runtime_loader.h revision ebdc1d48
1/*
2 * Copyright 2008-2009, Ingo Weinhold, ingo_weinhold@gmx.de.
3 * Copyright 2003-2011, Axel D��rfler, axeld@pinc-software.de.
4 * Distributed under the terms of the MIT License.
5 *
6 * Copyright 2002, Manuel J. Petit. All rights reserved.
7 * Copyright 2001, Travis Geiselbrecht. All rights reserved.
8 * Distributed under the terms of the NewOS License.
9 */
10
11#ifndef _RUNTIME_LOADER_H
12#define _RUNTIME_LOADER_H
13
14#include <image.h>
15#include <OS.h>
16
17#include <elf32.h>
18#include <elf64.h>
19
20
21// #pragma mark - runtime loader libroot interface
22
23
24struct user_space_program_args;
25struct SymbolLookupInfo;
26
27struct rld_export {
28	// runtime loader API export
29	image_id (*load_add_on)(char const *path, uint32 flags);
30	status_t (*unload_add_on)(image_id imageID);
31	image_id (*load_library)(char const *path, uint32 flags, void **_handle);
32	status_t (*unload_library)(void* handle);
33	status_t (*get_image_symbol)(image_id imageID, char const *symbolName,
34		int32 symbolType, bool recursive, image_id *_inImage, void **_location);
35	status_t (*get_library_symbol)(void* handle, void* caller,
36		const char* symbolName, void **_location);
37	status_t (*get_nth_image_symbol)(image_id imageID, int32 num,
38		char *symbolName, int32 *nameLength, int32 *symbolType,
39		void **_location);
40	status_t (*get_nearest_symbol_at_address)(void* address,
41		image_id* _imageID,	char** _imagePath, char** _imageName,
42		char** _symbolName, int32* _type, void** _location, bool* _exactMatch);
43	status_t (*test_executable)(const char *path, char *interpreter);
44	status_t (*get_executable_architecture)(const char *path,
45		const char** _architecture);
46	status_t (*get_next_image_dependency)(image_id id, uint32 *cookie,
47		const char **_name);
48	void* (*get_tls_address)(unsigned dso, addr_t offset);
49	void (*destroy_thread_tls)();
50
51	status_t (*reinit_after_fork)();
52
53	void (*call_atexit_hooks_for_range)(addr_t start, addr_t size);
54
55	void (*call_termination_hooks)();
56
57	const struct user_space_program_args *program_args;
58	const void* commpage_address;
59	int abi_version;
60};
61
62extern struct rld_export *__gRuntimeLoader;
63
64
65// #pragma mark - runtime loader debugger interface
66
67
68struct RuntimeLoaderSymbolPatcher;
69
70typedef struct elf_region_t {
71	area_id		id;
72	addr_t		start;
73	addr_t		size;
74	addr_t		vmstart;
75	addr_t		vmsize;
76	addr_t		fdstart;
77	addr_t		fdsize;
78	long		delta;
79	uint32		flags;
80} elf_region_t;
81
82typedef struct elf_version_info {
83	uint32		hash;			// version name hash
84	const char	*name;			// version name
85	const char	*file_name;		// dependency file name (needed versions only)
86} elf_version_info;
87
88typedef struct image_t {
89	// image identification
90	char				path[B_PATH_NAME_LENGTH];
91	char				name[B_OS_NAME_LENGTH];
92	image_id			id;
93	image_type			type;
94
95	struct image_t		*next;
96	struct image_t		*prev;
97	int32				ref_count;
98	uint32				flags;
99
100	uint32				api_version;
101	uint32				abi;
102
103	addr_t 				entry_point;
104	addr_t				init_routine;
105	addr_t				term_routine;
106	addr_t 				dynamic_ptr; 	// pointer to the dynamic section
107
108	// pointer to symbol participation data structures
109	uint32				*symhash;
110	elf_sym				*syms;
111	char				*strtab;
112	elf_rel				*rel;
113	int					rel_len;
114	elf_rela			*rela;
115	int					rela_len;
116	elf_rel				*pltrel;
117	int					pltrel_len;
118
119	unsigned			dso_tls_id;
120
121	uint32				num_needed;
122	struct image_t		**needed;
123
124	// versioning related structures
125	uint32				num_version_definitions;
126	elf_verdef			*version_definitions;
127	uint32				num_needed_versions;
128	elf_verneed			*needed_versions;
129	elf_versym			*symbol_versions;
130	elf_version_info	*versions;
131	uint32				num_versions;
132
133#ifdef __cplusplus
134	elf_sym*			(*find_undefined_symbol)(struct image_t* rootImage,
135							struct image_t* image,
136							const SymbolLookupInfo& lookupInfo,
137							struct image_t** foundInImage);
138#else
139	elf_sym*			(*find_undefined_symbol)(struct image_t* rootImage,
140							struct image_t* image,
141							const struct SymbolLookupInfo* lookupInfo,
142							struct image_t** foundInImage);
143#endif
144
145	// Singly-linked list of symbol patchers for symbols defined respectively
146	// referenced by this image.
