190c04ba36
readelf -S prints: There are 81999 section headers, starting at offset 0x1f488060: Section Headers: [Nr] Name Type Address Off Size ES Flg Lk Inf Al [ 0] NULL 0000000000000000 000000 01404f 00 81998 0 0 [ 1] .group GROUP 0000000000000000 000040 000008 04 81995 105027 4 ... [81995] .symtab SYMTAB 0000000000000000 d5d9298 2db310 18 81997 105026 8 [81996] .symtab_shndx SYMTAB SECTION INDICES 0000000000000000 d8b45a8 079dd8 04 81995 0 4 [81997] .strtab STRTAB 0000000000000000 d92e380 80460c 00 0 0 1 ... Looking at the documentation: Table 7–15 ELF sh_link and sh_info Interpretation sh_type - sh_link SHT_SYMTAB - The section header index of the associated string table. SHT_SYMTAB_SHNDX - The section header index of the associated symbol table. As seen, sh_link of a SHT_SYMTAB always points to a .strtab and readelf confirms that. So we need to use reverse mapping taken from [81996] .symtab_shndx SYMTAB SECTION INDICES 0000000000000000 d8b45a8 079dd8 04 81995 0 4 where sh_link points to 81995. libiberty/ChangeLog: PR lto/97290 * simple-object-elf.c (simple_object_elf_copy_lto_debug_sections): Use sh_link of a .symtab_shndx section.
1613 lines
49 KiB
C
1613 lines
49 KiB
C
/* simple-object-elf.c -- routines to manipulate ELF object files.
|
|
Copyright (C) 2010-2020 Free Software Foundation, Inc.
|
|
Written by Ian Lance Taylor, Google.
|
|
|
|
This program is free software; you can redistribute it and/or modify it
|
|
under the terms of the GNU General Public License as published by the
|
|
Free Software Foundation; either version 2, or (at your option) any
|
|
later version.
|
|
|
|
This program 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 General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, 51 Franklin Street - Fifth Floor,
|
|
Boston, MA 02110-1301, USA. */
|
|
|
|
#include "config.h"
|
|
#include "libiberty.h"
|
|
#include "simple-object.h"
|
|
|
|
#include <errno.h>
|
|
/* mingw.org's MinGW doesn't have ENOTSUP. */
|
|
#ifndef ENOTSUP
|
|
# define ENOTSUP ENOSYS
|
|
#endif
|
|
#include <stddef.h>
|
|
|
|
#ifdef HAVE_STDLIB_H
|
|
#include <stdlib.h>
|
|
#endif
|
|
|
|
#ifdef HAVE_STDINT_H
|
|
#include <stdint.h>
|
|
#endif
|
|
|
|
#ifdef HAVE_STRING_H
|
|
#include <string.h>
|
|
#endif
|
|
|
|
#ifdef HAVE_INTTYPES_H
|
|
#include <inttypes.h>
|
|
#endif
|
|
|
|
#include "simple-object-common.h"
|
|
|
|
/* ELF structures and constants. */
|
|
|
|
/* 32-bit ELF file header. */
|
|
|
|
typedef struct {
|
|
unsigned char e_ident[16]; /* ELF "magic number" */
|
|
unsigned char e_type[2]; /* Identifies object file type */
|
|
unsigned char e_machine[2]; /* Specifies required architecture */
|
|
unsigned char e_version[4]; /* Identifies object file version */
|
|
unsigned char e_entry[4]; /* Entry point virtual address */
|
|
unsigned char e_phoff[4]; /* Program header table file offset */
|
|
unsigned char e_shoff[4]; /* Section header table file offset */
|
|
unsigned char e_flags[4]; /* Processor-specific flags */
|
|
unsigned char e_ehsize[2]; /* ELF header size in bytes */
|
|
unsigned char e_phentsize[2]; /* Program header table entry size */
|
|
unsigned char e_phnum[2]; /* Program header table entry count */
|
|
unsigned char e_shentsize[2]; /* Section header table entry size */
|
|
unsigned char e_shnum[2]; /* Section header table entry count */
|
|
unsigned char e_shstrndx[2]; /* Section header string table index */
|
|
} Elf32_External_Ehdr;
|
|
|
|
/* 64-bit ELF file header. */
|
|
|
|
typedef struct {
|
|
unsigned char e_ident[16]; /* ELF "magic number" */
|
|
unsigned char e_type[2]; /* Identifies object file type */
|
|
unsigned char e_machine[2]; /* Specifies required architecture */
|
|
unsigned char e_version[4]; /* Identifies object file version */
|
|
unsigned char e_entry[8]; /* Entry point virtual address */
|
|
unsigned char e_phoff[8]; /* Program header table file offset */
|
|
unsigned char e_shoff[8]; /* Section header table file offset */
|
|
unsigned char e_flags[4]; /* Processor-specific flags */
|
|
unsigned char e_ehsize[2]; /* ELF header size in bytes */
|
|
unsigned char e_phentsize[2]; /* Program header table entry size */
|
|
unsigned char e_phnum[2]; /* Program header table entry count */
|
|
unsigned char e_shentsize[2]; /* Section header table entry size */
|
|
unsigned char e_shnum[2]; /* Section header table entry count */
|
|
unsigned char e_shstrndx[2]; /* Section header string table index */
|
|
} Elf64_External_Ehdr;
|
|
|
|
/* Indexes and values in e_ident field of Ehdr. */
|
|
|
|
#define EI_MAG0 0 /* File identification byte 0 index */
|
|
#define ELFMAG0 0x7F /* Magic number byte 0 */
|
|
|
|
#define EI_MAG1 1 /* File identification byte 1 index */
|
|
#define ELFMAG1 'E' /* Magic number byte 1 */
|
|
|
|
#define EI_MAG2 2 /* File identification byte 2 index */
|
|
#define ELFMAG2 'L' /* Magic number byte 2 */
|
|
|
|
#define EI_MAG3 3 /* File identification byte 3 index */
|
|
#define ELFMAG3 'F' /* Magic number byte 3 */
|
|
|
|
#define EI_CLASS 4 /* File class */
|
|
#define ELFCLASSNONE 0 /* Invalid class */
|
|
#define ELFCLASS32 1 /* 32-bit objects */
|
|
#define ELFCLASS64 2 /* 64-bit objects */
|
|
|
|
#define EI_DATA 5 /* Data encoding */
|
|
#define ELFDATANONE 0 /* Invalid data encoding */
|
|
#define ELFDATA2LSB 1 /* 2's complement, little endian */
|
|
#define ELFDATA2MSB 2 /* 2's complement, big endian */
|
|
|
|
#define EI_VERSION 6 /* File version */
|
|
#define EV_CURRENT 1 /* Current version */
|
|
|
|
#define EI_OSABI 7 /* Operating System/ABI indication */
|
|
|
|
/* Values for e_type field of Ehdr. */
|
|
|
|
#define ET_REL 1 /* Relocatable file */
|
|
|
|
/* Values for e_machine field of Ehdr. */
|
|
|
|
#define EM_SPARC 2 /* SUN SPARC */
|
|
#define EM_SPARC32PLUS 18 /* Sun's "v8plus" */
|
|
|
|
/* Special section index values. */
|
|
|
|
#define SHN_UNDEF 0 /* Undefined section */
|
|
#define SHN_LORESERVE 0xFF00 /* Begin range of reserved indices */
|
|
#define SHN_COMMON 0xFFF2 /* Associated symbol is in common */
|
|
#define SHN_XINDEX 0xFFFF /* Section index is held elsewhere */
|
|
#define SHN_HIRESERVE 0xffff /* End of reserved indices */
|
|
|
|
|
|
/* 32-bit ELF program header. */
|
|
|
|
typedef struct {
|
|
unsigned char p_type[4]; /* Identifies program segment type */
|
|
unsigned char p_offset[4]; /* Segment file offset */
|
|
unsigned char p_vaddr[4]; /* Segment virtual address */
|
|
unsigned char p_paddr[4]; /* Segment physical address */
|
|
unsigned char p_filesz[4]; /* Segment size in file */
|
|
unsigned char p_memsz[4]; /* Segment size in memory */
|
|
unsigned char p_flags[4]; /* Segment flags */
|
|
unsigned char p_align[4]; /* Segment alignment, file & memory */
|
|
} Elf32_External_Phdr;
|
|
|
|
