More linker cleanup.
Change-Id: I9fb3c7c0d4b4ffef0eeaf092d4e30ffe63a08671
diff --git a/linker/linker.cpp b/linker/linker.cpp
index e08eaba..f18443c 100755
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -41,7 +41,6 @@
// Private C library headers.
#include <private/bionic_tls.h>
-#include <private/debug_format.h>
#include <private/KernelArgumentBlock.h>
#include <private/logd.h>
#include <private/ScopedPthreadMutexLocker.h>
@@ -105,7 +104,7 @@
static soinfo* gLdPreloads[LDPRELOAD_MAX + 1];
-static int debug_verbosity;
+__LIBC_HIDDEN__ int gLdDebugVerbosity;
enum RelocationKind {
kRelocAbsolute = 0,
@@ -158,17 +157,15 @@
static char tmp_err_buf[768];
static char __linker_dl_err_buf[768];
-#define DL_ERR(fmt, x...) \
- do { \
- __libc_format_buffer(__linker_dl_err_buf, sizeof(__linker_dl_err_buf), fmt, ##x); \
- /* If LD_DEBUG is set high enough, send every dlerror(3) message to the log. */ \
- DEBUG(fmt "\n", ##x); \
- } while(0)
-const char* linker_get_error() {
+char* linker_get_error_buffer() {
return &__linker_dl_err_buf[0];
}
+size_t linker_get_error_buffer_size() {
+ return sizeof(__linker_dl_err_buf);
+}
+
/*
* This function is an empty stub where GDB locates a breakpoint to get notified
* about linker activity.
@@ -706,197 +703,34 @@
return fd;
}
-// Returns 'true' if the library is prelinked or on failure so we error out
-// either way. We no longer support prelinking.
-static bool is_prelinked(int fd, const char* name)
-{
- struct prelink_info_t {
- long mmap_addr;
- char tag[4]; // "PRE ".
- };
-
- off_t sz = lseek(fd, -sizeof(prelink_info_t), SEEK_END);
- if (sz < 0) {
- DL_ERR("lseek failed: %s", strerror(errno));
- return true;
- }
-
- prelink_info_t info;
- int rc = TEMP_FAILURE_RETRY(read(fd, &info, sizeof(info)));
- if (rc != sizeof(info)) {
- DL_ERR("could not read prelink_info_t structure for \"%s\": %s", name, strerror(errno));
- return true;
- }
-
- if (memcmp(info.tag, "PRE ", 4) == 0) {
- DL_ERR("prelinked libraries no longer supported: %s", name);
- return true;
- }
- return false;
-}
-
-/* verify_elf_header
- * Verifies the content of an ELF header.
- *
- * Args:
- *
- * Returns:
- * 0 on success
- * -1 if no valid ELF object is found @ base.
- */
-static int
-verify_elf_header(const Elf32_Ehdr* hdr)
-{
- if (hdr->e_ident[EI_MAG0] != ELFMAG0) return -1;
- if (hdr->e_ident[EI_MAG1] != ELFMAG1) return -1;
- if (hdr->e_ident[EI_MAG2] != ELFMAG2) return -1;
- if (hdr->e_ident[EI_MAG3] != ELFMAG3) return -1;
- if (hdr->e_type != ET_DYN) return -1;
-
- /* TODO: Should we verify anything else in the header? */
-#ifdef ANDROID_ARM_LINKER
- if (hdr->e_machine != EM_ARM) return -1;
-#elif defined(ANDROID_X86_LINKER)
- if (hdr->e_machine != EM_386) return -1;
-#elif defined(ANDROID_MIPS_LINKER)
- if (hdr->e_machine != EM_MIPS) return -1;
-#endif
- return 0;
-}
-
-struct scoped_fd {
- ~scoped_fd() {
- if (fd != -1) {
- close(fd);
- }
- }
- int fd;
-};
-
-struct soinfo_ptr {
- soinfo_ptr(const char* name) {
- const char* bname = strrchr(name, '/');
- ptr = soinfo_alloc(bname ? bname + 1 : name);
- }
- ~soinfo_ptr() {
- soinfo_free(ptr);
- }
- soinfo* release() {
- soinfo* result = ptr;
- ptr = NULL;
- return result;
- }
- soinfo* ptr;
-};
-
-// TODO: rewrite linker_phdr.h to use a class, then lose this.
-struct phdr_ptr {
- phdr_ptr() : phdr_mmap(NULL) {}
- ~phdr_ptr() {
- if (phdr_mmap != NULL) {
- phdr_table_unload(phdr_mmap, phdr_size);
- }
- }
- void* phdr_mmap;
- Elf32_Addr phdr_size;
-};
-
static soinfo* load_library(const char* name) {
// Open the file.
- scoped_fd fd;
- fd.fd = open_library(name);
- if (fd.fd == -1) {
+ int fd = open_library(name);
+ if (fd == -1) {
DL_ERR("library \"%s\" not found", name);
return NULL;
}
- // Read the ELF header.
- Elf32_Ehdr header[1];
- int ret = TEMP_FAILURE_RETRY(read(fd.fd, (void*)header, sizeof(header)));
- if (ret < 0) {
- DL_ERR("can't read file \"%s\": %s", name, strerror(errno));
- return NULL;
- }
- if (ret != (int)sizeof(header)) {
- DL_ERR("too small to be an ELF executable: %s", name);
- return NULL;
- }
- if (verify_elf_header(header) < 0) {
- DL_ERR("not a valid ELF executable: %s", name);
+ // Read the ELF header and load the segments.
