From bece04b5b41dd7730dd06aec0d6b15c53d1fbb5a Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Wed, 19 Jan 2022 18:10:31 -0800 Subject: [PATCH] kcov: fix generic Kconfig dependencies if ARCH_WANTS_NO_INSTR Until recent versions of GCC and Clang, it was not possible to disable KCOV instrumentation via a function attribute. The relevant function attribute was introduced in 540540d06e9d9 ("kcov: add __no_sanitize_coverage to fix noinstr for all architectures"). x86 was the first architecture to want a working noinstr, and at the time no compiler support for the attribute existed yet. Therefore, commit 0f1441b44e823 ("objtool: Fix noinstr vs KCOV") introduced the ability to NOP __sanitizer_cov_*() calls in .noinstr.text. However, this doesn't work for other architectures like arm64 and s390 that want a working noinstr per ARCH_WANTS_NO_INSTR. At the time of 0f1441b44e823, we didn't yet have ARCH_WANTS_NO_INSTR, but now we can move the Kconfig dependency checks to the generic KCOV option. KCOV will be available if: - architecture does not care about noinstr, OR - we have objtool support (like on x86), OR - GCC is 12.0 or newer, OR - Clang is 13.0 or newer. Link: https://lkml.kernel.org/r/20211201152604.3984495-1-elver@google.com Signed-off-by: Marco Elver Reviewed-by: Nathan Chancellor Acked-by: Peter Zijlstra (Intel) Cc: Mark Rutland Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Nick Desaulniers Cc: Dmitry Vyukov Cc: Andrey Konovalov Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/Kconfig | 2 +- lib/Kconfig.debug | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 1275bab8be2cb..f79a063d8ea38 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -78,7 +78,7 @@ config X86 select ARCH_HAS_FILTER_PGPROT select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_GCOV_PROFILE_ALL - select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION + select ARCH_HAS_KCOV if X86_64 select ARCH_HAS_MEM_ENCRYPT select ARCH_HAS_MEMBARRIER_SYNC_CORE select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 666e070feeb6b..1a5d168c388b1 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1979,6 +1979,8 @@ config KCOV bool "Code coverage for fuzzing" depends on ARCH_HAS_KCOV depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS + depends on !ARCH_WANTS_NO_INSTR || STACK_VALIDATION || \ + GCC_VERSION >= 120000 || CLANG_VERSION >= 130000 select DEBUG_FS select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC help -- 2.39.5