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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_MODULELOADER_H
3#define _LINUX_MODULELOADER_H
4/* The stuff needed for archs to support modules. */
5
6#include <linux/module.h>
7#include <linux/elf.h>
8
9/* These may be implemented by architectures that need to hook into the
10 * module loader code. Architectures that don't need to do anything special
11 * can just rely on the 'weak' default hooks defined in kernel/module.c.
12 * Note, however, that at least one of apply_relocate or apply_relocate_add
13 * must be implemented by each architecture.
14 */
15
16/* arch may override to do additional checking of ELF header architecture */
17bool module_elf_check_arch(Elf_Ehdr *hdr);
18
19/* Adjust arch-specific sections. Return 0 on success. */
20int module_frob_arch_sections(Elf_Ehdr *hdr,
21 Elf_Shdr *sechdrs,
22 char *secstrings,
23 struct module *mod);
24
25/* Additional bytes needed by arch in front of individual sections */
26unsigned int arch_mod_section_prepend(struct module *mod, unsigned int section);
27
28/* Determines if the section name is an init section (that is only used during
29 * module loading).
30 */
31bool module_init_section(const char *name);
32
33/* Determines if the section name is an exit section (that is only used during
34 * module unloading)
35 */
36bool module_exit_section(const char *name);
37
38/* Describes whether within_module_init() will consider this an init section
39 * or not. This behaviour changes with CONFIG_MODULE_UNLOAD.
40 */
41bool module_init_layout_section(const char *sname);
42
43/*
44 * Apply the given relocation to the (simplified) ELF. Return -error
45 * or 0.
46 */
47#ifdef CONFIG_MODULES_USE_ELF_REL
48int apply_relocate(Elf_Shdr *sechdrs,
49 const char *strtab,
50 unsigned int symindex,
51 unsigned int relsec,
52 struct module *mod);
53#else
54static inline int apply_relocate(Elf_Shdr *sechdrs,
55 const char *strtab,
56 unsigned int symindex,
57 unsigned int relsec,
58 struct module *me)
59{
60 printk(KERN_ERR "module %s: REL relocation unsupported\n",
61 module_name(me));
62 return -ENOEXEC;
63}
64#endif
65
66/*
67 * Apply the given add relocation to the (simplified) ELF. Return
68 * -error or 0
69 */
70#ifdef CONFIG_MODULES_USE_ELF_RELA
71int apply_relocate_add(Elf_Shdr *sechdrs,
72 const char *strtab,
73 unsigned int symindex,
74 unsigned int relsec,
75 struct module *mod);
76#ifdef CONFIG_LIVEPATCH
77/*
78 * Some architectures (namely x86_64 and ppc64) perform sanity checks when
79 * applying relocations. If a patched module gets unloaded and then later
80 * reloaded (and re-patched), klp re-applies relocations to the replacement
81 * function(s). Any leftover relocations from the previous loading of the
82 * patched module might trigger the sanity checks.
83 *
84 * To prevent that, when unloading a patched module, clear out any relocations
85 * that might trigger arch-specific sanity checks on a future module reload.
86 */
87void clear_relocate_add(Elf_Shdr *sechdrs,
88 const char *strtab,
89 unsigned int symindex,
90 unsigned int relsec,
91 struct module *me);
92#endif
93#else
94static inline int apply_relocate_add(Elf_Shdr *sechdrs,
95 const char *strtab,
96 unsigned int symindex,
97 unsigned int relsec,
98 struct module *me)
99{
100 printk(KERN_ERR "module %s: REL relocation unsupported\n",
101 module_name(me));
102 return -ENOEXEC;
103}
104#endif
105
106/* Any final processing of module before access. Return -error or 0. */
107int module_finalize(const Elf_Ehdr *hdr,
108 const Elf_Shdr *sechdrs,
109 struct module *mod);
110
111#ifdef CONFIG_MODULES
112void flush_module_init_free_work(void);
113#else
114static inline void flush_module_init_free_work(void)
115{
116}
117#endif
118
119/* Any cleanup needed when module leaves. */
120void module_arch_cleanup(struct module *mod);
121
122/* Any cleanup before freeing mod->module_init */
123void module_arch_freeing_init(struct module *mod);
124
125#endif
126

source code of linux/include/linux/moduleloader.h