" |
115 | |
116 | FILE *out = fmemopen (s: pldd.out.buffer, len: pldd.out.length, modes: "r" ); |
117 | TEST_VERIFY (out != NULL); |
118 | |
119 | /* First line is in the form of <pid>: <full path of executable> */ |
120 | TEST_COMPARE (fscanf (out, "%u: " STRINPUT (BUFFERLEN), &pid, buffer), 2); |
121 | |
122 | TEST_COMPARE (pid, *target_pid_ptr); |
123 | TEST_COMPARE (strcmp (basename (buffer), "tst-pldd" ), 0); |
124 | |
125 | /* It expects only one loader and libc loaded by the program. */ |
126 | bool interpreter_found = false, libc_found = false; |
127 | while (fgets (s: buffer, array_length (buffer), stream: out) != NULL) |
128 | { |
129 | /* Ignore vDSO. */ |
130 | if (buffer[0] != '/') |
131 | continue; |
132 | |
133 | /* Remove newline so baseline (buffer) can compare against the |
134 | LD_SO and LIBC_SO macros unmodified. */ |
135 | if (buffer[strlen(s: buffer)-1] == '\n') |
136 | buffer[strlen(s: buffer)-1] = '\0'; |
137 | |
138 | const char *libname = basename (filename: buffer); |
139 | |
140 | /* It checks for default names in case of build configure with |
141 | --enable-hardcoded-path-in-tests (BZ #24506). */ |
142 | if (in_str_list (libname, |
143 | strlist: (const char *const []) { "ld.so" , LD_SO, NULL })) |
144 | { |
145 | TEST_COMPARE (interpreter_found, false); |
146 | interpreter_found = true; |
147 | continue; |
148 | } |
149 | |
150 | if (in_str_list (libname, |
151 | strlist: (const char *const []) { "libc.so" , LIBC_SO, NULL })) |
152 | { |
153 | TEST_COMPARE (libc_found, false); |
154 | libc_found = true; |
155 | continue; |
156 | } |
157 | } |
158 | TEST_COMPARE (interpreter_found, true); |
159 | TEST_COMPARE (libc_found, true); |
160 | |
161 | fclose (stream: out); |
162 | } |
163 | |
164 | support_capture_subprocess_free (&pldd); |
165 | if (kill (pid: *target_pid_ptr, SIGKILL) != 0) |
166 | FAIL_EXIT1 ("Unable to kill target_process: errno=%d=%m\n" , errno); |
167 | xmunmap (addr: target_pid_ptr, length: sizeof (pid_t)); |
168 | |
169 | return 0; |
170 | } |
171 | |
172 | #include <support/test-driver.c> |
173 | |