/* 64-bit ELF program header. */
|
|
|
|
typedef struct {
|
|
unsigned char p_type[4]; /* Identifies program segment type */
|
|
unsigned char p_flags[4]; /* Segment flags */
|
|
unsigned char p_offset[8]; /* Segment file offset */
|
|
unsigned char p_vaddr[8]; /* Segment virtual address */
|
|
unsigned char p_paddr[8]; /* Segment physical address */
|
|
unsigned char p_filesz[8]; /* Segment size in file */
|
|
unsigned char p_memsz[8]; /* Segment size in memory */
|
|
unsigned char p_align[8]; /* Segment alignment, file & memory */
|
|
} Elf64_External_Phdr;
|
|
|
|
/* 32-bit ELF section header */
|
|
|
|
typedef struct {
|
|
unsigned char sh_name[4]; /* Section name, index in string tbl */
|
|
unsigned char sh_type[4]; /* Type of section */
|
|
unsigned char sh_flags[4]; /* Miscellaneous section attributes */
|
|
unsigned char sh_addr[4]; /* Section virtual addr at execution */
|
|
unsigned char sh_offset[4]; /* Section file offset */
|
|
unsigned char sh_size[4]; /* Size of section in bytes */
|
|
unsigned char sh_link[4]; /* Index of another section */
|
|
unsigned char sh_info[4]; /* Additional section information */
|
|
unsigned char sh_addralign[4]; /* Section alignment */
|
|
unsigned char sh_entsize[4]; /* Entry size if section holds table */
|
|
} Elf32_External_Shdr;
|
|
|
|
/* 64-bit ELF section header. */
|
|
|
|
typedef struct {
|
|
unsigned char sh_name[4]; /* Section name, index in string tbl */
|
|
unsigned char sh_type[4]; /* Type of section */
|
|
unsigned char sh_flags[8]; /* Miscellaneous section attributes */
|
|
unsigned char sh_addr[8]; /* Section virtual addr at execution */
|
|
unsigned char sh_offset[8]; /* Section file offset */
|
|
unsigned char sh_size[8]; /* Size of section in bytes */
|
|
unsigned char sh_link[4]; /* Index of another section */
|
|
unsigned char sh_info[4]; /* Additional section information */
|
|
unsigned char sh_addralign[8]; /* Section alignment */
|
|
unsigned char sh_entsize[8]; /* Entry size if section holds table */
|
|
} Elf64_External_Shdr;
|
|
|
|
/* Values for sh_type field. */
|
|
|
|
#define SHT_NULL 0 /* Section header table entry unused */
|
|
#define SHT_PROGBITS 1 /* Program data */
|
|
#define SHT_SYMTAB 2 /* Link editing symbol table */
|
|
#define SHT_STRTAB 3 /* A string table */
|
|
#define SHT_RELA 4 /* Relocation entries with addends */
|
|
#define SHT_REL 9 /* Relocation entries, no addends */
|
|
#define SHT_GROUP 17 /* Section contains a section group */
|
|
#define SHT_SYMTAB_SHNDX 18 /* Extended section indeces */
|
|
|
|
/* Values for sh_flags field. */
|
|
|
|
#define SHF_INFO_LINK 0x00000040 /* `sh_info' contains SHT index */
|
|
#define SHF_EXECINSTR 0x00000004 /* Executable section. */
|
|
#define SHF_EXCLUDE 0x80000000 /* Link editor is to exclude this
|
|
section from executable and
|
|
shared library that it builds
|
|
when those objects are not to be
|
|
further relocated. */
|
|
/* Symbol table entry. */
|
|
|
|
typedef struct
|
|
{
|
|
unsigned char st_name[4]; /* Symbol name (string tbl index) */
|
|
unsigned char st_value[4]; /* Symbol value */
|
|
unsigned char st_size[4]; /* Symbol size */
|
|
unsigned char st_info; /* Symbol type and binding */
|
|
unsigned char st_other; /* Symbol visibility */
|
|
unsigned char st_shndx[2]; /* Section index */
|
|
} Elf32_External_Sym;
|
|
|
|
typedef struct
|
|
{
|
|
unsigned char st_name[4]; /* Symbol name (string tbl index) */
|
|
unsigned char st_info; /* Symbol type and binding */
|
|
unsigned char st_other; /* Symbol visibility */
|
|
unsigned char st_shndx[2]; /* Section index */
|
|
unsigned char st_value[8]; /* Symbol value */
|
|
unsigned char st_size[8]; /* Symbol size */
|
|
} Elf64_External_Sym;
|
|
|
|
#define ELF_ST_BIND(val) (((unsigned char) (val)) >> 4)
|
|
#define ELF_ST_TYPE(val) ((val) & 0xf)
|
|
#define ELF_ST_INFO(bind, type) (((bind) << 4) + ((type) & 0xf))
|
|
|
|
#define STT_NOTYPE 0 /* Symbol type is unspecified */
|
|
#define STT_OBJECT 1 /* Symbol is a data object */
|
|
#define STT_FUNC 2 /* Symbol is a code object */
|
|
#define STT_TLS 6 /* Thread local data object */
|
|
#define STT_GNU_IFUNC 10 /* Symbol is an indirect code object */
|
|
|
|
#define STB_LOCAL 0 /* Local symbol */
|
|
#define STB_GLOBAL 1 /* Global symbol */
|
|
#define STB_WEAK 2 /* Weak global */
|
|
|
|
#define STV_DEFAULT 0 /* Visibility is specified by binding type */
|
|
#define STV_HIDDEN 2 /* Can only be seen inside currect component */
|
|
|
|
/* Functions to fetch and store different ELF types, depending on the
|
|
endianness and size. */
|
|
|
|
struct elf_type_functions
|
|
{
|
|
unsigned short (*fetch_Elf_Half) (const unsigned char *);
|
|
unsigned int (*fetch_Elf_Word) (const unsigned char *);
|
|
ulong_type (*fetch_Elf_Addr) (const unsigned char *);
|
|
void (*set_Elf_Half) (unsigned char *, unsigned short);
|
|
void (*set_Elf_Word) (unsigned char *, unsigned int);
|
|
void (*set_Elf_Addr) (unsigned char *, ulong_type);
|
|
};
|
|
|
|
static const struct elf_type_functions elf_big_32_functions =
|
|
{
|
|
simple_object_fetch_big_16,
|
|
simple_object_fetch_big_32,
|
|
simple_object_fetch_big_32_ulong,
|
|
simple_object_set_big_16,
|
|
simple_object_set_big_32,
|
|
simple_object_set_big_32_ulong
|
|
};
|
|
|
|
static const struct elf_type_functions elf_little_32_functions =
|
|
{
|
|
simple_object_fetch_little_16,
|
|
simple_object_fetch_little_32,
|
|
simple_object_fetch_little_32_ulong,
|
|
simple_object_set_little_16,
|
|
simple_object_set_little_32,
|
|
simple_object_set_little_32_ulong
|
|
};
|
|
|
|
#ifdef UNSIGNED_64BIT_TYPE
|
|
|
|
static const struct elf_type_functions elf_big_64_functions =
|
|
{
|
|
simple_object_fetch_big_16,
|
|
simple_object_fetch_big_32,
|
|
simple_object_fetch_big_64,
|
|
simple_object_set_big_16,
|
|
simple_object_set_big_32,
|
|
simple_object_set_big_64
|
|
};
|
|
|
|
static const struct elf_type_functions elf_little_64_functions =
|
|
{
|
|
simple_object_fetch_little_16,
|
|
simple_object_fetch_little_32,
|
|
simple_object_fetch_little_64,
|
|
simple_object_set_little_16,
|
|
simple_object_set_little_32,
|
|
simple_object_set_little_64
|
|
};
|
|
|
|
#endif
|
|
|
|
/* Hideous macro to fetch the value of a field from an external ELF
|
|
struct of some sort. TYPEFUNCS is the set of type functions.
|
|
BUFFER points to the external data. STRUCTTYPE is the appropriate
|
|
struct type. FIELD is a field within the struct. TYPE is the type
|
|
of the field in the struct: Elf_Half, Elf_Word, or Elf_Addr. */
|
|
|
|
#define ELF_FETCH_STRUCT_FIELD(TYPEFUNCS, STRUCTTYPE, FIELD, BUFFER, TYPE) \
|
|
((TYPEFUNCS)->fetch_ ## TYPE ((BUFFER) + offsetof (STRUCTTYPE, FIELD)))
|
|
|
|
/* Even more hideous macro to fetch the value of FIELD from BUFFER.
