[deliverable/babeltrace.git] / include / babeltrace / so-info.h

#ifndef _BABELTRACE_SO_INFO_H
#define _BABELTRACE_SO_INFO_H

/*
 * Babeltrace - Executable and Shared Object Debug Info Reader
 *
 * Copyright 2015 Antoine Busque <abusque@efficios.com>
 *
 * Author: Antoine Busque <abusque@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <stdint.h>
#include <stdbool.h>
#include <gelf.h>
#include <elfutils/libdw.h>
#include <babeltrace/babeltrace-internal.h>

#define DEFAULT_DEBUG_DIR "/usr/lib/debug"
#define DEBUG_SUBDIR ".debug/"
#define BUILD_ID_SUBDIR ".build-id/"
#define BUILD_ID_SUFFIX ".debug"

struct so_info {
	/* Base virtual memory address. */
	uint64_t low_addr;
	/* Upper bound of exec address space. */
	uint64_t high_addr;
	/* Size of exec address space. */
	uint64_t memsz;
	/* Paths to ELF and DWARF files. */
	char *elf_path;
	char *dwarf_path;
	/* libelf and libdw objects representing the files. */
	Elf *elf_file;
	Dwarf *dwarf_info;
	/* Optional build ID info. */
	uint8_t *build_id;
	size_t build_id_len;
	/* Optional debug link info. */
	char *dbg_link_filename;
	uint32_t dbg_link_crc;
	/* FDs to ELF and DWARF files. */
	int elf_fd;
	int dwarf_fd;
	/* Denotes whether the executable is position independent code. */
	bool is_pic:1;
	/* Denotes whether the SO only has ELF symbols and no DWARF info. */
	bool is_elf_only:1;
};

struct source_location {
	uint64_t line_no;
	char *filename;
};

/**
 * Initializes the so_info framework. Call this before calling
 * anything else.
 *
 * @returns		0 on success, -1 on failure
 */
BT_HIDDEN
int so_info_init(void);

/**
 * Instantiate a structure representing an ELF executable, possibly
 * with DWARF info, located at the given path.
 *
 * @param path		Path to the ELF file
 * @param low_addr	Base address of the executable
 * @param memsz	In-memory size of the executable
 * @returns		Pointer to the new so_info on success,
 *			NULL on failure.
 */
BT_HIDDEN
struct so_info *so_info_create(const char *path, uint64_t low_addr,
		uint64_t memsz);

/**
 * Destroy the given so_info instance
 *
 * @param so	so_info instance to destroy
 */
BT_HIDDEN
void so_info_destroy(struct so_info *so);

/**
 * Sets the build ID information for a given so_info instance.
 *
 * @param so		The so_info instance for which to set
 *			the build ID
 * @param build_id	Array of bytes containing the actual ID
 * @param build_id_len	Length in bytes of the build_id
 * @returns		0 on success, -1 on failure
 */
BT_HIDDEN
int so_info_set_build_id(struct so_info *so, uint8_t *build_id,
		size_t build_id_len);

/**
 * Sets the debug link information for a given so_info instance.
 *
 * @param so		The so_info instance for which to set
 *			the debug link
 * @param filename	Name of the separate debug info file
 * @param crc		Checksum for the debug info file
 * @returns		0 on success, -1 on failure
 */
BT_HIDDEN
int so_info_set_debug_link(struct so_info *so, char *filename, uint32_t crc);

/**
 * Returns whether or not the given SO info \p so contains the address
 * \p addr.
 *
 * @param so		so_info instance
 * @param addr		Address to lookup
 * @returns		1 if \p so contains \p addr, 0 if it does not,
 *			-1 on failure
 */
static inline
int so_info_has_address(struct so_info *so, uint64_t addr)
{
	if (!so) {
		return -1;
	}

	return addr >= so->low_addr && addr < so->high_addr;
}

/**
 * Get the name of the function containing a given address within an
 * executable.
 *
 * If no DWARF info is available, the function falls back to ELF
 * symbols and the "function name" is in fact the name of the closest
 * symbol, followed by the offset between the symbol and the address.
 *
 * On success, if found, the out parameter `func_name` is set. The ownership
 * of `func_name` is passed to the caller. On failure, `func_name` remains
 * unchanged.
 *
 * @param so		so_info instance for the executable containing
 *			the address
 * @param addr		Virtual memory address for which to find the
 *			function name
 * @param func_name	Out parameter, the function name.
 * @returns		0 on success, -1 on failure
 */
BT_HIDDEN
int so_info_lookup_function_name(struct so_info *so, uint64_t addr,
		char **func_name);

