Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2024 Google LLC
4 */
5
6#include <dwarf.h>
7#include <elfutils/libdw.h>
8#include <elfutils/libdwfl.h>
9#include <stdlib.h>
10#include <stdio.h>
11
12#include <hash.h>
13#include <hashtable.h>
14#include <xalloc.h>
15
16#ifndef __GENDWARFKSYMS_H
17#define __GENDWARFKSYMS_H
18
19/*
20 * Options -- in gendwarfksyms.c
21 */
22extern int debug;
23extern int dump_dies;
24extern int dump_die_map;
25extern int dump_types;
26extern int dump_versions;
27extern int stable;
28extern int symtypes;
29
30/*
31 * Output helpers
32 */
33#define __PREFIX "gendwarfksyms: "
34#define __println(prefix, format, ...) \
35 fprintf(stderr, prefix __PREFIX "%s: " format "\n", __func__, \
36 ##__VA_ARGS__)
37
38#define debug(format, ...) \
39 do { \
40 if (debug) \
41 __println("", format, ##__VA_ARGS__); \
42 } while (0)
43
44#define warn(format, ...) __println("warning: ", format, ##__VA_ARGS__)
45#define error(format, ...) \
46 do { \
47 __println("error: ", format, ##__VA_ARGS__); \
48 exit(1); \
49 } while (0)
50
51#define __die_debug(color, format, ...) \
52 do { \
53 if (dump_dies && dump_die_map) \
54 fprintf(stderr, \
55 "\033[" #color "m<" format ">\033[39m", \
56 __VA_ARGS__); \
57 } while (0)
58
59#define die_debug_r(format, ...) __die_debug(91, format, __VA_ARGS__)
60#define die_debug_g(format, ...) __die_debug(92, format, __VA_ARGS__)
61#define die_debug_b(format, ...) __die_debug(94, format, __VA_ARGS__)
62
63/*
64 * Error handling helpers
65 */
66#define __check(expr, test) \
67 ({ \
68 int __res = expr; \
69 if (test) \
70 error("`%s` failed: %d", #expr, __res); \
71 __res; \
72 })
73
74/* Error == non-zero values */
75#define check(expr) __check(expr, __res)
76/* Error == negative values */
77#define checkp(expr) __check(expr, __res < 0)
78
79/* Consistent aliases (DW_TAG_<type>_type) for DWARF tags */
80#define DW_TAG_enumerator_type DW_TAG_enumerator
81#define DW_TAG_formal_parameter_type DW_TAG_formal_parameter
82#define DW_TAG_member_type DW_TAG_member
83#define DW_TAG_template_type_parameter_type DW_TAG_template_type_parameter
84#define DW_TAG_typedef_type DW_TAG_typedef
85#define DW_TAG_variant_part_type DW_TAG_variant_part
86#define DW_TAG_variant_type DW_TAG_variant
87
88/*
89 * symbols.c
90 */
91
92/* See symbols.c:is_symbol_ptr */
93#define SYMBOL_PTR_PREFIX "__gendwarfksyms_ptr_"
94#define SYMBOL_PTR_PREFIX_LEN (sizeof(SYMBOL_PTR_PREFIX) - 1)
95
96static inline unsigned int addr_hash(uintptr_t addr)
97{
98 return hash_ptr((const void *)addr);
99}
100
101enum symbol_state {
102 SYMBOL_UNPROCESSED,
103 SYMBOL_MAPPED,
104 SYMBOL_PROCESSED
105};
106
107struct symbol_addr {
108 uint32_t section;
109 Elf64_Addr address;
110};
111
112struct symbol {
113 const char *name;
114 struct symbol_addr addr;
115 struct hlist_node addr_hash;
116 struct hlist_node name_hash;
117 enum symbol_state state;
118 uintptr_t die_addr;
119 uintptr_t ptr_die_addr;
120 unsigned long crc;
121};
122
123typedef void (*symbol_callback_t)(struct symbol *, void *arg);
124
125bool is_symbol_ptr(const char *name);
126int symbol_read_exports(FILE *file);
127void symbol_read_symtab(int fd);
128struct symbol *symbol_get(const char *name);
129void symbol_set_ptr(struct symbol *sym, Dwarf_Die *ptr);
130void symbol_set_die(struct symbol *sym, Dwarf_Die *die);
131void symbol_set_crc(struct symbol *sym, unsigned long crc);
132void symbol_for_each(symbol_callback_t func, void *arg);
133void symbol_print_versions(void);
134void symbol_free(void);
135
136/*
137 * die.c
138 */
139
140enum die_state {
141 DIE_INCOMPLETE,
142 DIE_FQN,
