vmbase: Define Bionic TLS from Rust
Move the definition of __bionic_tls to Rust and generalize accessing it
through the TPIDR_EL0 in vmbase::bionic, reducing the amount of ASM we
have and giving typed accesses to the TLS from Rust.
Use the linker script to now define __stack_chk_guard at an offset from
__bionic_tls, which can't be done from Rust.
Note that TPIDR_EL0 can't be configured from rust_entry because the
compiler will dereference it during function entry to access
__stack_chk_guard and Rust doesn't support LLVM's
__attribute__((no_stack_protector)).
Test: atest DebugPolicyHostTests#testNoAdbInDebugPolicy_withDebugLevelNone_boots
Test: atest rialto_test vmbase_example.integration_test
Change-Id: Ife1e43a972758bff1cace87d80319465bb643e6d
diff --git a/vmbase/sections.ld b/vmbase/sections.ld
index 5232d30..c7ef0ec 100644
--- a/vmbase/sections.ld
+++ b/vmbase/sections.ld
@@ -107,6 +107,9 @@
. = init_stack_pointer;
} >writable_data
+ /* Make our Bionic stack protector compatible with mainline LLVM */
+ __stack_chk_guard = __bionic_tls + 40;
+
/*
* Remove unused sections from the image.
*/