[lttng-ust.git] / src / common / elf.h

/*
 * SPDX-License-Identifier: LGPL-2.1-or-later
 *
 * Copyright (C) 2015 Antoine Busque <abusque@efficios.com>
 */

#ifndef _UST_COMMON_ELF_H
#define _UST_COMMON_ELF_H

#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <elf.h>

#include <lttng/ust-endian.h>

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;
	uint64_t p_vaddr;
};

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;
};

/*
 * Determine native endianness in order to convert when reading an ELF
 * file if there is a mismatch.
 */
#if LTTNG_UST_BYTE_ORDER == LTTNG_UST_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 = lttng_ust_bswap_64(x);	\
			break;			\
		case 4:				\
			x = lttng_ust_bswap_32(x);	\
			break;			\
		case 2:				\
			x = lttng_ust_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);	\
		bswap((phdr).p_vaddr);	\
	} 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;	\
		(dst_phdr).p_vaddr = (src_phdr).p_vaddr;	\
	} 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)

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)
	__attribute__((visibility("hidden")));

void lttng_ust_elf_destroy(struct lttng_ust_elf *elf)
	__attribute__((visibility("hidden")));

uint8_t lttng_ust_elf_is_pic(struct lttng_ust_elf *elf)
	__attribute__((visibility("hidden")));

int lttng_ust_elf_get_memsz(struct lttng_ust_elf *elf, uint64_t *memsz)
	__attribute__((visibility("hidden")));

int lttng_ust_elf_get_build_id(struct lttng_ust_elf *elf, uint8_t **build_id,
			size_t *length, int *found)
	__attribute__((visibility("hidden")));

int lttng_ust_elf_get_debug_link(struct lttng_ust_elf *elf, char **filename,
			uint32_t *crc, int *found)
	__attribute__((visibility("hidden")));

