In preparation for adding arm64 GCS support make the map_shadow_stack()
SHADOW_STACK_SET_TOKEN flag generic and add _SET_MARKER. The existing
flag indicates that a token usable for stack switch should be added to
the top of the newly mapped GCS region while the new flag indicates that
a top of stack marker suitable for use by unwinders should be added
above that.

For arm64 the top of stack marker is all bits 0.

Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Yury Khrustalev <yury.khrustalev@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/x86/include/uapi/asm/mman.h | 3 ---
 include/uapi/asm-generic/mman.h  | 4 ++++
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/uapi/asm/mman.h b/arch/x86/include/uapi/asm/mman.h
index 46cdc941f958..ac1e6277212b 100644
--- a/arch/x86/include/uapi/asm/mman.h
+++ b/arch/x86/include/uapi/asm/mman.h
@@ -5,9 +5,6 @@
 #define MAP_32BIT	0x40		/* only give out 32bit addresses */
 #define MAP_ABOVE4G	0x80		/* only map above 4GB */
 
-/* Flags for map_shadow_stack(2) */
-#define SHADOW_STACK_SET_TOKEN	(1ULL << 0)	/* Set up a restore token in the shadow stack */
-
 #include <asm-generic/mman.h>
 
 #endif /* _ASM_X86_MMAN_H */
diff --git a/include/uapi/asm-generic/mman.h b/include/uapi/asm-generic/mman.h
index 57e8195d0b53..5e3d61ddbd8c 100644
--- a/include/uapi/asm-generic/mman.h
+++ b/include/uapi/asm-generic/mman.h
@@ -19,4 +19,8 @@
 #define MCL_FUTURE	2		/* lock all future mappings */
 #define MCL_ONFAULT	4		/* lock all pages that are faulted in */
 
+#define SHADOW_STACK_SET_TOKEN (1ULL << 0)     /* Set up a restore token in the shadow stack */
+#define SHADOW_STACK_SET_MARKER (1ULL << 1)     /* Set up a top of stack marker in the shadow stack */
+
+
 #endif /* __ASM_GENERIC_MMAN_H */

-- 
2.39.2