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termux-elf-cleaner: Move to standalone repo

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This commit is contained in:
Fredrik Fornwall 2017-04-04 23:14:39 +02:00
parent 37cc7f1eec
commit d2c4f7c6e0
3 changed files with 5 additions and 370 deletions
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10
packages/termux-elf-cleaner/build.sh
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@ -1,7 +1,7 @@
TERMUX_PKG_HOMEPAGE=https://termux.com/ TERMUX_PKG_HOMEPAGE=https://github.com/termux/termux-elf-cleaner
TERMUX_PKG_DESCRIPTION="Cleaner of ELF files for Android" TERMUX_PKG_DESCRIPTION="Cleaner of ELF files for Android"
TERMUX_PKG_VERSION=1.1 TERMUX_PKG_VERSION=1.1
TERMUX_PKG_SRCURL=https://github.com/termux/termux-elf-cleaner/archive/v${TERMUX_PKG_VERSION}.tar.gz
termux_step_make_install () { TERMUX_PKG_SHA256=66612b294e197ab7bfac807e497581df58424af6a7c855f89fc12eafa3dc1b8c
$CXX $CFLAGS $LDFLAGS -std=c++14 -Wall -Wextra -pedantic -Werror $TERMUX_PKG_BUILDER_DIR/*.cpp -o $TERMUX_PREFIX/bin/termux-elf-cleaner TERMUX_PKG_FOLDERNAME=termux-elf-cleaner-$TERMUX_PKG_VERSION
} TERMUX_PKG_BUILD_IN_SRC=yes

211
packages/termux-elf-cleaner/elf.h
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@ -1,211 +0,0 @@
#ifndef ELF_H_INCLUDED
#define ELF_H_INCLUDED
#include <stdint.h>
/* Type for a 16-bit quantity. */
typedef uint16_t Elf32_Half;
typedef uint16_t Elf64_Half;
/* Types for signed and unsigned 32-bit quantities. */
typedef uint32_t Elf32_Word;
typedef int32_t Elf32_Sword;
typedef uint32_t Elf64_Word;
typedef int32_t Elf64_Sword;
/* Types for signed and unsigned 64-bit quantities. */
typedef uint64_t Elf32_Xword;
typedef int64_t Elf32_Sxword;
typedef uint64_t Elf64_Xword;
typedef int64_t Elf64_Sxword;
/* Type of addresses. */
typedef uint32_t Elf32_Addr;
typedef uint64_t Elf64_Addr;
/* Type of file offsets. */
typedef uint32_t Elf32_Off;
typedef uint64_t Elf64_Off;
/* Type for section indices, which are 16-bit quantities. */
typedef uint16_t Elf32_Section;
typedef uint16_t Elf64_Section;
/* Type for version symbol information. */
typedef Elf32_Half Elf32_Versym;
typedef Elf64_Half Elf64_Versym;
/* The ELF file header. This appears at the start of every ELF file. */
typedef struct {
unsigned char e_ident[16]; /* Magic number and other info */
Elf32_Half e_type; /* Object file type */
Elf32_Half e_machine; /* Architecture */
Elf32_Word e_version; /* Object file version */
Elf32_Addr e_entry; /* Entry point virtual address */
Elf32_Off e_phoff; /* Program header table (usually follows elf header directly) file offset */
Elf32_Off e_shoff; /* Section header table (at end of file) file offset */
Elf32_Word e_flags; /* Processor-specific flags */
Elf32_Half e_ehsize; /* ELF header size in bytes */
Elf32_Half e_phentsize; /* Program header table entry size */
Elf32_Half e_phnum; /* Program header table entry count */
Elf32_Half e_shentsize; /* Section header table entry size */
Elf32_Half e_shnum; /* Section header table entry count */
Elf32_Half e_shstrndx; /* Section header string table index */
} Elf32_Ehdr;
typedef struct {