+ ElfReader elf_reader(name, fd);
+ if (!elf_reader.Load()) {
return NULL;
}
- // Read the program header table.
- const Elf32_Phdr* phdr_table;
- phdr_ptr phdr_holder;
- ret = phdr_table_load(fd.fd, header->e_phoff, header->e_phnum,
- &phdr_holder.phdr_mmap, &phdr_holder.phdr_size, &phdr_table);
- if (ret < 0) {
- DL_ERR("can't load program header table: %s: %s", name, strerror(errno));
+ const char* bname = strrchr(name, '/');
+ soinfo* si = soinfo_alloc(bname ? bname + 1 : name);
+ if (si == NULL) {
return NULL;
}
- size_t phdr_count = header->e_phnum;
-
- // Get the load extents.
- Elf32_Addr ext_sz = phdr_table_get_load_size(phdr_table, phdr_count);
- TRACE("[ '%s' wants sz=0x%08x ]\n", name, ext_sz);
- if (ext_sz == 0) {
- DL_ERR("no loadable segments in file: %s", name);
- return NULL;
- }
-
- // We no longer support pre-linked libraries.
- if (is_prelinked(fd.fd, name)) {
- return NULL;
- }
-
- // Reserve address space for all loadable segments.
- void* load_start = NULL;
- Elf32_Addr load_size = 0;
- Elf32_Addr load_bias = 0;
- ret = phdr_table_reserve_memory(phdr_table,
- phdr_count,
- &load_start,
- &load_size,
- &load_bias);
- if (ret < 0) {
- DL_ERR("can't reserve %d bytes in address space for \"%s\": %s",
- ext_sz, name, strerror(errno));
- return NULL;
- }
-
- TRACE("[ allocated memory for %s @ %p (0x%08x) ]\n", name, load_start, load_size);
-
- /* Map all the segments in our address space with default protections */
- ret = phdr_table_load_segments(phdr_table,
- phdr_count,
- load_bias,
- fd.fd);
- if (ret < 0) {
- DL_ERR("can't map loadable segments for \"%s\": %s",
- name, strerror(errno));
- return NULL;
- }
-
- soinfo_ptr si(name);
- if (si.ptr == NULL) {
- return NULL;
- }
-
- si.ptr->base = (Elf32_Addr) load_start;
- si.ptr->size = load_size;
- si.ptr->load_bias = load_bias;
- si.ptr->flags = 0;
- si.ptr->entry = 0;
- si.ptr->dynamic = NULL;
- si.ptr->phnum = phdr_count;
- si.ptr->phdr = phdr_table_get_loaded_phdr(phdr_table, phdr_count, load_bias);
- if (si.ptr->phdr == NULL) {
- DL_ERR("can't find loaded PHDR for \"%s\"", name);
- return NULL;
- }
-
- return si.release();
+ si->base = elf_reader.load_start();
+ si->size = elf_reader.load_size();
+ si->load_bias = elf_reader.load_bias();
+ si->flags = 0;
+ si->entry = 0;
+ si->dynamic = NULL;
+ si->phnum = elf_reader.phdr_count();
+ si->phdr = elf_reader.loaded_phdr();
+ return si;
}
static soinfo *find_loaded_library(const char *name)
@@ -1686,7 +1520,7 @@
for (size_t i = 0; gLdPreloadNames[i] != NULL; i++) {
soinfo* lsi = find_library(gLdPreloadNames[i]);
if (lsi == NULL) {
- strlcpy(tmp_err_buf, linker_get_error(), sizeof(tmp_err_buf));
+ strlcpy(tmp_err_buf, linker_get_error_buffer(), sizeof(tmp_err_buf));
DL_ERR("could not load library \"%s\" needed by \"%s\"; caused by %s",
gLdPreloadNames[i], si->name, tmp_err_buf);
return false;
@@ -1704,7 +1538,7 @@
DEBUG("%s needs %s\n", si->name, library_name);
soinfo* lsi = find_library(library_name);
if (lsi == NULL) {
- strlcpy(tmp_err_buf, linker_get_error(), sizeof(tmp_err_buf));
+ strlcpy(tmp_err_buf, linker_get_error_buffer(), sizeof(tmp_err_buf));
DL_ERR("could not load library \"%s\" needed by \"%s\"; caused by %s",
library_name, si->name, tmp_err_buf);
return false;
@@ -1804,7 +1638,7 @@
// Get a few environment variables.
const char* LD_DEBUG = linker_env_get("LD_DEBUG");
if (LD_DEBUG != NULL) {
- debug_verbosity = atoi(LD_DEBUG);
+ gLdDebugVerbosity = atoi(LD_DEBUG);
}
// Normally, these are cleaned by linker_env_init, but the test
@@ -1890,9 +1724,7 @@
somain = si;
if (!soinfo_link_image(si)) {
- const char* msg = "CANNOT LINK EXECUTABLE\n";
- write(2, __linker_dl_err_buf, strlen(__linker_dl_err_buf));
- write(2, msg, strlen(msg));
+ __libc_format_fd(2, "CANNOT LINK EXECUTABLE: %s\n", linker_get_error_buffer());
exit(EXIT_FAILURE);
}