[mirror_ubuntu-jammy-kernel.git] / tools / objtool / elf.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
 */

#ifndef _OBJTOOL_ELF_H
#define _OBJTOOL_ELF_H

#include <stdio.h>
#include <gelf.h>
#include <linux/list.h>
#include <linux/hashtable.h>
#include <linux/rbtree.h>
#include <linux/jhash.h>

#ifdef LIBELF_USE_DEPRECATED
# define elf_getshdrnum    elf_getshnum
# define elf_getshdrstrndx elf_getshstrndx
#endif

/*
 * Fallback for systems without this "read, mmaping if possible" cmd.
 */
#ifndef ELF_C_READ_MMAP
#define ELF_C_READ_MMAP ELF_C_READ
#endif

struct section {
	struct list_head list;
	struct hlist_node hash;
	struct hlist_node name_hash;
	GElf_Shdr sh;
	struct rb_root symbol_tree;
	struct list_head symbol_list;
	struct list_head reloc_list;
	struct section *base, *reloc;
	struct symbol *sym;
	Elf_Data *data;
	char *name;
	int idx;
	unsigned int len;
	bool changed, text, rodata, noinstr;
};

struct symbol {
	struct list_head list;
	struct rb_node node;
	struct hlist_node hash;
	struct hlist_node name_hash;
	GElf_Sym sym;
	struct section *sec;
	char *name;
	unsigned int idx;
	unsigned char bind, type;
	unsigned long offset;
	unsigned int len;
	struct symbol *pfunc, *cfunc, *alias;
	bool uaccess_safe;
};

struct reloc {
	struct list_head list;
	struct hlist_node hash;
	union {
		GElf_Rela rela;
		GElf_Rel  rel;
	};
	struct section *sec;
	struct symbol *sym;
	unsigned long offset;
	unsigned int type;
	int addend;
	int idx;
	bool jump_table_start;
};

#define ELF_HASH_BITS	20

struct elf {
	Elf *elf;
	GElf_Ehdr ehdr;
	int fd;
	bool changed;
	char *name;
	struct list_head sections;
	DECLARE_HASHTABLE(symbol_hash, ELF_HASH_BITS);
	DECLARE_HASHTABLE(symbol_name_hash, ELF_HASH_BITS);
	DECLARE_HASHTABLE(section_hash, ELF_HASH_BITS);
	DECLARE_HASHTABLE(section_name_hash, ELF_HASH_BITS);
	DECLARE_HASHTABLE(reloc_hash, ELF_HASH_BITS);
};

#define OFFSET_STRIDE_BITS	4
#define OFFSET_STRIDE		(1UL << OFFSET_STRIDE_BITS)
#define OFFSET_STRIDE_MASK	(~(OFFSET_STRIDE - 1))

#define for_offset_range(_offset, _start, _end)			\
	for (_offset = ((_start) & OFFSET_STRIDE_MASK);		\
	     _offset >= ((_start) & OFFSET_STRIDE_MASK) &&	\
	     _offset <= ((_end) & OFFSET_STRIDE_MASK);		\
	     _offset += OFFSET_STRIDE)

static inline u32 sec_offset_hash(struct section *sec, unsigned long offset)
{
	u32 ol, oh, idx = sec->idx;

	offset &= OFFSET_STRIDE_MASK;

	ol = offset;
	oh = (offset >> 16) >> 16;

	__jhash_mix(ol, oh, idx);

	return ol;
}

static inline u32 reloc_hash(struct reloc *reloc)
{
	return sec_offset_hash(reloc->sec, reloc->offset);
}

struct elf *elf_open_read(const char *name, int flags);
struct section *elf_create_section(struct elf *elf, const char *name, size_t entsize, int nr);
struct section *elf_create_reloc_section(struct elf *elf, struct section *base, int reltype);
void elf_add_reloc(struct elf *elf, struct reloc *reloc);
int elf_write_insn(struct elf *elf, struct section *sec,
		   unsigned long offset, unsigned int len,
		   const char *insn);
int elf_write_reloc(struct elf *elf, struct reloc *reloc);
int elf_write(struct elf *elf);
void elf_close(struct elf *elf);

struct section *find_section_by_name(const struct elf *elf, const char *name);
struct symbol *find_func_by_offset(struct section *sec, unsigned long offset);
struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
struct symbol *find_symbol_by_name(const struct elf *elf, const char *name);
struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset);
struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset);
struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,
				     unsigned long offset, unsigned int len);
struct symbol *find_func_containing(struct section *sec, unsigned long offset);
int elf_rebuild_reloc_section(struct elf *elf, struct section *sec);