unsigned char e_ident[16]; /* Magic number and other info */
Elf64_Half e_type; /* Object file type */
Elf64_Half e_machine; /* Architecture */
Elf64_Word e_version; /* Object file version */
Elf64_Addr e_entry; /* Entry point virtual address */
Elf64_Off e_phoff; /* Program header table file offset */
Elf64_Off e_shoff; /* Section header table file offset */
Elf64_Word e_flags; /* Processor-specific flags */
Elf64_Half e_ehsize; /* ELF header size in bytes */
Elf64_Half e_phentsize; /* Program header table entry size */
Elf64_Half e_phnum; /* Program header table entry count */
Elf64_Half e_shentsize; /* Section header table entry size */
Elf64_Half e_shnum; /* Section header table entry count */
Elf64_Half e_shstrndx; /* Section header string table index */
} Elf64_Ehdr;
/* Section header entry. The number of section entries in the file are determined by the "e_shnum" field of the ELF header.*/
typedef struct {
Elf32_Word sh_name; /* Section name (string tbl index) */
Elf32_Word sh_type; /* Section type */
Elf32_Word sh_flags; /* Section flags */
Elf32_Addr sh_addr; /* Section virtual addr at execution */
Elf32_Off sh_offset; /* Section file offset */
Elf32_Word sh_size; /* Section size in bytes */
Elf32_Word sh_link; /* Link to another section */
Elf32_Word sh_info; /* Additional section information */
Elf32_Word sh_addralign; /* Section alignment */
Elf32_Word sh_entsize; /* Entry size if section holds table */
} Elf32_Shdr;
typedef struct {
Elf64_Word sh_name; /* Section name (string tbl index) */
Elf64_Word sh_type; /* Section type */
Elf64_Xword sh_flags; /* Section flags */
Elf64_Addr sh_addr; /* Section virtual addr at execution */
Elf64_Off sh_offset; /* Section file offset */
Elf64_Xword sh_size; /* Section size in bytes */
Elf64_Word sh_link; /* Link to another section */
Elf64_Word sh_info; /* Additional section information */
Elf64_Xword sh_addralign; /* Section alignment */
Elf64_Xword sh_entsize; /* Entry size if section holds table */
} Elf64_Shdr;
/* Legal values for sh_type (section type). */
#define SHT_NULL 0 /* Section header table entry unused */
#define SHT_PROGBITS 1 /* Program data */
#define SHT_SYMTAB 2 /* Symbol table */
#define SHT_STRTAB 3 /* String table */
#define SHT_RELA 4 /* Relocation entries with addends */
#define SHT_HASH 5 /* Symbol hash table */
#define SHT_DYNAMIC 6 /* Dynamic linking information. Contains Elf32_Dyn/Elf64_Dyn entries. */
#define SHT_NOTE 7 /* Notes */
#define SHT_NOBITS 8 /* Program space with no data (bss) */
#define SHT_REL 9 /* Relocation entries, no addends */
#define SHT_SHLIB 10 /* Reserved */
#define SHT_DYNSYM 11 /* Dynamic linker symbol table */
#define SHT_INIT_ARRAY 14 /* Array of constructors */
#define SHT_FINI_ARRAY 15 /* Array of destructors */
#define SHT_PREINIT_ARRAY 16 /* Array of pre-constructors */
#define SHT_GROUP 17 /* Section group */
#define SHT_SYMTAB_SHNDX 18 /* Extended section indeces */
#define SHT_NUM 19 /* Number of defined types. */
#define SHT_LOOS 0x60000000 /* Start OS-specific. */
#define SHT_GNU_ATTRIBUTES 0x6ffffff5 /* Object attributes. */
#define SHT_GNU_HASH 0x6ffffff6 /* GNU-style hash table. */
