aboutsummaryrefslogtreecommitdiff
path: root/elf/tst-dlopen-nodelete-reloc.c
blob: 0cf8ab63356c2f559588ee225551fabbc8ef8a8f (plain)
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
/* Test interactions of dlopen, NODELETE, and relocations.
   Copyright (C) 2019-2024 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, see
   <https://www.gnu.org/licenses/>.  */

/* This test exercises NODELETE propagation due to data relocations
   and unique symbols, and the interaction with already-loaded
   objects.  Some test objects are written in C++, to produce unique
   symbol definitions.

   First test: Global scope variant, data relocation as the NODELETE
   trigger.  mod1 is loaded first with a separate dlopen call.

      mod2 ---(may_finalize_mod1 relocation dependency)---> mod1
    (NODELETE)                                   (marked as NODELETE)

   Second test: Local scope variant, data relocation.  mod3 is loaded
   first, then mod5.

      mod5 ---(DT_NEEDED)--->  mod4  ---(DT_NEEDED)---> mod3
    (NODELETE)           (not NODELETE)                  ^
        \                                               / (marked as
         `--(may_finalize_mod3 relocation dependency)--/   NODELETE)

   Third test: Shared local scope with unique symbol.  mod6 is loaded
   first, then mod7.  No explicit dependencies between the two
   objects, so first object has to be opened with RTLD_GLOBAL.

      mod7 ---(unique symbol)---> mod6
                          (marked as NODELETE)

   Forth test: Non-shared scopes with unique symbol.  mod8 and mod10
   are loaded from the main program.  mod8 loads mod9 from an ELF
   constructor, mod10 loads mod11.  There are no DT_NEEDED
   dependencies.  mod9 is promoted to the global scope form the main
   program.  The unique symbol dependency is:

      mod9 ---(unique symbol)---> mod11
                          (marked as NODELETE)

   Fifth test: Shared local scope with unique symbol, like test 3, but
   this time, there is also a DT_NEEDED dependency (so no RTLD_GLOBAL
   needed):

                 DT_NEEDED
      mod13 ---(unique symbol)---> mod12
                          (marked as NODELETE)

   Sixth test: NODELETE status is retained after relocation failure
   with unique symbol dependency.  The object graph ensures that the
   unique symbol binding is processed before the dlopen failure.

                                        DT_NEEDED
     mod17  --(DT_NEEDED)--> mod15 --(unique symbol)--> mod14
       \                       ^                  (RTLD_NODELETE)
        \                 (DT_NEEDED)
         \                     |
          `---(DT_NEEDED)--> mod16
                       (fails to relocate)

   mod14 is loaded first, and the loading mod17 is attempted.
   mod14 must remain NODELETE after opening mod17 failed.  */

#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <support/check.h>
#include <support/xdlfcn.h>

static int
do_test (void)
{
  /* First case: global scope, regular data symbol.  Open the object
     which is not NODELETE initially.  */
  void *mod1 = xdlopen ("tst-dlopen-nodelete-reloc-mod1.so",
                        RTLD_NOW | RTLD_GLOBAL);
  /* This is used to indicate that the ELF destructor may be
     called.  */
  bool *may_finalize_mod1 = xdlsym (mod1, "may_finalize_mod1");
  /* Open the NODELETE object.  */
  void *mod2 = xdlopen ("tst-dlopen-nodelete-reloc-mod2.so", RTLD_NOW);
  /* This has no effect because the DSO is directly marked as
     NODELETE.  */
  xdlclose (mod2);
  /* This has no effect because the DSO has been indirectly marked as
     NODELETE due to a relocation dependency.  */
  xdlclose (mod1);

  /* Second case: local scope, regular data symbol.  Open the object
     which is not NODELETE initially.  */
  void *mod3 = xdlopen ("tst-dlopen-nodelete-reloc-mod3.so", RTLD_NOW);
  bool *may_finalize_mod3 = xdlsym (mod3, "may_finalize_mod3");
  /* Open the NODELETE object.  */
  void *mod5 = xdlopen ("tst-dlopen-nodelete-reloc-mod5.so", RTLD_NOW);
  /* Again those have no effect because of NODELETE.  */
  xdlclose (mod5);
  xdlclose (mod3);