#endif	/* _UST_COMMON_ELF_H */
Commit	Line	Data
8e2aed3f	1	/*
c0c0989a	2	* SPDX-License-Identifier: LGPL-2.1-or-later
8e2aed3f	3	*
c0c0989a	4	* Copyright (C) 2015 Antoine Busque <abusque@efficios.com>
8e2aed3f AB	5	*/
8e2aed3f AB	6
9d315d6d MJ	7	#ifndef _UST_COMMON_ELF_H
9d315d6d MJ	8	#define _UST_COMMON_ELF_H
c0c0989a	9
8e2aed3f AB	10	#include <stdlib.h>
	11	#include <stdint.h>
	12	#include <stdio.h>
4667b192 MJ	13	#include <elf.h>
	14
	15	#include <lttng/ust-endian.h>
8e2aed3f AB	16
	17	struct lttng_ust_elf_ehdr {
	18	uint16_t e_type;
	19	uint16_t e_machine;
	20	uint32_t e_version;
	21	uint64_t e_entry;
	22	uint64_t e_phoff;
	23	uint64_t e_shoff;
	24	uint32_t e_flags;
	25	uint16_t e_ehsize;
	26	uint16_t e_phentsize;
	27	uint16_t e_phnum;
	28	uint16_t e_shentsize;
	29	uint16_t e_shnum;
	30	uint16_t e_shstrndx;
	31	};
	32
	33	struct lttng_ust_elf_phdr {
	34	uint32_t p_type;
	35	uint64_t p_offset;
	36	uint64_t p_filesz;
	37	uint64_t p_memsz;
	38	uint64_t p_align;
e1f0c569	39	uint64_t p_vaddr;
8e2aed3f AB	40	};
	41
	42	struct lttng_ust_elf_shdr {
	43	uint32_t sh_name;
	44	uint32_t sh_type;
	45	uint64_t sh_flags;
	46	uint64_t sh_addr;
	47	uint64_t sh_offset;
	48	uint64_t sh_size;
	49	uint32_t sh_link;
	50	uint32_t sh_info;
	51	uint64_t sh_addralign;
	52	uint64_t sh_entsize;
	53	};
	54
	55	struct lttng_ust_elf_nhdr {
	56	uint32_t n_namesz;
	57	uint32_t n_descsz;
	58	uint32_t n_type;
	59	};
	60
	61	struct lttng_ust_elf {
	62	/* Offset in bytes to start of section names string table. */
f5a6717a	63	off_t section_names_offset;
8e2aed3f	64	/* Size in bytes of section names string table. */
f5a6717a	65	size_t section_names_size;
8e2aed3f	66	char *path;
405be658	67	int fd;
8e2aed3f AB	68	struct lttng_ust_elf_ehdr *ehdr;
	69	uint8_t bitness;
	70	uint8_t endianness;
	71	};
	72
4667b192 MJ	73	/*
	74	* Determine native endianness in order to convert when reading an ELF
	75	* file if there is a mismatch.
	76	*/
baa8acf3	77	#if LTTNG_UST_BYTE_ORDER == LTTNG_UST_LITTLE_ENDIAN
4667b192 MJ	78	#define NATIVE_ELF_ENDIANNESS ELFDATA2LSB
	79	#else
	80	#define NATIVE_ELF_ENDIANNESS ELFDATA2MSB
	81	#endif
	82
	83	/*
	84	* The size in bytes of the debug link CRC as contained in an ELF
	85	* section.
	86	*/
	87	#define ELF_CRC_SIZE 4
	88	/*
	89	* ELF notes are aligned on 4 bytes. ref: ELF specification version
	90	* 1.1 p. 2-5.
	91	*/
	92	#define ELF_NOTE_ENTRY_ALIGN 4
	93	/*
	94	* Within an ELF note, the `desc` field is also aligned on 4
	95	* bytes. ref: ELF specification version 1.1 p. 2-5.
	96	*/
	97	#define ELF_NOTE_DESC_ALIGN 4
	98
	99	#define bswap(x) \
	100	do { \
	101	switch (sizeof(x)) { \
	102	case 8: \
baa8acf3	103	x = lttng_ust_bswap_64(x); \
4667b192 MJ	104	break; \
4667b192 MJ	105	case 4: \
baa8acf3	106	x = lttng_ust_bswap_32(x); \
4667b192 MJ	107	break; \
4667b192 MJ	108	case 2: \
baa8acf3	109	x = lttng_ust_bswap_16(x); \
4667b192 MJ	110	break; \
	111	case 1: \
	112	break; \
	113	default: \
	114	abort(); \
	115	} \
	116	} while (0)
	117
	118	#define bswap_phdr(phdr) \
	119	do { \
	120	bswap((phdr).p_type); \
	121	bswap((phdr).p_offset); \
	122	bswap((phdr).p_filesz); \
	123	bswap((phdr).p_memsz); \
	124	bswap((phdr).p_align); \
	125	bswap((phdr).p_vaddr); \
	126	} while (0)
	127
	128	#define bswap_shdr(shdr) \
	129	do { \
	130	bswap((shdr).sh_name); \
	131	bswap((shdr).sh_type); \
	132	bswap((shdr).sh_flags); \
	133	bswap((shdr).sh_addr); \
	134	bswap((shdr).sh_offset); \