#define SHT_GNU_LIBLIST 0x6ffffff7 /* Prelink library list */
#define SHT_CHECKSUM 0x6ffffff8 /* Checksum for DSO content. */
#define SHT_LOSUNW 0x6ffffffa /* Sun-specific low bound. */
#define SHT_SUNW_move 0x6ffffffa
#define SHT_SUNW_COMDAT 0x6ffffffb
#define SHT_SUNW_syminfo 0x6ffffffc
#define SHT_GNU_verdef 0x6ffffffd /* Version definition section. */
#define SHT_GNU_verneed 0x6ffffffe /* Version needs section. */
#define SHT_GNU_versym 0x6fffffff /* Version symbol table. */
#define SHT_HISUNW 0x6fffffff /* Sun-specific high bound. */
#define SHT_HIOS 0x6fffffff /* End OS-specific type */
#define SHT_LOPROC 0x70000000 /* Start of processor-specific */
#define SHT_HIPROC 0x7fffffff /* End of processor-specific */
#define SHT_LOUSER 0x80000000 /* Start of application-specific */
#define SHT_HIUSER 0x8fffffff /* End of application-specific */
/* Dynamic section entry. */
typedef struct {
Elf32_Sword d_tag; /* Dynamic entry type */
union { Elf32_Word d_val; Elf32_Addr d_ptr; } d_un; /* Integer or address value */
} Elf32_Dyn;
typedef struct {
Elf64_Sxword d_tag; /* Dynamic entry type */
union { Elf64_Xword d_val; Elf64_Addr d_ptr; } d_un; /* Integer or address value */
} Elf64_Dyn;
/* Legal values for d_tag (dynamic entry type). */
#define DT_NULL 0 /* Marks end of dynamic section */
#define DT_NEEDED 1 /* Name of needed library */
#define DT_PLTRELSZ 2 /* Size in bytes of PLT relocs */
#define DT_PLTGOT 3 /* Processor defined value */
#define DT_HASH 4 /* Address of symbol hash table */
#define DT_STRTAB 5 /* Address of string table */
#define DT_SYMTAB 6 /* Address of symbol table */
#define DT_RELA 7 /* Address of Rela relocs */
#define DT_RELASZ 8 /* Total size of Rela relocs */
#define DT_RELAENT 9 /* Size of one Rela reloc */
#define DT_STRSZ 10 /* Size of string table */
#define DT_SYMENT 11 /* Size of one symbol table entry */
#define DT_INIT 12 /* Address of init function */
#define DT_FINI 13 /* Address of termination function */
#define DT_SONAME 14 /* Name of shared object */
#define DT_RPATH 15 /* Library search path (deprecated) */
#define DT_SYMBOLIC 16 /* Start symbol search here */
#define DT_REL 17 /* Address of Rel relocs */
#define DT_RELSZ 18 /* Total size of Rel relocs */
#define DT_RELENT 19 /* Size of one Rel reloc */
#define DT_PLTREL 20 /* Type of reloc in PLT */
#define DT_DEBUG 21 /* For debugging; unspecified */
#define DT_TEXTREL 22 /* Reloc might modify .text */
#define DT_JMPREL 23 /* Address of PLT relocs */
#define DT_BIND_NOW 24 /* Process relocations of object */
#define DT_INIT_ARRAY 25 /* Array with addresses of init fct */
#define DT_FINI_ARRAY 26 /* Array with addresses of fini fct */
#define DT_INIT_ARRAYSZ 27 /* Size in bytes of DT_INIT_ARRAY */
#define DT_FINI_ARRAYSZ 28 /* Size in bytes of DT_FINI_ARRAY */
#define DT_RUNPATH 29 /* Library search path */
#define DT_FLAGS 30 /* Flags for the object being loaded */
#define DT_ENCODING 32 /* Start of encoded range */
#define DT_PREINIT_ARRAY 32 /* Array with addresses of preinit fct*/
#define DT_PREINIT_ARRAYSZ 33 /* size in bytes of DT_PREINIT_ARRAY */
#define DT_NUM 34 /* Number used */
