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
|
From 6ee65ed6ddbf04402fad0bec6aa9c73b9d982ae4 Mon Sep 17 00:00:00 2001
From: Ulrich Drepper <drepper@gmail.com>
Date: Fri, 27 Jan 2012 15:05:19 -0500
Subject: [PATCH] Sort objects before relocations
---
ChangeLog | 11 ++++
Makeconfig | 6 ++
NEWS | 4 +-
elf/Makefile | 15 +++++-
elf/dl-open.c | 128 ++++++++++++++++++++++++++++++++++++------------
elf/tst-relsort1.c | 19 +++++++
elf/tst-relsort1mod1.c | 7 +++
elf/tst-relsort1mod2.c | 7 +++
8 files changed, 160 insertions(+), 37 deletions(-)
create mode 100644 elf/tst-relsort1.c
create mode 100644 elf/tst-relsort1mod1.c
create mode 100644 elf/tst-relsort1mod2.c
diff --git a/Makeconfig b/Makeconfig
index 2db2821..68547b2 100644
--- a/Makeconfig
+++ b/Makeconfig
@@ -900,6 +900,12 @@ else
libdl = $(common-objpfx)dlfcn/libdl.a
endif
+ifeq ($(build-shared),yes)
+libm = $(common-objpfx)math/libm.so$(libm.so-version)
+else
+libm = $(common-objpfx)math/libm.a
+endif
+
# These are the subdirectories containing the library source. The order
# is more or less arbitrary. The sorting step will take care of the
# dependencies.
diff --git a/elf/Makefile b/elf/Makefile
index 052e763..3f1772a 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -124,7 +124,8 @@ distribute := rtld-Rules \
tst-initordera1.c tst-initordera2.c tst-initorderb1.c \
tst-initorderb2.c tst-initordera3.c tst-initordera4.c \
tst-initorder.c \
- tst-initorder2.c
+ tst-initorder2.c \
+ tst-relsort1.c tst-relsort1mod1.c tst-relsort1mod2.c
CFLAGS-dl-runtime.c = -fexceptions -fasynchronous-unwind-tables
CFLAGS-dl-lookup.c = -fexceptions -fasynchronous-unwind-tables
@@ -227,7 +228,7 @@ tests += loadtest restest1 preloadtest loadfail multiload origtest resolvfail \
tst-audit1 tst-audit2 \
tst-stackguard1 tst-addr1 tst-thrlock \
tst-unique1 tst-unique2 tst-unique3 tst-unique4 \
- tst-initorder tst-initorder2
+ tst-initorder tst-initorder2 tst-relsort1
# reldep9
test-srcs = tst-pathopt
selinux-enabled := $(shell cat /selinux/enforce 2> /dev/null)
@@ -290,7 +291,9 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
tst-initordera1 tst-initorderb1 \
tst-initordera2 tst-initorderb2 \
tst-initordera3 tst-initordera4 \
- tst-initorder2a tst-initorder2b tst-initorder2c tst-initorder2d
+ tst-initorder2a tst-initorder2b tst-initorder2c \
+ tst-initorder2d \
+ tst-relsort1mod1 tst-relsort1mod2
ifeq (yes,$(have-initfini-array))
modules-names += tst-array2dep tst-array5dep
endif
@@ -1195,3 +1198,9 @@ CFLAGS-tst-auditmod6b.c += $(AVX-CFLAGS)
CFLAGS-tst-auditmod6c.c += $(AVX-CFLAGS)
CFLAGS-tst-auditmod7b.c += $(AVX-CFLAGS)
endif
+
+$(objpfx)tst-relsort1: $(libdl)
+$(objpfx)tst-relsort1mod1.so: $(libm) $(objpfx)tst-relsort1mod2.so
+$(objpfx)tst-relsort1mod2.so: $(libm)
+$(objpfx)tst-relsort1.out: $(objpfx)tst-relsort1mod1.so \
+ $(objpfx)tst-relsort1mod2.so
diff --git a/elf/dl-open.c b/elf/dl-open.c
index a0b5c50..a56bdc1 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -1,5 +1,5 @@
/* Load a shared object at runtime, relocate it, and run its initializer.
- Copyright (C) 1996-2007, 2009, 2010, 2011 Free Software Foundation, Inc.
