about summary refs log tree commit diff
path: root/elf/dl-misc.c
blob: 2f37675b461d984ac1adced04ee61835f08e1807 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
/* Miscellaneous support functions for dynamic linker
   Copyright (C) 1997-2002, 2003 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <assert.h>
#include <fcntl.h>
#include <ldsodefs.h>
#include <limits.h>
#include <link.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <sysdep.h>
#include <stdio-common/_itoa.h>
#include <bits/libc-lock.h>

#ifndef MAP_ANON
/* This is the only dl-sysdep.c function that is actually needed at run-time
   by _dl_map_object.  */

int
_dl_sysdep_open_zero_fill (void)
{
  return __open ("/dev/zero", O_RDONLY);
}
#endif

/* Read the whole contents of FILE into new mmap'd space with given
   protections.  *SIZEP gets the size of the file.  On error MAP_FAILED
   is returned.  */

void *
internal_function
_dl_sysdep_read_whole_file (const char *file, size_t *sizep, int prot)
{
  void *result = MAP_FAILED;
  struct stat64 st;
  int fd = __open (file, O_RDONLY);
  if (fd >= 0)
    {
      if (__fxstat64 (_STAT_VER, fd, &st) >= 0)
	{
	  *sizep = st.st_size;

	  /* No need to map the file if it is empty.  */
	  if (*sizep != 0)
	    /* Map a copy of the file contents.  */
	    result = __mmap (NULL, *sizep, prot,
#ifdef MAP_COPY
			     MAP_COPY
#else
			     MAP_PRIVATE
#endif
#ifdef MAP_FILE
			     | MAP_FILE
#endif
			     , fd, 0);
	}
      __close (fd);
    }
  return result;
}


/* Bare-bones printf implementation.  This function only knows about
   the formats and flags needed and can handle only up to 64 stripes in
   the output.  */
static void
_dl_debug_vdprintf (int fd, int tag_p, const char *fmt, va_list arg)
{
  const int niovmax = 64;
  struct iovec iov[niovmax];
  int niov = 0;
  pid_t pid = 0;
  char pidbuf[12];

  while (*fmt != '\0')
    {
      const char *startp = fmt;

      if (tag_p > 0)
	{
	  /* Generate the tag line once.  It consists of the PID and a
	     colon followed by a tab.  */
	  if (pid == 0)
	    {
	      char *p;
	      pid = __getpid ();
	      assert (pid >= 0 && sizeof (pid_t) <= 4);
	      p = _itoa (pid, &pidbuf[10], 10, 0);
	      while (p > pidbuf)
		*--p = ' ';
	      pidbuf[10] = ':';
	      pidbuf[11] = '\t';
	    }

	  /* Append to the output.  */
	  assert (niov < niovmax);
	  iov[niov].iov_len = 12;
	  iov[niov++].iov_base = pidbuf;

	  /* No more tags until we see the next newline.  */
	  tag_p = -1;
	}

      /* Skip everything except % and \n (if tags are needed).  */
      while (*fmt != '\0' && *fmt != '%' && (! tag_p || *fmt != '\n'))
	++fmt;

      /* Append constant string.  */
      assert (niov < niovmax);
      if ((iov[niov].iov_len = fmt - startp) != 0)
	iov[niov++].iov_base = (char *) startp;

      if (*fmt == '%')
	{
	  /* It is a format specifier.  */
	  char fill = ' ';
	  int width = -1;
	  int prec = -1;
#if LONG_MAX != INT_MAX
	  int long_mod = 0;
#endif

	  /* Recognize zero-digit fill flag.  */
	  if (*++fmt == '0')
	    {
	      fill = '0';
	      ++fmt;
	    }

	  /* See whether with comes from a parameter.  Note that no other
	     way to specify the width is implemented.  */
	  if (*fmt == '*')
	    {
	      width = va_arg (arg, int);
	      ++fmt;
	    }

	  /* Handle precision.  */
	  if (*fmt == '.' && fmt[1] == '*')
	    {
	      prec = va_arg (arg, int);
	      fmt += 2;
	    }

