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 */
17 bool module_elf_check_arch(Elf_Ehdr *hdr);
18
19 /* Adjust arch-specific sections. Return 0 on success. */
20 int 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 */
26 unsigned 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. */
30 void *module_alloc(unsigned long size);
31
32 /* Free memory returned from module_alloc. */
33 void 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 */
38 bool 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 */
43 bool 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 */
48 bool 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
55 int apply_relocate(Elf_Shdr *sechdrs,
56 const char *strtab,
57 unsigned int symindex,
58 unsigned int relsec,
59 struct module *mod);
60 #else
apply_relocate(Elf_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)61 static 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
78 int 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 */
94 void 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
apply_relocate_add(Elf_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)101 static 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. */
114 int module_finalize(const Elf_Ehdr *hdr,
115 const Elf_Shdr *sechdrs,
116 struct module *mod);
117
118 #ifdef CONFIG_MODULES
119 void flush_module_init_free_work(void);
120 #else
flush_module_init_free_work(void)121 static inline void flush_module_init_free_work(void)
122 {
123 }
124 #endif
125
126 /* Any cleanup needed when module leaves. */
127 void module_arch_cleanup(struct module *mod);
128
129 /* Any cleanup before freeing mod->module_init */
130 void 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