Fix TLS access for ARMv6 and beyond.
For performance reasons, we don't call the kernel helper. Instead, we directly
access the TLS register on ARMv6 and higher. For ARMv5TE, keep using the hard-coded
address populated by the kernel on each task switch.
NOTE: Since we don't call the kernel helper, this must precisely match your
kernel configuration. This is controlled by setting the ARCH_ARM_HAVE_TLS_REGISTER
variable to 'true' in your board configuration file.
diff --git a/libc/Android.mk b/libc/Android.mk
index 59a4c6b..12d5c92 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -366,6 +366,16 @@
ifeq ($(TARGET_ARCH),arm)
libc_common_cflags += -fstrict-aliasing
libc_crt_target_cflags := -mthumb-interwork
+ #
+ # Define HAVE_ARM_TLS_REGISTER macro to indicate to the C library
+ # that it should access the hardware TLS register directly in
+ # private/bionic_tls.h
+ #
+ # The value must match your kernel configuration
+ #
+ ifeq ($(ARCH_ARM_HAVE_TLS_REGISTER),true)
+ libc_common_cflags += -DHAVE_ARM_TLS_REGISTER
+ endif
else # !arm
ifeq ($(TARGET_ARCH),x86)
libc_crt_target_cflags := -m32