[PATCH] Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang"

[PATCH] Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang"

[Marco Elver]

This reverts commit ea91a1d45d19469001a4955583187b0d75915759.

Since df05c0e9496c ("Documentation: Raise the minimum supported version
of LLVM to 11.0.0") the minimum Clang version is now 11.0, which fixed
the UBSAN/KCSAN vs. KCOV incompatibilities.

Link: https://bugs.llvm.org/show_bug.cgi?id=45831
Link: https://lkml.kernel.org/r/YaodyZzu0MTCJcvO@elver.google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
---
 lib/Kconfig.kcsan | 11 -----------
 lib/Kconfig.ubsan | 12 ------------
 2 files changed, 23 deletions(-)

diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan
index 63b70b8c5551..de022445fbba 100644
--- a/lib/Kconfig.kcsan
+++ b/lib/Kconfig.kcsan
@@ -10,21 +10,10 @@ config HAVE_KCSAN_COMPILER
 	  For the list of compilers that support KCSAN, please see
 	  <file:Documentation/dev-tools/kcsan.rst>.
 
-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 && HAVE_KCSAN_COMPILER
 	depends on 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 236c5cefc4cc..f3c57ed51838 100644
--- a/lib/Kconfig.ubsan
+++ b/lib/Kconfig.ubsan
@@ -27,16 +27,6 @@ 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 CC_HAS_UBSAN_BOUNDS
 	def_bool $(cc-option,-fsanitize=bounds)
 
@@ -46,7 +36,6 @@ config CC_HAS_UBSAN_ARRAY_BOUNDS
 config UBSAN_BOUNDS
 	bool "Perform array index bounds checking"
 	default UBSAN
-	depends on !UBSAN_KCOV_BROKEN
 	depends on CC_HAS_UBSAN_ARRAY_BOUNDS || CC_HAS_UBSAN_BOUNDS
 	help
 	  This option enables detection of directly indexed out of bounds
@@ -72,7 +61,6 @@ config UBSAN_ARRAY_BOUNDS
 config UBSAN_LOCAL_BOUNDS
 	bool "Perform array local bounds checking"
 	depends on UBSAN_TRAP
-	depends on !UBSAN_KCOV_BROKEN
 	depends on $(cc-option,-fsanitize=local-bounds)
 	help
 	  This option enables -fsanitize=local-bounds which traps when an
-- 
2.35.0.rc0.227.g00780c9af4-goog

Re: [PATCH] Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang"

[Kees Cook]

On Fri, Jan 28, 2022 at 11:56:31AM +0100, Marco Elver wrote:
> This reverts commit ea91a1d45d19469001a4955583187b0d75915759.
> 
> Since df05c0e9496c ("Documentation: Raise the minimum supported version
> of LLVM to 11.0.0") the minimum Clang version is now 11.0, which fixed
> the UBSAN/KCSAN vs. KCOV incompatibilities.
> 
> Link: https://bugs.llvm.org/show_bug.cgi?id=45831
> Link: https://lkml.kernel.org/r/YaodyZzu0MTCJcvO@elver.google.com
> Signed-off-by: Marco Elver <elver@google.com>

Yup, good to get rid of it.

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook