Clean up TLS_SLOT_BIONIC_PREINIT usage a bit
- It is only needed for dynamic executables, so move the initialization
out of __libc_init_main_thread and just before the solib constructor
calls. For static executables, the slot was initialized, then never
used or cleared. Instead, leave it clear.
- For static executables, __libc_init_main_thread already initialized the
stack guard, so remove the redundant __init_thread_stack_guard call.
- Simplify the slot access/clearing a bit in __libc_preinit.
- Remove the "__libc_init_common() will change the TLS area so the old one
won't be accessible anyway." comment. AFAICT, it's incorrect -- the
main thread's TLS area in a dynamic executable is initialized to a
static pthread_internal_t object in the linker, then reused by libc.so.
Test: adb shell /data/nativetest/bionic-unit-tests/bionic-unit-tests
Test: adb shell /data/nativetest/bionic-unit-tests-static/bionic-unit-tests-static
Change-Id: Ie2da6f5be3ad563fa65b38eaadf8ba6ecc6a64b6
diff --git a/libc/bionic/__libc_init_main_thread.cpp b/libc/bionic/__libc_init_main_thread.cpp
index efa7dee..a18a831 100644
--- a/libc/bionic/__libc_init_main_thread.cpp
+++ b/libc/bionic/__libc_init_main_thread.cpp
@@ -81,8 +81,7 @@
// We don't want to free the main thread's stack even when the main thread exits
// because things like environment variables with global scope live on it.
- // We also can't free the pthread_internal_t itself, since that lives on the main
- // thread's stack rather than on the heap.
+ // We also can't free the pthread_internal_t itself, since it is a static variable.
// The main thread has no mmap allocated space for stack or pthread_internal_t.
main_thread.mmap_size = 0;
@@ -102,9 +101,5 @@
__init_thread(&main_thread);
- // Store a pointer to the kernel argument block in a TLS slot to be
- // picked up by the libc constructor.
- main_thread.tls[TLS_SLOT_BIONIC_PREINIT] = &args;
-
__init_alternate_signal_stack(&main_thread);
}