diff --git a/linker/linker_phdr.cpp b/linker/linker_phdr.cpp
index 43651727146e10baab80492c373f95b6405dda0f..ffd4de28a8e670043c382e289b82a8abbec77a56 100644 (file)
--- a/linker/linker_phdr.cpp
+++ b/linker/linker_phdr.cpp
#include "linker_phdr.h"
#include <errno.h>
-#include <machine/exec.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "linker.h"
#include "linker_debug.h"
+static int GetTargetElfMachine() {
+#if defined(__arm__)
+ return EM_ARM;
+#elif defined(__aarch64__)
+ return EM_AARCH64;
+#elif defined(__i386__)
+ return EM_386;
+#elif defined(__mips__)
+ return EM_MIPS;
+#elif defined(__x86_64__)
+ return EM_X86_64;
+#endif
+}
+
/**
TECHNICAL NOTE ON ELF LOADING.
MAYBE_MAP_FLAG((x), PF_R, PROT_READ) | \
MAYBE_MAP_FLAG((x), PF_W, PROT_WRITE))
-ElfReader::ElfReader(const char* name, int fd)
- : name_(name), fd_(fd),
+ElfReader::ElfReader(const char* name, int fd, off64_t file_offset)
+ : name_(name), fd_(fd), file_offset_(file_offset),
phdr_num_(0), phdr_mmap_(nullptr), phdr_table_(nullptr), phdr_size_(0),
load_start_(nullptr), load_size_(0), load_bias_(0),
loaded_phdr_(nullptr) {
}
bool ElfReader::ReadElfHeader() {
- ssize_t rc = TEMP_FAILURE_RETRY(read(fd_, &header_, sizeof(header_)));
+ ssize_t rc = TEMP_FAILURE_RETRY(pread64(fd_, &header_, sizeof(header_), file_offset_));
if (rc < 0) {
DL_ERR("can't read file \"%s\": %s", name_, strerror(errno));
return false;
}
+
if (rc != sizeof(header_)) {
DL_ERR("\"%s\" is too small to be an ELF executable: only found %zd bytes", name_,
static_cast<size_t>(rc));
return false;
}
- if (header_.e_machine != ELF_TARG_MACH) {
+ if (header_.e_machine != GetTargetElfMachine()) {
DL_ERR("\"%s\" has unexpected e_machine: %d", name_, header_.e_machine);
return false;
}
phdr_size_ = page_max - page_min;
- void* mmap_result = mmap(nullptr, phdr_size_, PROT_READ, MAP_PRIVATE, fd_, page_min);
+ void* mmap_result = mmap64(nullptr, phdr_size_, PROT_READ, MAP_PRIVATE, fd_, file_offset_ + page_min);
if (mmap_result == MAP_FAILED) {
DL_ERR("\"%s\" phdr mmap failed: %s", name_, strerror(errno));
return false;
ElfW(Addr) file_length = file_end - file_page_start;
if (file_length != 0) {
- void* seg_addr = mmap(reinterpret_cast<void*>(seg_page_start),
+ void* seg_addr = mmap64(reinterpret_cast<void*>(seg_page_start),
file_length,
PFLAGS_TO_PROT(phdr->p_flags),
MAP_FIXED|MAP_PRIVATE,
fd_,
- file_page_start);
+ file_offset_ + file_page_start);
if (seg_addr == MAP_FAILED) {
DL_ERR("couldn't map \"%s\" segment %zd: %s", name_, i, strerror(errno));
return false;
* load_bias -> load bias
* Output:
* dynamic -> address of table in memory (null on failure).
+ * dynamic_flags -> protection flags for section (unset on failure)
* Return:
* void
*/
void phdr_table_get_dynamic_section(const ElfW(Phdr)* phdr_table, size_t phdr_count,
- ElfW(Addr) load_bias, ElfW(Dyn)** dynamic) {
+ ElfW(Addr) load_bias, ElfW(Dyn)** dynamic,
+ ElfW(Word)* dynamic_flags) {
*dynamic = nullptr;
for (const ElfW(Phdr)* phdr = phdr_table, *phdr_limit = phdr + phdr_count; phdr < phdr_limit; phdr++) {
if (phdr->p_type == PT_DYNAMIC) {
*dynamic = reinterpret_cast<ElfW(Dyn)*>(load_bias + phdr->p_vaddr);
+ if (dynamic_flags) {
+ *dynamic_flags = phdr->p_flags;
+ }
return;
}
}
}
-// Returns the address of the program header table as it appears in the loaded
-// segments in memory. This is in contrast with 'phdr_table_' which
-// is temporary and will be released before the library is relocated.
+// Sets loaded_phdr_ to the address of the program header table as it appears
+// in the loaded segments in memory. This is in contrast with phdr_table_,
+// which is temporary and will be released before the library is relocated.
bool ElfReader::FindPhdr() {
const ElfW(Phdr)* phdr_limit = phdr_table_ + phdr_num_;