+ Copyright (C) 1996-2007, 2009, 2010, 2011, 2012 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
@@ -302,45 +302,109 @@ dl_open_worker (void *a)
if (GLRO(dl_lazy))
reloc_mode |= mode & RTLD_LAZY;
- /* Relocate the objects loaded. We do this in reverse order so that copy
- relocs of earlier objects overwrite the data written by later objects. */
-
+ /* Sort the objects by dependency for the relocation process. This
+ allows IFUNC relocations to work and it also means copy
+ relocation of dependencies are if necessary overwritten. */
+ size_t nmaps = 0;
struct link_map *l = new;
- while (l->l_next)
- l = l->l_next;
- while (1)
+ do
+ {
+ if (! l->l_real->l_relocated)
+ ++nmaps;
+ l = l->l_next;
+ }
+ while (l != NULL);
+ struct link_map *maps[nmaps];
+ nmaps = 0;
+ l = new;
+ do
{
if (! l->l_real->l_relocated)
+ maps[nmaps++] = l;
+ l = l->l_next;
+ }
+ while (l != NULL);
+ if (nmaps > 1)
+ {
+ char seen[nmaps];
+ memset (seen, '\0', nmaps);
+ size_t i = 0;
+ while (1)
{
-#ifdef SHARED
- if (__builtin_expect (GLRO(dl_profile) != NULL, 0))
+ ++seen[i];
+ struct link_map *thisp = maps[i];
+
+ /* Find the last object in the list for which the current one is
+ a dependency and move the current object behind the object
+ with the dependency. */
+ size_t k = nmaps - 1;
+ while (k > i)
{
- /* If this here is the shared object which we want to profile
- make sure the profile is started. We can find out whether
- this is necessary or not by observing the `_dl_profile_map'
- variable. If was NULL but is not NULL afterwars we must
- start the profiling. */
- struct link_map *old_profile_map = GL(dl_profile_map);
+ struct link_map **runp = maps[k]->l_initfini;
+ if (runp != NULL)
+ /* Look through the dependencies of the object. */
+ while (*runp != NULL)
+ if (__builtin_expect (*runp++ == thisp, 0))
+ {
+ /* Move the current object to the back past the last
+ object with it as the dependency. */
+ memmove (&maps[i], &maps[i + 1],
+ (k - i) * sizeof (maps[0]));
+ maps[k] = thisp;
+
+ if (seen[i + 1] > 1)
+ {
+ ++i;
+ goto next_clear;
+ }
+
+ char this_seen = seen[i];
+ memmove (&seen[i], &seen[i + 1],
+ (k - i) * sizeof (seen[0]));
+ seen[k] = this_seen;
+
+ goto next;
+ }
+
+ --k;
+ }
- _dl_relocate_object (l, l->l_scope, reloc_mode | RTLD_LAZY, 1);
+ if (++i == nmaps)
+ break;
+ next_clear:
+ memset (&seen[i], 0, (nmaps - i) * sizeof (seen[0]));
+ next:;
+ }
+ }
- if (old_profile_map == NULL && GL(dl_profile_map) != NULL)
- {
- /* We must prepare the profiling. */
- _dl_start_profile ();
+ for (size_t i = nmaps; i-- > 0; )
+ {
+ l = maps[i];
- /* Prevent unloading the object. */
- GL(dl_profile_map)->l_flags_1 |= DF_1_NODELETE;
- }
+#ifdef SHARED
+ if (__builtin_expect (GLRO(dl_profile) != NULL, 0))
+ {
+ /* If this here is the shared object which we want to profile
+ make sure the profile is started. We can find out whether
+ this is necessary or not by observing the `_dl_profile_map'
+ variable. If it was NULL but is not NULL afterwars we must
+ start the profiling. */
+ struct link_map *old_profile_map = GL(dl_profile_map);
+
+ _dl_relocate_object (l, l->l_scope, reloc_mode | RTLD_LAZY, 1);
+
+ if (old_profile_map == NULL && GL(dl_profile_map) != NULL)
+ {
+ /* We must prepare the profiling. */
+ _dl_start_profile ();
+
+ /* Prevent unloading the object. */
+ GL(dl_profile_map)->l_flags_1 |= DF_1_NODELETE;
}
- else
-#endif
- _dl_relocate_object (l, l->l_scope, reloc_mode, 0);
}
-
- if (l == new)
- break;
- l = l->l_prev;
+ else
+#endif
+ _dl_relocate_object (l, l->l_scope, reloc_mode, 0);
}
/* If the file is not loaded now as a dependency, add the search
diff --git a/elf/tst-relsort1.c b/elf/tst-relsort1.c
new file mode 100644
index 0000000..972100c
--- /dev/null
+++ b/elf/tst-relsort1.c
@@ -0,0 +1,19 @@
+#include <dlfcn.h>
+#include <stdio.h>
+
+
+static int
+do_test ()
+{
+ const char lib[] = "$ORIGIN/tst-relsort1mod1.so";
+ void *h = dlopen (lib, RTLD_NOW);
+ if (h == NULL)
+ {
+ puts (dlerror ());
+ return 1;
+ }
+ return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
diff --git a/elf/tst-relsort1mod1.c b/elf/tst-relsort1mod1.c
new file mode 100644
index 0000000..9e4a943
--- /dev/null
+++ b/elf/tst-relsort1mod1.c
@@ -0,0 +1,7 @@
+extern int foo (double);
+
+int
+bar (void)
+{
+ return foo (1.2);
+}
diff --git a/elf/tst-relsort1mod2.c b/elf/tst-relsort1mod2.c
new file mode 100644
index 0000000..a2c3e55
--- /dev/null
+++ b/elf/tst-relsort1mod2.c
@@ -0,0 +1,7 @@
+#include <math.h>
+
+int
+foo (double d)
+{
+ return floor (d) != 0.0;
+}
--
1.7.3.4
|
