Commit 51c2ee6d authored by Nick Desaulniers's avatar Nick Desaulniers Committed by Kees Cook
Browse files

Kconfig: Introduce ARCH_WANTS_NO_INSTR and CC_HAS_NO_PROFILE_FN_ATTR 

We don't want compiler instrumentation to touch noinstr functions,
which are annotated with the no_profile_instrument_function function
attribute. Add a Kconfig test for this and make GCOV depend on it, and
in the future, PGO.

If an architecture is using noinstr, it should denote that via this
Kconfig value. That makes Kconfigs that depend on noinstr able to express
dependencies in an architecturally agnostic way.

Cc: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/lkml/YMTn9yjuemKFLbws@hirez.programming.kicks-ass.net/
Link: https://lore.kernel.org/lkml/YMcssV%2Fn5IBGv4f0@hirez.programming.kicks-ass.net/


Suggested-by: default avatarNathan Chancellor <nathan@kernel.org>
Suggested-by: default avatarPeter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: default avatarPeter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: default avatarNathan Chancellor <nathan@kernel.org>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Acked-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210621231822.2848305-4-ndesaulniers@google.com
parent ae4d682d

arch/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -285,6 +285,13 @@ config ARCH_THREAD_STACK_ALLOCATOR 
config ARCH_WANTS_DYNAMIC_TASK_STRUCT

	bool



config ARCH_WANTS_NO_INSTR

	bool

	help

	  An architecture should select this if the noinstr macro is being used on

	  functions to denote that the toolchain should avoid instrumenting such

	  functions and is required for correctness.



config ARCH_32BIT_OFF_T

	bool

	depends on !64BIT

arch/arm64/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -93,6 +93,7 @@ config ARM64 
	select ARCH_WANT_FRAME_POINTERS

	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)

	select ARCH_WANT_LD_ORPHAN_WARN

	select ARCH_WANTS_NO_INSTR

	select ARCH_HAS_UBSAN_SANITIZE_ALL

	select ARM_AMBA

	select ARM_ARCH_TIMER

arch/s390/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -117,6 +117,7 @@ config S390 
	select ARCH_USE_BUILTIN_BSWAP

	select ARCH_USE_CMPXCHG_LOCKREF

	select ARCH_WANTS_DYNAMIC_TASK_STRUCT

	select ARCH_WANTS_NO_INSTR

	select ARCH_WANT_DEFAULT_BPF_JIT

	select ARCH_WANT_IPC_PARSE_VERSION

	select BUILDTIME_TABLE_SORT

arch/x86/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -113,6 +113,7 @@ config X86 
	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH

	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64

	select ARCH_WANTS_DYNAMIC_TASK_STRUCT

	select ARCH_WANTS_NO_INSTR

	select ARCH_WANT_HUGE_PMD_SHARE

	select ARCH_WANT_LD_ORPHAN_WARN

	select ARCH_WANTS_THP_SWAP		if X86_64

init/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -83,6 +83,9 @@ config TOOLS_SUPPORT_RELR 
config CC_HAS_ASM_INLINE

	def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)



config CC_HAS_NO_PROFILE_FN_ATTR

	def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)



config CONSTRUCTORS

	bool