[lttng-ust.git] / include / lttng / ust-elf.h

#ifndef _LTTNG_UST_ELF_H
#define _LTTNG_UST_ELF_H
/*
 * Copyright (C) 2015  Antoine Busque <abusque@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <byteswap.h>
#include <elf.h>
#include <lttng/ust-endian.h>

/*
 * Determine native endianness in order to convert when reading an ELF
 * file if there is a mismatch.
 */
#if BYTE_ORDER == LITTLE_ENDIAN
#define NATIVE_ELF_ENDIANNESS ELFDATA2LSB
#else
#define NATIVE_ELF_ENDIANNESS ELFDATA2MSB
#endif

/*
 * The size in bytes of the debug link CRC as contained in an ELF
 * section.
 */
#define ELF_CRC_SIZE		4
/*
 * ELF notes are aligned on 4 bytes. ref: ELF specification version
 * 1.1 p. 2-5.
 */
#define ELF_NOTE_ENTRY_ALIGN	4
/*
 * Within an ELF note, the `desc` field is also aligned on 4
 * bytes. ref: ELF specification version 1.1 p. 2-5.
 */
#define ELF_NOTE_DESC_ALIGN	4

#define bswap(x)				\
	do {					\
		switch (sizeof(x)) {		\
		case 8:				\
			x = bswap_64(x);	\
			break;			\
		case 4:				\
			x = bswap_32(x);	\
			break;			\
		case 2:				\
			x = bswap_16(x);	\
			break;			\
		case 1:				\
			break;			\
		default:			\
			abort();		\
		}				\
	} while (0)

#define bswap_phdr(phdr)		\
	do {				\
		bswap((phdr).p_type);	\
		bswap((phdr).p_offset); \
		bswap((phdr).p_filesz); \
		bswap((phdr).p_memsz);	\
		bswap((phdr).p_align);	\
	} while (0)

#define bswap_shdr(shdr)		    \
	do {				    \
		bswap((shdr).sh_name);	    \
		bswap((shdr).sh_type);	    \
		bswap((shdr).sh_flags);	    \
		bswap((shdr).sh_addr);	    \
		bswap((shdr).sh_offset);    \
		bswap((shdr).sh_size);	    \
		bswap((shdr).sh_link);	    \
		bswap((shdr).sh_info);	    \
		bswap((shdr).sh_addralign); \
		bswap((shdr).sh_entsize);   \
	} while (0)

#define bswap_ehdr(ehdr)				\
	do {						\
		bswap((ehdr).e_type);			\
		bswap((ehdr).e_machine);		\
		bswap((ehdr).e_version);		\
		bswap((ehdr).e_entry);			\
		bswap((ehdr).e_phoff);			\
		bswap((ehdr).e_shoff);			\
		bswap((ehdr).e_flags);			\
		bswap((ehdr).e_ehsize);			\
		bswap((ehdr).e_phentsize);		\
		bswap((ehdr).e_phnum);			\
		bswap((ehdr).e_shentsize);		\
		bswap((ehdr).e_shnum);			\
		bswap((ehdr).e_shstrndx);		\
	} while (0)

#define copy_phdr(src_phdr, dst_phdr)				\
	do {							\
		(dst_phdr).p_type = (src_phdr).p_type;		\
		(dst_phdr).p_offset = (src_phdr).p_offset;	\
		(dst_phdr).p_filesz = (src_phdr).p_filesz;	\
		(dst_phdr).p_memsz = (src_phdr).p_memsz;	\
		(dst_phdr).p_align = (src_phdr).p_align;	\
	} while (0)

#define copy_shdr(src_shdr, dst_shdr)					\
	do {								\
		(dst_shdr).sh_name = (src_shdr).sh_name;		\
		(dst_shdr).sh_type = (src_shdr).sh_type;		\
		(dst_shdr).sh_flags = (src_shdr).sh_flags;		\
		(dst_shdr).sh_addr = (src_shdr).sh_addr;		\
		(dst_shdr).sh_offset = (src_shdr).sh_offset;		\
		(dst_shdr).sh_size = (src_shdr).sh_size;		\
		(dst_shdr).sh_link = (src_shdr).sh_link;		\
		(dst_shdr).sh_info = (src_shdr).sh_info;		\
		(dst_shdr).sh_addralign = (src_shdr).sh_addralign;	\
		(dst_shdr).sh_entsize = (src_shdr).sh_entsize;		\
	} while (0)