#define for_each_sec(file, sec)						\
	list_for_each_entry(sec, &file->elf->sections, list)

#endif /* _OBJTOOL_ELF_H */
Commit	Line	Data
1ccea77e	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
442f04c3 JP	2	/*
442f04c3 JP	3	* Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
442f04c3 JP	4	*/
	5
	6	#ifndef _OBJTOOL_ELF_H
	7	#define _OBJTOOL_ELF_H
	8
	9	#include <stdio.h>
	10	#include <gelf.h>
	11	#include <linux/list.h>
042ba73f	12	#include <linux/hashtable.h>
2a362ecc	13	#include <linux/rbtree.h>
ae358196	14	#include <linux/jhash.h>
442f04c3	15
2e51f262 JB	16	#ifdef LIBELF_USE_DEPRECATED
	17	# define elf_getshdrnum elf_getshnum
	18	# define elf_getshdrstrndx elf_getshstrndx
	19	#endif
	20
627fce14 JP	21	/*
	22	* Fallback for systems without this "read, mmaping if possible" cmd.
	23	*/
	24	#ifndef ELF_C_READ_MMAP
	25	#define ELF_C_READ_MMAP ELF_C_READ
	26	#endif
	27
442f04c3 JP	28	struct section {
442f04c3 JP	29	struct list_head list;
53038996	30	struct hlist_node hash;
ae358196	31	struct hlist_node name_hash;
442f04c3	32	GElf_Shdr sh;
2a362ecc	33	struct rb_root symbol_tree;
a196e171	34	struct list_head symbol_list;
f1974222 MH	35	struct list_head reloc_list;
f1974222 MH	36	struct section base, reloc;
442f04c3	37	struct symbol *sym;
baa41469	38	Elf_Data *data;
442f04c3 JP	39	char *name;
442f04c3 JP	40	int idx;
442f04c3	41	unsigned int len;
c4a33939	42	bool changed, text, rodata, noinstr;
442f04c3 JP	43	};
	44
	45	struct symbol {
	46	struct list_head list;
2a362ecc	47	struct rb_node node;
042ba73f	48	struct hlist_node hash;
cdb3d057	49	struct hlist_node name_hash;
442f04c3 JP	50	GElf_Sym sym;
	51	struct section *sec;
	52	char *name;
042ba73f	53	unsigned int idx;
442f04c3 JP	54	unsigned char bind, type;
	55	unsigned long offset;
	56	unsigned int len;
09f30d83	57	struct symbol pfunc, cfunc, *alias;
ea24213d	58	bool uaccess_safe;
442f04c3 JP	59	};
442f04c3 JP	60
f1974222	61	struct reloc {
442f04c3	62	struct list_head list;
042ba73f	63	struct hlist_node hash;
fb414783 MH	64	union {
	65	GElf_Rela rela;
	66	GElf_Rel rel;
	67	};
e7c2bc37	68	struct section *sec;
442f04c3	69	struct symbol *sym;
042ba73f	70	unsigned long offset;
fdabdd0b	71	unsigned int type;
442f04c3	72	int addend;
fdabdd0b	73	int idx;
bd98c813	74	bool jump_table_start;
442f04c3 JP	75	};
442f04c3 JP	76
34f7c96d PZ	77	#define ELF_HASH_BITS 20
34f7c96d PZ	78
442f04c3 JP	79	struct elf {
	80	Elf *elf;
	81	GElf_Ehdr ehdr;
	82	int fd;
2b10be23	83	bool changed;
442f04c3 JP	84	char *name;
442f04c3 JP	85	struct list_head sections;
34f7c96d PZ	86	DECLARE_HASHTABLE(symbol_hash, ELF_HASH_BITS);
	87	DECLARE_HASHTABLE(symbol_name_hash, ELF_HASH_BITS);
	88	DECLARE_HASHTABLE(section_hash, ELF_HASH_BITS);
	89	DECLARE_HASHTABLE(section_name_hash, ELF_HASH_BITS);
