Bump soinfo version
This includes:
1. Placing has_ifunc after fields with version = 0
2. Switch to has_min_version(v) function.
3. Minor soinfo initialization refactoring (placement new + ctor)
Change-Id: I1bf5fde4d930914012ce5f3ad5acb48217da9b2d
diff --git a/linker/dlfcn.cpp b/linker/dlfcn.cpp
index 5d6db8e..e15f54d 100644
--- a/linker/dlfcn.cpp
+++ b/linker/dlfcn.cpp
@@ -232,17 +232,12 @@
static unsigned g_libdl_chains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
#endif
-// Defined as global because we do not yet have access
-// to synchronization functions __cxa_guard_* needed
-// to define statics inside functions.
-static soinfo __libdl_info;
+static soinfo __libdl_info("libdl.so", nullptr);
// This is used by the dynamic linker. Every process gets these symbols for free.
soinfo* get_libdl_info() {
- if (__libdl_info.name[0] == '\0') {
- // initialize
- strncpy(__libdl_info.name, "libdl.so", sizeof(__libdl_info.name));
- __libdl_info.flags = FLAG_LINKED | FLAG_NEW_SOINFO;
+ if ((__libdl_info.flags & FLAG_LINKED) == 0) {
+ __libdl_info.flags |= FLAG_LINKED;
__libdl_info.strtab = ANDROID_LIBDL_STRTAB;
__libdl_info.symtab = g_libdl_symtab;
__libdl_info.nbucket = sizeof(g_libdl_buckets)/sizeof(unsigned);
diff --git a/linker/linker.cpp b/linker/linker.cpp
index e88195f..6a55571 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -35,9 +35,10 @@
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
-#include <sys/stat.h>
#include <unistd.h>
+#include <new>
+
// Private C library headers.
#include "private/bionic_tls.h"
#include "private/KernelArgumentBlock.h"
@@ -290,17 +291,7 @@
return NULL;
}
- soinfo* si = g_soinfo_allocator.alloc();
-
- // Initialize the new element.
- memset(si, 0, sizeof(soinfo));
- strlcpy(si->name, name, sizeof(si->name));
- si->flags = FLAG_NEW_SOINFO;
-
- if (file_stat != NULL) {
- si->set_st_dev(file_stat->st_dev);
- si->set_st_ino(file_stat->st_ino);
- }
+ soinfo* si = new (g_soinfo_allocator.alloc()) soinfo(name, file_stat);
sonext->next = si;
sonext = si;
@@ -466,6 +457,19 @@
return NULL;
}
+soinfo::soinfo(const char* name, const struct stat* file_stat) {
+ memset(this, 0, sizeof(*this));
+
+ strlcpy(this->name, name, sizeof(this->name));
+ flags = FLAG_NEW_SOINFO;
+ version = SOINFO_VERSION;
+
+ if (file_stat != NULL) {
+ set_st_dev(file_stat->st_dev);
+ set_st_ino(file_stat->st_ino);
+ }
+}
+
void soinfo::resolve_ifunc_symbols() {
if (!get_has_ifuncs()) {
return;
@@ -860,7 +864,7 @@
TRACE("unloading '%s'", si->name);
si->CallDestructors();
- if ((si->flags | FLAG_NEW_SOINFO) != 0) {
+ if (si->has_min_version(0)) {
si->get_children().for_each([&] (soinfo* child) {
TRACE("%s needs to unload %s", si->name, child->name);
soinfo_unload(child);
@@ -1585,16 +1589,14 @@
}
void soinfo::add_child(soinfo* child) {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return;
+ if (has_min_version(0)) {
+ this->children.push_front(child);
+ child->parents.push_front(this);
}
-
- this->children.push_front(child);
- child->parents.push_front(this);
}
void soinfo::remove_all_links() {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
+ if (!has_min_version(0)) {
return;
}
@@ -1617,51 +1619,45 @@
}
void soinfo::set_st_dev(dev_t dev) {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return;
+ if (has_min_version(0)) {
+ st_dev = dev;
}
-
- st_dev = dev;
}
void soinfo::set_st_ino(ino_t ino) {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return;
+ if (has_min_version(0)) {
+ st_ino = ino;
}
-
- st_ino = ino;
}
void soinfo::set_has_ifuncs(bool ifuncs) {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return;
+ if (has_min_version(1)) {
+ has_ifuncs = ifuncs;
}
-
- has_ifuncs = ifuncs;
}
dev_t soinfo::get_st_dev() {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return 0;
+ if (has_min_version(0)) {
+ return st_dev;
}
- return st_dev;
+ return 0;
};
ino_t soinfo::get_st_ino() {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return 0;
+ if (has_min_version(0)) {
+ return st_ino;
}
- return st_ino;
+ return 0;
}
bool soinfo::get_has_ifuncs() {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return false;
+ if (has_min_version(1)) {
+ return has_ifuncs;
}
- return has_ifuncs;
+ return false;
}
// This is a return on get_children() in case
@@ -1669,11 +1665,11 @@
static soinfo::soinfo_list_t g_empty_list;
soinfo::soinfo_list_t& soinfo::get_children() {
- if ((this->flags & FLAG_NEW_SOINFO) == 0) {
- return g_empty_list;
+ if (has_min_version(0)) {
+ return this->children;
}
- return this->children;
+ return g_empty_list;
}
/* Force any of the closed stdin, stdout and stderr to be associated with
@@ -2135,7 +2131,12 @@
/*
* This is linker soinfo for GDB. See details below.
