Enable pointer authentication
The same way as in TF-A make memory protection be selectable
via the BRANCH_PROTECTION variable:
unset: Default value. mbranch-protection flag is not provided
0: Turns off all types of branch protection
1: Enables all types of branch protection features
2: Return address signing to its standard level
3: Extend the signing to include leaf functions
4: Turn on branch target identification mechanism
Signed-off-by: Gabor Toth <gabor.toth2@arm.com>
Change-Id: Ide8035599e131986e7bcfd50d0a3b5234ac6354f
diff --git a/environments/arm-linux/default_toolchain_file.cmake b/environments/arm-linux/default_toolchain_file.cmake
index 308c2a7..5869fa4 100644
--- a/environments/arm-linux/default_toolchain_file.cmake
+++ b/environments/arm-linux/default_toolchain_file.cmake
@@ -22,17 +22,26 @@
set(TS_WARNING_FLAGS "-Wall -Werror" CACHE STRING "Compiler flags affecting generating warning messages.")
set(TS_MANDATORY_LINKER_FLAGS "" CACHE STRING "Linker flags needed for correct builds.")
-set(BTI_ENABLED unset CACHE STRING "Enable Branch Target Identification (BTI)")
-set_property(CACHE BTI_ENABLED PROPERTY STRINGS unset OFF ON)
+# branch-protection enables bti/pac while compile force-bti tells the linker to
+# warn if some object files lack the .note.gnu.property section with the BTI
+# flag, and to turn on the BTI flag in the output anyway.
+set(BRANCH_PROTECTION unset CACHE STRING "Enable branch protection")
+set_property(CACHE BRANCH_PROTECTION PROPERTY STRINGS unset 0 1 2 3 4)
-if(BTI_ENABLED STREQUAL "ON")
- # branch-protection enables bti while compile force-bti tells the linker to
- # warn if some object files lack the .note.gnu.property section with the BTI
- # flag, and to turn on the BTI flag in the output anyway.
+if(BRANCH_PROTECTION STREQUAL "0")
+ set(TS_MANDATORY_AARCH_FLAGS "${TS_MANDATORY_AARCH_FLAGS} -mbranch-protection=none")
+elseif(BRANCH_PROTECTION STREQUAL "1")
+ set(TS_MANDATORY_AARCH_FLAGS "${TS_MANDATORY_AARCH_FLAGS} -mbranch-protection=standard")
+ set(TS_MANDATORY_LINKER_FLAGS "${TS_MANDATORY_LINKER_FLAGS} -zforce-bti")
+ add_compile_definitions("BTI_ENABLED")
+elseif(BRANCH_PROTECTION STREQUAL "2")
+ set(TS_MANDATORY_AARCH_FLAGS "${TS_MANDATORY_AARCH_FLAGS} -mbranch-protection=pac-ret")
+elseif(BRANCH_PROTECTION STREQUAL "3")
+ set(TS_MANDATORY_AARCH_FLAGS "${TS_MANDATORY_AARCH_FLAGS} -mbranch-protection=pac-ret+leaf")
+elseif(BRANCH_PROTECTION STREQUAL "4")
set(TS_MANDATORY_AARCH_FLAGS "${TS_MANDATORY_AARCH_FLAGS} -mbranch-protection=bti")
set(TS_MANDATORY_LINKER_FLAGS "${TS_MANDATORY_LINKER_FLAGS} -zforce-bti")
-elseif(BTI_ENABLED STREQUAL "OFF")
- set(TS_MANDATORY_AARCH_FLAGS "${TS_MANDATORY_AARCH_FLAGS} -mbranch-protection=none")
+ add_compile_definitions("BTI_ENABLED")
endif()
# Set flags affecting all build types