/**
 * Get the source location (file name and line number) for a given
 * address within an executable.
 *
 * If no DWARF info is available, the source location cannot be found
 * and the function will return unsuccesfully.
 *
 * On success, if found, the out parameter `src_loc` is set. The ownership
 * of `src_loc` is passed to the caller. On failure, `src_loc` remains
 * unchanged.
 *
 * @param so		so_info instance for the executable containing
 *			the address
 * @param addr		Virtual memory address for which to find the
 *			source location
 * @param src_loc	Out parameter, the source location
 * @returns		0 on success, -1 on failure
 */
BT_HIDDEN
int so_info_lookup_source_location(struct so_info *so, uint64_t addr,
		struct source_location **src_loc);

/**
 * Destroy the given source_location instance
 *
 * @param src_loc	source_location instance to destroy
 */
BT_HIDDEN
void source_location_destroy(struct source_location *src_loc);

#endif	/* _BABELTRACE_SO_INFO_H */
Commit	Line	Data
b5a8598f AB	1	#ifndef _BABELTRACE_SO_INFO_H
	2	#define _BABELTRACE_SO_INFO_H
	3
	4	/*
	5	* Babeltrace - Executable and Shared Object Debug Info Reader
	6	*
	7	* Copyright 2015 Antoine Busque <abusque@efficios.com>
	8	*
	9	* Author: Antoine Busque <abusque@efficios.com>
	10	*
	11	* Permission is hereby granted, free of charge, to any person obtaining a copy
	12	* of this software and associated documentation files (the "Software"), to deal
	13	* in the Software without restriction, including without limitation the rights
	14	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	15	* copies of the Software, and to permit persons to whom the Software is
	16	* furnished to do so, subject to the following conditions:
	17	*
	18	* The above copyright notice and this permission notice shall be included in
	19	* all copies or substantial portions of the Software.
	20	*
	21	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	22	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	23	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	24	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	25	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	26	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	27	* SOFTWARE.
	28	*/
	29
	30	#include <stdint.h>
	31	#include <stdbool.h>
	32	#include <gelf.h>
	33	#include <elfutils/libdw.h>
	34	#include <babeltrace/babeltrace-internal.h>
	35
	36	#define DEFAULT_DEBUG_DIR "/usr/lib/debug"
	37	#define DEBUG_SUBDIR ".debug/"
	38	#define BUILD_ID_SUBDIR ".build-id/"
	39	#define BUILD_ID_SUFFIX ".debug"
	40
	41	struct so_info {
	42	/* Base virtual memory address. */
	43	uint64_t low_addr;
	44	/* Upper bound of exec address space. */
	45	uint64_t high_addr;
	46	/* Size of exec address space. */
	47	uint64_t memsz;
	48	/* Paths to ELF and DWARF files. */
	49	char *elf_path;
	50	char *dwarf_path;
	51	/* libelf and libdw objects representing the files. */
	52	Elf *elf_file;
	53	Dwarf *dwarf_info;
	54	/* Optional build ID info. */
	55	uint8_t *build_id;
	56	size_t build_id_len;
	57	/* Optional debug link info. */
	58	char *dbg_link_filename;
	59	uint32_t dbg_link_crc;
	60	/* FDs to ELF and DWARF files. */
	61	int elf_fd;
	62	int dwarf_fd;
	63	/* Denotes whether the executable is position independent code. */
	64	bool is_pic:1;
65	/* Denotes whether the SO only has ELF symbols and no DWARF info. */
66	bool is_elf_only:1;
67	};
68
69	struct source_location {
70	uint64_t line_no;
71	char *filename;
72	};
73
74	/**
75	* Initializes the so_info framework. Call this before calling
76	* anything else.
77	*
78	* @returns 0 on success, -1 on failure
79	*/
80	BT_HIDDEN
81	int so_info_init(void);
82
83	/**
84	* Instantiate a structure representing an ELF executable, possibly
85	* with DWARF info, located at the given path.