|
|
SIZE is 32 or 64. STRUCTTYPE is the name of the struct from
|
|
elf/external.h: Ehdr, Shdr, etc. FIELD is the name of a field in
|
|
the struct. TYPE is the type of the field in the struct: Elf_Half,
|
|
Elf_Word, or Elf_Addr. */
|
|
|
|
#define ELF_FETCH_SIZED_FIELD(TYPEFUNCS, SIZE, STRUCTTYPE, BUFFER, \
|
|
FIELD, TYPE) \
|
|
ELF_FETCH_STRUCT_FIELD (TYPEFUNCS, \
|
|
Elf ## SIZE ## _External_ ## STRUCTTYPE, \
|
|
FIELD, BUFFER, TYPE)
|
|
|
|
/* Like ELF_FETCH_SIZED_FIELD but taking an ELFCLASS value. */
|
|
|
|
#define ELF_FETCH_FIELD(TYPEFUNCS, CLASS, STRUCTTYPE, BUFFER, \
|
|
FIELD, TYPE) \
|
|
((CLASS) == ELFCLASS32 \
|
|
? ELF_FETCH_SIZED_FIELD (TYPEFUNCS, 32, STRUCTTYPE, BUFFER, FIELD, \
|
|
TYPE) \
|
|
: ELF_FETCH_SIZED_FIELD (TYPEFUNCS, 64, STRUCTTYPE, BUFFER, FIELD, \
|
|
TYPE))
|
|
|
|
/* Hideous macro to set the value of a field in an external ELF
|
|
structure to VAL. TYPEFUNCS is the set of type functions. BUFFER
|
|
points to the external data. STRUCTTYPE is the appropriate
|
|
structure type. FIELD is a field within the struct. TYPE is the
|
|
type of the field in the struct: Elf_Half, Elf_Word, or
|
|
Elf_Addr. */
|
|
|
|
#define ELF_SET_STRUCT_FIELD(TYPEFUNCS, STRUCTTYPE, FIELD, BUFFER, TYPE, VAL) \
|
|
(TYPEFUNCS)->set_ ## TYPE ((BUFFER) + offsetof (STRUCTTYPE, FIELD), (VAL))
|
|
|
|
/* Even more hideous macro to set the value of FIELD in BUFFER to VAL.
|
|
SIZE is 32 or 64. STRUCTTYPE is the name of the struct from
|
|
elf/external.h: Ehdr, Shdr, etc. FIELD is the name of a field in
|
|
the struct. TYPE is the type of the field in the struct: Elf_Half,
|
|
Elf_Word, or Elf_Addr. */
|
|
|
|
#define ELF_SET_SIZED_FIELD(TYPEFUNCS, SIZE, STRUCTTYPE, BUFFER, FIELD, \
|
|
TYPE, VAL) \
|
|
ELF_SET_STRUCT_FIELD (TYPEFUNCS, \
|
|
Elf ## SIZE ## _External_ ## STRUCTTYPE, \
|
|
FIELD, BUFFER, TYPE, VAL)
|
|
|
|
/* Like ELF_SET_SIZED_FIELD but taking an ELFCLASS value. */
|
|
|
|
#define ELF_SET_FIELD(TYPEFUNCS, CLASS, STRUCTTYPE, BUFFER, FIELD, \
|
|
TYPE, VAL) \
|
|
((CLASS) == ELFCLASS32 \
|
|
? ELF_SET_SIZED_FIELD (TYPEFUNCS, 32, STRUCTTYPE, BUFFER, FIELD, \
|
|
TYPE, VAL) \
|
|
: ELF_SET_SIZED_FIELD (TYPEFUNCS, 64, STRUCTTYPE, BUFFER, FIELD, \
|
|
TYPE, VAL))
|
|
|
|
/* Private data for an simple_object_read. */
|
|
|
|
struct simple_object_elf_read
|
|
{
|
|
/* Type functions. */
|
|
const struct elf_type_functions* type_functions;
|
|
/* Elf data. */
|
|
unsigned char ei_data;
|
|
/* Elf class. */
|
|
unsigned char ei_class;
|
|
/* ELF OS ABI. */
|
|
unsigned char ei_osabi;
|
|
/* Elf machine number. */
|
|
unsigned short machine;
|
|
/* Processor specific flags. */
|
|
unsigned int flags;
|
|
/* File offset of section headers. */
|
|
ulong_type shoff;
|
|
/* Number of sections. */
|
|
unsigned int shnum;
|
|
/* Index of string table section header. */
|
|
unsigned int shstrndx;
|
|
};
|
|
|
|
/* Private data for an simple_object_attributes. */
|
|
|
|
struct simple_object_elf_attributes
|
|
{
|
|
/* Type functions. */
|
|
const struct elf_type_functions* type_functions;
|
|
/* Elf data. */
|
|
unsigned char ei_data;
|
|
/* Elf class. */
|
|
unsigned char ei_class;
|
|
/* ELF OS ABI. */
|
|
unsigned char ei_osabi;
|
|
/* Elf machine number. */
|
|
unsigned short machine;
|
|
/* Processor specific flags. */
|
|
unsigned int flags;
|
|
};
|
|
|
|
/* Private data for an simple_object_write. */
|
|
|
|
struct simple_object_elf_write
|
|
{
|
|
struct simple_object_elf_attributes attrs;
|
|
unsigned char *shdrs;
|
|
};
|
|
|
|
/* See if we have an ELF file. */
|
|
|
|
static void *
|
|
simple_object_elf_match (unsigned char header[SIMPLE_OBJECT_MATCH_HEADER_LEN],
|
|
int descriptor, off_t offset,
|
|
const char *segment_name ATTRIBUTE_UNUSED,
|
|
const char **errmsg, int *err)
|
|
{
|
|
unsigned char ei_data;
|
|
unsigned char ei_class;
|
|
const struct elf_type_functions *type_functions;
|
|
unsigned char ehdr[sizeof (Elf64_External_Ehdr)];
|
|
struct simple_object_elf_read *eor;
|
|
|
|
if (header[EI_MAG0] != ELFMAG0
|
|
|| header[EI_MAG1] != ELFMAG1
|
|
|| header[EI_MAG2] != ELFMAG2
|
|
|| header[EI_MAG3] != ELFMAG3
|
|
|| header[EI_VERSION] != EV_CURRENT)
|
|
{
|
|
*errmsg = NULL;
|
|
*err = 0;
|
|
return NULL;
|
|
}
|
|
|
|
ei_data = header[EI_DATA];
|
|
if (ei_data != ELFDATA2LSB && ei_data != ELFDATA2MSB)
|
|
{
|
|
*errmsg = "unknown ELF endianness";
|
|
*err = 0;
|
|
return NULL;
|
|
}
|
|
|
|
ei_class = header[EI_CLASS];
|
|
switch (ei_class)
|
|
{
|
|
case ELFCLASS32:
|
|
type_functions = (ei_data == ELFDATA2LSB
|
|
? &elf_little_32_functions
|
|
: &elf_big_32_functions);
|
|
break;
|
|
|
|
case ELFCLASS64:
|
|
#ifndef UNSIGNED_64BIT_TYPE
|
|
*errmsg = "64-bit ELF objects not supported";
|
|
*err = 0;
|
|
return NULL;
|
|
#else
|
|
type_functions = (ei_data == ELFDATA2LSB
|
|
? &elf_little_64_functions
|
|
: &elf_big_64_functions);
|
|
break;
|
|
#endif
|
|
|
|
default:
|
|
*errmsg = "unrecognized ELF size";
|
|
*err = 0;
|
|
return NULL;
|
|
}
|
|
|
|
if (!simple_object_internal_read (descriptor, offset, ehdr, sizeof ehdr,
|
|
errmsg, err))
|
|
return NULL;
|
|
|
|
eor = XNEW (struct simple_object_elf_read);
|
|
eor->type_functions = type_functions;
|
|
eor->ei_data = ei_data;
|
|
eor->ei_class = ei_class;
|
|
eor->ei_osabi = header[EI_OSABI];
|
|
eor->machine = ELF_FETCH_FIELD (type_functions, ei_class, Ehdr, ehdr,
|
|
e_machine, Elf_Half);
|
|
eor->flags = ELF_FETCH_FIELD (type_functions, ei_class, Ehdr, ehdr,
|
|
e_flags, Elf_Word);
|
|
eor->shoff = ELF_FETCH_FIELD (type_functions, ei_class, Ehdr, ehdr,
|
|
e_shoff, Elf_Addr);
|
|
eor->shnum = ELF_FETCH_FIELD (type_functions, ei_class, Ehdr, ehdr,
|
|
e_shnum, Elf_Half);
|
|
eor->shstrndx = ELF_FETCH_FIELD (type_functions, ei_class, Ehdr, ehdr,
|
|
e_shstrndx, Elf_Half);
|
|
|
|
if ((eor->shnum == 0 || eor->shstrndx == SHN_XINDEX)
|
|
&& eor->shoff != 0)
|
|
{
|
|
unsigned char shdr[sizeof (Elf64_External_Shdr)];
|
|
|
|
/* Object file has more than 0xffff sections. */
|
|
|
|
if (!simple_object_internal_read (descriptor, offset + eor->shoff, shdr,
|
|
(ei_class == ELFCLASS32
|
|
? sizeof (Elf32_External_Shdr)
|
|
: sizeof (Elf64_External_Shdr)),
|
|
errmsg, err))
|
|
{
|
|
XDELETE (eor);
|
|
return NULL;
|
|
}
|
|
|
|
if (eor->shnum == 0)
|
|
eor->shnum = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_size, Elf_Addr);
|
|
|
|
if (eor->shstrndx == SHN_XINDEX)
|
|
{
|
|
eor->shstrndx = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_link, Elf_Word);
|
|
|
|
/* Versions of the GNU binutils between 2.12 and 2.18 did
|
|
not handle objects with more than SHN_LORESERVE sections
|
|
correctly. All large section indexes were offset by
|
|
0x100. There is more information at
|
|
http://sourceware.org/bugzilla/show_bug.cgi?id-5900 .
