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/* Allocator used for allocating struct module, core sections and init
29   sections.  Returns NULL on failure. */
30void *module_alloc(unsigned long size);
31
32/* Free memory returned from module_alloc. */
33void module_memfree(void *module_region);
34
35/* Determines if the section name is an init section (that is only used during
36 * module loading).
37 */
38bool module_init_section(const char *name);
39
40/* Determines if the section name is an exit section (that is only used during
41 * module unloading)
42 */
43bool module_exit_section(const char *name);
44
45/* Describes whether within_module_init() will consider this an init section
46 * or not. This behaviour changes with CONFIG_MODULE_UNLOAD.
47 */
48bool module_init_layout_section(const char *sname);
49
50/*
51 * Apply the given relocation to the (simplified) ELF.  Return -error
52 * or 0.
53 */
54#ifdef CONFIG_MODULES_USE_ELF_REL
55int apply_relocate(Elf_Shdr *sechdrs,
56		   const char *strtab,
57		   unsigned int symindex,
58		   unsigned int relsec,
59		   struct module *mod);
60#else
61static inline int apply_relocate(Elf_Shdr *sechdrs,
62				 const char *strtab,
63				 unsigned int symindex,
64				 unsigned int relsec,
65				 struct module *me)
66{
67	printk(KERN_ERR "module %s: REL relocation unsupported\n",
68	       module_name(me));
69	return -ENOEXEC;
70}
71#endif
72
73/*
74 * Apply the given add relocation to the (simplified) ELF.  Return
75 * -error or 0
76 */
77#ifdef CONFIG_MODULES_USE_ELF_RELA
78int apply_relocate_add(Elf_Shdr *sechdrs,
79		       const char *strtab,
80		       unsigned int symindex,
81		       unsigned int relsec,
82		       struct module *mod);
83#ifdef CONFIG_LIVEPATCH
84/*
85 * Some architectures (namely x86_64 and ppc64) perform sanity checks when
86 * applying relocations.  If a patched module gets unloaded and then later
87 * reloaded (and re-patched), klp re-applies relocations to the replacement
88 * function(s).  Any leftover relocations from the previous loading of the
89 * patched module might trigger the sanity checks.
90 *
91 * To prevent that, when unloading a patched module, clear out any relocations
92 * that might trigger arch-specific sanity checks on a future module reload.
93 */
94void clear_relocate_add(Elf_Shdr *sechdrs,
95		   const char *strtab,
96		   unsigned int symindex,
97		   unsigned int relsec,
98		   struct module *me);
99#endif
100#else
101static inline int apply_relocate_add(Elf_Shdr *sechdrs,
102				     const char *strtab,
103				     unsigned int symindex,
104				     unsigned int relsec,
105				     struct module *me)
106{
107	printk(KERN_ERR "module %s: REL relocation unsupported\n",
108	       module_name(me));
109	return -ENOEXEC;
110}
111#endif
112
113/* Any final processing of module before access.  Return -error or 0. */
114int module_finalize(const Elf_Ehdr *hdr,
115		    const Elf_Shdr *sechdrs,
116		    struct module *mod);
117
118#ifdef CONFIG_MODULES
119void flush_module_init_free_work(void);
120#else
121static inline void flush_module_init_free_work(void)
122{
123}
124#endif
125
126/* Any cleanup needed when module leaves. */
127void module_arch_cleanup(struct module *mod);
128
129/* Any cleanup before freeing mod->module_init */
130void module_arch_freeing_init(struct module *mod);
131
132#if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
133		!defined(CONFIG_KASAN_VMALLOC)
134#include <linux/kasan.h>
135#define MODULE_ALIGN (PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
136#else
137#define MODULE_ALIGN PAGE_SIZE
138#endif
139
140#endif
141