From: Arnd Bergmann <a...@arndb.de> Clang does not allow -fsanitize-coverage=trace-{pc,cmp} together with -fsanitize=bounds or with ubsan:
clang: error: argument unused during compilation: '-fsanitize-coverage=trace-pc' [-Werror,-Wunused-command-line-argument] clang: error: argument unused during compilation: '-fsanitize-coverage=trace-cmp' [-Werror,-Wunused-command-line-argument] To avoid the warning, check whether clang can handle this correctly or disallow ubsan and kcsan when kcov is enabled. Link: https://bugs.llvm.org/show_bug.cgi?id=45831 Link: https://lore.kernel.org/lkml/20200505142341.1096942-1-a...@arndb.de Acked-by: Marco Elver <el...@google.com> Signed-off-by: Arnd Bergmann <a...@arndb.de> Signed-off-by: Marco Elver <el...@google.com> --- This patch is already in -rcu tree, but since since the series is based on -tip, to avoid conflict it is required for the subsequent patches. --- lib/Kconfig.kcsan | 11 +++++++++++ lib/Kconfig.ubsan | 11 +++++++++++ 2 files changed, 22 insertions(+) diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan index ea28245c6c1d..a7276035ca0d 100644 --- a/lib/Kconfig.kcsan +++ b/lib/Kconfig.kcsan @@ -3,9 +3,20 @@ config HAVE_ARCH_KCSAN bool +config KCSAN_KCOV_BROKEN + def_bool KCOV && CC_HAS_SANCOV_TRACE_PC + depends on CC_IS_CLANG + depends on !$(cc-option,-Werror=unused-command-line-argument -fsanitize=thread -fsanitize-coverage=trace-pc) + help + Some versions of clang support either KCSAN and KCOV but not the + combination of the two. + See https://bugs.llvm.org/show_bug.cgi?id=45831 for the status + in newer releases. + menuconfig KCSAN bool "KCSAN: dynamic data race detector" depends on HAVE_ARCH_KCSAN && DEBUG_KERNEL && !KASAN + depends on !KCSAN_KCOV_BROKEN select STACKTRACE help The Kernel Concurrency Sanitizer (KCSAN) is a dynamic diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan index 48469c95d78e..3baea77bf37f 100644 --- a/lib/Kconfig.ubsan +++ b/lib/Kconfig.ubsan @@ -26,9 +26,20 @@ config UBSAN_TRAP the system. For some system builders this is an acceptable trade-off. +config UBSAN_KCOV_BROKEN + def_bool KCOV && CC_HAS_SANCOV_TRACE_PC + depends on CC_IS_CLANG + depends on !$(cc-option,-Werror=unused-command-line-argument -fsanitize=bounds -fsanitize-coverage=trace-pc) + help + Some versions of clang support either UBSAN or KCOV but not the + combination of the two. + See https://bugs.llvm.org/show_bug.cgi?id=45831 for the status + in newer releases. + config UBSAN_BOUNDS bool "Perform array index bounds checking" default UBSAN + depends on !UBSAN_KCOV_BROKEN help This option enables detection of directly indexed out of bounds array accesses, where the array size is known at compile time. -- 2.26.2.761.g0e0b3e54be-goog