*/
-static soinfo linker_soinfo_for_gdb;
+#if defined(__LP64__)
+#define LINKER_PATH "/system/bin/linker64"
+#else
+#define LINKER_PATH "/system/bin/linker"
+#endif
+static soinfo linker_soinfo_for_gdb(LINKER_PATH, nullptr);
/* gdb expects the linker to be in the debug shared object list.
* Without this, gdb has trouble locating the linker's ".text"
@@ -2145,12 +2146,6 @@
* be on the soinfo list.
*/
static void init_linker_info_for_gdb(ElfW(Addr) linker_base) {
-#if defined(__LP64__)
- strlcpy(linker_soinfo_for_gdb.name, "/system/bin/linker64", sizeof(linker_soinfo_for_gdb.name));
-#else
- strlcpy(linker_soinfo_for_gdb.name, "/system/bin/linker", sizeof(linker_soinfo_for_gdb.name));
-#endif
- linker_soinfo_for_gdb.flags = FLAG_NEW_SOINFO;
linker_soinfo_for_gdb.base = linker_base;
/*
@@ -2369,10 +2364,6 @@
* function, or other GOT reference will generate a segfault.
*/
extern "C" ElfW(Addr) __linker_init(void* raw_args) {
- // Initialize static variables.
- solist = get_libdl_info();
- sonext = get_libdl_info();
-
KernelArgumentBlock args(raw_args);
ElfW(Addr) linker_addr = args.getauxval(AT_BASE);
@@ -2380,8 +2371,7 @@
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_addr);
ElfW(Phdr)* phdr = reinterpret_cast<ElfW(Phdr)*>(linker_addr + elf_hdr->e_phoff);
- soinfo linker_so;
- memset(&linker_so, 0, sizeof(soinfo));
+ soinfo linker_so("[dynamic linker]", nullptr);
// If the linker is not acting as PT_INTERP entry_point is equal to
// _start. Which means that the linker is running as an executable and
@@ -2393,7 +2383,6 @@
__libc_fatal("This is %s, the helper program for shared library executables.\n", args.argv[0]);
}
- strcpy(linker_so.name, "[dynamic linker]");
linker_so.base = linker_addr;
linker_so.size = phdr_table_get_load_size(phdr, elf_hdr->e_phnum);
linker_so.load_bias = get_elf_exec_load_bias(elf_hdr);
@@ -2417,6 +2406,13 @@
// Initialize the linker's own global variables
linker_so.CallConstructors();
+ // Initialize static variables. Note that in order to
+ // get correct libdl_info we need to call constructors
+ // before get_libdl_info().
+ solist = get_libdl_info();
+ sonext = get_libdl_info();
+
+
// We have successfully fixed our own relocations. It's safe to run
// the main part of the linker now.
args.abort_message_ptr = &g_abort_message;
diff --git a/linker/linker.h b/linker/linker.h
index 684561a..5e21f70 100644
--- a/linker/linker.h
+++ b/linker/linker.h
@@ -30,6 +30,7 @@
#define _LINKER_H_
#include <elf.h>
+#include <inttypes.h>
#include <link.h>
#include <unistd.h>
#include <android/dlext.h>
@@ -88,6 +89,8 @@
#define FLAG_LINKER 0x00000010 // The linker itself
#define FLAG_NEW_SOINFO 0x40000000 // new soinfo format
+#define SOINFO_VERSION 1
+
#define SOINFO_NAME_LEN 128
typedef void (*linker_function_t)();
@@ -195,6 +198,9 @@
bool has_text_relocations;
#endif
bool has_DT_SYMBOLIC;
+
+ soinfo(const char* name, const struct stat* file_stat);
+
void CallConstructors();
void CallDestructors();
void CallPreInitConstructors();
@@ -209,10 +215,11 @@
dev_t get_st_dev();
bool get_has_ifuncs();
-
-
soinfo_list_t& get_children();
+ bool inline has_min_version(uint32_t min_version) {
+ return (flags & FLAG_NEW_SOINFO) != 0 && version >= min_version;
+ }
private:
void CallArray(const char* array_name, linker_function_t* functions, size_t count, bool reverse);
void CallFunction(const char* function_name, linker_function_t function);
@@ -221,10 +228,9 @@
private:
// This part of the structure is only available
// when FLAG_NEW_SOINFO is set in this->flags.
- unsigned int version;
+ uint32_t version;
- bool has_ifuncs;
-
+ // version >= 0
dev_t st_dev;
ino_t st_ino;
@@ -232,6 +238,8 @@
soinfo_list_t children;
soinfo_list_t parents;
+ // version >= 1
+ bool has_ifuncs;
};
extern soinfo* get_libdl_info();