1/* libunwind - a platform-independent unwind library
2   Copyright (C) 2002-2003 Hewlett-Packard Co
3	Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
4
5This file is part of libunwind.
6
7Permission is hereby granted, free of charge, to any person obtaining
8a copy of this software and associated documentation files (the
9"Software"), to deal in the Software without restriction, including
10without limitation the rights to use, copy, modify, merge, publish,
11distribute, sublicense, and/or sell copies of the Software, and to
12permit persons to whom the Software is furnished to do so, subject to
13the following conditions:
14
15The above copyright notice and this permission notice shall be
16included in all copies or substantial portions of the Software.
17
18THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
22LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
23OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
24WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
25
26/* This file tests dynamic code-generation via function-cloning.  */
27
28#include "flush-cache.h"
29
30#include "compiler.h"
31
32#include <libunwind.h>
33#include <stdio.h>
34#include <stdlib.h>
35#include <string.h>
36#include <unistd.h>
37#include <signal.h>
38#include <sys/mman.h>
39
40#if UNW_TARGET_ARM
41#define MAX_FUNC_SIZE   96 	/* FIXME: arch/compiler dependent */
42#else
43#define MAX_FUNC_SIZE	2048	/* max. size of cloned function */
44#endif
45
46#define panic(args...)				\
47	{ fprintf (stderr, args); exit (-1); }
48
49typedef void (*template_t) (int, void (*)(),
50			    int (*)(const char *, ...), const char *,
51			    const char **);
52
53int verbose;
54
55static const char *strarr[] =
56  {
57    "i", "ii", "iii", "iv", "v", "vi", "vii", "viii", "ix", "x", NULL
58  };
59
60#ifdef __ia64__
61struct fdesc
62  {
63    long code;
64    long gp;
65  };
66# define get_fdesc(fdesc,func)	(fdesc = *(struct fdesc *) &(func))
67# define get_funcp(fdesc)	((template_t) &(fdesc))
68# define get_gp(fdesc)		((fdesc).gp)
69#elif __arm__
70struct fdesc
71  {
72    long code;
73    long is_thumb;
74  };
75/* Workaround GCC bug: https://bugs.launchpad.net/gcc-linaro/+bug/721531 */
76# define get_fdesc(fdesc,func)  ({long tmp = (long) &(func); \
77                                  (fdesc).code = (long) &(func) & ~0x1; \
78                                  (fdesc).is_thumb = tmp & 0x1;})
79/*# define get_fdesc(fdesc,func)  ({(fdesc).code = (long) &(func) & ~0x1; \
80                                  (fdesc).is_thumb = (long) &(func) & 0x1;})*/
81# define get_funcp(fdesc)       ((template_t) ((fdesc).code | (fdesc).is_thumb))
82# define get_gp(fdesc)          (0)
83#else
84struct fdesc
85  {
86    long code;
87  };
88# define get_fdesc(fdesc,func)	(fdesc.code = (long) &(func))
89# define get_funcp(fdesc)	((template_t) (fdesc).code)
90# define get_gp(fdesc)		(0)
91#endif
92
93void
94template (int i, template_t self,
95	  int (*printer)(const char *, ...), const char *fmt, const char **arr)
96{
97  (*printer) (fmt, arr[11 - i][0], arr[11 - i] + 1);
98  if (i > 0)
99    (*self) (i - 1, self, printer, fmt, arr);
100}
101
102static void
103sighandler (int signal)
104{
105  unw_cursor_t cursor;
106  char name[128], off[32];
107  unw_word_t ip, offset;
108  unw_context_t uc;
109  int count;
110
111  if (verbose)
112    printf ("caught signal %d\n", signal);
113
114  unw_getcontext (&uc);
115  unw_init_local (&cursor, &uc);
116
117  count = 0;
118  while (!unw_is_signal_frame (&cursor))
119    {
120      if (unw_step (&cursor) < 0)
121	panic ("failed to find signal frame!\n");
122
123      if (count++ > 20)
124	{
125	  panic ("Too many steps to the signal frame (%d)\n", count);
126	  break;
127	}
128    }
129  unw_step (&cursor);
130
131  count = 0;
132  do
133    {
134      unw_get_reg (&cursor, UNW_REG_IP, &ip);
135      name[0] = '\0';
136      off[0] = '\0';
137      if (unw_get_proc_name (&cursor, name, sizeof (name), &offset) == 0
138	  && offset > 0)
139	snprintf (off, sizeof (off), "+0x%lx", (long) offset);
140      if (verbose)
141	printf ("ip = %lx <%s%s>\n", (long) ip, name, off);
142      ++count;
143
144      if (count > 20)
145	{
146	  panic ("Too many steps (%d)\n", count);
147	  break;
148	}
149
150    }
151  while (unw_step (&cursor) > 0);
152
153  if (count != 13)
154    panic ("FAILURE: expected 13, not %d frames below signal frame\n", count);
155
156  if (verbose)
157    printf ("SUCCESS\n");
158  exit (0);
159}
160
161int
162dev_null (const char *format UNUSED, ...)
163{
164  return 0;
165}
166
167int
168main (int argc, char *argv[] UNUSED)
169{
170  unw_dyn_region_info_t *region;
171  unw_dyn_info_t di;
172  struct fdesc fdesc;
173  template_t funcp;
174  void *mem;
175
176  if (argc > 1)
177    ++verbose;
178
179  mem = malloc (getpagesize ());
180
181  get_fdesc (fdesc, template);
182
183  if (verbose)
184    printf ("old code @ %p, new code @ %p\n", (void *) fdesc.code, mem);
185
186  memcpy (mem, (void *) fdesc.code, MAX_FUNC_SIZE);
187  mprotect ((void *) ((long) mem & ~(getpagesize () - 1)),
188	    2*getpagesize(), PROT_READ | PROT_WRITE | PROT_EXEC);
189
190  flush_cache (mem, MAX_FUNC_SIZE);
191
192  signal (SIGSEGV, sighandler);
193
194  /* register the new function: */
195  region = alloca (_U_dyn_region_info_size (2));
196  region->next = NULL;
197  region->insn_count = 3 * (MAX_FUNC_SIZE / 16);
198  region->op_count = 2;
199  _U_dyn_op_alias (&region->op[0], 0, -1, fdesc.code);
200  _U_dyn_op_stop (&region->op[1]);
201
202  memset (&di, 0, sizeof (di));
203  di.start_ip = (long) mem;
204  di.end_ip = (long) mem + 16*region->insn_count/3;
205  di.gp = get_gp (fdesc);
206  di.format = UNW_INFO_FORMAT_DYNAMIC;
207  di.u.pi.name_ptr = (unw_word_t) "copy_of_template";
208  di.u.pi.regions = region;
209
210  _U_dyn_register (&di);
211
212  /* call new function: */
213  fdesc.code = (long) mem;
214  funcp = get_funcp (fdesc);
215
216  if (verbose)
217    (*funcp) (10, funcp, printf, "iteration %c%s\n", strarr);
218  else
219    (*funcp) (10, funcp, dev_null, "iteration %c%s\n", strarr);
220
221  _U_dyn_cancel (&di);
222  return -1;
223}
224