147	struct RuntimeLoaderSymbolPatcher	*defined_symbol_patchers;
148	struct RuntimeLoaderSymbolPatcher	*undefined_symbol_patchers;
149
150	// describes the text and data regions
151	uint32				num_regions;
152	elf_region_t		regions[1];
153} image_t;
154
155typedef struct image_queue_t {
156	image_t *head;
157	image_t *tail;
158} image_queue_t;
159
160// image_t::flags
161#define	IMAGE_FLAG_RTLD_MASK			0x03
162			// RTLD_{LAZY,NOW} | RTLD_{LOCAL,GLOBAL}
163
164#define STRING(image, offset) ((char*)(&(image)->strtab[(offset)]))
165#define SYMNAME(image, sym) STRING(image, (sym)->st_name)
166#define SYMBOL(image, num) (&(image)->syms[num])
167#define HASHTABSIZE(image) ((image)->symhash[0])
168#define HASHBUCKETS(image) ((unsigned int*)&(image)->symhash[2])
169#define HASHCHAINS(image) ((unsigned int*)&(image)->symhash[2+HASHTABSIZE(image)])
170
171
172// The name of the area the runtime loader creates for debugging purposes.
173#define RUNTIME_LOADER_DEBUG_AREA_NAME	"_rld_debug_"
174
175// The contents of the runtime loader debug area.
176typedef struct runtime_loader_debug_area {
177	image_queue_t	*loaded_images;
178} runtime_loader_debug_area;
179
180
181// #pragma mark - runtime loader add-on interface
182
183
184// symbol patcher callback
185typedef void runtime_loader_symbol_patcher(void* cookie,
186	struct image_t* rootImage, struct image_t* image, const char* name,
187	struct image_t** foundInImage, void** symbol, int32* type);
188
189// interface provided to add-ons
190struct runtime_loader_add_on_export {
191	status_t	(*register_defined_symbol_patcher)(struct image_t* image,
192					runtime_loader_symbol_patcher* patcher, void* cookie);
193	void		(*unregister_defined_symbol_patcher)(struct image_t* image,
194					runtime_loader_symbol_patcher* patcher, void* cookie);
195	status_t	(*register_undefined_symbol_patcher)(struct image_t* image,
196					runtime_loader_symbol_patcher* patcher, void* cookie);
197	void		(*unregister_undefined_symbol_patcher)(struct image_t* image,
198					runtime_loader_symbol_patcher* patcher, void* cookie);
199};
200
201
202#define RUNTIME_LOADER_ADD_ON_VERSION	1
203
204typedef struct runtime_loader_add_on {
205	uint32	version;
206	uint32	flags;
207
208	// called after the add-on image has been loaded
209	void	(*init)(struct rld_export* standardInterface,
210				struct runtime_loader_add_on_export* addOnInterface);
211
212	// called whenever the respective image event occurs
213	void	(*image_loaded)(struct image_t* image);
214	void	(*image_relocated)(struct image_t* image);
215	void	(*image_initialized)(struct image_t* image);
216	void	(*image_uninitializing)(struct image_t* image);
217	void	(*image_unloading)(struct image_t* image);
218} runtime_loader_add_on;
219
220// This is the variable a preloaded shared object has to export to get picked up
221// by the runtime loader as an add-on.
222extern runtime_loader_add_on __gRuntimeLoaderAddOn;
223
224#endif	// _RUNTIME_LOADER_H
225