summary refs log tree commit diff
path: root/sysdeps/tile/dl-runtime.c
blob: bcc00bc74bbb5d9955da89e80f8306a677be6cac (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
/* Copyright (C) 2011-2014 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.

   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, see
   <http://www.gnu.org/licenses/>.  */

/* Like x86_64, we pass the index of the relocation and not its offset.
   In _dl_profile_fixup and _dl_call_pltexit we also use the index.
   Therefore it is wasteful to compute the offset in the trampoline
   just to reverse the operation immediately afterwards.  */
#define reloc_offset reloc_arg * sizeof (PLTREL)
#define reloc_index  reloc_arg

#include <elf/dl-runtime.c>

#include <sys/mman.h>
#include <arch/sim.h>
#include <dl-unmap-segments.h>

/* Like realpath(), but simplified: no dynamic memory use, no lstat(),
   no set_errno(), no valid "rpath" on error, etc.  This handles some
   simple cases where the simulator might not have a valid entry for
   a loaded Elf object, in particular dlopen() with a relative path.
   For this relatively rare case, one could also imagine using
   link_map.l_origin to avoid the getcwd() here, but the simpler code
   here seems like a better solution.  */
static char *
dl_realpath (const char *name, char *rpath)
{
  char *dest;
  const char *start, *end;

  if (name[0] != '/')
    {
      if (!__getcwd (rpath, PATH_MAX))
        return NULL;
      dest = __rawmemchr (rpath, '\0');
    }
  else
    {
      rpath[0] = '/';
      dest = rpath + 1;
    }

  for (start = end = name; *start; start = end)
    {
      /* Skip sequence of multiple path-separators.  */
      while (*start == '/')
	++start;

      /* Find end of path component.  */
      for (end = start; *end && *end != '/'; ++end)
	/* Nothing.  */;

      if (end - start == 0)
	break;
      else if (end - start == 1 && start[0] == '.')
	/* nothing */;
      else if (end - start == 2 && start[0] == '.' && start[1] == '.')
	{
	  /* Back up to previous component, ignore if at root already.  */
	  if (dest > rpath + 1)
	    while ((--dest)[-1] != '/');
	}
      else
	{
	  if (dest[-1] != '/')
	    *dest++ = '/';

	  if (dest + (end - start) >= rpath + PATH_MAX)
            return NULL;

	  dest = __mempcpy (dest, start, end - start);
	  *dest = '\0';
	}
    }
  if (dest > rpath + 1 && dest[-1] == '/')
    --dest;
  *dest = '\0';

  return rpath;
}

/* Support notifying the simulator about new objects.  */
void internal_function
_dl_after_load (struct link_map *l)
{
  int shift;
  char pathbuf[PATH_MAX];
  char *path;

  /* Don't bother if not in the simulator. */
  if (__insn_mfspr (SPR_SIM_CONTROL) == 0)
    return;

#define DLPUTC(c) __insn_mtspr (SPR_SIM_CONTROL,                         \
                                (SIM_CONTROL_DLOPEN                      \
                                 | ((c) << _SIM_CONTROL_OPERATOR_BITS)))

  /* Write the library address in hex.  */
  DLPUTC ('0');
  DLPUTC ('x');
  for (shift = (int) sizeof (unsigned long) * 8 - 4; shift >= 0; shift -= 4)
    DLPUTC ("0123456789abcdef"[(l->l_map_start >> shift) & 0xF]);
  DLPUTC (':');

  /* Write the library path, including the terminating '\0'.  */
  path = dl_realpath (l->l_name, pathbuf) ?: l->l_name;
  for (size_t i = 0;; i++)
    {
      DLPUTC (path[i]);
      if (path[i] == '\0')
        break;
    }
#undef DLPUTC
}

/* Support notifying the simulator about removed objects prior to munmap().  */
static void
sim_dlclose (ElfW(Addr) map_start)
{
  int shift;

  /* Don't bother if not in the simulator.  */
  if (__insn_mfspr (SPR_SIM_CONTROL) == 0)
    return;

#define DLPUTC(c) __insn_mtspr (SPR_SIM_CONTROL,                         \
                                (SIM_CONTROL_DLCLOSE                     \
                                 | ((c) << _SIM_CONTROL_OPERATOR_BITS)))

  /* Write the library address in hex.  */
  DLPUTC ('0');
  DLPUTC ('x');
  for (shift = (int) sizeof (unsigned long) * 8 - 4; shift >= 0; shift -= 4)
    DLPUTC ("0123456789abcdef"[(map_start >> shift) & 0xF]);
  DLPUTC ('\0');

#undef DLPUTC
}

void internal_function
_dl_unmap (struct link_map *map)
{
  sim_dlclose (map->l_map_start);
  _dl_unmap_segments (map);
}