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authorDan Li <ashimida@linux.alibaba.com>2022-03-03 10:43:23 +0300
committerKees Cook <keescook@chromium.org>2022-03-10 20:22:09 +0300
commitafcf5441b9ff22ac57244cd45ff102ebc2e32d1a (patch)
tree09e566a2d90c1de122dd348ff2e483fd815d725d /arch/Kconfig
parent575d6b77fa2697afd2b3a443f7f879faa65ae0ca (diff)
downloadlinux-afcf5441b9ff22ac57244cd45ff102ebc2e32d1a.tar.xz
arm64: Add gcc Shadow Call Stack support
Shadow call stacks will be available in GCC >= 12, this patch makes the corresponding kernel configuration available when compiling the kernel with the gcc. Note that the implementation in GCC is slightly different from Clang. With SCS enabled, functions will only pop x30 once in the epilogue, like: str x30, [x18], #8 stp x29, x30, [sp, #-16]! ...... - ldp x29, x30, [sp], #16 //clang + ldr x29, [sp], #16 //GCC ldr x30, [x18, #-8]! Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ce09ab17ddd21f73ff2caf6eec3b0ee9b0e1a11e Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Dan Li <ashimida@linux.alibaba.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220303074323.86282-1-ashimida@linux.alibaba.com
Diffstat (limited to 'arch/Kconfig')
-rw-r--r--arch/Kconfig19
1 files changed, 10 insertions, 9 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index c5b50bfe31c1..cabfac22f2fb 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -599,21 +599,22 @@ config STACKPROTECTOR_STRONG
config ARCH_SUPPORTS_SHADOW_CALL_STACK
bool
help
- An architecture should select this if it supports Clang's Shadow
- Call Stack and implements runtime support for shadow stack
+ An architecture should select this if it supports the compiler's
+ Shadow Call Stack and implements runtime support for shadow stack
switching.
config SHADOW_CALL_STACK
- bool "Clang Shadow Call Stack"
- depends on CC_IS_CLANG && ARCH_SUPPORTS_SHADOW_CALL_STACK
+ bool "Shadow Call Stack"
+ depends on ARCH_SUPPORTS_SHADOW_CALL_STACK
depends on DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER
help
- This option enables Clang's Shadow Call Stack, which uses a
- shadow stack to protect function return addresses from being
- overwritten by an attacker. More information can be found in
- Clang's documentation:
+ This option enables the compiler's Shadow Call Stack, which
+ uses a shadow stack to protect function return addresses from
+ being overwritten by an attacker. More information can be found
+ in the compiler's documentation:
- https://clang.llvm.org/docs/ShadowCallStack.html
+ - Clang: https://clang.llvm.org/docs/ShadowCallStack.html
+ - GCC: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html#Instrumentation-Options
Note that security guarantees in the kernel differ from the
ones documented for user space. The kernel must store addresses