f1974222	90	DECLARE_HASHTABLE(reloc_hash, ELF_HASH_BITS);
442f04c3 JP	91	};
442f04c3 JP	92
74b873e4 PZ	93	#define OFFSET_STRIDE_BITS 4
	94	#define OFFSET_STRIDE (1UL << OFFSET_STRIDE_BITS)
	95	#define OFFSET_STRIDE_MASK (~(OFFSET_STRIDE - 1))
	96
53fb6e99 JP	97	#define for_offset_range(_offset, _start, _end) \
	98	for (_offset = ((_start) & OFFSET_STRIDE_MASK); \
	99	_offset >= ((_start) & OFFSET_STRIDE_MASK) && \
	100	_offset <= ((_end) & OFFSET_STRIDE_MASK); \
74b873e4 PZ	101	_offset += OFFSET_STRIDE)
74b873e4 PZ	102
8b5fa6bc PZ	103	static inline u32 sec_offset_hash(struct section *sec, unsigned long offset)
8b5fa6bc PZ	104	{
74b873e4 PZ	105	u32 ol, oh, idx = sec->idx;
	106
	107	offset &= OFFSET_STRIDE_MASK;
	108
	109	ol = offset;
963d5669	110	oh = (offset >> 16) >> 16;
8b5fa6bc PZ	111
	112	__jhash_mix(ol, oh, idx);
	113
	114	return ol;
	115	}
	116
f1974222	117	static inline u32 reloc_hash(struct reloc *reloc)
8b5fa6bc	118	{
f1974222	119	return sec_offset_hash(reloc->sec, reloc->offset);
8b5fa6bc	120	}
442f04c3	121
bc359ff2	122	struct elf elf_open_read(const char name, int flags);
894e48ca	123	struct section elf_create_section(struct elf elf, const char *name, size_t entsize, int nr);
fb414783	124	struct section elf_create_reloc_section(struct elf elf, struct section *base, int reltype);
f1974222	125	void elf_add_reloc(struct elf elf, struct reloc reloc);
fdabdd0b PZ	126	int elf_write_insn(struct elf elf, struct section sec,
	127	unsigned long offset, unsigned int len,
	128	const char *insn);
d832c005	129	int elf_write_reloc(struct elf elf, struct reloc reloc);
2b10be23	130	int elf_write(struct elf *elf);
894e48ca IM	131	void elf_close(struct elf *elf);
	132
	133	struct section find_section_by_name(const struct elf elf, const char *name);
7acfe531	134	struct symbol find_func_by_offset(struct section sec, unsigned long offset);
442f04c3	135	struct symbol find_symbol_by_offset(struct section sec, unsigned long offset);
894e48ca	136	struct symbol find_symbol_by_name(const struct elf elf, const char *name);
b490f453	137	struct symbol find_symbol_containing(const struct section sec, unsigned long offset);
f1974222 MH	138	struct reloc find_reloc_by_dest(const struct elf elf, struct section *sec, unsigned long offset);
f1974222 MH	139	struct reloc find_reloc_by_dest_range(const struct elf elf, struct section *sec,
8b5fa6bc	140	unsigned long offset, unsigned int len);
53d20720	141	struct symbol find_func_containing(struct section sec, unsigned long offset);
d832c005	142	int elf_rebuild_reloc_section(struct elf elf, struct section sec);
442f04c3	143
baa41469 JP	144	#define for_each_sec(file, sec) \
baa41469 JP	145	list_for_each_entry(sec, &file->elf->sections, list)
442f04c3 JP	146
442f04c3 JP	147	#endif /* _OBJTOOL_ELF_H */