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 indicats 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 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..d6a282687af5 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 merker in the shadow stack */ + + #endif /* __ASM_GENERIC_MMAN_H */