commit 18621fb30c50e7ee8bc71001a4f42236d29a6133
author Tamas Petz <tamas.petz@arm.com> Thu Aug 27 15:39:49 2020 +0200
committer Tamas Petz <tamas.petz@arm.com> Fri Sep 04 11:28:59 2020 +0200
tree b07152ca808f5e5346ca50d8df2b0a14a3f424e8
parent 42b6530b1bdde8e7f8e52d738a62b084d1f44f3b

Update crtbegin.c and crt*.S to support Armv8.5-A BTI

These files are linked to all ELF files therefore they must support BTI.

Test: Tested on FVP with BTI enabled using a patched clang.

Co-authored-by: Gabor Kertesz <gabor.kertesz@arm.com>
Co-authored-by: Daniel Kiss   <daniel.kiss@arm.com>
Co-authored-by: Tamas Petz    <tamas.petz@arm.com>

Change-Id: If5df0722e649bcdb8c4afb0531831dff42103c9c

libc/arch-common/bionic/crtbegin.c

diff --git a/libc/arch-common/bionic/crtbegin.c b/libc/arch-common/bionic/crtbegin.c
index b7043dc..1f8dfd2 100644
--- a/libc/arch-common/bionic/crtbegin.c
+++ b/libc/arch-common/bionic/crtbegin.c
@@ -49,7 +49,7 @@
 #define POST "; .size _start, .-_start"
 
 #if defined(__aarch64__)
-__asm__(PRE "mov x0,sp; b _start_main" POST);
+__asm__(PRE "/* BTI J */ hint #36; mov x0,sp; b _start_main" POST);
 #elif defined(__arm__)
 __asm__(PRE "mov r0,sp; b _start_main" POST);
 #elif defined(__i386__)