|
|
Fortunately these object files are easy to detect, as the
|
|
GNU binutils always put the section header string table
|
|
near the end of the list of sections. Thus if the
|
|
section header string table index is larger than the
|
|
number of sections, then we know we have to subtract
|
|
0x100 to get the real section index. */
|
|
if (eor->shstrndx >= eor->shnum
|
|
&& eor->shstrndx >= SHN_LORESERVE + 0x100)
|
|
eor->shstrndx -= 0x100;
|
|
}
|
|
}
|
|
|
|
if (eor->shstrndx >= eor->shnum)
|
|
{
|
|
*errmsg = "invalid ELF shstrndx >= shnum";
|
|
*err = 0;
|
|
XDELETE (eor);
|
|
return NULL;
|
|
}
|
|
|
|
if (eor->shstrndx == 0)
|
|
{
|
|
*errmsg = "invalid ELF shstrndx == 0";
|
|
*err = 0;
|
|
XDELETE (eor);
|
|
return NULL;
|
|
}
|
|
|
|
return (void *) eor;
|
|
}
|
|
|
|
/* Find all sections in an ELF file. */
|
|
|
|
static const char *
|
|
simple_object_elf_find_sections (simple_object_read *sobj,
|
|
int (*pfn) (void *, const char *,
|
|
off_t offset, off_t length),
|
|
void *data,
|
|
int *err)
|
|
{
|
|
struct simple_object_elf_read *eor =
|
|
(struct simple_object_elf_read *) sobj->data;
|
|
const struct elf_type_functions *type_functions = eor->type_functions;
|
|
unsigned char ei_class = eor->ei_class;
|
|
size_t shdr_size;
|
|
unsigned int shnum;
|
|
unsigned char *shdrs;
|
|
const char *errmsg;
|
|
unsigned char *shstrhdr;
|
|
size_t name_size;
|
|
off_t shstroff;
|
|
unsigned char *names;
|
|
unsigned int i;
|
|
|
|
shdr_size = (ei_class == ELFCLASS32
|
|
? sizeof (Elf32_External_Shdr)
|
|
: sizeof (Elf64_External_Shdr));
|
|
|
|
/* Read the section headers. We skip section 0, which is not a
|
|
useful section. */
|
|
|
|
shnum = eor->shnum;
|
|
shdrs = XNEWVEC (unsigned char, shdr_size * (shnum - 1));
|
|
|
|
if (!simple_object_internal_read (sobj->descriptor,
|
|
sobj->offset + eor->shoff + shdr_size,
|
|
shdrs,
|
|
shdr_size * (shnum - 1),
|
|
&errmsg, err))
|
|
{
|
|
XDELETEVEC (shdrs);
|
|
return errmsg;
|
|
}
|
|
|
|
/* Read the section names. */
|
|
|
|
shstrhdr = shdrs + (eor->shstrndx - 1) * shdr_size;
|
|
name_size = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shstrhdr, sh_size, Elf_Addr);
|
|
shstroff = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shstrhdr, sh_offset, Elf_Addr);
|
|
names = XNEWVEC (unsigned char, name_size);
|
|
if (!simple_object_internal_read (sobj->descriptor,
|
|
sobj->offset + shstroff,
|
|
names, name_size, &errmsg, err))
|
|
{
|
|
XDELETEVEC (names);
|
|
XDELETEVEC (shdrs);
|
|
return errmsg;
|
|
}
|
|
|
|
for (i = 1; i < shnum; ++i)
|
|
{
|
|
unsigned char *shdr;
|
|
unsigned int sh_name;
|
|
const char *name;
|
|
off_t offset;
|
|
off_t length;
|
|
|
|
shdr = shdrs + (i - 1) * shdr_size;
|
|
sh_name = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_name, Elf_Word);
|
|
if (sh_name >= name_size)
|
|
{
|
|
*err = 0;
|
|
XDELETEVEC (names);
|
|
XDELETEVEC (shdrs);
|
|
return "ELF section name out of range";
|
|
}
|
|
|
|
name = (const char *) names + sh_name;
|
|
offset = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_offset, Elf_Addr);
|
|
length = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_size, Elf_Addr);
|
|
|
|
if (!(*pfn) (data, name, offset, length))
|
|
break;
|
|
}
|
|
|
|
XDELETEVEC (names);
|
|
XDELETEVEC (shdrs);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Fetch the attributes for an simple_object_read. */
|
|
|
|
static void *
|
|
simple_object_elf_fetch_attributes (simple_object_read *sobj,
|
|
const char **errmsg ATTRIBUTE_UNUSED,
|
|
int *err ATTRIBUTE_UNUSED)
|
|
{
|
|
struct simple_object_elf_read *eor =
|
|
(struct simple_object_elf_read *) sobj->data;
|
|
struct simple_object_elf_attributes *ret;
|
|
|
|
ret = XNEW (struct simple_object_elf_attributes);
|
|
ret->type_functions = eor->type_functions;
|
|
ret->ei_data = eor->ei_data;
|
|
ret->ei_class = eor->ei_class;
|
|
ret->ei_osabi = eor->ei_osabi;
|
|
ret->machine = eor->machine;
|
|
ret->flags = eor->flags;
|
|
return ret;
|
|
}
|
|
|
|
/* Release the privata data for an simple_object_read. */
|
|
|
|
static void
|
|
simple_object_elf_release_read (void *data)
|
|
{
|
|
XDELETE (data);
|
|
}
|
|
|
|
/* Compare two attributes structures. */
|
|
|
|
static const char *
|
|
simple_object_elf_attributes_merge (void *todata, void *fromdata, int *err)
|
|
{
|
|
struct simple_object_elf_attributes *to =
|
|
(struct simple_object_elf_attributes *) todata;
|
|
struct simple_object_elf_attributes *from =
|
|
(struct simple_object_elf_attributes *) fromdata;
|
|
|
|
if (to->ei_data != from->ei_data || to->ei_class != from->ei_class)
|
|
{
|
|
*err = 0;
|
|
return "ELF object format mismatch";
|
|
}
|
|
|
|
if (to->machine != from->machine)
|
|
{
|
|
int ok;
|
|
|
|
/* EM_SPARC and EM_SPARC32PLUS are compatible and force an
|
|
output of EM_SPARC32PLUS. */
|
|
ok = 0;
|
|
switch (to->machine)
|
|
{
|
|
case EM_SPARC:
|
|
if (from->machine == EM_SPARC32PLUS)
|
|
{
|
|
to->machine = from->machine;
|
|
ok = 1;
|
|
}
|
|
break;
|
|
|
|
case EM_SPARC32PLUS:
|
|
if (from->machine == EM_SPARC)
|
|
ok = 1;
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
if (!ok)
|
|
{
|
|
*err = 0;
|
|
return "ELF machine number mismatch";
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Release the private data for an attributes structure. */
|
|
|
|
static void
|
|
simple_object_elf_release_attributes (void *data)
|
|
{
|
|
XDELETE (data);
|
|
}
|
|
|
|
/* Prepare to write out a file. */
|
|
|
|
static void *
|
|
simple_object_elf_start_write (void *attributes_data,
|
|
const char **errmsg ATTRIBUTE_UNUSED,
|
|
int *err ATTRIBUTE_UNUSED)
|
|
{
|
|
struct simple_object_elf_attributes *attrs =
|
|
(struct simple_object_elf_attributes *) attributes_data;
|
|
struct simple_object_elf_write *ret;
|
|
|
|
/* We're just going to record the attributes, but we need to make a
|
|
copy because the user may delete them. */
|
|
ret = XNEW (struct simple_object_elf_write);
|
|
ret->attrs = *attrs;
|
|
ret->shdrs = NULL;
|
|
return ret;
|
|
}
|
|
|
|
/* Write out an ELF ehdr. */
|
|
|
|
static int
|
|
simple_object_elf_write_ehdr (simple_object_write *sobj, int descriptor,
|
|
const char **errmsg, int *err)
|
|
{
|
|
struct simple_object_elf_attributes *attrs =
|
|
(struct simple_object_elf_attributes *) sobj->data;
|
|
const struct elf_type_functions* fns;
|
|
unsigned char cl;
|
|
size_t ehdr_size;
|
|
unsigned char buf[sizeof (Elf64_External_Ehdr)];
|
|
simple_object_write_section *section;
|
|
unsigned int shnum;
|
|
unsigned int shstrndx;
|
|
|
|
fns = attrs->type_functions;
|
|
cl = attrs->ei_class;
|
|
|
|
shnum = 0;
|
|
for (section = sobj->sections; section != NULL; section = section->next)
|
|
++shnum;
|
|
if (shnum > 0)
|
|
{
|
|
/* Add a section header for the dummy section and one for