  /* Third case: Unique symbol.  */
  void *mod6 = xdlopen ("tst-dlopen-nodelete-reloc-mod6.so",
                        RTLD_NOW | RTLD_GLOBAL);
  bool *may_finalize_mod6 = xdlsym (mod6, "may_finalize_mod6");
  void *mod7 = xdlopen ("tst-dlopen-nodelete-reloc-mod7.so", RTLD_NOW);
  bool *may_finalize_mod7 = xdlsym (mod7, "may_finalize_mod7");
  /* This should not have any effect because of the unique symbol and
     the resulting NODELETE status.  */
  xdlclose (mod6);
  /* mod7 is not NODELETE and can be closed.  */
  *may_finalize_mod7 = true;
  xdlclose (mod7);

  /* Fourth case: Unique symbol, indirect loading.  */
  void *mod8 = xdlopen ("tst-dlopen-nodelete-reloc-mod8.so", RTLD_NOW);
  /* Also promote to global scope.  */
  void *mod9 = xdlopen ("tst-dlopen-nodelete-reloc-mod9.so",
                        RTLD_NOW | RTLD_NOLOAD | RTLD_GLOBAL);
  bool *may_finalize_mod9 = xdlsym (mod9, "may_finalize_mod9");
  xdlclose (mod9);              /* Drop mod9 reference.  */
  void *mod10 = xdlopen ("tst-dlopen-nodelete-reloc-mod10.so", RTLD_NOW);
  void *mod11 = xdlopen ("tst-dlopen-nodelete-reloc-mod11.so",
                        RTLD_NOW | RTLD_NOLOAD);
  bool *may_finalize_mod11 = xdlsym (mod11, "may_finalize_mod11");
  xdlclose (mod11);              /* Drop mod11 reference.  */
  /* mod11 is not NODELETE and can be closed.  */
  *may_finalize_mod11 = true;
  /* Trigger closing of mod11, too.  */
  xdlclose (mod10);
  /* Does not trigger closing of mod9.  */
  xdlclose (mod8);

  /* Fifth case: Unique symbol, with DT_NEEDED dependency.  */
  void *mod12 = xdlopen ("tst-dlopen-nodelete-reloc-mod12.so", RTLD_NOW);
  bool *may_finalize_mod12 = xdlsym (mod12, "may_finalize_mod12");
  void *mod13 = xdlopen ("tst-dlopen-nodelete-reloc-mod13.so", RTLD_NOW);
  bool *may_finalize_mod13 = xdlsym (mod13, "may_finalize_mod13");
  /* This should not have any effect because of the unique symbol. */
  xdlclose (mod12);
  /* mod13 is not NODELETE and can be closed.  */
  *may_finalize_mod13 = true;
  xdlclose (mod13);

  /* Sixth case: Unique symbol binding must not cause loss of NODELETE
     status.  */
  void *mod14 = xdlopen ("tst-dlopen-nodelete-reloc-mod14.so",
                         RTLD_NOW | RTLD_NODELETE);
  bool *may_finalize_mod14 = xdlsym (mod14, "may_finalize_mod14");
  TEST_VERIFY (dlopen ("tst-dlopen-nodelete-reloc-mod17.so", RTLD_NOW)
               == NULL);
  const char *message = dlerror ();
  printf ("info: test 6 message: %s\n", message);
  /* This must not close the object, it must still be NODELETE.  */
  xdlclose (mod14);
  xdlopen ("tst-dlopen-nodelete-reloc-mod14.so", RTLD_NOW | RTLD_NOLOAD);

  /* Prepare for process exit.  Destructors for NODELETE objects will
     be invoked.  */
  *may_finalize_mod1 = true;
  *may_finalize_mod3 = true;
  *may_finalize_mod6 = true;
  *may_finalize_mod9 = true;
  *may_finalize_mod12 = true;
  *may_finalize_mod14 = true;
  return 0;
}

#include <support/test-driver.c>