#define copy_ehdr(src_ehdr, dst_ehdr)					\
	do {								\
		(dst_ehdr).e_type = (src_ehdr).e_type;			\
		(dst_ehdr).e_machine = (src_ehdr).e_machine;		\
		(dst_ehdr).e_version = (src_ehdr).e_version;		\
		(dst_ehdr).e_entry = (src_ehdr).e_entry;		\
		(dst_ehdr).e_phoff = (src_ehdr).e_phoff;		\
		(dst_ehdr).e_shoff = (src_ehdr).e_shoff;		\
		(dst_ehdr).e_flags = (src_ehdr).e_flags;		\
		(dst_ehdr).e_ehsize = (src_ehdr).e_ehsize;		\
		(dst_ehdr).e_phentsize = (src_ehdr).e_phentsize;	\
		(dst_ehdr).e_phnum = (src_ehdr).e_phnum;		\
		(dst_ehdr).e_shentsize = (src_ehdr).e_shentsize;	\
		(dst_ehdr).e_shnum = (src_ehdr).e_shnum;		\
		(dst_ehdr).e_shstrndx = (src_ehdr).e_shstrndx;		\
	} while (0)

struct lttng_ust_elf_ehdr {
	uint16_t e_type;
	uint16_t e_machine;
	uint32_t e_version;
	uint64_t e_entry;
	uint64_t e_phoff;
	uint64_t e_shoff;
	uint32_t e_flags;
	uint16_t e_ehsize;
	uint16_t e_phentsize;
	uint16_t e_phnum;
	uint16_t e_shentsize;
	uint16_t e_shnum;
	uint16_t e_shstrndx;
};

struct lttng_ust_elf_phdr {
	uint32_t p_type;
	uint64_t p_offset;
	uint64_t p_filesz;
	uint64_t p_memsz;
	uint64_t p_align;
};

struct lttng_ust_elf_shdr {
	uint32_t sh_name;
	uint32_t sh_type;
	uint64_t sh_flags;
	uint64_t sh_addr;
	uint64_t sh_offset;
	uint64_t sh_size;
	uint32_t sh_link;
	uint32_t sh_info;
	uint64_t sh_addralign;
	uint64_t sh_entsize;
};

struct lttng_ust_elf_nhdr {
	uint32_t n_namesz;
	uint32_t n_descsz;
	uint32_t n_type;
};

struct lttng_ust_elf {
	/* Offset in bytes to start of section names string table. */
	off_t section_names_offset;
	/* Size in bytes of section names string table. */
	size_t section_names_size;
	char *path;
	int fd;
	struct lttng_ust_elf_ehdr *ehdr;
	uint8_t bitness;
	uint8_t endianness;
};

static inline
int is_elf_32_bit(struct lttng_ust_elf *elf)
{
	return elf->bitness == ELFCLASS32;
}

static inline
int is_elf_native_endian(struct lttng_ust_elf *elf)
{
	return elf->endianness == NATIVE_ELF_ENDIANNESS;
}

struct lttng_ust_elf *lttng_ust_elf_create(const char *path);
void lttng_ust_elf_destroy(struct lttng_ust_elf *elf);
uint8_t lttng_ust_elf_is_pic(struct lttng_ust_elf *elf);
int lttng_ust_elf_get_memsz(struct lttng_ust_elf *elf, uint64_t *memsz);
int lttng_ust_elf_get_build_id(struct lttng_ust_elf *elf, uint8_t **build_id,
			size_t *length, int *found);
int lttng_ust_elf_get_debug_link(struct lttng_ust_elf *elf, char **filename,
			uint32_t *crc, int *found);

