Expose libc_shared_globals to libc.so with symbol
Previously, the address of the global variable was communicated from the
dynamic linker to libc.so using a field of KernelArgumentBlock, which is
communicated using the TLS_SLOT_BIONIC_PREINIT slot.
As long as this function isn't called during relocations (i.e. while
executing an ifunc), it always return a non-NULL value. If it's called
before its PLT entry is relocated, I expect a crash.
I removed the __libc_init_shared_globals function. It's currently empty,
and I don't think there's one point in libc's initialization where
shared globals should be initialized.
Bug: http://b/25751302
Test: bionic unit tests
Change-Id: I614d25e7ef5e0d2ccc40d5c821dee10f1ec61c2e
diff --git a/libc/bionic/libc_init_static.cpp b/libc/bionic/libc_init_static.cpp
index ef1c393..10fc151 100644
--- a/libc/bionic/libc_init_static.cpp
+++ b/libc/bionic/libc_init_static.cpp
@@ -100,10 +100,6 @@
// Initializing the globals requires TLS to be available for errno.
__libc_init_main_thread(args);
- static libc_shared_globals shared_globals;
- __libc_shared_globals = &shared_globals;
- __libc_init_shared_globals(&shared_globals);
-
__libc_init_globals(args);
__libc_init_AT_SECURE(args);
@@ -155,3 +151,8 @@
extern "C" void android_set_application_target_sdk_version(int target) {
g_target_sdk_version = target;
}
+
+__LIBC_HIDDEN__ libc_shared_globals* __libc_shared_globals() {
+ static libc_shared_globals globals;
+ return &globals;
+}