#define DT_LOOS 0x6000000d /* Start of OS-specific */
#define DT_HIOS 0x6ffff000 /* End of OS-specific */
#define DT_VERDEF 0x6ffffffc
#define DT_VERDEFNUM 0x6ffffffd
#define DT_LOPROC 0x70000000 /* Start of processor-specific */
#define DT_HIPROC 0x7fffffff /* End of processor-specific */
/* Symbol table entry. */
typedef struct {
Elf32_Word st_name; /* Symbol name (string tbl index) */
Elf32_Addr st_value; /* Symbol value */
Elf32_Word st_size; /* Symbol size */
unsigned char st_info; /* Symbol type and binding */
unsigned char st_other; /* Symbol visibility */
Elf32_Section st_shndx; /* Section index */
} Elf32_Sym;
typedef struct {
Elf64_Word st_name; /* Symbol name (string tbl index) */
unsigned char st_info; /* Symbol type and binding */
unsigned char st_other; /* Symbol visibility */
Elf64_Section st_shndx; /* Section index */
Elf64_Addr st_value; /* Symbol value */
Elf64_Xword st_size; /* Symbol size */
} Elf64_Sym;
#endif

154
packages/termux-elf-cleaner/termux-elf-cleaner.cpp
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#include <algorithm>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#ifdef __APPLE__
# include "elf.h"
#else
# include <elf.h>
#endif
#define DT_VERSYM 0x6ffffff0
#define DT_VERNEEDED 0x6ffffffe
#define DT_VERNEEDNUM 0x6fffffff
template<typename ElfHeaderType /*Elf{32,64}_Ehdr*/,
typename ElfSectionHeaderType /*Elf{32,64}_Shdr*/,
typename ElfDynamicSectionEntryType /* Elf{32,64}_Dyn */>
bool process_elf(uint8_t* bytes, size_t elf_file_size, char const* file_name)
{
if (sizeof(ElfSectionHeaderType) > elf_file_size) {
fprintf(stderr, "termux-elf-cleaner: Elf header for '%s' would end at %zu but file size only %zu\n", file_name, sizeof(ElfSectionHeaderType), elf_file_size);
return false;
}
ElfHeaderType* elf_hdr = reinterpret_cast<ElfHeaderType*>(bytes);
size_t last_section_header_byte = elf_hdr->e_shoff + sizeof(ElfSectionHeaderType) * elf_hdr->e_shnum;
if (last_section_header_byte > elf_file_size) {
fprintf(stderr, "termux-elf-cleaner: Section header for '%s' would end at %zu but file size only %zu\n", file_name, last_section_header_byte, elf_file_size);
return false;
}
ElfSectionHeaderType* section_header_table = reinterpret_cast<ElfSectionHeaderType*>(bytes + elf_hdr->e_shoff);
for (unsigned int i = 1; i < elf_hdr->e_shnum; i++) {
ElfSectionHeaderType* section_header_entry = section_header_table + i;
if (section_header_entry->sh_type == SHT_DYNAMIC) {
size_t const last_dynamic_section_byte = section_header_entry->sh_offset + section_header_entry->sh_size;
if (last_dynamic_section_byte > elf_file_size) {
fprintf(stderr, "termux-elf-cleaner: Dynamic section for '%s' would end at %zu but file size only %zu\n", file_name, last_dynamic_section_byte, elf_file_size);
return false;
}
size_t const dynamic_section_entries = section_header_entry->sh_size / sizeof(ElfDynamicSectionEntryType);
ElfDynamicSectionEntryType* const dynamic_section =
reinterpret_cast<ElfDynamicSectionEntryType*>(bytes + section_header_entry->sh_offset);
unsigned int last_nonnull_entry_idx = 0;
for (unsigned int j = dynamic_section_entries - 1; j > 0; j--) {