#endif	/* _LTTNG_UST_ELF_H */
Commit	Line	Data
8e2aed3f AB	1	#ifndef _LTTNG_UST_ELF_H
	2	#define _LTTNG_UST_ELF_H
	3	/*
	4	* Copyright (C) 2015 Antoine Busque <abusque@efficios.com>
	5	*
	6	* This library is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU Lesser General Public
	8	* License as published by the Free Software Foundation; either
	9	* version 2.1 of the License, or (at your option) any later version.
	10	*
	11	* This library is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	* Lesser General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU Lesser General Public
	17	* License along with this library; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	19	*/
	20
	21	#include <stdlib.h>
	22	#include <stdint.h>
	23	#include <stdio.h>
	24	#include <byteswap.h>
	25	#include <elf.h>
	26	#include <lttng/ust-endian.h>
	27
	28	/*
	29	* Determine native endianness in order to convert when reading an ELF
	30	* file if there is a mismatch.
	31	*/
	32	#if BYTE_ORDER == LITTLE_ENDIAN
	33	#define NATIVE_ELF_ENDIANNESS ELFDATA2LSB
	34	#else
	35	#define NATIVE_ELF_ENDIANNESS ELFDATA2MSB
	36	#endif
	37
	38	/*
	39	* The size in bytes of the debug link CRC as contained in an ELF
	40	* section.
	41	*/
	42	#define ELF_CRC_SIZE 4
	43	/*
	44	* ELF notes are aligned on 4 bytes. ref: ELF specification version
	45	* 1.1 p. 2-5.
	46	*/
	47	#define ELF_NOTE_ENTRY_ALIGN 4
	48	/*
	49	* Within an ELF note, the `desc` field is also aligned on 4
	50	* bytes. ref: ELF specification version 1.1 p. 2-5.
	51	*/
	52	#define ELF_NOTE_DESC_ALIGN 4
	53
	54	#define bswap(x) \
	55	do { \
	56	switch (sizeof(x)) { \
	57	case 8: \
	58	x = bswap_64(x); \
	59	break; \
	60	case 4: \
	61	x = bswap_32(x); \
	62	break; \
	63	case 2: \
	64	x = bswap_16(x); \
65	break; \
66	case 1: \
67	break; \
68	default: \
69	abort(); \
70	} \
71	} while (0)
72
73	#define bswap_phdr(phdr) \
74	do { \
75	bswap((phdr).p_type); \
76	bswap((phdr).p_offset); \
77	bswap((phdr).p_filesz); \
78	bswap((phdr).p_memsz); \
79	bswap((phdr).p_align); \
80	} while (0)
81
82	#define bswap_shdr(shdr) \
83	do { \
84	bswap((shdr).sh_name); \
85	bswap((shdr).sh_type); \
86	bswap((shdr).sh_flags); \
87	bswap((shdr).sh_addr); \
88	bswap((shdr).sh_offset); \
89	bswap((shdr).sh_size); \
90	bswap((shdr).sh_link); \
91	bswap((shdr).sh_info); \
92	bswap((shdr).sh_addralign); \
93	bswap((shdr).sh_entsize); \
94	} while (0)
95
96	#define bswap_ehdr(ehdr) \
97	do { \
98	bswap((ehdr).e_type); \
99	bswap((ehdr).e_machine); \
100	bswap((ehdr).e_version); \
101	bswap((ehdr).e_entry); \
102	bswap((ehdr).e_phoff); \
103	bswap((ehdr).e_shoff); \
104	bswap((ehdr).e_flags); \
105	bswap((ehdr).e_ehsize); \
106	bswap((ehdr).e_phentsize); \
107	bswap((ehdr).e_phnum); \
108	bswap((ehdr).e_shentsize); \
109	bswap((ehdr).e_shnum); \
110	bswap((ehdr).e_shstrndx); \
111	} while (0)
112
113	#define copy_phdr(src_phdr, dst_phdr) \
114	do { \
115	(dst_phdr).p_type = (src_phdr).p_type; \
116	(dst_phdr).p_offset = (src_phdr).p_offset; \
117	(dst_phdr).p_filesz = (src_phdr).p_filesz; \
118	(dst_phdr).p_memsz = (src_phdr).p_memsz; \
119	(dst_phdr).p_align = (src_phdr).p_align; \
120	} while (0)
121
122	#define copy_shdr(src_shdr, dst_shdr) \
123	do { \
124	(dst_shdr).sh_name = (src_shdr).sh_name; \
