1 // SPDX-License-Identifier: GPL-2.0-only 1
2 // Copyright 2023 Google LLC
3 // Authors: Ard Biesheuvel <ardb@google.com>
4 // Peter Collingbourne <pcc@google.co
5
6 #include <linux/elf.h>
7 #include <linux/init.h>
8 #include <linux/types.h>
9
10 #include "pi.h"
11
12 extern const Elf64_Rela rela_start[], rela_end
13 extern const u64 relr_start[], relr_end[];
14
15 void __init relocate_kernel(u64 offset)
16 {
17 u64 *place = NULL;
18
19 for (const Elf64_Rela *rela = rela_sta
20 if (ELF64_R_TYPE(rela->r_info)
21 continue;
22 *(u64 *)(rela->r_offset + offs
23 }
24
25 if (!IS_ENABLED(CONFIG_RELR) || !offse
26 return;
27
28 /*
29 * Apply RELR relocations.
30 *
31 * RELR is a compressed format for sto
32 * encoded sequence of entries looks l
33 * [ AAAAAAAA BBBBBBB1 BBBBBBB1 ... AA
34 *
35 * i.e. start with an address, followe
36 * address entry encodes 1 relocation.
37 * encode up to 63 relocations each, a
38 * the last address entry.
39 *
40 * The bitmap entries must have 1 in t
41 * assumption here is that an address
42 * addresses are not supported. Any od
43 * RELA section, which is handled abov
44 *
45 * With the exception of the least sig
46 * bitmap corresponds with a machine w
47 * word, and the bit value indicates w
48 * to be applied to it. The second lea
49 * machine word immediately following
50 * that follows represents the next wo
51 * single bitmap can encode up to 63 r
52 */
53 for (const u64 *relr = relr_start; rel
54 if ((*relr & 1) == 0) {
55 place = (u64 *)(*relr
56 *place++ += offset;
57 } else {
58 for (u64 *p = place, r
59 if (r & 1)
60 *p +=
61 place += 63;
62 }
63 }
64 }
65
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