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authorMarco Elver <elver@google.com>2022-01-20 03:10:31 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-20 07:52:55 +0100
commitbece04b5b41dd7730dd06aec0d6b15c53d1fbb5a (patch)
tree80e2c0030164cc60b37aff27866f922067315081
parentlib/Kconfig.debug: make TEST_KMOD depend on PAGE_SIZE_LESS_THAN_256KB (diff)
downloadlinux-bece04b5b41dd7730dd06aec0d6b15c53d1fbb5a.tar.xz
linux-bece04b5b41dd7730dd06aec0d6b15c53d1fbb5a.zip
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 <elver@google.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/x86/Kconfig2
-rw-r--r--lib/Kconfig.debug2
2 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 1275bab8be2c..f79a063d8ea3 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 666e070feeb6..1a5d168c388b 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
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