1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* Module internals
3 *
4 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#include <linux/elf.h>
9#include <linux/compiler.h>
10#include <linux/module.h>
11#include <linux/mutex.h>
12#include <linux/rculist.h>
13#include <linux/rcupdate.h>
14#include <linux/mm.h>
15
16#ifndef ARCH_SHF_SMALL
17#define ARCH_SHF_SMALL 0
18#endif
19
20/* If this is set, the section belongs in the init part of the module */
21#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG - 1))
22/* Maximum number of characters written by module_flags() */
23#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
24
25#ifndef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
26#define	data_layout core_layout
27#endif
28
29/*
30 * Modules' sections will be aligned on page boundaries
31 * to ensure complete separation of code and data, but
32 * only when CONFIG_STRICT_MODULE_RWX=y
33 */
34static inline unsigned int strict_align(unsigned int size)
35{
36	if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
37		return PAGE_ALIGN(size);
38	else
39		return size;
40}
41
42extern struct mutex module_mutex;
43extern struct list_head modules;
44
45extern struct module_attribute *modinfo_attrs[];
46extern size_t modinfo_attrs_count;
47
48/* Provided by the linker */
49extern const struct kernel_symbol __start___ksymtab[];
50extern const struct kernel_symbol __stop___ksymtab[];
51extern const struct kernel_symbol __start___ksymtab_gpl[];
52extern const struct kernel_symbol __stop___ksymtab_gpl[];
53extern const s32 __start___kcrctab[];
54extern const s32 __start___kcrctab_gpl[];
55
56struct load_info {
57	const char *name;
58	/* pointer to module in temporary copy, freed at end of load_module() */
59	struct module *mod;
60	Elf_Ehdr *hdr;
61	unsigned long len;
62	Elf_Shdr *sechdrs;
63	char *secstrings, *strtab;
64	unsigned long symoffs, stroffs, init_typeoffs, core_typeoffs;
65	struct _ddebug *debug;
66	unsigned int num_debug;
67	bool sig_ok;
68#ifdef CONFIG_KALLSYMS
69	unsigned long mod_kallsyms_init_off;
70#endif
71#ifdef CONFIG_MODULE_DECOMPRESS
72	struct page **pages;
73	unsigned int max_pages;
74	unsigned int used_pages;
75#endif
76	struct {
77		unsigned int sym, str, mod, vers, info, pcpu;
78	} index;
79};
80
81enum mod_license {
82	NOT_GPL_ONLY,
83	GPL_ONLY,
84};
85
86struct find_symbol_arg {
87	/* Input */
88	const char *name;
89	bool gplok;
90	bool warn;
91
92	/* Output */
93	struct module *owner;
94	const s32 *crc;
95	const struct kernel_symbol *sym;
96	enum mod_license license;
97};
98
99int mod_verify_sig(const void *mod, struct load_info *info);
100int try_to_force_load(struct module *mod, const char *reason);
101bool find_symbol(struct find_symbol_arg *fsa);
102struct module *find_module_all(const char *name, size_t len, bool even_unformed);
103int cmp_name(const void *name, const void *sym);
104long module_get_offset(struct module *mod, unsigned int *size, Elf_Shdr *sechdr,
105		       unsigned int section);
106char *module_flags(struct module *mod, char *buf, bool show_state);
107size_t module_flags_taint(unsigned long taints, char *buf);
108
109static inline void module_assert_mutex_or_preempt(void)
110{
111#ifdef CONFIG_LOCKDEP
112	if (unlikely(!debug_locks))
113		return;
114
115	WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
116		     !lockdep_is_held(&module_mutex));
117#endif
118}
119
120static inline unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
121{
122#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
123	return (unsigned long)offset_to_ptr(&sym->value_offset);
124#else
125	return sym->value;
126#endif
127}
128
129#ifdef CONFIG_LIVEPATCH
130int copy_module_elf(struct module *mod, struct load_info *info);
131void free_module_elf(struct module *mod);
132#else /* !CONFIG_LIVEPATCH */
133static inline int copy_module_elf(struct module *mod, struct load_info *info)
134{
135	return 0;
136}
137
138static inline void free_module_elf(struct module *mod) { }
139#endif /* CONFIG_LIVEPATCH */
140
141static inline bool set_livepatch_module(struct module *mod)
142{
143#ifdef CONFIG_LIVEPATCH
144	mod->klp = true;
145	return true;
146#else
147	return false;
148#endif
149}
150
151#ifdef CONFIG_MODULE_UNLOAD_TAINT_TRACKING
152struct mod_unload_taint {
153	struct list_head list;
154	char name[MODULE_NAME_LEN];
155	unsigned long taints;
156	u64 count;
157};
158
159int try_add_tainted_module(struct module *mod);
160void print_unloaded_tainted_modules(void);
161#else /* !CONFIG_MODULE_UNLOAD_TAINT_TRACKING */
162static inline int try_add_tainted_module(struct module *mod)
163{
164	return 0;
165}
166
167static inline void print_unloaded_tainted_modules(void)
168{
169}
170#endif /* CONFIG_MODULE_UNLOAD_TAINT_TRACKING */
171
172#ifdef CONFIG_MODULE_DECOMPRESS