	135	bswap((shdr).sh_size); \
	136	bswap((shdr).sh_link); \
	137	bswap((shdr).sh_info); \
	138	bswap((shdr).sh_addralign); \
	139	bswap((shdr).sh_entsize); \
	140	} while (0)
	141
	142	#define bswap_ehdr(ehdr) \
	143	do { \
	144	bswap((ehdr).e_type); \
	145	bswap((ehdr).e_machine); \
	146	bswap((ehdr).e_version); \
	147	bswap((ehdr).e_entry); \
	148	bswap((ehdr).e_phoff); \
	149	bswap((ehdr).e_shoff); \
	150	bswap((ehdr).e_flags); \
	151	bswap((ehdr).e_ehsize); \
	152	bswap((ehdr).e_phentsize); \
	153	bswap((ehdr).e_phnum); \
	154	bswap((ehdr).e_shentsize); \
	155	bswap((ehdr).e_shnum); \
	156	bswap((ehdr).e_shstrndx); \
	157	} while (0)
	158
	159	#define copy_phdr(src_phdr, dst_phdr) \
	160	do { \
	161	(dst_phdr).p_type = (src_phdr).p_type; \
	162	(dst_phdr).p_offset = (src_phdr).p_offset; \
	163	(dst_phdr).p_filesz = (src_phdr).p_filesz; \
	164	(dst_phdr).p_memsz = (src_phdr).p_memsz; \
	165	(dst_phdr).p_align = (src_phdr).p_align; \
	166	(dst_phdr).p_vaddr = (src_phdr).p_vaddr; \
	167	} while (0)
	168
	169	#define copy_shdr(src_shdr, dst_shdr) \
	170	do { \
	171	(dst_shdr).sh_name = (src_shdr).sh_name; \
	172	(dst_shdr).sh_type = (src_shdr).sh_type; \
	173	(dst_shdr).sh_flags = (src_shdr).sh_flags; \
174	(dst_shdr).sh_addr = (src_shdr).sh_addr; \
175	(dst_shdr).sh_offset = (src_shdr).sh_offset; \
176	(dst_shdr).sh_size = (src_shdr).sh_size; \
177	(dst_shdr).sh_link = (src_shdr).sh_link; \
178	(dst_shdr).sh_info = (src_shdr).sh_info; \
179	(dst_shdr).sh_addralign = (src_shdr).sh_addralign; \
180	(dst_shdr).sh_entsize = (src_shdr).sh_entsize; \
181	} while (0)
182
183	#define copy_ehdr(src_ehdr, dst_ehdr) \
184	do { \
185	(dst_ehdr).e_type = (src_ehdr).e_type; \
186	(dst_ehdr).e_machine = (src_ehdr).e_machine; \
187	(dst_ehdr).e_version = (src_ehdr).e_version; \
188	(dst_ehdr).e_entry = (src_ehdr).e_entry; \
189	(dst_ehdr).e_phoff = (src_ehdr).e_phoff; \
190	(dst_ehdr).e_shoff = (src_ehdr).e_shoff; \
191	(dst_ehdr).e_flags = (src_ehdr).e_flags; \
192	(dst_ehdr).e_ehsize = (src_ehdr).e_ehsize; \
193	(dst_ehdr).e_phentsize = (src_ehdr).e_phentsize; \
194	(dst_ehdr).e_phnum = (src_ehdr).e_phnum; \
195	(dst_ehdr).e_shentsize = (src_ehdr).e_shentsize; \
196	(dst_ehdr).e_shnum = (src_ehdr).e_shnum; \
197	(dst_ehdr).e_shstrndx = (src_ehdr).e_shstrndx; \
198	} while (0)
199
200	static inline
201	int is_elf_32_bit(struct lttng_ust_elf *elf)
202	{
203	return elf->bitness == ELFCLASS32;
204	}
205
206	static inline
207	int is_elf_native_endian(struct lttng_ust_elf *elf)
208	{
209	return elf->endianness == NATIVE_ELF_ENDIANNESS;
210	}
211
212	struct lttng_ust_elf lttng_ust_elf_create(const char path)
213	__attribute__((visibility("hidden")));
214
215	void lttng_ust_elf_destroy(struct lttng_ust_elf *elf)
216	__attribute__((visibility("hidden")));
217
218	uint8_t lttng_ust_elf_is_pic(struct lttng_ust_elf *elf)
219	__attribute__((visibility("hidden")));
220
221	int lttng_ust_elf_get_memsz(struct lttng_ust_elf elf, uint64_t memsz)
222	__attribute__((visibility("hidden")));
223
8e2aed3f	224	int lttng_ust_elf_get_build_id(struct lttng_ust_elf elf, uint8_t *build_id,
4667b192 MJ	225	size_t length, int found)
	226	__attribute__((visibility("hidden")));
	227
8e2aed3f	228	int lttng_ust_elf_get_debug_link(struct lttng_ust_elf elf, char *filename,
4667b192 MJ	229	uint32_t crc, int found)
4667b192 MJ	230	__attribute__((visibility("hidden")));
8e2aed3f	231
9d315d6d	232	#endif /* _UST_COMMON_ELF_H */