Bump minimum supported version of LLVM to 11.0.0

RFC PATCH In review Nathan Chancellor 7 participants 14 messages Nov 29, 2021 – Dec 3, 2021

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Nathan Chancellor

author maintainer

2021-11-29 16:57 UTC #0 lore raw

cover Bump minimum supported version of LLVM to 11.0.0

This patch series raises the minimum supported version of LLVM to 11.0.0.

Patch #1 outlines the issue, goes over the potential impact of the change, and does the actual bump. Subsequent patches clean up the various checks that are always true after the bump.

I have marked this revision as RFC to give various parties the option to comment on this bump before it is done, namely KernelCI and Linaro's LKFT, who are still testing clang-10. I have added some other folks to CC that I know are testing with clang to see if this impacts them in any way (as I would like to impact as few people as possible) but as far as I am aware, most other CIs and developers are testing closer to tip of tree. If that is not true, scream so that we can see what can be done about that. If I missed anyone who is actively testing with clang, please key them in and I will make sure to include them in future revisions (if any are needed).

It probably makes sense for this series to live in -mm.

Nathan Chancellor (6):
Documentation: Raise the minimum supported version of LLVM to 11.0.0 mm, slab: Remove compiler check in __kmalloc_index arch/Kconfig: Remove CLANG_VERSION check in HAS_LTO_CLANG Revert "ARM: 9070/1: Make UNWINDER_ARM depend on ld.bfd or ld.lld

    11.0.0+"

gcov: Remove compiler version check init/Kconfig: Drop linker version check for LD_ORPHAN_WARN

 Documentation/process/changes.rst | 2 +-
 arch/Kconfig                      | 3 +--
 arch/arm/Kconfig.debug            | 2 --
 include/linux/slab.h              | 3 +--
 init/Kconfig                      | 1 -
 kernel/gcov/Kconfig               | 1 -
 scripts/min-tool-version.sh       | 2 +-
 7 files changed, 4 insertions(+), 10 deletions(-)

base-commit: d58071a8a76d779eedab38033ae4c821c30295a5

Signature · 1 line

2.34.1

Nathan Chancellor

author maintainer

2021-11-29 16:57 UTC #1 lore raw

RFC PATCH 1/6 Documentation: Raise the minimum supported version of LLVM to 11.0.0

LLVM versions prior to 11.0.0 have a harder time with dead code elimination, which can cause issues with commonly used expressions such as BUILD_BUG_ON and the bitmask functions/macros in bitfield.h (see the first two issues links below).

Whenever there is an issue within LLVM that has been resolved in a later release, the only course of action is to gate the problematic configuration or source code on the toolchain verson or raise the minimum supported version of LLVM for building the kernel, as LLVM has a limited support lifetime compared to GCC. GCC major releases will typically see a few point releases across a two year period on average whereas LLVM major releases are only supported until the next major release and will only see one or two point releases within that timeframe. For example, GCC 8.1 was released in May 2018 and GCC 8.5 was released in May 2021, whereas LLVM 12.0.0 was released in April 2021 and its only point release, 12.0.1, was released in July 2021, giving a minimal window for fixes to be backported.

To resolve these build errors around improper dead code elimination, raise the minimum supported version of LLVM for building the kernel to 11.0.0. Doing so is a more proper solution than mucking around with core kernel macros that have always worked with GCC or disabling drivers for using these macros in a proper manner. This type of issue may continue to crop up and require patching, which creates more debt for bumping the minimum supported version in the future.

This should have a minimal impact to distributions. Using a script to pull several different Docker images and check the output of 'clang --version':

archlinux:latest: clang version 13.0.0

debian:oldoldstable-slim: clang version 3.8.1-24 (tags/RELEASE_381/final) debian:oldstable-slim: clang version 7.0.1-8+deb10u2 (tags/RELEASE_701/final) debian:stable-slim: Debian clang version 11.0.1-2 debian:testing-slim: Debian clang version 11.1.0-4 debian:unstable-slim: Debian clang version 11.1.0-4

fedora:34: clang version 12.0.1 (Fedora 12.0.1-1.fc34) fedora:latest: clang version 13.0.0 (Fedora 13.0.0-3.fc35) fedora:rawhide: clang version 13.0.0 (Fedora 13.0.0-5.fc36)

opensuse/leap:15.2: clang version 9.0.1
opensuse/leap:latest: clang version 11.0.1
opensuse/tumbleweed:latest: clang version 13.0.0

ubuntu:bionic: clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final) ubuntu:latest: clang version 10.0.0-4ubuntu1 ubuntu:hirsute: Ubuntu clang version 12.0.0-3ubuntu1~21.04.2 ubuntu:rolling: Ubuntu clang version 13.0.0-2 ubuntu:devel: Ubuntu clang version 13.0.0-9

In every case, the distribution's version of clang is either older than the current minimum supported version of LLVM 10.0.1 or equal to or greater than the proposed 11.0.0 so nothing should change.

Another benefit of this change is LLVM=1 works better with arm64 and x86_64 since commit f12b034afeb3 ("scripts/Makefile.clang: default to LLVM_IAS=1") enabled the integrated assembler by default, which only works well with clang 11+ (clang-10 required it to be disabled to successfully build a kernel).

