1 /* Test program for unwinding of complicated DWARF expressions.
2 Copyright (C) 2013, 2015, 2018 Red Hat, Inc.
3 This file is part of elfutils.
4
5 This file is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
9
10 elfutils is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17
18 #include <config.h>
19 #include <inttypes.h>
20 #include <stdio_ext.h>
21 #include <locale.h>
22 #include <errno.h>
23 #include <unistd.h>
24 #include <sys/types.h>
25 #include ELFUTILS_HEADER(dwfl)
26 #include "system.h"
27
28 #ifndef __linux__
29
30 int
main(int argc,char ** argv)31 main (int argc __attribute__ ((unused)), char **argv)
32 {
33 fprintf (stderr, "%s: Unwinding not supported for this architecture\n",
34 argv[0]);
35 return 77;
36 }
37
38 #else /* __linux__ */
39 #include <sys/ptrace.h>
40 #include <sys/wait.h>
41 #include <signal.h>
42
43 #define main cleanup_13_main
44 #include "cleanup-13.c"
45 #undef main
46
47 static void
report_pid(Dwfl * dwfl,pid_t pid)48 report_pid (Dwfl *dwfl, pid_t pid)
49 {
50 int result = dwfl_linux_proc_report (dwfl, pid);
51 if (result < 0)
52 error (2, 0, "dwfl_linux_proc_report: %s", dwfl_errmsg (-1));
53 else if (result > 0)
54 error (2, result, "dwfl_linux_proc_report");
55
56 if (dwfl_report_end (dwfl, NULL, NULL) != 0)
57 error (2, 0, "dwfl_report_end: %s", dwfl_errmsg (-1));
58
59 result = dwfl_linux_proc_attach (dwfl, pid, true);
60 if (result < 0)
61 error (2, 0, "dwfl_linux_proc_attach: %s", dwfl_errmsg (-1));
62 else if (result > 0)
63 error (2, result, "dwfl_linux_proc_attach");
64 }
65
66 static Dwfl *
pid_to_dwfl(pid_t pid)67 pid_to_dwfl (pid_t pid)
68 {
69 static char *debuginfo_path;
70 static const Dwfl_Callbacks proc_callbacks =
71 {
72 .find_debuginfo = dwfl_standard_find_debuginfo,
73 .debuginfo_path = &debuginfo_path,
74
75 .find_elf = dwfl_linux_proc_find_elf,
76 };
77 Dwfl *dwfl = dwfl_begin (&proc_callbacks);
78 if (dwfl == NULL)
79 error (2, 0, "dwfl_begin: %s", dwfl_errmsg (-1));
80 report_pid (dwfl, pid);
81 return dwfl;
82 }
83
84 static int
frame_callback(Dwfl_Frame * state,void * frame_arg)85 frame_callback (Dwfl_Frame *state, void *frame_arg)
86 {
87 Dwarf_Addr pc;
88 bool isactivation;
89 if (! dwfl_frame_pc (state, &pc, &isactivation))
90 {
91 error (0, 0, "%s", dwfl_errmsg (-1));
92 return DWARF_CB_ABORT;
93 }
94 Dwarf_Addr pc_adjusted = pc - (isactivation ? 0 : 1);
95
96 /* Get PC->SYMNAME. */
97 Dwfl_Thread *thread = dwfl_frame_thread (state);
98 Dwfl *dwfl = dwfl_thread_dwfl (thread);
99 Dwfl_Module *mod = dwfl_addrmodule (dwfl, pc_adjusted);
100 const char *symname = NULL;
101 if (mod)
102 symname = dwfl_module_addrname (mod, pc_adjusted);
103
104 printf ("%#" PRIx64 "\t%s\n", (uint64_t) pc, symname ?: "<null>");
105
106 if (symname && (strcmp (symname, "main") == 0
107 || strcmp (symname, ".main") == 0))
108 {
109 kill (dwfl_pid (dwfl), SIGKILL);
110 exit (0);
111 }
112
113 return DWARF_CB_OK;
114 }
115
116 static int
thread_callback(Dwfl_Thread * thread,void * thread_arg)117 thread_callback (Dwfl_Thread *thread, void *thread_arg)
118 {
119 if (dwfl_thread_getframes (thread, frame_callback, NULL) == -1)
120 error (1, 0, "dwfl_thread_getframes: %s", dwfl_errmsg (-1));
121
122 /* frame_callback shall exit (0) on success. */
123 printf ("dwfl_thread_getframes returned, main not found\n");
124 return DWARF_CB_ABORT;
125 }
126
127 int
128 __attribute__((section(".main"))) /* Defeat -freorder-blocks-and-partition */
main(int argc,char ** argv)129 main (int argc __attribute__ ((unused)), char **argv)
130 {
131 /* We use no threads here which can interfere with handling a stream. */
132 __fsetlocking (stdin, FSETLOCKING_BYCALLER);
133 __fsetlocking (stdout, FSETLOCKING_BYCALLER);
134 __fsetlocking (stderr, FSETLOCKING_BYCALLER);
135
136 /* Set locale. */
137 (void) setlocale (LC_ALL, "");
138
139 elf_version (EV_CURRENT);
140
141 pid_t pid = fork ();
142 switch (pid)
143 {
144 case -1:
145 perror ("fork failed");
146 exit (-1);
147 case 0:;
148 long l = ptrace (PTRACE_TRACEME, 0, NULL, NULL);
149 if (l != 0)
150 {
151 perror ("PTRACE_TRACEME failed");
152 exit (-1);
153 }
154 cleanup_13_main ();
155 printf ("cleanup_13_main returned, impossible...\n");
156 exit (-1);
157 default:
158 break;
159 }
160
161 errno = 0;
162 int status;
163 pid_t got = waitpid (pid, &status, 0);
164 if (got != pid)
165 error (1, errno, "waitpid returned %d", got);
166 if (!WIFSTOPPED (status))
167 error (1, 0, "unexpected wait status %u", status);
168 if (WSTOPSIG (status) != SIGABRT)
169 error (1, 0, "unexpected signal %u", WSTOPSIG (status));
170
171 Dwfl *dwfl = pid_to_dwfl (pid);
172 if (dwfl_getthreads (dwfl, thread_callback, NULL) == -1)
173 error (1, 0, "dwfl_getthreads: %s", dwfl_errmsg (-1));
174
175 /* There is an exit (0) call if we find the "main" frame, */
176 printf ("dwfl_getthreads returned, main not found\n");
177 exit (-1);
178 }
179
180 #endif /* ! __linux__ */
181
182