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
|
/*
* arch/xtensa/kernel/module.c
*
* Module support.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2006 Tensilica Inc.
*
* Chris Zankel <chris@zankel.net>
*
*/
#include <linux/module.h>
#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/cache.h>
#undef DEBUG_RELOCATE
static int
decode_calln_opcode (unsigned char *location)
{
#ifdef __XTENSA_EB__
return (location[0] & 0xf0) == 0x50;
#endif
#ifdef __XTENSA_EL__
return (location[0] & 0xf) == 0x5;
#endif
}
static int
decode_l32r_opcode (unsigned char *location)
{
#ifdef __XTENSA_EB__
return (location[0] & 0xf0) == 0x10;
#endif
#ifdef __XTENSA_EL__
return (location[0] & 0xf) == 0x1;
#endif
}
int apply_relocate_add(Elf32_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
unsigned int relsec,
struct module *mod)
{
unsigned int i;
Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
Elf32_Sym *sym;
unsigned char *location;
uint32_t value;
#ifdef DEBUG_RELOCATE
printk("Applying relocate section %u to %u\n", relsec,
sechdrs[relsec].sh_info);
#endif
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
location = (char *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ rela[i].r_offset;
sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+ ELF32_R_SYM(rela[i].r_info);
value = sym->st_value + rela[i].r_addend;
switch (ELF32_R_TYPE(rela[i].r_info)) {
case R_XTENSA_NONE:
case R_XTENSA_DIFF8:
case R_XTENSA_DIFF16:
case R_XTENSA_DIFF32:
case R_XTENSA_ASM_EXPAND:
break;
case R_XTENSA_32:
case R_XTENSA_PLT:
*(uint32_t *)location += value;
break;
case R_XTENSA_SLOT0_OP:
if (decode_calln_opcode(location)) {
value -= ((unsigned long)location & -4) + 4;
if ((value & 3) != 0 ||
((value + (1 << 19)) >> 20) != 0) {
printk("%s: relocation out of range, "
"section %d reloc %d "
"sym '%s'\n",
mod->name, relsec, i,
strtab + sym->st_name);
return -ENOEXEC;
}
value = (signed int)value >> 2;
#ifdef __XTENSA_EB__
location[0] = ((location[0] & ~0x3) |
((value >> 16) & 0x3));
location[1] = (value >> 8) & 0xff;
location[2] = value & 0xff;
#endif
#ifdef __XTENSA_EL__
location[0] = ((location[0] & ~0xc0) |
((value << 6) & 0xc0));
location[1] = (value >> 2) & 0xff;
location[2] = (value >> 10) & 0xff;
#endif
} else if (decode_l32r_opcode(location)) {
value -= (((unsigned long)location + 3) & -4);
if ((value & 3) != 0 ||
(signed int)value >> 18 != -1) {
printk("%s: relocation out of range, "
"section %d reloc %d "
"sym '%s'\n",
mod->name, relsec, i,
strtab + sym->st_name);
return -ENOEXEC;
}
value = (signed int)value >> 2;
#ifdef __XTENSA_EB__
location[1] = (value >> 8) & 0xff;
location[2] = value & 0xff;
#endif
#ifdef __XTENSA_EL__
location[1] = value & 0xff;
location[2] = (value >> 8) & 0xff;
#endif
}
/* FIXME: Ignore any other opcodes. The Xtensa
assembler currently assumes that the linker will
always do relaxation and so all PC-relative
operands need relocations. (The assembler also
writes out the tentative PC-relative values,
assuming no link-time relaxation, so it is usually
safe to ignore the relocations.) If the
assembler's "--no-link-relax" flag can be made to
work, and if all kernel modules can be assembled
with that flag, then unexpected relocations could
be detected here. */
break;
case R_XTENSA_SLOT1_OP:
case R_XTENSA_SLOT2_OP:
case R_XTENSA_SLOT3_OP:
case R_XTENSA_SLOT4_OP:
case R_XTENSA_SLOT5_OP:
case R_XTENSA_SLOT6_OP:
case R_XTENSA_SLOT7_OP:
case R_XTENSA_SLOT8_OP:
case R_XTENSA_SLOT9_OP:
case R_XTENSA_SLOT10_OP:
case R_XTENSA_SLOT11_OP:
case R_XTENSA_SLOT12_OP:
case R_XTENSA_SLOT13_OP:
case R_XTENSA_SLOT14_OP:
printk("%s: unexpected FLIX relocation: %u\n",
mod->name,
ELF32_R_TYPE(rela[i].r_info));
return -ENOEXEC;
case R_XTENSA_SLOT0_ALT:
case R_XTENSA_SLOT1_ALT:
case R_XTENSA_SLOT2_ALT:
case R_XTENSA_SLOT3_ALT:
case R_XTENSA_SLOT4_ALT:
case R_XTENSA_SLOT5_ALT:
case R_XTENSA_SLOT6_ALT:
case R_XTENSA_SLOT7_ALT:
case R_XTENSA_SLOT8_ALT:
case R_XTENSA_SLOT9_ALT:
case R_XTENSA_SLOT10_ALT:
case R_XTENSA_SLOT11_ALT:
case R_XTENSA_SLOT12_ALT:
case R_XTENSA_SLOT13_ALT:
case R_XTENSA_SLOT14_ALT:
printk("%s: unexpected ALT relocation: %u\n",
mod->name,
ELF32_R_TYPE(rela[i].r_info));
return -ENOEXEC;
default:
printk("%s: unexpected relocation: %u\n",
mod->name,
ELF32_R_TYPE(rela[i].r_info));
return -ENOEXEC;
}
}
return 0;
}
|
