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 /*
46 * Apply the given relocation to the (simplified) ELF. Return -error
47 * or 0.
48 */
49 #ifdef CONFIG_MODULES_USE_ELF_REL
50 int apply_relocate(Elf_Shdr *sechdrs,
51 const char *strtab,
52 unsigned int symindex,
53 unsigned int relsec,
54 struct module *mod);
55 #else
apply_relocate(Elf_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)56 static inline int apply_relocate(Elf_Shdr *sechdrs,
57 const char *strtab,
58 unsigned int symindex,
59 unsigned int relsec,
60 struct module *me)
61 {
62 printk(KERN_ERR "module %s: REL relocation unsupported\n",
63 module_name(me));
64 return -ENOEXEC;
65 }
66 #endif
67
68 /*
69 * Apply the given add relocation to the (simplified) ELF. Return
70 * -error or 0
71 */
72 #ifdef CONFIG_MODULES_USE_ELF_RELA
73 int apply_relocate_add(Elf_Shdr *sechdrs,
74 const char *strtab,
75 unsigned int symindex,
76 unsigned int relsec,
77 struct module *mod);
78 #ifdef CONFIG_LIVEPATCH
79 /*
80 * Some architectures (namely x86_64 and ppc64) perform sanity checks when
81 * applying relocations. If a patched module gets unloaded and then later
82 * reloaded (and re-patched), klp re-applies relocations to the replacement
83 * function(s). Any leftover relocations from the previous loading of the
84 * patched module might trigger the sanity checks.
85 *
86 * To prevent that, when unloading a patched module, clear out any relocations
87 * that might trigger arch-specific sanity checks on a future module reload.
88 */
89 void clear_relocate_add(Elf_Shdr *sechdrs,
90 const char *strtab,
91 unsigned int symindex,
92 unsigned int relsec,
93 struct module *me);
94 #endif
95 #else
apply_relocate_add(Elf_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)96 static inline int apply_relocate_add(Elf_Shdr *sechdrs,
97 const char *strtab,
98 unsigned int symindex,
99 unsigned int relsec,
100 struct module *me)
101 {
102 printk(KERN_ERR "module %s: REL relocation unsupported\n",
103 module_name(me));
104 return -ENOEXEC;
105 }
106 #endif
107
108 /* Any final processing of module before access. Return -error or 0. */
109 int module_finalize(const Elf_Ehdr *hdr,
110 const Elf_Shdr *sechdrs,
111 struct module *mod);
112
113 /* Any cleanup needed when module leaves. */
114 void module_arch_cleanup(struct module *mod);
115
116 /* Any cleanup before freeing mod->module_init */
117 void module_arch_freeing_init(struct module *mod);
118
119 #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
120 !defined(CONFIG_KASAN_VMALLOC)
121 #include <linux/kasan.h>
122 #define MODULE_ALIGN (PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
123 #else
124 #define MODULE_ALIGN PAGE_SIZE
125 #endif
126
127 #endif
128