125	(dst_shdr).sh_type = (src_shdr).sh_type; \
126	(dst_shdr).sh_flags = (src_shdr).sh_flags; \
127	(dst_shdr).sh_addr = (src_shdr).sh_addr; \
128	(dst_shdr).sh_offset = (src_shdr).sh_offset; \
129	(dst_shdr).sh_size = (src_shdr).sh_size; \
130	(dst_shdr).sh_link = (src_shdr).sh_link; \
131	(dst_shdr).sh_info = (src_shdr).sh_info; \
132	(dst_shdr).sh_addralign = (src_shdr).sh_addralign; \
133	(dst_shdr).sh_entsize = (src_shdr).sh_entsize; \
134	} while (0)
135
136	#define copy_ehdr(src_ehdr, dst_ehdr) \
137	do { \
138	(dst_ehdr).e_type = (src_ehdr).e_type; \
139	(dst_ehdr).e_machine = (src_ehdr).e_machine; \
140	(dst_ehdr).e_version = (src_ehdr).e_version; \
141	(dst_ehdr).e_entry = (src_ehdr).e_entry; \
142	(dst_ehdr).e_phoff = (src_ehdr).e_phoff; \
143	(dst_ehdr).e_shoff = (src_ehdr).e_shoff; \
144	(dst_ehdr).e_flags = (src_ehdr).e_flags; \
145	(dst_ehdr).e_ehsize = (src_ehdr).e_ehsize; \
146	(dst_ehdr).e_phentsize = (src_ehdr).e_phentsize; \
147	(dst_ehdr).e_phnum = (src_ehdr).e_phnum; \
148	(dst_ehdr).e_shentsize = (src_ehdr).e_shentsize; \
149	(dst_ehdr).e_shnum = (src_ehdr).e_shnum; \
150	(dst_ehdr).e_shstrndx = (src_ehdr).e_shstrndx; \
151	} while (0)
152
153	struct lttng_ust_elf_ehdr {
154	uint16_t e_type;
155	uint16_t e_machine;
156	uint32_t e_version;
157	uint64_t e_entry;
158	uint64_t e_phoff;
159	uint64_t e_shoff;
160	uint32_t e_flags;
161	uint16_t e_ehsize;
162	uint16_t e_phentsize;
163	uint16_t e_phnum;
164	uint16_t e_shentsize;
165	uint16_t e_shnum;
166	uint16_t e_shstrndx;
167	};
168
169	struct lttng_ust_elf_phdr {
170	uint32_t p_type;
171	uint64_t p_offset;
172	uint64_t p_filesz;
173	uint64_t p_memsz;
174	uint64_t p_align;
175	};
176
177	struct lttng_ust_elf_shdr {
178	uint32_t sh_name;
179	uint32_t sh_type;
180	uint64_t sh_flags;
181	uint64_t sh_addr;
182	uint64_t sh_offset;
183	uint64_t sh_size;
184	uint32_t sh_link;
185	uint32_t sh_info;
186	uint64_t sh_addralign;
187	uint64_t sh_entsize;
188	};
189
190	struct lttng_ust_elf_nhdr {
191	uint32_t n_namesz;
192	uint32_t n_descsz;
193	uint32_t n_type;
194	};
195
196	struct lttng_ust_elf {
197	/* Offset in bytes to start of section names string table. */
f5a6717a	198	off_t section_names_offset;
8e2aed3f	199	/* Size in bytes of section names string table. */
f5a6717a	200	size_t section_names_size;
8e2aed3f	201	char *path;
405be658	202	int fd;
8e2aed3f AB	203	struct lttng_ust_elf_ehdr *ehdr;
	204	uint8_t bitness;
	205	uint8_t endianness;
	206	};
	207
	208	static inline
	209	int is_elf_32_bit(struct lttng_ust_elf *elf)
	210	{
	211	return elf->bitness == ELFCLASS32;
	212	}
	213
	214	static inline
	215	int is_elf_native_endian(struct lttng_ust_elf *elf)
	216	{
	217	return elf->endianness == NATIVE_ELF_ENDIANNESS;
	218	}
	219
	220	struct lttng_ust_elf lttng_ust_elf_create(const char path);
	221	void lttng_ust_elf_destroy(struct lttng_ust_elf *elf);
f5eb039d	222	uint8_t lttng_ust_elf_is_pic(struct lttng_ust_elf *elf);
8e2aed3f AB	223	int lttng_ust_elf_get_memsz(struct lttng_ust_elf elf, uint64_t memsz);
	224	int lttng_ust_elf_get_build_id(struct lttng_ust_elf elf, uint8_t *build_id,
	225	size_t length, int found);
	226	int lttng_ust_elf_get_debug_link(struct lttng_ust_elf elf, char *filename,
	227	uint32_t crc, int found);
	228
	229	#endif /* _LTTNG_UST_ELF_H */