Commit 3630e82a authored by Mark Brown's avatar Mark Brown Committed by Catalin Marinas
Browse files

mman: Add map_shadow_stack() flags 



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: default avatarThiago Jung Bauermann <thiago.bauermann@linaro.org>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarYury Khrustalev <yury.khrustalev@arm.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-5-222b78d87eee@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 91e102e7

arch/x86/include/uapi/asm/mman.h

+0 −3
Original line number Diff line number Diff line
@@ -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 */

include/uapi/asm-generic/mman.h

+4 −0
Original line number Diff line number Diff line
@@ -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 */