ElfDynamicSectionEntryType* dynamic_section_entry = dynamic_section + j;
if (dynamic_section_entry->d_tag != DT_NULL) {
last_nonnull_entry_idx = j;
break;
}
}
for (unsigned int j = 0; j < dynamic_section_entries; j++) {
ElfDynamicSectionEntryType* dynamic_section_entry = dynamic_section + j;
char const* removed_name = nullptr;
switch (dynamic_section_entry->d_tag) {
case DT_VERSYM: removed_name = "DT_VERSYM"; break;
case DT_VERNEEDED: removed_name = "DT_VERNEEDED"; break;
case DT_VERNEEDNUM: removed_name = "DT_VERNEEDNUM"; break;
case DT_VERDEF: removed_name = "DT_VERDEF"; break;
case DT_VERDEFNUM: removed_name = "DT_VERDEFNUM"; break;
case DT_RPATH: removed_name = "DT_RPATH"; break;
case DT_RUNPATH: removed_name = "DT_RUNPATH"; break;
}
if (removed_name != nullptr) {
printf("termux-elf-cleaner: Removing the %s dynamic section entry from '%s'\n", removed_name, file_name);
// Tag the entry with DT_NULL and put it last:
dynamic_section_entry->d_tag = DT_NULL;
// Decrease j to process new entry index:
std::swap(dynamic_section[j--], dynamic_section[last_nonnull_entry_idx--]);
}
}
} else if (section_header_entry->sh_type == SHT_GNU_verdef ||
section_header_entry->sh_type == SHT_GNU_verneed ||
section_header_entry->sh_type == SHT_GNU_versym) {
printf("termux-elf-cleaner: Removing version section from '%s'\n", file_name);
section_header_entry->sh_type = SHT_NULL;
}
}
return true;
}
int main(int argc, char const** argv)
{
if (argc < 2 || (argc == 2 && strcmp(argv[1], "-h")==0)) {
fprintf(stderr, "usage: %s <filename>\n", argv[0]);
fprintf(stderr, " Processes ELF files to remove DT_VERNEEDED, DT_VERNEEDNUM, DT_RPATH\n"
" and DT_RUNPATH entries (which the Android linker warns about)\n");
return 1;
}
for (int i = 1; i < argc; i++) {
char const* file_name = argv[i];
int fd = open(file_name, O_RDWR);
if (fd < 0) {
char* error_message;
if (asprintf(&error_message, "open(\"%s\")", file_name) == -1) error_message = (char*) "open()";
perror(error_message);
return 1;
}
struct stat st;
if (fstat(fd, &st) < 0) { perror("fstat()"); return 1; }
if (st.st_size < (long long) sizeof(Elf32_Ehdr)) {
close(fd);
continue;
}
void* mem = mmap(0, st.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (mem == MAP_FAILED) { perror("mmap()"); return 1; }
uint8_t* bytes = reinterpret_cast<uint8_t*>(mem);
if (!(bytes[0] == 0x7F && bytes[1] == 'E' && bytes[2] == 'L' && bytes[3] == 'F')) {
// Not the ELF magic number.
munmap(mem, st.st_size);
close(fd);
continue;
}
if (bytes[/*EI_DATA*/5] != 1) {
fprintf(stderr, "termux-elf-cleaner: Not little endianness in '%s'\n", file_name);
munmap(mem, st.st_size);
close(fd);
continue;
}
uint8_t const bit_value = bytes[/*EI_CLASS*/4];
if (bit_value == 1) {
if (!process_elf<Elf32_Ehdr, Elf32_Shdr, Elf32_Dyn>(bytes, st.st_size, file_name)) return 1;
} else if (bit_value == 2) {
if (!process_elf<Elf64_Ehdr, Elf64_Shdr, Elf64_Dyn>(bytes, st.st_size, file_name)) return 1;
} else {
printf("termux-elf-cleaner: Incorrect bit value %d in '%s'\n", bit_value, file_name);
return 1;
}
if (msync(mem, st.st_size, MS_SYNC) < 0) { perror("msync()"); return 1; }
munmap(mem, st.st_size);
close(fd);
}
return 0;
}