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
|
// vim:ts=8:sw=2:et:
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "leaky.h"
#ifdef USE_BFD
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <libgen.h>
#include <bfd.h>
#include <cxxabi.h>
static bfd *try_debug_file(const char *filename, unsigned long crc32)
{
int fd = open(filename, O_RDONLY);
if (fd < 0)
return nullptr;
unsigned char buf[4*1024];
unsigned long crc = 0;
while (1) {
ssize_t count = read(fd, buf, sizeof(buf));
if (count <= 0)
break;
crc = bfd_calc_gnu_debuglink_crc32(crc, buf, count);
}
close(fd);
if (crc != crc32)
return nullptr;
bfd *object = bfd_openr(filename, nullptr);
if (!bfd_check_format(object, bfd_object)) {
bfd_close(object);
return nullptr;
}
return object;
}
static bfd *find_debug_file(bfd *lib, const char *aFileName)
{
// check for a separate debug file with symbols
asection *sect = bfd_get_section_by_name(lib, ".gnu_debuglink");
if (!sect)
return nullptr;
bfd_size_type debuglinkSize = bfd_section_size (objfile->obfd, sect);
char *debuglink = new char[debuglinkSize];
bfd_get_section_contents(lib, sect, debuglink, 0, debuglinkSize);
// crc checksum is aligned to 4 bytes, and after the NUL.
int crc_offset = (int(strlen(debuglink)) & ~3) + 4;
unsigned long crc32 = bfd_get_32(lib, debuglink + crc_offset);
// directory component
char *dirbuf = strdup(aFileName);
const char *dir = dirname(dirbuf);
static const char debug_subdir[] = ".debug";
// This is gdb's default global debugging info directory, but gdb can
// be instructed to use a different directory.
static const char global_debug_dir[] = "/usr/lib/debug";
char *filename =
new char[strlen(global_debug_dir) + strlen(dir) + crc_offset + 3];
// /path/debuglink
sprintf(filename, "%s/%s", dir, debuglink);
bfd *debugFile = try_debug_file(filename, crc32);
if (!debugFile) {
// /path/.debug/debuglink
sprintf(filename, "%s/%s/%s", dir, debug_subdir, debuglink);
debugFile = try_debug_file(filename, crc32);
if (!debugFile) {
// /usr/lib/debug/path/debuglink
sprintf(filename, "%s/%s/%s", global_debug_dir, dir, debuglink);
debugFile = try_debug_file(filename, crc32);
}
}
delete[] filename;
free(dirbuf);
delete[] debuglink;
return debugFile;
}
// Use an indirect array to avoid copying tons of objects
Symbol ** leaky::ExtendSymbols(int num)
{
long n = numExternalSymbols + num;
externalSymbols = (Symbol**)
realloc(externalSymbols,
(size_t) (sizeof(externalSymbols[0]) * n));
Symbol *new_array = new Symbol[n];
for (int i = 0; i < num; i++) {
externalSymbols[i + numExternalSymbols] = &new_array[i];
}
lastSymbol = externalSymbols + n;
Symbol **sp = externalSymbols + numExternalSymbols;
numExternalSymbols = n;
return sp;
}
#define NEXT_SYMBOL do { sp++; \
if (sp >= lastSymbol) { \
sp = ExtendSymbols(16384); \
} \
} while (0)
void leaky::ReadSymbols(const char *aFileName, u_long aBaseAddress)
{
int initialSymbols = usefulSymbols;
if (nullptr == externalSymbols) {
externalSymbols = (Symbol**) calloc(sizeof(Symbol*),10000);
Symbol *new_array = new Symbol[10000];
for (int i = 0; i < 10000; i++) {
externalSymbols[i] = &new_array[i];
}
numExternalSymbols = 10000;
}
Symbol** sp = externalSymbols + usefulSymbols;
lastSymbol = externalSymbols + numExternalSymbols;
// Create a dummy symbol for the library so, if it doesn't have any
// symbols, we show it by library.
(*sp)->Init(aFileName, aBaseAddress);
NEXT_SYMBOL;
bfd_boolean kDynamic = (bfd_boolean) false;
static int firstTime = 1;
if (firstTime) {
firstTime = 0;
bfd_init ();
}
bfd* lib = bfd_openr(aFileName, nullptr);
if (nullptr == lib) {
return;
}
if (!bfd_check_format(lib, bfd_object)) {
bfd_close(lib);
return;
}
bfd *symbolFile = find_debug_file(lib, aFileName);
// read mini symbols
PTR minisyms;
unsigned int size;
long symcount = 0;
if (symbolFile) {
symcount = bfd_read_minisymbols(symbolFile, kDynamic, &minisyms, &size);
if (symcount == 0) {
bfd_close(symbolFile);
} else {
bfd_close(lib);
}
}
if (symcount == 0) {
symcount = bfd_read_minisymbols(lib, kDynamic, &minisyms, &size);
if (symcount == 0) {
// symtab is empty; try dynamic symbols
kDynamic = (bfd_boolean) true;
symcount = bfd_read_minisymbols(lib, kDynamic, &minisyms, &size);
}
symbolFile = lib;
}
asymbol* store;
store = bfd_make_empty_symbol(symbolFile);
// Scan symbols
size_t demangle_buffer_size = 128;
char *demangle_buffer = (char*) malloc(demangle_buffer_size);
bfd_byte* from = (bfd_byte *) minisyms;
bfd_byte* fromend = from + symcount * size;
for (; from < fromend; from += size) {
asymbol *sym;
sym = bfd_minisymbol_to_symbol(symbolFile, kDynamic, (const PTR) from, store);
symbol_info syminfo;
bfd_get_symbol_info (symbolFile, sym, &syminfo);
// if ((syminfo.type == 'T') || (syminfo.type == 't')) {
const char* nm = bfd_asymbol_name(sym);
if (nm && nm[0]) {
char* dnm = nullptr;
if (strncmp("__thunk", nm, 7)) {
dnm =
abi::__cxa_demangle(nm, demangle_buffer, &demangle_buffer_size, 0);
if (dnm) {
demangle_buffer = dnm;
}
}
(*sp)->Init(dnm ? dnm : nm, syminfo.value + aBaseAddress);
NEXT_SYMBOL;
}
// }
}
free(demangle_buffer);
demangle_buffer = nullptr;
bfd_close(symbolFile);
int interesting = sp - externalSymbols;
if (!quiet) {
printf("%s provided %d symbols\n", aFileName,
interesting - initialSymbols);
}
usefulSymbols = interesting;
}
#endif /* USE_BFD */
|
