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 /* Determines if the section name is an init section (that is only used during
29 * module loading).
30 */
31 bool 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 */
36 bool 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 */
41 bool 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
48 int apply_relocate(Elf_Shdr *sechdrs,
49 const char *strtab,
50 unsigned int symindex,
51 unsigned int relsec,
52 struct module *mod);
53 #else
apply_relocate(Elf_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)54 static 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
71 int 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 */
87 void 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
apply_relocate_add(Elf_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)94 static 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. */
107 int module_finalize(const Elf_Ehdr *hdr,
108 const Elf_Shdr *sechdrs,
109 struct module *mod);
110
111 #ifdef CONFIG_MODULES
112 void flush_module_init_free_work(void);
113 #else
flush_module_init_free_work(void)114 static inline void flush_module_init_free_work(void)
115 {
116 }
117 #endif
118
119 /* Any cleanup needed when module leaves. */
120 void module_arch_cleanup(struct module *mod);
121
122 /* Any cleanup before freeing mod->module_init */
123 void module_arch_freeing_init(struct module *mod);
124
125 #endif
126