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
|
/* Copyright (C) 2011-2022 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/>. */
#define E(name) E_(name, CLASS)
#define E_(name, cl) E__(name, cl)
#define E__(name, cl) name##cl
#define EW(type) EW_(Elf, CLASS, type)
#define EW_(e, w, t) EW__(e, w, _##t)
#define EW__(e, w, t) e##w##t
#include <dl-r_debug.h>
struct E(link_map)
{
EW(Addr) l_addr;
EW(Addr) l_name;
EW(Addr) l_ld;
EW(Addr) l_next;
EW(Addr) l_prev;
EW(Addr) l_real;
Lmid_t l_ns;
EW(Addr) l_libname;
};
#if CLASS == __ELF_NATIVE_CLASS
_Static_assert (offsetof (struct link_map, l_addr)
== offsetof (struct E(link_map), l_addr), "l_addr");
_Static_assert (offsetof (struct link_map, l_name)
== offsetof (struct E(link_map), l_name), "l_name");
_Static_assert (offsetof (struct link_map, l_next)
== offsetof (struct E(link_map), l_next), "l_next");
#endif
struct E(libname_list)
{
EW(Addr) name;
EW(Addr) next;
};
#if CLASS == __ELF_NATIVE_CLASS
_Static_assert (offsetof (struct libname_list, name)
== offsetof (struct E(libname_list), name), "name");
_Static_assert (offsetof (struct libname_list, next)
== offsetof (struct E(libname_list), next), "next");
#endif
struct E(r_debug)
{
int r_version;
#if CLASS == 64
int pad;
#endif
EW(Addr) r_map;
};
#if CLASS == __ELF_NATIVE_CLASS
_Static_assert (offsetof (struct r_debug, r_version)
== offsetof (struct E(r_debug), r_version), "r_version");
_Static_assert (offsetof (struct r_debug, r_map)
== offsetof (struct E(r_debug), r_map), "r_map");
#endif
static int
E(find_maps) (const char *exe, int memfd, pid_t pid, void *auxv,
size_t auxv_size)
{
EW(Addr) phdr = 0;
unsigned int phnum = 0;
unsigned int phent = 0;
EW(auxv_t) *auxvXX = (EW(auxv_t) *) auxv;
for (int i = 0; i < auxv_size / sizeof (EW(auxv_t)); ++i)
switch (auxvXX[i].a_type)
{
case AT_PHDR:
phdr = auxvXX[i].a_un.a_val;
break;
case AT_PHNUM:
phnum = auxvXX[i].a_un.a_val;
break;
case AT_PHENT:
phent = auxvXX[i].a_un.a_val;
break;
default:
break;
}
if (phdr == 0 || phnum == 0 || phent == 0)
error (EXIT_FAILURE, 0, gettext ("cannot find program header of process"));
EW(Phdr) *p = xmalloc (phnum * phent);
if (pread (memfd, p, phnum * phent, phdr) != phnum * phent)
error (EXIT_FAILURE, 0, gettext ("cannot read program header"));
/* Determine the load offset. We need this for interpreting the
other program header entries so we do this in a separate loop.
Fortunately it is the first time unless someone does something
stupid when linking the application. */
EW(Addr) offset = 0;
for (unsigned int i = 0; i < phnum; ++i)
if (p[i].p_type == PT_PHDR)
{
offset = phdr - p[i].p_vaddr;
break;
}
EW(Addr) list = 0;
char *interp = NULL;
for (unsigned int i = 0; i < phnum; ++i)
if (p[i].p_type == PT_DYNAMIC)
{
EW(Dyn) *dyn = xmalloc (p[i].p_filesz);
if (pread (memfd, dyn, p[i].p_filesz, offset + p[i].p_vaddr)
!= p[i].p_filesz)
error (EXIT_FAILURE, 0, gettext ("cannot read dynamic section"));
/* Search for the struct r_debug. */
for (unsigned int j = 0; j < p[i].p_filesz / sizeof (EW(Dyn)); ++j)
{
EW(Addr) off = offset + p[i].p_vaddr + sizeof (EW(Dyn)) * j;
off = E(r_debug_offset) (&dyn[j], memfd, off);
if (off != 0)
{
struct E(r_debug) r;
if (pread (memfd, &r, sizeof (r), off)
!= sizeof (r))
error (EXIT_FAILURE, 0, gettext ("cannot read r_debug"));
if (r.r_map != 0)
{
list = r.r_map;
break;
}
}
}
free (dyn);
break;
}
else if (p[i].p_type == PT_INTERP)
{
interp = xmalloc (p[i].p_filesz);
if (pread (memfd, interp, p[i].p_filesz, offset + p[i].p_vaddr)
!= p[i].p_filesz)
error (EXIT_FAILURE, 0, gettext ("cannot read program interpreter"));
}
if (list == 0)
{
if (interp == NULL)
{
// XXX check whether the executable itself is the loader
exit (EXIT_FAILURE);
}
// XXX perhaps try finding ld.so and _r_debug in it
exit (EXIT_FAILURE);
}
free (p);
free (interp);
/* Print the PID and program name first. */
printf ("%lu:\t%s\n", (unsigned long int) pid, exe);
/* Iterate over the list of objects and print the information. */
struct scratch_buffer tmpbuf;
scratch_buffer_init (&tmpbuf);
int status = 0;
do
{
struct E(link_map) m;
if (pread (memfd, &m, sizeof (m), list) != sizeof (m))
error (EXIT_FAILURE, 0, gettext ("cannot read link map"));
EW(Addr) name_offset = m.l_name;
while (1)
{
ssize_t n = pread (memfd, tmpbuf.data, tmpbuf.length, name_offset);
if (n == -1)
error (EXIT_FAILURE, 0, gettext ("cannot read object name"));
if (memchr (tmpbuf.data, '\0', n) != NULL)
break;
if (!scratch_buffer_grow (&tmpbuf))
error (EXIT_FAILURE, 0,
gettext ("cannot allocate buffer for object name"));
}
/* The m.l_name and m.l_libname.name for loader linkmap points to same
values (since BZ#387 fix). Trying to use l_libname name as the
shared object name might lead to an infinite loop (BZ#18035). */
/* Skip over the executable. */
if (((char *)tmpbuf.data)[0] != '\0')
printf ("%s\n", (char *)tmpbuf.data);
list = m.l_next;
}
while (list != 0);
scratch_buffer_free (&tmpbuf);
return status;
}
#undef CLASS
|