	  /* Recognize the l modifier.  It is only important on some
	     platforms where long and int have a different size.  We
	     can use the same code for size_t.  */
	  if (*fmt == 'l' || *fmt == 'Z')
	    {
#if LONG_MAX != INT_MAX
	      long_mod = 1;
#endif
	      ++fmt;
	    }

	  switch (*fmt)
	    {
	      /* Integer formatting.  */
	    case 'u':
	    case 'x':
	      {
		/* We have to make a difference if long and int have a
		   different size.  */
#if LONG_MAX != INT_MAX
		unsigned long int num = (long_mod
					 ? va_arg (arg, unsigned long int)
					 : va_arg (arg, unsigned int));
#else
		unsigned long int num = va_arg (arg, unsigned int);
#endif
		/* We use alloca() to allocate the buffer with the most
		   pessimistic guess for the size.  Using alloca() allows
		   having more than one integer formatting in a call.  */
		char *buf = (char *) alloca (3 * sizeof (unsigned long int));
		char *endp = &buf[3 * sizeof (unsigned long int)];
		char *cp = _itoa (num, endp, *fmt == 'x' ? 16 : 10, 0);

		/* Pad to the width the user specified.  */
		if (width != -1)
		  while (endp - cp < width)
		    *--cp = fill;

		iov[niov].iov_base = cp;
		iov[niov].iov_len = endp - cp;
		++niov;
	      }
	      break;

	    case 's':
	      /* Get the string argument.  */
	      iov[niov].iov_base = va_arg (arg, char *);
	      iov[niov].iov_len = strlen (iov[niov].iov_base);
	      if (prec != -1)
		iov[niov].iov_len = MIN ((size_t) prec, iov[niov].iov_len);
	      ++niov;
	      break;

	    case '%':
	      iov[niov].iov_base = (void *) fmt;
	      iov[niov].iov_len = 1;
	      ++niov;
	      break;

	    default:
	      assert (! "invalid format specifier");
	    }
	  ++fmt;
	}
      else if (*fmt == '\n')
	{
	  /* See whether we have to print a single newline character.  */
	  if (fmt == startp)
	    {
	      iov[niov].iov_base = (char *) startp;
	      iov[niov++].iov_len = 1;
	    }
	  else
	    /* No, just add it to the rest of the string.  */
	    ++iov[niov - 1].iov_len;

	  /* Next line, print a tag again.  */
	  tag_p = 1;
	  ++fmt;
	}
    }

  /* Finally write the result.  */
#ifdef INTERNAL_SYSCALL
  INTERNAL_SYSCALL (writev, 3, fd, &iov, niov);
#elif RTLD_PRIVATE_ERRNO
  /* We have to take this lock just to be sure we don't clobber the private
     errno when it's being used by another thread that cares about it.
     Yet we must be sure not to try calling the lock functions before
     the thread library is fully initialized.  */
  if (__builtin_expect (INTUSE (_dl_starting_up), 0))
    __writev (fd, iov, niov);
  else
    {
      __rtld_lock_lock_recursive (GL(dl_load_lock));
      __writev (fd, iov, niov);
      __rtld_lock_unlock_recursive (GL(dl_load_lock));
    }
#else
  __writev (fd, iov, niov);
#endif
}


/* Write to debug file.  */
void
_dl_debug_printf (const char *fmt, ...)
{
  va_list arg;

  va_start (arg, fmt);
  _dl_debug_vdprintf (GL(dl_debug_fd), 1, fmt, arg);
  va_end (arg);
}
INTDEF(_dl_debug_printf)


/* Write to debug file but don't start with a tag.  */
void
_dl_debug_printf_c (const char *fmt, ...)
{
  va_list arg;

  va_start (arg, fmt);
  _dl_debug_vdprintf (GL(dl_debug_fd), -1, fmt, arg);
  va_end (arg);
}


/* Write the given file descriptor.  */
void
_dl_dprintf (int fd, const char *fmt, ...)
{
  va_list arg;

  va_start (arg, fmt);
  _dl_debug_vdprintf (fd, 0, fmt, arg);
  va_end (arg);
}