86	*
87	* @param path Path to the ELF file
88	* @param low_addr Base address of the executable
89	* @param memsz In-memory size of the executable
90	* @returns Pointer to the new so_info on success,
91	* NULL on failure.
92	*/
93	BT_HIDDEN
94	struct so_info so_info_create(const char path, uint64_t low_addr,
95	uint64_t memsz);
96
97	/**
98	* Destroy the given so_info instance
99	*
100	* @param so so_info instance to destroy
101	*/
102	BT_HIDDEN
103	void so_info_destroy(struct so_info *so);
104
105	/**
106	* Sets the build ID information for a given so_info instance.
107	*
108	* @param so The so_info instance for which to set
109	* the build ID
110	* @param build_id Array of bytes containing the actual ID
111	* @param build_id_len Length in bytes of the build_id
112	* @returns 0 on success, -1 on failure
113	*/
114	BT_HIDDEN
115	int so_info_set_build_id(struct so_info so, uint8_t build_id,
116	size_t build_id_len);
117
118	/**
119	* Sets the debug link information for a given so_info instance.
120	*
121	* @param so The so_info instance for which to set
122	* the debug link
123	* @param filename Name of the separate debug info file
124	* @param crc Checksum for the debug info file
125	* @returns 0 on success, -1 on failure
126	*/
127	BT_HIDDEN
128	int so_info_set_debug_link(struct so_info so, char filename, uint32_t crc);
129
130	/**
131	* Returns whether or not the given SO info \p so contains the address
132	* \p addr.
133	*
134	* @param so so_info instance
135	* @param addr Address to lookup
136	* @returns 1 if \p so contains \p addr, 0 if it does not,
137	* -1 on failure
138	*/
139	static inline
140	int so_info_has_address(struct so_info *so, uint64_t addr)
141	{
142	if (!so) {
143	return -1;
144	}
145
146	return addr >= so->low_addr && addr < so->high_addr;
147	}
148
149	/**
150	* Get the name of the function containing a given address within an
151	* executable.
152	*
153	* If no DWARF info is available, the function falls back to ELF
154	* symbols and the "function name" is in fact the name of the closest
155	* symbol, followed by the offset between the symbol and the address.
156	*
157	* On success, if found, the out parameter `func_name` is set. The ownership
158	* of `func_name` is passed to the caller. On failure, `func_name` remains
159	* unchanged.
160	*
161	* @param so so_info instance for the executable containing
162	* the address
163	* @param addr Virtual memory address for which to find the
164	* function name
165	* @param func_name Out parameter, the function name.
166	* @returns 0 on success, -1 on failure
167	*/
168	BT_HIDDEN
169	int so_info_lookup_function_name(struct so_info *so, uint64_t addr,
170	char **func_name);
171
172	/**
173	* Get the source location (file name and line number) for a given
174	* address within an executable.
175	*
176	* If no DWARF info is available, the source location cannot be found
177	* and the function will return unsuccesfully.
178	*
179	* On success, if found, the out parameter `src_loc` is set. The ownership
180	* of `src_loc` is passed to the caller. On failure, `src_loc` remains
181	* unchanged.
182	*
183	* @param so so_info instance for the executable containing
184	* the address
185	* @param addr Virtual memory address for which to find the
186	* source location
187	* @param src_loc Out parameter, the source location
188	* @returns 0 on success, -1 on failure
189	*/
190	BT_HIDDEN
191	int so_info_lookup_source_location(struct so_info *so, uint64_t addr,
192	struct source_location **src_loc);
193
194	/**
195	* Destroy the given source_location instance
196	*
197	* @param src_loc source_location instance to destroy
198	*/
199	BT_HIDDEN
200	void source_location_destroy(struct source_location *src_loc);
201
202	#endif /* _BABELTRACE_SO_INFO_H */