|
|
.shstrtab. */
|
|
shnum += 2;
|
|
}
|
|
|
|
ehdr_size = (cl == ELFCLASS32
|
|
? sizeof (Elf32_External_Ehdr)
|
|
: sizeof (Elf64_External_Ehdr));
|
|
memset (buf, 0, sizeof (Elf64_External_Ehdr));
|
|
|
|
buf[EI_MAG0] = ELFMAG0;
|
|
buf[EI_MAG1] = ELFMAG1;
|
|
buf[EI_MAG2] = ELFMAG2;
|
|
buf[EI_MAG3] = ELFMAG3;
|
|
buf[EI_CLASS] = cl;
|
|
buf[EI_DATA] = attrs->ei_data;
|
|
buf[EI_VERSION] = EV_CURRENT;
|
|
buf[EI_OSABI] = attrs->ei_osabi;
|
|
|
|
ELF_SET_FIELD (fns, cl, Ehdr, buf, e_type, Elf_Half, ET_REL);
|
|
ELF_SET_FIELD (fns, cl, Ehdr, buf, e_machine, Elf_Half, attrs->machine);
|
|
ELF_SET_FIELD (fns, cl, Ehdr, buf, e_version, Elf_Word, EV_CURRENT);
|
|
/* e_entry left as zero. */
|
|
/* e_phoff left as zero. */
|
|
ELF_SET_FIELD (fns, cl, Ehdr, buf, e_shoff, Elf_Addr, ehdr_size);
|
|
ELF_SET_FIELD (fns, cl, Ehdr, buf, e_flags, Elf_Word, attrs->flags);
|
|
ELF_SET_FIELD (fns, cl, Ehdr, buf, e_ehsize, Elf_Half, ehdr_size);
|
|
ELF_SET_FIELD (fns, cl, Ehdr, buf, e_phentsize, Elf_Half,
|
|
(cl == ELFCLASS32
|
|
? sizeof (Elf32_External_Phdr)
|
|
: sizeof (Elf64_External_Phdr)));
|
|
/* e_phnum left as zero. */
|
|
ELF_SET_FIELD (fns, cl, Ehdr, buf, e_shentsize, Elf_Half,
|
|
(cl == ELFCLASS32
|
|
? sizeof (Elf32_External_Shdr)
|
|
: sizeof (Elf64_External_Shdr)));
|
|
ELF_SET_FIELD (fns, cl, Ehdr, buf, e_shnum, Elf_Half,
|
|
shnum >= SHN_LORESERVE ? 0 : shnum);
|
|
if (shnum == 0)
|
|
shstrndx = 0;
|
|
else
|
|
{
|
|
shstrndx = shnum - 1;
|
|
if (shstrndx >= SHN_LORESERVE)
|
|
shstrndx = SHN_XINDEX;
|
|
}
|
|
ELF_SET_FIELD (fns, cl, Ehdr, buf, e_shstrndx, Elf_Half, shstrndx);
|
|
|
|
return simple_object_internal_write (descriptor, 0, buf, ehdr_size,
|
|
errmsg, err);
|
|
}
|
|
|
|
/* Write out an ELF shdr. */
|
|
|
|
static int
|
|
simple_object_elf_write_shdr (simple_object_write *sobj, int descriptor,
|
|
off_t offset, unsigned int sh_name,
|
|
unsigned int sh_type, unsigned int sh_flags,
|
|
off_t sh_addr,
|
|
unsigned int sh_offset, unsigned int sh_size,
|
|
unsigned int sh_link, unsigned int sh_info,
|
|
size_t sh_addralign,
|
|
size_t sh_entsize,
|
|
const char **errmsg, int *err)
|
|
{
|
|
struct simple_object_elf_attributes *attrs =
|
|
(struct simple_object_elf_attributes *) sobj->data;
|
|
const struct elf_type_functions* fns;
|
|
unsigned char cl;
|
|
size_t shdr_size;
|
|
unsigned char buf[sizeof (Elf64_External_Shdr)];
|
|
|
|
fns = attrs->type_functions;
|
|
cl = attrs->ei_class;
|
|
|
|
shdr_size = (cl == ELFCLASS32
|
|
? sizeof (Elf32_External_Shdr)
|
|
: sizeof (Elf64_External_Shdr));
|
|
memset (buf, 0, sizeof (Elf64_External_Shdr));
|
|
|
|
ELF_SET_FIELD (fns, cl, Shdr, buf, sh_name, Elf_Word, sh_name);
|
|
ELF_SET_FIELD (fns, cl, Shdr, buf, sh_type, Elf_Word, sh_type);
|
|
ELF_SET_FIELD (fns, cl, Shdr, buf, sh_flags, Elf_Addr, sh_flags);
|
|
ELF_SET_FIELD (fns, cl, Shdr, buf, sh_addr, Elf_Addr, sh_addr);
|
|
ELF_SET_FIELD (fns, cl, Shdr, buf, sh_offset, Elf_Addr, sh_offset);
|
|
ELF_SET_FIELD (fns, cl, Shdr, buf, sh_size, Elf_Addr, sh_size);
|
|
ELF_SET_FIELD (fns, cl, Shdr, buf, sh_link, Elf_Word, sh_link);
|
|
ELF_SET_FIELD (fns, cl, Shdr, buf, sh_info, Elf_Word, sh_info);
|
|
ELF_SET_FIELD (fns, cl, Shdr, buf, sh_addralign, Elf_Addr, sh_addralign);
|
|
ELF_SET_FIELD (fns, cl, Shdr, buf, sh_entsize, Elf_Addr, sh_entsize);
|
|
|
|
return simple_object_internal_write (descriptor, offset, buf, shdr_size,
|
|
errmsg, err);
|
|
}
|
|
|
|
/* Write out a complete ELF file.
|
|
Ehdr
|
|
initial dummy Shdr
|
|
user-created Shdrs
|
|
.shstrtab Shdr
|
|
user-created section data
|
|
.shstrtab data */
|
|
|
|
static const char *
|
|
simple_object_elf_write_to_file (simple_object_write *sobj, int descriptor,
|
|
int *err)
|
|
{
|
|
struct simple_object_elf_write *eow =
|
|
(struct simple_object_elf_write *) sobj->data;
|
|
struct simple_object_elf_attributes *attrs = &eow->attrs;
|
|
unsigned char cl;
|
|
size_t ehdr_size;
|
|
size_t shdr_size;
|
|
const char *errmsg;
|
|
simple_object_write_section *section;
|
|
unsigned int shnum;
|
|
size_t shdr_offset;
|
|
size_t sh_offset;
|
|
unsigned int first_sh_size;
|
|
unsigned int first_sh_link;
|
|
size_t sh_name;
|
|
unsigned char zero;
|
|
unsigned secnum;
|
|
|
|
if (!simple_object_elf_write_ehdr (sobj, descriptor, &errmsg, err))
|
|
return errmsg;
|
|
|
|
cl = attrs->ei_class;
|
|
if (cl == ELFCLASS32)
|
|
{
|
|
ehdr_size = sizeof (Elf32_External_Ehdr);
|
|
shdr_size = sizeof (Elf32_External_Shdr);
|
|
}
|
|
else
|
|
{
|
|
ehdr_size = sizeof (Elf64_External_Ehdr);
|
|
shdr_size = sizeof (Elf64_External_Shdr);
|
|
}
|
|
|
|
shnum = 0;
|
|
for (section = sobj->sections; section != NULL; section = section->next)
|
|
++shnum;
|
|
if (shnum == 0)
|
|
return NULL;
|
|
|
|
/* Add initial dummy Shdr and .shstrtab. */
|
|
shnum += 2;
|
|
|
|
shdr_offset = ehdr_size;
|
|
sh_offset = shdr_offset + shnum * shdr_size;
|
|
|
|
if (shnum < SHN_LORESERVE)
|
|
first_sh_size = 0;
|
|
else
|
|
first_sh_size = shnum;
|
|
if (shnum - 1 < SHN_LORESERVE)
|
|
first_sh_link = 0;
|
|
else
|
|
first_sh_link = shnum - 1;
|
|
if (!simple_object_elf_write_shdr (sobj, descriptor, shdr_offset,
|
|
0, 0, 0, 0, 0, first_sh_size, first_sh_link,
|
|
0, 0, 0, &errmsg, err))
|
|
return errmsg;
|
|
|
|
shdr_offset += shdr_size;
|
|
|
|
sh_name = 1;
|
|
secnum = 0;
|
|
for (section = sobj->sections; section != NULL; section = section->next)
|
|
{
|
|
size_t mask;
|
|
size_t new_sh_offset;
|
|
size_t sh_size;
|
|
struct simple_object_write_section_buffer *buffer;
|
|
unsigned int sh_type = SHT_PROGBITS;
|
|
unsigned int sh_flags = 0;
|
|
off_t sh_addr = 0;
|
|
unsigned int sh_link = 0;
|
|
unsigned int sh_info = 0;
|
|
size_t sh_addralign = 1U << section->align;
|
|
size_t sh_entsize = 0;
|
|
if (eow->shdrs)
|
|
{
|
|
sh_type = ELF_FETCH_FIELD (attrs->type_functions, attrs->ei_class, Shdr,
|
|
eow->shdrs + secnum * shdr_size,
|
|
sh_type, Elf_Word);
|
|
sh_flags = ELF_FETCH_FIELD (attrs->type_functions, attrs->ei_class, Shdr,
|
|
eow->shdrs + secnum * shdr_size,
|
|
sh_flags, Elf_Addr);
|
|
sh_addr = ELF_FETCH_FIELD (attrs->type_functions, attrs->ei_class, Shdr,
|
|
eow->shdrs + secnum * shdr_size,
|
|
sh_addr, Elf_Addr);
|
|
sh_link = ELF_FETCH_FIELD (attrs->type_functions, attrs->ei_class, Shdr,
|
|
eow->shdrs + secnum * shdr_size,
|
|
sh_link, Elf_Word);
|
|
sh_info = ELF_FETCH_FIELD (attrs->type_functions, attrs->ei_class, Shdr,
|
|
eow->shdrs + secnum * shdr_size,
|
|
sh_info, Elf_Word);
|
|
sh_addralign = ELF_FETCH_FIELD (attrs->type_functions, attrs->ei_class, Shdr,
|
|
eow->shdrs + secnum * shdr_size,
|
|
sh_addralign, Elf_Addr);
|
|
sh_entsize = ELF_FETCH_FIELD (attrs->type_functions, attrs->ei_class, Shdr,
|
|
eow->shdrs + secnum * shdr_size,
|
|
sh_entsize, Elf_Addr);
|
|
secnum++;
