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
|
/* dl-x86_64.c - arch-dependent part of loadable module support */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2002,2005,2007,2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/dl.h>
#include <grub/elf.h>
#include <grub/misc.h>
#include <grub/err.h>
#include <grub/i18n.h>
/* Check if EHDR is a valid ELF header. */
grub_err_t
grub_arch_dl_check_header (void *ehdr)
{
Elf64_Ehdr *e = ehdr;
/* Check the magic numbers. */
if (e->e_ident[EI_CLASS] != ELFCLASS64
|| e->e_ident[EI_DATA] != ELFDATA2LSB
|| e->e_machine != EM_X86_64)
return grub_error (GRUB_ERR_BAD_OS, N_("invalid arch-dependent ELF magic"));
return GRUB_ERR_NONE;
}
/* Relocate symbols. */
grub_err_t
grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr,
Elf_Shdr *s, grub_dl_segment_t seg)
{
Elf64_Rela *rel, *max;
for (rel = (Elf64_Rela *) ((char *) ehdr + s->sh_offset),
max = (Elf64_Rela *) ((char *) rel + s->sh_size);
rel < max;
rel = (Elf64_Rela *) ((char *) rel + s->sh_entsize))
{
Elf64_Word *addr32;
Elf64_Xword *addr64;
Elf64_Sym *sym;
if (seg->size < rel->r_offset)
return grub_error (GRUB_ERR_BAD_MODULE,
"reloc offset is out of the segment");
addr32 = (Elf64_Word *) ((char *) seg->addr + rel->r_offset);
addr64 = (Elf64_Xword *) addr32;
sym = (Elf64_Sym *) ((char *) mod->symtab
+ mod->symsize * ELF_R_SYM (rel->r_info));
switch (ELF_R_TYPE (rel->r_info))
{
case R_X86_64_64:
*addr64 += rel->r_addend + sym->st_value;
break;
case R_X86_64_PC32:
case R_X86_64_PLT32:
{
grub_int64_t value;
value = ((grub_int32_t) *addr32) + rel->r_addend + sym->st_value -
(Elf64_Xword) (grub_addr_t) seg->addr - rel->r_offset;
if (value != (grub_int32_t) value)
return grub_error (GRUB_ERR_BAD_MODULE, "relocation out of range");
*addr32 = value;
}
break;
case R_X86_64_PC64:
{
*addr64 += rel->r_addend + sym->st_value -
(Elf64_Xword) (grub_addr_t) seg->addr - rel->r_offset;
}
break;
case R_X86_64_32:
{
grub_uint64_t value = *addr32 + rel->r_addend + sym->st_value;
if (value != (grub_uint32_t) value)
return grub_error (GRUB_ERR_BAD_MODULE, "relocation out of range");
*addr32 = value;
}
break;
case R_X86_64_32S:
{
grub_int64_t value = ((grub_int32_t) *addr32) + rel->r_addend + sym->st_value;
if (value != (grub_int32_t) value)
return grub_error (GRUB_ERR_BAD_MODULE, "relocation out of range");
*addr32 = value;
}
break;
default:
{
char rel_info[17]; /* log16(2^64) = 16, plus NUL. */
grub_snprintf (rel_info, sizeof (rel_info) - 1, "%" PRIxGRUB_UINT64_T,
ELF_R_TYPE (rel->r_info));
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
N_("relocation 0x%s is not implemented yet"), rel_info);
}
}
}
return GRUB_ERR_NONE;
}
|
