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
|
/* dl.c - arch-dependent part of loadable module support */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2013 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/mm.h>
#include <grub/i18n.h>
#include <grub/cpu/reloc.h>
#define LDR 0x58000050
#define BR 0xd61f0200
/*
* Check if EHDR is a valid ELF header.
*/
grub_err_t
grub_arch_dl_check_header (void *ehdr)
{
Elf_Ehdr *e = ehdr;
/* Check the magic numbers. */
if (e->e_ident[EI_CLASS] != ELFCLASS64
|| e->e_ident[EI_DATA] != ELFDATA2LSB || e->e_machine != EM_AARCH64)
return grub_error (GRUB_ERR_BAD_OS,
N_("invalid arch-dependent ELF magic"));
return GRUB_ERR_NONE;
}
#pragma GCC diagnostic ignored "-Wcast-align"
/*
* Unified function for both REL and RELA
*/
grub_err_t
grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr,
Elf_Shdr *s, grub_dl_segment_t seg)
{
Elf_Rel *rel, *max;
unsigned unmatched_adr_got_page = 0;
for (rel = (Elf_Rel *) ((char *) ehdr + s->sh_offset),
max = (Elf_Rel *) ((char *) rel + s->sh_size);
rel < max;
rel = (Elf_Rel *) ((char *) rel + s->sh_entsize))
{
Elf_Sym *sym;
void *place;
grub_uint64_t sym_addr;
if (rel->r_offset >= seg->size)
return grub_error (GRUB_ERR_BAD_MODULE,
"reloc offset is out of the segment");
sym = (Elf_Sym *) ((char *) mod->symtab
+ mod->symsize * ELF_R_SYM (rel->r_info));
sym_addr = sym->st_value;
if (s->sh_type == SHT_RELA)
sym_addr += ((Elf_Rela *) rel)->r_addend;
place = (void *) ((grub_addr_t) seg->addr + rel->r_offset);
switch (ELF_R_TYPE (rel->r_info))
{
case R_AARCH64_ABS64:
{
grub_uint64_t *abs_place = place;
grub_dprintf ("dl", " reloc_abs64 %p => 0x%016llx\n",
place, (unsigned long long) sym_addr);
*abs_place = (grub_uint64_t) sym_addr;
}
break;
case R_AARCH64_ADD_ABS_LO12_NC:
grub_arm64_set_abs_lo12 (place, sym_addr);
break;
case R_AARCH64_LDST64_ABS_LO12_NC:
grub_arm64_set_abs_lo12_ldst64 (place, sym_addr);
break;
case R_AARCH64_CALL26:
case R_AARCH64_JUMP26:
{
grub_int64_t offset = sym_addr - (grub_uint64_t) place;
if (!grub_arm_64_check_xxxx26_offset (offset))
{
struct grub_arm64_trampoline *tp = mod->trampptr;
mod->trampptr = tp + 1;
tp->ldr = LDR;
tp->br = BR;
tp->addr = sym_addr;
offset = (grub_uint8_t *) tp - (grub_uint8_t *) place;
}
if (!grub_arm_64_check_xxxx26_offset (offset))
return grub_error (GRUB_ERR_BAD_MODULE,
"trampoline out of range");
grub_arm64_set_xxxx26_offset (place, offset);
}
break;
case R_AARCH64_PREL32:
{
grub_int64_t value;
Elf64_Word *addr32 = place;
value = ((grub_int32_t) *addr32) + sym_addr -
(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");
grub_dprintf("dl", " reloc_prel32 %p => 0x%016llx\n",
place, (unsigned long long) sym_addr);
*addr32 = value;
}
break;
case R_AARCH64_ADR_GOT_PAGE:
{
grub_uint64_t *gp = mod->gotptr;
Elf_Rela *rel2;
grub_int64_t gpoffset = ((grub_uint64_t) gp & ~0xfffULL) - (((grub_uint64_t) place) & ~0xfffULL);
*gp = (grub_uint64_t) sym_addr;
mod->gotptr = gp + 1;
unmatched_adr_got_page++;
grub_dprintf("dl", " reloc_got %p => 0x%016llx (0x%016llx)\n",
place, (unsigned long long) sym_addr, (unsigned long long) gp);
if (!grub_arm64_check_hi21_signed (gpoffset))
return grub_error (GRUB_ERR_BAD_MODULE,
"HI21 out of range");
grub_arm64_set_hi21(place, gpoffset);
for (rel2 = (Elf_Rela *) ((char *) rel + s->sh_entsize);
rel2 < (Elf_Rela *) max;
rel2 = (Elf_Rela *) ((char *) rel2 + s->sh_entsize))
if (ELF_R_SYM (rel2->r_info)
== ELF_R_SYM (rel->r_info)
&& ((Elf_Rela *) rel)->r_addend == rel2->r_addend
&& ELF_R_TYPE (rel2->r_info) == R_AARCH64_LD64_GOT_LO12_NC)
{
grub_arm64_set_abs_lo12_ldst64 ((void *) ((grub_addr_t) seg->addr + rel2->r_offset),
(grub_uint64_t)gp);
break;
}
if (rel2 >= (Elf_Rela *) max)
return grub_error (GRUB_ERR_BAD_MODULE,
"ADR_GOT_PAGE without matching LD64_GOT_LO12_NC");
}
break;
case R_AARCH64_LD64_GOT_LO12_NC:
if (unmatched_adr_got_page == 0)
return grub_error (GRUB_ERR_BAD_MODULE,
"LD64_GOT_LO12_NC without matching ADR_GOT_PAGE");
unmatched_adr_got_page--;
break;
case R_AARCH64_ADR_PREL_PG_HI21:
{
grub_int64_t offset = (sym_addr & ~0xfffULL) - (((grub_uint64_t) place) & ~0xfffULL);
if (!grub_arm64_check_hi21_signed (offset))
return grub_error (GRUB_ERR_BAD_MODULE,
"HI21 out of range");
grub_arm64_set_hi21 (place, offset);
}
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;
}
|