|
|
}
|
|
|
|
mask = sh_addralign - 1;
|
|
new_sh_offset = sh_offset + mask;
|
|
new_sh_offset &= ~ mask;
|
|
while (new_sh_offset > sh_offset)
|
|
{
|
|
unsigned char zeroes[16];
|
|
size_t write;
|
|
|
|
memset (zeroes, 0, sizeof zeroes);
|
|
write = new_sh_offset - sh_offset;
|
|
if (write > sizeof zeroes)
|
|
write = sizeof zeroes;
|
|
if (!simple_object_internal_write (descriptor, sh_offset, zeroes,
|
|
write, &errmsg, err))
|
|
return errmsg;
|
|
sh_offset += write;
|
|
}
|
|
|
|
sh_size = 0;
|
|
for (buffer = section->buffers; buffer != NULL; buffer = buffer->next)
|
|
{
|
|
if (!simple_object_internal_write (descriptor, sh_offset + sh_size,
|
|
((const unsigned char *)
|
|
buffer->buffer),
|
|
buffer->size, &errmsg, err))
|
|
return errmsg;
|
|
sh_size += buffer->size;
|
|
}
|
|
|
|
if (!simple_object_elf_write_shdr (sobj, descriptor, shdr_offset,
|
|
sh_name, sh_type, sh_flags,
|
|
sh_addr, sh_offset,
|
|
sh_size, sh_link, sh_info,
|
|
sh_addralign, sh_entsize,
|
|
&errmsg, err))
|
|
return errmsg;
|
|
|
|
shdr_offset += shdr_size;
|
|
sh_name += strlen (section->name) + 1;
|
|
sh_offset += sh_size;
|
|
}
|
|
|
|
if (!simple_object_elf_write_shdr (sobj, descriptor, shdr_offset,
|
|
sh_name, SHT_STRTAB, 0, 0, sh_offset,
|
|
sh_name + strlen (".shstrtab") + 1, 0, 0,
|
|
1, 0, &errmsg, err))
|
|
return errmsg;
|
|
|
|
/* .shstrtab has a leading zero byte. */
|
|
zero = 0;
|
|
if (!simple_object_internal_write (descriptor, sh_offset, &zero, 1,
|
|
&errmsg, err))
|
|
return errmsg;
|
|
++sh_offset;
|
|
|
|
for (section = sobj->sections; section != NULL; section = section->next)
|
|
{
|
|
size_t len;
|
|
|
|
len = strlen (section->name) + 1;
|
|
if (!simple_object_internal_write (descriptor, sh_offset,
|
|
(const unsigned char *) section->name,
|
|
len, &errmsg, err))
|
|
return errmsg;
|
|
sh_offset += len;
|
|
}
|
|
|
|
if (!simple_object_internal_write (descriptor, sh_offset,
|
|
(const unsigned char *) ".shstrtab",
|
|
strlen (".shstrtab") + 1, &errmsg, err))
|
|
return errmsg;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Release the private data for an simple_object_write structure. */
|
|
|
|
static void
|
|
simple_object_elf_release_write (void *data)
|
|
{
|
|
struct simple_object_elf_write *eow = (struct simple_object_elf_write *) data;
|
|
if (eow->shdrs)
|
|
XDELETE (eow->shdrs);
|
|
XDELETE (data);
|
|
}
|
|
|
|
/* Copy all sections in an ELF file. */
|
|
|
|
static const char *
|
|
simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj,
|
|
simple_object_write *dobj,
|
|
char *(*pfn) (const char *),
|
|
int *err)
|
|
{
|
|
struct simple_object_elf_read *eor =
|
|
(struct simple_object_elf_read *) sobj->data;
|
|
const struct elf_type_functions *type_functions = eor->type_functions;
|
|
struct simple_object_elf_write *eow =
|
|
(struct simple_object_elf_write *) dobj->data;
|
|
unsigned char ei_class = eor->ei_class;
|
|
size_t shdr_size;
|
|
unsigned int shnum;
|
|
unsigned char *shdrs;
|
|
const char *errmsg;
|
|
unsigned char *shstrhdr;
|
|
size_t name_size;
|
|
off_t shstroff;
|
|
unsigned char *names;
|
|
unsigned int i;
|
|
int changed;
|
|
int *pfnret;
|
|
const char **pfnname;
|
|
unsigned new_i;
|
|
unsigned *sh_map;
|
|
unsigned first_shndx = 0;
|
|
unsigned int *symtab_indices_shndx;
|
|
|
|
shdr_size = (ei_class == ELFCLASS32
|
|
? sizeof (Elf32_External_Shdr)
|
|
: sizeof (Elf64_External_Shdr));
|
|
|
|
/* Read the section headers. We skip section 0, which is not a
|
|
useful section. */
|
|
|
|
shnum = eor->shnum;
|
|
shdrs = XNEWVEC (unsigned char, shdr_size * (shnum - 1));
|
|
|
|
if (!simple_object_internal_read (sobj->descriptor,
|
|
sobj->offset + eor->shoff + shdr_size,
|
|
shdrs,
|
|
shdr_size * (shnum - 1),
|
|
&errmsg, err))
|
|
{
|
|
XDELETEVEC (shdrs);
|
|
return errmsg;
|
|
}
|
|
|
|
/* Read the section names. */
|
|
|
|
shstrhdr = shdrs + (eor->shstrndx - 1) * shdr_size;
|
|
name_size = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shstrhdr, sh_size, Elf_Addr);
|
|
shstroff = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shstrhdr, sh_offset, Elf_Addr);
|
|
names = XNEWVEC (unsigned char, name_size);
|
|
if (!simple_object_internal_read (sobj->descriptor,
|
|
sobj->offset + shstroff,
|
|
names, name_size, &errmsg, err))
|
|
{
|
|
XDELETEVEC (names);
|
|
XDELETEVEC (shdrs);
|
|
return errmsg;
|
|
}
|
|
|
|
pfnret = XNEWVEC (int, shnum);
|
|
pfnname = XNEWVEC (const char *, shnum);
|
|
|
|
/* Map of symtab to index section. */
|
|
symtab_indices_shndx = XCNEWVEC (unsigned int, shnum - 1);
|
|
|
|
/* First perform the callbacks to know which sections to preserve and
|
|
what name to use for those. */
|
|
for (i = 1; i < shnum; ++i)
|
|
{
|
|
unsigned char *shdr;
|
|
unsigned int sh_name, sh_type;
|
|
const char *name;
|
|
char *ret;
|
|
|
|
shdr = shdrs + (i - 1) * shdr_size;
|
|
sh_name = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_name, Elf_Word);
|
|
if (sh_name >= name_size)
|
|
{
|
|
*err = 0;
|
|
XDELETEVEC (names);
|
|
XDELETEVEC (shdrs);
|
|
return "ELF section name out of range";
|
|
}
|
|
|
|
name = (const char *) names + sh_name;
|
|
|
|
ret = (*pfn) (name);
|
|
pfnret[i - 1] = ret == NULL ? -1 : 0;
|
|
pfnname[i - 1] = ret == NULL ? name : ret;
|
|
if (first_shndx == 0
|
|
&& pfnret[i - 1] == 0)
|
|
first_shndx = i;
|
|
|
|
/* Remember the indexes of existing SHT_SYMTAB_SHNDX sections. */
|
|
sh_type = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_type, Elf_Word);
|
|
if (sh_type == SHT_SYMTAB_SHNDX)
|
|
{
|
|
unsigned int sh_link;
|
|
sh_link = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_link, Elf_Word);
|
|
symtab_indices_shndx[sh_link - 1] = i - 1;
|
|
/* Always discard the extended index sections, after
|
|
copying it will not be needed. This way we don't need to
|
|
update it and deal with the ordering constraints of
|
|
processing the existing symtab and changing the index. */
|
|
pfnret[i - 1] = -1;
|
|
}
|
|
}
|
|
|
|
/* Mark sections as preserved that are required by to be preserved
|
|
sections. */
|
|
do
|
|
{
|
|
changed = 0;
|
|
for (i = 1; i < shnum; ++i)
|
|
{
|
|
unsigned char *shdr;
|
|
unsigned int sh_type, sh_info, sh_link;
|
|
off_t offset;
|
|
off_t length;
|
|
|
|
shdr = shdrs + (i - 1) * shdr_size;
|
|
sh_type = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_type, Elf_Word);
|
|
sh_info = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_info, Elf_Word);
|
|
sh_link = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_link, Elf_Word);
|
|
if (sh_type == SHT_GROUP)
|
|
{
|
|
/* Mark groups containing copied sections. */
|
|
unsigned entsize = ELF_FETCH_FIELD (type_functions, ei_class,
|
|
Shdr, shdr, sh_entsize,
|
|
Elf_Addr);
|
|
unsigned char *ent, *buf;
|
|
int keep = 0;
|
|