173int module_decompress(struct load_info *info, const void *buf, size_t size);
174void module_decompress_cleanup(struct load_info *info);
175#else
176static inline int module_decompress(struct load_info *info,
177				    const void *buf, size_t size)
178{
179	return -EOPNOTSUPP;
180}
181
182static inline void module_decompress_cleanup(struct load_info *info)
183{
184}
185#endif
186
187struct mod_tree_root {
188#ifdef CONFIG_MODULES_TREE_LOOKUP
189	struct latch_tree_root root;
190#endif
191	unsigned long addr_min;
192	unsigned long addr_max;
193};
194
195extern struct mod_tree_root mod_tree;
196extern struct mod_tree_root mod_data_tree;
197
198#ifdef CONFIG_MODULES_TREE_LOOKUP
199void mod_tree_insert(struct module *mod);
200void mod_tree_remove_init(struct module *mod);
201void mod_tree_remove(struct module *mod);
202struct module *mod_find(unsigned long addr, struct mod_tree_root *tree);
203#else /* !CONFIG_MODULES_TREE_LOOKUP */
204
205static inline void mod_tree_insert(struct module *mod) { }
206static inline void mod_tree_remove_init(struct module *mod) { }
207static inline void mod_tree_remove(struct module *mod) { }
208static inline struct module *mod_find(unsigned long addr, struct mod_tree_root *tree)
209{
210	struct module *mod;
211
212	list_for_each_entry_rcu(mod, &modules, list,
213				lockdep_is_held(&module_mutex)) {
214		if (within_module(addr, mod))
215			return mod;
216	}
217
218	return NULL;
219}
220#endif /* CONFIG_MODULES_TREE_LOOKUP */
221
222void module_enable_ro(const struct module *mod, bool after_init);
223void module_enable_nx(const struct module *mod);
224void module_enable_x(const struct module *mod);
225int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
226				char *secstrings, struct module *mod);
227bool module_check_misalignment(const struct module *mod);
228
229#ifdef CONFIG_MODULE_SIG
230int module_sig_check(struct load_info *info, int flags);
231#else /* !CONFIG_MODULE_SIG */
232static inline int module_sig_check(struct load_info *info, int flags)
233{
234	return 0;
235}
236#endif /* !CONFIG_MODULE_SIG */
237
238#ifdef CONFIG_DEBUG_KMEMLEAK
239void kmemleak_load_module(const struct module *mod, const struct load_info *info);
240#else /* !CONFIG_DEBUG_KMEMLEAK */
241static inline void kmemleak_load_module(const struct module *mod,
242					const struct load_info *info) { }
243#endif /* CONFIG_DEBUG_KMEMLEAK */
244
245#ifdef CONFIG_KALLSYMS
246void init_build_id(struct module *mod, const struct load_info *info);
247void layout_symtab(struct module *mod, struct load_info *info);
248void add_kallsyms(struct module *mod, const struct load_info *info);
249unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
250
251static inline bool sect_empty(const Elf_Shdr *sect)
252{
253	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
254}
255#else /* !CONFIG_KALLSYMS */
256static inline void init_build_id(struct module *mod, const struct load_info *info) { }
257static inline void layout_symtab(struct module *mod, struct load_info *info) { }
258static inline void add_kallsyms(struct module *mod, const struct load_info *info) { }
259#endif /* CONFIG_KALLSYMS */
260
261#ifdef CONFIG_SYSFS
262int mod_sysfs_setup(struct module *mod, const struct load_info *info,
263		    struct kernel_param *kparam, unsigned int num_params);
264void mod_sysfs_teardown(struct module *mod);
265void init_param_lock(struct module *mod);
266#else /* !CONFIG_SYSFS */
267static inline int mod_sysfs_setup(struct module *mod,
268			   	  const struct load_info *info,
269			   	  struct kernel_param *kparam,
270			   	  unsigned int num_params)
271{
272	return 0;
273}
274
275static inline void mod_sysfs_teardown(struct module *mod) { }
276static inline void init_param_lock(struct module *mod) { }
277#endif /* CONFIG_SYSFS */
278
279#ifdef CONFIG_MODVERSIONS
280int check_version(const struct load_info *info,
281		  const char *symname, struct module *mod, const s32 *crc);
282void module_layout(struct module *mod, struct modversion_info *ver, struct kernel_param *kp,
283		   struct kernel_symbol *ks, struct tracepoint * const *tp);
284int check_modstruct_version(const struct load_info *info, struct module *mod);
285int same_magic(const char *amagic, const char *bmagic, bool has_crcs);
286#else /* !CONFIG_MODVERSIONS */
287static inline int check_version(const struct load_info *info,
288				const char *symname,
289				struct module *mod,
290				const s32 *crc)
291{
292	return 1;
293}
294
295static inline int check_modstruct_version(const struct load_info *info,
296					  struct module *mod)
297{
298	return 1;
299}
300
301static inline int same_magic(const char *amagic, const char *bmagic, bool has_crcs)
302{
303	return strcmp(amagic, bmagic) == 0;
304}
305#endif /* CONFIG_MODVERSIONS */
306