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
|
/* Copyright (C) 2003, 2004 Red Hat, Inc.
* Contributed by Alexandre Oliva <aoliva@redhat.com>
* Copyright (C) 2006-2011 Analog Devices, Inc.
*
* Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
*/
#include <inline-hashtab.h>
/* Initialize a DL_LOADADDR_TYPE given a got pointer and a complete load map. */
static __always_inline void
__dl_init_loadaddr_map(struct elf32_fdpic_loadaddr *loadaddr, Elf32_Addr dl_boot_got_pointer,
struct elf32_fdpic_loadmap *map)
{
if (map->version != 0) {
SEND_EARLY_STDERR("Invalid loadmap version number\n");
_dl_exit(-1);
}
if (map->nsegs == 0) {
SEND_EARLY_STDERR("Invalid segment count in loadmap\n");
_dl_exit(-1);
}
loadaddr->got_value = (void *)dl_boot_got_pointer;
loadaddr->map = map;
}
/*
* Figure out how many LOAD segments there are in the given headers,
* and allocate a block for the load map big enough for them.
* got_value will be properly initialized later on, with INIT_GOT.
*/
static __always_inline int
__dl_init_loadaddr(struct elf32_fdpic_loadaddr *loadaddr, Elf32_Phdr *ppnt,
int pcnt)
{
int count = 0, i;
size_t size;
for (i = 0; i < pcnt; i++)
if (ppnt[i].p_type == PT_LOAD)
count++;
loadaddr->got_value = 0;
size = sizeof(struct elf32_fdpic_loadmap) +
(sizeof(struct elf32_fdpic_loadseg) * count);
loadaddr->map = _dl_malloc(size);
if (!loadaddr->map)
_dl_exit(-1);
loadaddr->map->version = 0;
loadaddr->map->nsegs = 0;
return count;
}
/* Incrementally initialize a load map. */
static __always_inline void
__dl_init_loadaddr_hdr(struct elf32_fdpic_loadaddr loadaddr, void *addr,
Elf32_Phdr *phdr, int maxsegs)
{
struct elf32_fdpic_loadseg *segdata;
if (loadaddr.map->nsegs == maxsegs)
_dl_exit(-1);
segdata = &loadaddr.map->segs[loadaddr.map->nsegs++];
segdata->addr = (Elf32_Addr)addr;
segdata->p_vaddr = phdr->p_vaddr;
segdata->p_memsz = phdr->p_memsz;
#if defined(__SUPPORT_LD_DEBUG__)
if (_dl_debug)
_dl_dprintf(_dl_debug_file, "%i: mapped %x at %x, size %x\n",
loadaddr.map->nsegs - 1,
segdata->p_vaddr, segdata->addr, segdata->p_memsz);
#endif
}
/* Replace an existing entry in the load map. */
static __always_inline void
__dl_update_loadaddr_hdr(struct elf32_fdpic_loadaddr loadaddr, void *addr,
Elf32_Phdr *phdr)
{
struct elf32_fdpic_loadseg *segdata;
void *oldaddr;
int i;
for (i = 0; i < loadaddr.map->nsegs; i++)
if (loadaddr.map->segs[i].p_vaddr == phdr->p_vaddr &&
loadaddr.map->segs[i].p_memsz == phdr->p_memsz)
break;
if (i == loadaddr.map->nsegs)
_dl_exit(-1);
segdata = loadaddr.map->segs + i;
oldaddr = (void *)segdata->addr;
_dl_munmap(oldaddr, segdata->p_memsz);
segdata->addr = (Elf32_Addr)addr;
#if defined (__SUPPORT_LD_DEBUG__)
if (_dl_debug)
_dl_dprintf(_dl_debug_file, "%i: changed mapping %x at %x (old %x), size %x\n",
loadaddr.map->nsegs - 1,
segdata->p_vaddr, segdata->addr, oldaddr, segdata->p_memsz);
#endif
}
#ifndef __dl_loadaddr_unmap
static __always_inline void
__dl_loadaddr_unmap(struct elf32_fdpic_loadaddr loadaddr,
struct funcdesc_ht *funcdesc_ht)
{
int i;
for (i = 0; i < loadaddr.map->nsegs; i++)
_dl_munmap((void *)loadaddr.map->segs[i].addr,
loadaddr.map->segs[i].p_memsz);
/*
* _dl_unmap is only called for dlopen()ed libraries, for which
* calling free() is safe, or before we've completed the initial
* relocation, in which case calling free() is probably pointless,
* but still safe.
*/
_dl_free(loadaddr.map);
if (funcdesc_ht)
htab_delete(funcdesc_ht);
}
#endif
/* Figure out whether the given address is in one of the mapped segments. */
static __always_inline int
__dl_addr_in_loadaddr(void *p, struct elf32_fdpic_loadaddr loadaddr)
{
struct elf32_fdpic_loadmap *map = loadaddr.map;
int c;
for (c = 0; c < map->nsegs; c++)
if ((void *)map->segs[c].addr <= p &&
(char *)p < (char *)map->segs[c].addr + map->segs[c].p_memsz)
return 1;
return 0;
}
static int
hash_pointer(void *p)
{
return (int) ((long)p >> 3);
}
static int
eq_pointer(void *p, void *q)
{
struct funcdesc_value *entry = p;
return entry->entry_point == q;
}
void *
_dl_funcdesc_for (void *entry_point, void *got_value)
{
struct elf_resolve *tpnt = ((void**)got_value)[2];
struct funcdesc_ht *ht = tpnt->funcdesc_ht;
struct funcdesc_value **entry;
_dl_assert(got_value == tpnt->loadaddr.got_value);
if (!ht) {
ht = htab_create();
if (!ht)
return (void*)-1;
tpnt->funcdesc_ht = ht;
}
entry = htab_find_slot(ht, entry_point, 1, hash_pointer, eq_pointer);
if (*entry) {
_dl_assert((*entry)->entry_point == entry_point);
return _dl_stabilize_funcdesc(*entry);
}
*entry = _dl_malloc(sizeof(**entry));
(*entry)->entry_point = entry_point;
(*entry)->got_value = got_value;
return _dl_stabilize_funcdesc(*entry);
}
static __always_inline void const *
_dl_lookup_address(void const *address)
{
struct elf_resolve *rpnt;
struct funcdesc_value const *fd;
/* Make sure we don't make assumptions about its alignment. */
__asm__ ("" : "+r" (address));
if ((Elf32_Addr)address & 7)
/* It's not a function descriptor. */
return address;
fd = address;
for (rpnt = _dl_loaded_modules; rpnt; rpnt = rpnt->next) {
if (!rpnt->funcdesc_ht)
continue;
if (fd->got_value != rpnt->loadaddr.got_value)
continue;
address = htab_find_slot(rpnt->funcdesc_ht, (void *)fd->entry_point, 0,
hash_pointer, eq_pointer);
if (address && *(struct funcdesc_value *const*)address == fd) {
address = (*(struct funcdesc_value *const*)address)->entry_point;
break;
} else
address = fd;
}
return address;
}
|
