2015-06-13 01:03:31 +02:00
|
|
|
#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_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)
|
|
|
|
{
|
|
|
|
if (sizeof(ElfSectionHeaderType) > elf_file_size) {
|
2015-07-23 23:30:40 +02:00
|
|
|
fprintf(stderr, "ERROR: Elf header would end at %zu but file size only %zu\n", sizeof(ElfSectionHeaderType), elf_file_size);
|
2015-06-13 01:03:31 +02:00
|
|
|
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) {
|
2015-07-23 23:30:40 +02:00
|
|
|
fprintf(stderr, "ERROR: Section header would end at %zu but file size only %zu\n", last_section_header_byte, elf_file_size);
|
2015-06-13 01:03:31 +02:00
|
|
|
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) {
|
2015-07-23 23:30:40 +02:00
|
|
|
fprintf(stderr, "ERROR: Dynamic section would end at %zu but file size only %zu\n", last_dynamic_section_byte, elf_file_size);
|
2015-06-13 01:03:31 +02:00
|
|
|
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;
|
|
|
|
switch (dynamic_section_entry->d_tag) {
|
|
|
|
case DT_VERNEEDED:
|
|
|
|
case DT_VERNEEDNUM:
|
|
|
|
case DT_RPATH:
|
|
|
|
case DT_RUNPATH:
|
|
|
|
char const* removed_name;
|
|
|
|
switch (dynamic_section_entry->d_tag) {
|
|
|
|
case DT_VERNEEDED: removed_name = "DT_VERNEEDED"; break;
|
|
|
|
case DT_VERNEEDNUM: removed_name = "DT_VERNEEDNUM"; break;
|
|
|
|
case DT_RPATH: removed_name = "DT_RPATH"; break;
|
|
|
|
case DT_RUNPATH: removed_name = "DT_RUNPATH"; break;
|
|
|
|
}
|
|
|
|
printf("Removing the %s dynamic section entry\n", removed_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--]);
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
int main(int argc, char **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++) {
|
|
|
|
int fd = open(argv[i], O_RDWR);
|
|
|
|
if (fd < 0) { perror("open()"); return 1; }
|
|
|
|
|
|
|
|
struct stat st;
|
|
|
|
if (fstat(fd, &st) < 0) { perror("fstat()"); return 1; }
|
|
|
|
|
|
|
|
if (st.st_size < (long long) sizeof(Elf32_Ehdr)) 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')) {
|
|
|
|
munmap(mem, st.st_size);
|
|
|
|
close(fd);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
uint8_t bit_value = bytes[4];
|
|
|
|
if (!(bit_value == 1 || bit_value == 2)) {
|
|
|
|
printf("ERROR: Incorrect bit value: %d\n", bit_value);
|
|
|
|
return 1;
|
|
|
|
} else if (bit_value == 1) {
|
|
|
|
if (!process_elf<Elf32_Ehdr, Elf32_Shdr, Elf32_Dyn>(bytes, st.st_size)) return 1;
|
|
|
|
} else {
|
|
|
|
if (!process_elf<Elf64_Ehdr, Elf64_Shdr, Elf64_Dyn>(bytes, st.st_size)) return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (msync(mem, st.st_size, MS_SYNC) < 0) { perror("msync()"); return 1; }
|
|
|
|
|
|
|
|
munmap(mem, st.st_size);
|
|
|
|
close(fd);
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|