[PATCH v6 01/23] aarch64: Add asm helpers for GCS

[Yury Khrustalev]

From: Szabolcs Nagy <szabolcs.nagy@arm.com>

The Guarded Control Stack instructions can be present even if the
hardware does not support the extension (runtime checked feature),
so the asm code should be backward compatible with old assemblers.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
---
 sysdeps/aarch64/sysdep.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sysdeps/aarch64/sysdep.h b/sysdeps/aarch64/sysdep.h
index 464674e89c..661d9fe8c1 100644
--- a/sysdeps/aarch64/sysdep.h
+++ b/sysdeps/aarch64/sysdep.h
@@ -74,6 +74,13 @@ strip_pac (void *p)
 #define PACIASP		hint	25
 #define AUTIASP		hint	29
 
+/* Guarded Control Stack support.  */
+#define CHKFEAT_X16	hint	40
+#define MRS_GCSPR(x)	mrs	x, s3_3_c2_c5_1
+#define GCSPOPM(x)	sysl	x, #3, c7, c7, #1
+#define GCSSS1(x)	sys	#3, c7, c7, #2, x
+#define GCSSS2(x)	sysl	x, #3, c7, c7, #3
+
 /* GNU_PROPERTY_AARCH64_* macros from elf.h for use in asm code.  */
 #define FEATURE_1_AND 0xc0000000
 #define FEATURE_1_BTI 1
-- 
2.39.5