1 /* Test program for unwinding of complicated DWARF expressions.
2    Copyright (C) 2013 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 <assert.h>
20 #include <signal.h>
21 #include <inttypes.h>
22 #include <stdio_ext.h>
23 #include <locale.h>
24 #include <errno.h>
25 #include <sys/ptrace.h>
26 #include ELFUTILS_HEADER(dwfl)
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 
40 static void cleanup_13_abort (void);
41 #define main cleanup_13_main
42 #include "cleanup-13.c"
43 #undef main
44 
45 static void
report_pid(Dwfl * dwfl,pid_t pid)46 report_pid (Dwfl *dwfl, pid_t pid)
47 {
48   int result = dwfl_linux_proc_report (dwfl, pid);
49   if (result < 0)
50     error (2, 0, "dwfl_linux_proc_report: %s", dwfl_errmsg (-1));
51   else if (result > 0)
52     error (2, result, "dwfl_linux_proc_report");
53 
54   if (dwfl_report_end (dwfl, NULL, NULL) != 0)
55     error (2, 0, "dwfl_report_end: %s", dwfl_errmsg (-1));
56 
57   result = dwfl_linux_proc_attach (dwfl, pid, true);
58   if (result < 0)
59     error (2, 0, "dwfl_linux_proc_attach: %s", dwfl_errmsg (-1));
60   else if (result > 0)
61     error (2, result, "dwfl_linux_proc_attach");
62 }
63 
64 static Dwfl *
pid_to_dwfl(pid_t pid)65 pid_to_dwfl (pid_t pid)
66 {
67   static char *debuginfo_path;
68   static const Dwfl_Callbacks proc_callbacks =
69     {
70       .find_debuginfo = dwfl_standard_find_debuginfo,
71       .debuginfo_path = &debuginfo_path,
72 
73       .find_elf = dwfl_linux_proc_find_elf,
74     };
75   Dwfl *dwfl = dwfl_begin (&proc_callbacks);
76   if (dwfl == NULL)
77     error (2, 0, "dwfl_begin: %s", dwfl_errmsg (-1));
78   report_pid (dwfl, pid);
79   return dwfl;
80 }
81 
82 static int
frame_callback(Dwfl_Frame * state,void * frame_arg)83 frame_callback (Dwfl_Frame *state, void *frame_arg)
84 {
85   Dwarf_Addr pc;
86   bool isactivation;
87   if (! dwfl_frame_pc (state, &pc, &isactivation))
88     {
89       error (0, 0, "%s", dwfl_errmsg (-1));
90       return DWARF_CB_ABORT;
91     }
92   Dwarf_Addr pc_adjusted = pc - (isactivation ? 0 : 1);
93 
94   /* Get PC->SYMNAME.  */
95   Dwfl_Thread *thread = dwfl_frame_thread (state);
96   Dwfl *dwfl = dwfl_thread_dwfl (thread);
97   Dwfl_Module *mod = dwfl_addrmodule (dwfl, pc_adjusted);
98   const char *symname = NULL;
99   if (mod)
100     symname = dwfl_module_addrname (mod, pc_adjusted);
101 
102   printf ("%#" PRIx64 "\t%s\n", (uint64_t) pc, symname);
103 
104   if (symname && (strcmp (symname, "main") == 0
105 		  || strcmp (symname, ".main") == 0))
106     {
107       kill (dwfl_pid (dwfl), SIGKILL);
108       exit (0);
109     }
110 
111   return DWARF_CB_OK;
112 }
113 
114 static int
thread_callback(Dwfl_Thread * thread,void * thread_arg)115 thread_callback (Dwfl_Thread *thread, void *thread_arg)
116 {
117   dwfl_thread_getframes (thread, frame_callback, NULL);
118   error (1, 0, "dwfl_thread_getframes: %s", dwfl_errmsg (-1));
119 }
120 
121 int
main(int argc,char ** argv)122 main (int argc __attribute__ ((unused)), char **argv)
123 {
124   /* We use no threads here which can interfere with handling a stream.  */
125   __fsetlocking (stdin, FSETLOCKING_BYCALLER);
126   __fsetlocking (stdout, FSETLOCKING_BYCALLER);
127   __fsetlocking (stderr, FSETLOCKING_BYCALLER);
128 
129   /* Set locale.  */
130   (void) setlocale (LC_ALL, "");
131 
132   elf_version (EV_CURRENT);
133 
134   pid_t pid = fork ();
135   switch (pid)
136   {
137     case -1:
138       abort ();
139     case 0:;
140       long l = ptrace (PTRACE_TRACEME, 0, NULL, NULL);
141       assert_perror (errno);
142       assert (l == 0);
143       cleanup_13_main ();
144       abort ();
145     default:
146       break;
147   }
148 
149   errno = 0;
150   int status;
151   pid_t got = waitpid (pid, &status, 0);
152   assert_perror (errno);
153   assert (got == pid);
154   assert (WIFSTOPPED (status));
155   assert (WSTOPSIG (status) == SIGABRT);
156 
157   Dwfl *dwfl = pid_to_dwfl (pid);
158   dwfl_getthreads (dwfl, thread_callback, NULL);
159 
160   /* There is an exit (0) call if we find the "main" frame,  */
161   error (1, 0, "dwfl_getthreads: %s", dwfl_errmsg (-1));
162 }
163 
164 #endif /* ! __linux__ */
165 
166