offset = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_offset, Elf_Addr);
|
|
length = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_size, Elf_Addr);
|
|
buf = XNEWVEC (unsigned char, length);
|
|
if (!simple_object_internal_read (sobj->descriptor,
|
|
sobj->offset + offset, buf,
|
|
(size_t) length, &errmsg, err))
|
|
{
|
|
XDELETEVEC (buf);
|
|
XDELETEVEC (names);
|
|
XDELETEVEC (shdrs);
|
|
return errmsg;
|
|
}
|
|
for (ent = buf + entsize; ent < buf + length; ent += entsize)
|
|
{
|
|
unsigned sec = type_functions->fetch_Elf_Word (ent);
|
|
if (pfnret[sec - 1] == 0)
|
|
keep = 1;
|
|
}
|
|
if (keep)
|
|
{
|
|
changed |= (pfnret[sh_link - 1] == -1
|
|
|| pfnret[i - 1] == -1);
|
|
pfnret[sh_link - 1] = 0;
|
|
pfnret[i - 1] = 0;
|
|
}
|
|
}
|
|
if (sh_type == SHT_RELA
|
|
|| sh_type == SHT_REL)
|
|
{
|
|
/* Mark relocation sections and symtab of copied sections. */
|
|
if (pfnret[sh_info - 1] == 0)
|
|
{
|
|
changed |= (pfnret[sh_link - 1] == -1
|
|
|| pfnret[i - 1] == -1);
|
|
pfnret[sh_link - 1] = 0;
|
|
pfnret[i - 1] = 0;
|
|
}
|
|
}
|
|
if (sh_type == SHT_SYMTAB)
|
|
{
|
|
/* Mark strings sections of copied symtabs. */
|
|
if (pfnret[i - 1] == 0)
|
|
{
|
|
changed |= pfnret[sh_link - 1] == -1;
|
|
pfnret[sh_link - 1] = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
while (changed);
|
|
|
|
/* Compute a mapping of old -> new section numbers. */
|
|
sh_map = XNEWVEC (unsigned, shnum);
|
|
sh_map[0] = 0;
|
|
new_i = 1;
|
|
for (i = 1; i < shnum; ++i)
|
|
{
|
|
if (pfnret[i - 1] == -1)
|
|
sh_map[i] = 0;
|
|
else
|
|
sh_map[i] = new_i++;
|
|
}
|
|
if (new_i - 1 >= SHN_LORESERVE)
|
|
{
|
|
*err = ENOTSUP;
|
|
return "Too many copied sections";
|
|
}
|
|
eow->shdrs = XNEWVEC (unsigned char, shdr_size * (new_i - 1));
|
|
|
|
/* Then perform the actual copying. */
|
|
new_i = 0;
|
|
for (i = 1; i < shnum; ++i)
|
|
{
|
|
unsigned char *shdr;
|
|
unsigned int sh_name, sh_type;
|
|
const char *name;
|
|
off_t offset;
|
|
off_t length;
|
|
simple_object_write_section *dest;
|
|
off_t flags;
|
|
unsigned char *buf;
|
|
|
|
if (pfnret[i - 1])
|
|
continue;
|
|
|
|
new_i++;
|
|
shdr = shdrs + (i - 1) * shdr_size;
|
|
sh_name = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_name, Elf_Word);
|
|
if (sh_name >= name_size)
|
|
{
|
|
*err = 0;
|
|
XDELETEVEC (names);
|
|
XDELETEVEC (shdrs);
|
|
XDELETEVEC (symtab_indices_shndx);
|
|
return "ELF section name out of range";
|
|
}
|
|
|
|
name = pfnname[i - 1];
|
|
offset = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_offset, Elf_Addr);
|
|
length = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_size, Elf_Addr);
|
|
sh_type = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_type, Elf_Word);
|
|
|
|
dest = simple_object_write_create_section (dobj, pfnname[i - 1],
|
|
0, &errmsg, err);
|
|
if (dest == NULL)
|
|
{
|
|
XDELETEVEC (names);
|
|
XDELETEVEC (shdrs);
|
|
XDELETEVEC (symtab_indices_shndx);
|
|
return errmsg;
|
|
}
|
|
|
|
/* Record the SHDR of the source. */
|
|
memcpy (eow->shdrs + (new_i - 1) * shdr_size, shdr, shdr_size);
|
|
shdr = eow->shdrs + (new_i - 1) * shdr_size;
|
|
|
|
/* Copy the data.
|
|
??? This is quite wasteful and ideally would be delayed until
|
|
write_to_file (). Thus it questions the interfacing
|
|
which eventually should contain destination creation plus
|
|
writing. */
|
|
buf = XNEWVEC (unsigned char, length);
|
|
if (!simple_object_internal_read (sobj->descriptor,
|
|
sobj->offset + offset, buf,
|
|
(size_t) length, &errmsg, err))
|
|
{
|
|
XDELETEVEC (buf);
|
|
XDELETEVEC (names);
|
|
XDELETEVEC (shdrs);
|
|
XDELETEVEC (symtab_indices_shndx);
|
|
return errmsg;
|
|
}
|
|
|
|
/* If we are processing .symtab purge any symbols
|
|
in discarded sections. */
|
|
if (sh_type == SHT_SYMTAB)
|
|
{
|
|
unsigned entsize = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_entsize, Elf_Addr);
|
|
size_t prevailing_name_idx = 0;
|
|
unsigned char *ent;
|
|
unsigned *shndx_table = NULL;
|
|
/* Read the section index table if present. */
|
|
if (symtab_indices_shndx[i - 1] != 0)
|
|
{
|
|
unsigned char *sidxhdr = shdrs + symtab_indices_shndx[i - 1] * shdr_size;
|
|
off_t sidxoff = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
sidxhdr, sh_offset, Elf_Addr);
|
|
size_t sidxsz = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
sidxhdr, sh_size, Elf_Addr);
|
|
unsigned int shndx_type
|
|
= ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
sidxhdr, sh_type, Elf_Word);
|
|
if (shndx_type != SHT_SYMTAB_SHNDX)
|
|
return "Wrong section type of a SYMTAB SECTION INDICES section";
|
|
shndx_table = (unsigned *)XNEWVEC (char, sidxsz);
|
|
simple_object_internal_read (sobj->descriptor,
|
|
sobj->offset + sidxoff,
|
|
(unsigned char *)shndx_table,
|
|
sidxsz, &errmsg, err);
|
|
}
|
|
|
|
/* Find a WEAK HIDDEN symbol which name we will use for removed
|
|
symbols. We know there's a prevailing weak hidden symbol
|
|
at the start of the .debug_info section. */
|
|
for (ent = buf; ent < buf + length; ent += entsize)
|
|
{
|
|
unsigned st_shndx = ELF_FETCH_FIELD (type_functions, ei_class,
|
|
Sym, ent,
|
|
st_shndx, Elf_Half);
|
|
unsigned char *st_info;
|
|
unsigned char *st_other;
|
|
if (ei_class == ELFCLASS32)
|
|
{
|
|
st_info = &((Elf32_External_Sym *)ent)->st_info;
|
|
st_other = &((Elf32_External_Sym *)ent)->st_other;
|
|
}
|
|
else
|
|
{
|
|
st_info = &((Elf64_External_Sym *)ent)->st_info;
|
|
st_other = &((Elf64_External_Sym *)ent)->st_other;
|
|
}
|
|
if (st_shndx == SHN_XINDEX)
|
|
st_shndx = type_functions->fetch_Elf_Word
|
|
((unsigned char *)(shndx_table + (ent - buf) / entsize));
|
|
|
|
if (st_shndx != SHN_COMMON
|
|
&& !(st_shndx != SHN_UNDEF
|
|
&& st_shndx < shnum
|
|
&& pfnret[st_shndx - 1] == -1)
|
|
&& ELF_ST_BIND (*st_info) == STB_WEAK
|
|
&& *st_other == STV_HIDDEN)
|
|
{
|
|
prevailing_name_idx = ELF_FETCH_FIELD (type_functions,
|
|
ei_class, Sym, ent,
|
|
st_name, Elf_Word);
|
|
break;
|
|
}
|
|
}
|
|
|
|
for (ent = buf; ent < buf + length; ent += entsize)
|
|
{
|
|
unsigned st_shndx = ELF_FETCH_FIELD (type_functions, ei_class,
|
|
Sym, ent,
|
|
st_shndx, Elf_Half);
|
|
unsigned raw_st_shndx = st_shndx;
|
|
unsigned char *st_info;
|
|
unsigned char *st_other;
|
|
int discard = 0;
|
|
if (ei_class == ELFCLASS32)
|
|
{
|
|
st_info = &((Elf32_External_Sym *)ent)->st_info;
|
|
st_other = &((Elf32_External_Sym *)ent)->st_other;
|
|
}
|
|
else
|
|
{
|
|
st_info = &((Elf64_External_Sym *)ent)->st_info;
|
|
st_other = &((Elf64_External_Sym *)ent)->st_other;
|
|
}
|
|
if (st_shndx == SHN_XINDEX)
|
|
st_shndx = type_functions->fetch_Elf_Word
|
|
((unsigned char *)(shndx_table + (ent - buf) / entsize));
|
|
/* Eliminate all COMMONs - this includes __gnu_lto_slim
|
|
which otherwise cause endless LTO plugin invocation.