143 DIE_UNEXPANDED,
144 DIE_COMPLETE,
145 DIE_SYMBOL,
146 DIE_LAST = DIE_SYMBOL
147};
148
149enum die_fragment_type {
150 FRAGMENT_EMPTY,
151 FRAGMENT_STRING,
152 FRAGMENT_LINEBREAK,
153 FRAGMENT_DIE
154};
155
156struct die_fragment {
157 enum die_fragment_type type;
158 union {
159 char *str;
160 int linebreak;
161 uintptr_t addr;
162 } data;
163 struct list_head list;
164};
165
166#define CASE_CONST_TO_STR(name) \
167 case name: \
168 return #name;
169
170static inline const char *die_state_name(enum die_state state)
171{
172 switch (state) {
173 CASE_CONST_TO_STR(DIE_INCOMPLETE)
174 CASE_CONST_TO_STR(DIE_FQN)
175 CASE_CONST_TO_STR(DIE_UNEXPANDED)
176 CASE_CONST_TO_STR(DIE_COMPLETE)
177 CASE_CONST_TO_STR(DIE_SYMBOL)
178 }
179
180 error("unexpected die_state: %d", state);
181}
182
183struct die {
184 enum die_state state;
185 bool mapped;
186 char *fqn;
187 int tag;
188 uintptr_t addr;
189 struct list_head fragments;
190 struct hlist_node hash;
191};
192
193typedef void (*die_map_callback_t)(struct die *, void *arg);
194
195int __die_map_get(uintptr_t addr, enum die_state state, struct die **res);
196struct die *die_map_get(Dwarf_Die *die, enum die_state state);
197void die_map_add_string(struct die *pd, const char *str);
198void die_map_add_linebreak(struct die *pd, int linebreak);
199void die_map_for_each(die_map_callback_t func, void *arg);
200void die_map_add_die(struct die *pd, struct die *child);
201void die_map_free(void);
202
203/*
204 * cache.c
205 */
206
207#define CACHE_HASH_BITS 10
208
209/* A cache for addresses we've already seen. */
210struct cache {
211 HASHTABLE_DECLARE(cache, 1 << CACHE_HASH_BITS);
212};
213
214void cache_set(struct cache *cache, unsigned long key, int value);
215int cache_get(struct cache *cache, unsigned long key);
216void cache_init(struct cache *cache);
217void cache_free(struct cache *cache);
218
219static inline void cache_mark_expanded(struct cache *cache, void *addr)
220{
221 cache_set(cache, (unsigned long)addr, 1);
222}
223
224static inline bool cache_was_expanded(struct cache *cache, void *addr)
225{
226 return cache_get(cache, (unsigned long)addr) == 1;
227}
228
229/*
230 * dwarf.c
231 */
232
233struct expansion_state {
234 bool expand;
235 const char *current_fqn;
236};
237
238struct kabi_state {
239 int members;
240 Dwarf_Die placeholder;
241 const char *orig_name;
242};
243
244struct state {
245 struct symbol *sym;
246 Dwarf_Die die;
247
248 /* List expansion */
249 bool first_list_item;
250
251 /* Structure expansion */
252 struct expansion_state expand;
253 struct cache expansion_cache;
254
255 /* Reserved or ignored members */
256 struct kabi_state kabi;
257};
258
259typedef int (*die_callback_t)(struct state *state, struct die *cache,
260 Dwarf_Die *die);
261typedef bool (*die_match_callback_t)(Dwarf_Die *die);
262bool match_all(Dwarf_Die *die);
263
264int process_die_container(struct state *state, struct die *cache,
265 Dwarf_Die *die, die_callback_t func,
266 die_match_callback_t match);
267
268void process_cu(Dwarf_Die *cudie);
269
270/*
271 * types.c
272 */
273
274void generate_symtypes_and_versions(FILE *file);
275
276/*
277 * kabi.c
278 */
279
280bool kabi_get_byte_size(const char *fqn, unsigned long *value);
281bool kabi_is_enumerator_ignored(const char *fqn, const char *field);
282bool kabi_get_enumerator_value(const char *fqn, const char *field,
283 unsigned long *value);
284bool kabi_is_declonly(const char *fqn);
285bool kabi_get_type_string(const char *type, const char **str);
286
287void kabi_read_rules(int fd);
288void kabi_free(void);
289
290#endif /* __GENDWARFKSYMS_H */