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1/*
2 * Copyright (C) 2012 ARM Ltd.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16#ifndef __ASM_MODULE_H
17#define __ASM_MODULE_H
18
19#include <asm-generic/module.h>
20
21#define MODULE_ARCH_VERMAGIC "aarch64"
22
23#ifdef CONFIG_ARM64_MODULE_PLTS
24struct mod_plt_sec {
25 int plt_shndx;
26 int plt_num_entries;
27 int plt_max_entries;
28};
29
30struct mod_arch_specific {
31 struct mod_plt_sec core;
32 struct mod_plt_sec init;
33
34 /* for CONFIG_DYNAMIC_FTRACE */
35 struct plt_entry *ftrace_trampoline;
36};
37#endif
38
39u64 module_emit_plt_entry(struct module *mod, Elf64_Shdr *sechdrs,
40 void *loc, const Elf64_Rela *rela,
41 Elf64_Sym *sym);
42
43u64 module_emit_veneer_for_adrp(struct module *mod, Elf64_Shdr *sechdrs,
44 void *loc, u64 val);
45
46#ifdef CONFIG_RANDOMIZE_BASE
47extern u64 module_alloc_base;
48#else
49#define module_alloc_base ((u64)_etext - MODULES_VSIZE)
50#endif
51
52struct plt_entry {
53 /*
54 * A program that conforms to the AArch64 Procedure Call Standard
55 * (AAPCS64) must assume that a veneer that alters IP0 (x16) and/or
56 * IP1 (x17) may be inserted at any branch instruction that is
57 * exposed to a relocation that supports long branches. Since that
58 * is exactly what we are dealing with here, we are free to use x16
59 * as a scratch register in the PLT veneers.
60 */
61 __le32 adrp; /* adrp x16, .... */
62 __le32 add; /* add x16, x16, #0x.... */
63 __le32 br; /* br x16 */
64};
65
66static inline bool is_forbidden_offset_for_adrp(void *place)
67{
68 return IS_ENABLED(CONFIG_ARM64_ERRATUM_843419) &&
69 cpus_have_const_cap(ARM64_WORKAROUND_843419) &&
70 ((u64)place & 0xfff) >= 0xff8;
71}
72
73struct plt_entry get_plt_entry(u64 dst, void *pc);
74bool plt_entries_equal(const struct plt_entry *a, const struct plt_entry *b);
75
76#endif /* __ASM_MODULE_H */