|
|
FIXME: remove the condition once we remove emission
|
|
of __gnu_lto_slim symbol. */
|
|
if (st_shndx == SHN_COMMON)
|
|
discard = 1;
|
|
/* We also need to remove symbols refering to sections
|
|
we'll eventually remove as with fat LTO objects
|
|
we otherwise get duplicate symbols at final link
|
|
(with GNU ld, gold is fine and ignores symbols in
|
|
sections marked as EXCLUDE). ld/20513 */
|
|
else if (st_shndx != SHN_UNDEF
|
|
&& st_shndx < shnum
|
|
&& pfnret[st_shndx - 1] == -1)
|
|
discard = 1;
|
|
/* We also need to remove global UNDEFs which can
|
|
cause link fails later. */
|
|
else if (st_shndx == SHN_UNDEF
|
|
&& ELF_ST_BIND (*st_info) == STB_GLOBAL)
|
|
discard = 1;
|
|
|
|
if (discard)
|
|
{
|
|
/* Make discarded symbols undefined and unnamed
|
|
in case it is local. */
|
|
int bind = ELF_ST_BIND (*st_info);
|
|
int other = STV_DEFAULT;
|
|
if (bind == STB_LOCAL)
|
|
{
|
|
/* Make discarded local symbols unnamed and
|
|
defined in the first prevailing section. */
|
|
ELF_SET_FIELD (type_functions, ei_class, Sym,
|
|
ent, st_name, Elf_Word, 0);
|
|
ELF_SET_FIELD (type_functions, ei_class, Sym,
|
|
ent, st_shndx, Elf_Half,
|
|
sh_map[first_shndx]);
|
|
}
|
|
else
|
|
{
|
|
/* Make discarded global symbols hidden weak
|
|
undefined and sharing a name of a prevailing
|
|
symbol. */
|
|
bind = STB_WEAK;
|
|
other = STV_HIDDEN;
|
|
ELF_SET_FIELD (type_functions, ei_class, Sym,
|
|
ent, st_name, Elf_Word,
|
|
prevailing_name_idx);
|
|
ELF_SET_FIELD (type_functions, ei_class, Sym,
|
|
ent, st_shndx, Elf_Half, SHN_UNDEF);
|
|
}
|
|
*st_other = other;
|
|
*st_info = ELF_ST_INFO (bind, STT_NOTYPE);
|
|
ELF_SET_FIELD (type_functions, ei_class, Sym,
|
|
ent, st_value, Elf_Addr, 0);
|
|
ELF_SET_FIELD (type_functions, ei_class, Sym,
|
|
ent, st_size, Elf_Word, 0);
|
|
}
|
|
else if (raw_st_shndx < SHN_LORESERVE
|
|
|| raw_st_shndx == SHN_XINDEX)
|
|
/* Remap the section reference. */
|
|
ELF_SET_FIELD (type_functions, ei_class, Sym,
|
|
ent, st_shndx, Elf_Half, sh_map[st_shndx]);
|
|
}
|
|
XDELETEVEC (shndx_table);
|
|
}
|
|
else if (sh_type == SHT_GROUP)
|
|
{
|
|
/* Remap section indices in groups and remove removed members. */
|
|
unsigned char *ent, *dst;
|
|
for (dst = ent = buf + 4; ent < buf + length; ent += 4)
|
|
{
|
|
unsigned shndx = type_functions->fetch_Elf_Word (ent);
|
|
if (pfnret[shndx - 1] == -1)
|
|
;
|
|
else
|
|
{
|
|
type_functions->set_Elf_Word (dst, sh_map[shndx]);
|
|
dst += 4;
|
|
}
|
|
}
|
|
/* Adjust the length. */
|
|
length = dst - buf;
|
|
}
|
|
|
|
errmsg = simple_object_write_add_data (dobj, dest,
|
|
buf, length, 1, err);
|
|
XDELETEVEC (buf);
|
|
if (errmsg)
|
|
{
|
|
XDELETEVEC (names);
|
|
XDELETEVEC (shdrs);
|
|
XDELETEVEC (symtab_indices_shndx);
|
|
return errmsg;
|
|
}
|
|
|
|
flags = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_flags, Elf_Addr);
|
|
/* Remap the section references. */
|
|
{
|
|
unsigned int sh_info, sh_link;
|
|
if (flags & SHF_INFO_LINK || sh_type == SHT_REL || sh_type == SHT_RELA)
|
|
{
|
|
sh_info = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_info, Elf_Word);
|
|
if (sh_info < SHN_LORESERVE
|
|
|| sh_info > SHN_HIRESERVE)
|
|
sh_info = sh_map[sh_info];
|
|
ELF_SET_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_info, Elf_Word, sh_info);
|
|
}
|
|
sh_link = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_link, Elf_Word);
|
|
if (sh_link < SHN_LORESERVE
|
|
|| sh_link > SHN_HIRESERVE)
|
|
sh_link = sh_map[sh_link];
|
|
ELF_SET_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_link, Elf_Word, sh_link);
|
|
}
|
|
/* The debugobj doesn't contain any code, thus no trampolines.
|
|
Even when the original object needs trampolines, debugobj
|
|
doesn't. */
|
|
if (strcmp (name, ".note.GNU-stack") == 0)
|
|
flags &= ~SHF_EXECINSTR;
|
|
/* Clear SHF_EXCLUDE on to be preserved sections. */
|
|
flags &= ~SHF_EXCLUDE;
|
|
ELF_SET_FIELD (type_functions, ei_class, Shdr,
|
|
shdr, sh_flags, Elf_Addr, flags);
|
|
}
|
|
|
|
XDELETEVEC (names);
|
|
XDELETEVEC (shdrs);
|
|
XDELETEVEC (pfnret);
|
|
XDELETEVEC (pfnname);
|
|
XDELETEVEC (symtab_indices_shndx);
|
|
XDELETEVEC (sh_map);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
|
|
/* The ELF functions. */
|
|
|
|
const struct simple_object_functions simple_object_elf_functions =
|
|
{
|
|
simple_object_elf_match,
|
|
simple_object_elf_find_sections,
|
|
simple_object_elf_fetch_attributes,
|
|
simple_object_elf_release_read,
|
|
simple_object_elf_attributes_merge,
|
|
simple_object_elf_release_attributes,
|
|
simple_object_elf_start_write,
|
|
simple_object_elf_write_to_file,
|
|
simple_object_elf_release_write,
|
|
simple_object_elf_copy_lto_debug_sections
|
|
};
|