libc: Prepare support for Armv8.3-A PAuth and Armv8.5-A BTI in *.S
The instruction "bti c" is added through ENTRY*() macro,
using __bionic_asm_custom_entry(f).
The .note.gnu.property section is added with the new macro
NOTE_GNU_PROPERTY(). BTI and PAuth features are automatically
selected based on the presence of __ARM_FEATURE_* macros.
Furthermore, gensyscalls.py got updated to append the new
macro to the generated syscalls-arm64.S.
Test: Tested on FVP with BTI enabled.
Change-Id: I40ffe294b8426421125fffd0a9758567d919a09d
diff --git a/libc/private/bionic_asm.h b/libc/private/bionic_asm.h
index 6409563..6d4f7d5 100644
--- a/libc/private/bionic_asm.h
+++ b/libc/private/bionic_asm.h
@@ -35,6 +35,7 @@
#define __bionic_asm_custom_entry(f)
#define __bionic_asm_custom_end(f)
#define __bionic_asm_function_type @function
+#define __bionic_asm_custom_note_gnu_section()
#if defined(__aarch64__)
#include <private/bionic_asm_arm64.h>
@@ -83,4 +84,7 @@
.globl alias; \
.equ alias, original
+#define NOTE_GNU_PROPERTY() \
+ __bionic_asm_custom_note_gnu_section()
+
#endif