Link https://github.com/ClangBuiltLinux/linux/issues/1293

Link https://github.com/ClangBuiltLinux/linux/issues/1506

Link https://github.com/ClangBuiltLinux/linux/issues/1511

Link https://github.com/llvm/llvm-project/commit/fa496ce3c6774097080c8a9cb808da56f383b938

Link https://groups.google.com/g/clang-built-linux/c/mPQb9_ZWW0s/m/W7o6S-QTBAAJ

Link https://github.com/ClangBuiltLinux/misc-scripts

Signed-off-by Nathan Chancellor <[email protected]>

---
 Documentation/process/changes.rst | 2 +-
 scripts/min-tool-version.sh       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

Documentation/process/changes.rst +1 -1

index b398b8576417..17182b537141 100644
@@ -30,7 +30,7 @@ you probably needn't concern yourself with pcmciautils.
         Program        Minimal version       Command to check the version
 ====================== ===============  ========================================
 GNU C                  5.1              gcc --version
-Clang/LLVM (optional)  10.0.1           clang --version
+Clang/LLVM (optional)  11.0.0           clang --version
 GNU make               3.81             make --version
 binutils               2.23             ld -v
 flex                   2.5.35           flex --version

scripts/min-tool-version.sh +1 -1

index 4edc708baa63..7c20252a90c6 100755
@@ -28,7 +28,7 @@ llvm)
 	if [ "$SRCARCH" = s390 ]; then
 		echo 13.0.0
 	else
-		echo 10.0.1
+		echo 11.0.0
 	fi
 	;;
 *)

Signature · 1 line

2.34.1

Nathan Chancellor

author maintainer

2021-11-29 16:57 UTC #2 lore raw

RFC PATCH 2/6 mm, slab: Remove compiler check in __kmalloc_index

In reply to Nathan Chancellor

The minimum supported version of LLVM has been raised to 11.0.0, meaning this check is always true, so it can be dropped.

Signed-off-by Nathan Chancellor <[email protected]>

---
 include/linux/slab.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

include/linux/slab.h +1 -2

index 181045148b06..d3fb5ac71c24 100644
@@ -411,8 +411,7 @@ static __always_inline unsigned int __kmalloc_index(size_t size,
 	if (size <=  16 * 1024 * 1024) return 24;
 	if (size <=  32 * 1024 * 1024) return 25;
 
-	if ((IS_ENABLED(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION >= 110000)
-	    && !IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant)
+	if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant)
 		BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()");
 	else
 		BUG();

Signature · 1 line

2.34.1

Nathan Chancellor

author maintainer

2021-11-29 16:58 UTC #3 lore raw

RFC PATCH 3/6 arch/Kconfig: Remove CLANG_VERSION check in HAS_LTO_CLANG

In reply to Nathan Chancellor

The minimum supported version of LLVM has been raised to 11.0.0, meaning this check is always true, so it can be dropped.

Signed-off-by Nathan Chancellor <[email protected]>

---
 arch/Kconfig | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

arch/Kconfig +1 -2

index d3c4ab249e9c..86e071f693ce 100644
@@ -648,8 +648,7 @@ config ARCH_SUPPORTS_LTO_CLANG_THIN
 
 config HAS_LTO_CLANG
 	def_bool y
-	# Clang >= 11: https://github.com/ClangBuiltLinux/linux/issues/510
-	depends on CC_IS_CLANG && CLANG_VERSION >= 110000 && LD_IS_LLD && AS_IS_LLVM
+	depends on CC_IS_CLANG && LD_IS_LLD && AS_IS_LLVM
 	depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm)
 	depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm)
 	depends on ARCH_SUPPORTS_LTO_CLANG

Signature · 1 line

2.34.1

Nathan Chancellor

author maintainer

2021-11-29 16:58 UTC #4 lore raw

RFC PATCH 4/6 Revert "ARM: 9070/1: Make UNWINDER_ARM depend on ld.bfd or ld.lld 11.0.0+"

In reply to Nathan Chancellor

This reverts commit 7411cfc3c91a08a884463bbc7623087ecc2efdd8.

The minimum supported version of LLVM has been raised to 11.0.0, meaning this check is always true, so it can be dropped.

Signed-off-by Nathan Chancellor <[email protected]>

---
 arch/arm/Kconfig.debug | 2 --
 1 file changed, 2 deletions(-)

arch/arm/Kconfig.debug +0 -2

index 98436702e0c7..cd2d74b625c1 100644
@@ -66,8 +66,6 @@ config UNWINDER_FRAME_POINTER
 config UNWINDER_ARM
 	bool "ARM EABI stack unwinder"
 	depends on AEABI && !FUNCTION_GRAPH_TRACER
-	# https://github.com/ClangBuiltLinux/linux/issues/732
-	depends on !LD_IS_LLD || LLD_VERSION >= 110000
 	select ARM_UNWIND
 	help
 	  This option enables stack unwinding support in the kernel

Signature · 1 line

2.34.1

Nathan Chancellor

author maintainer

2021-11-29 16:58 UTC #5 lore raw

RFC PATCH 5/6 gcov: Remove compiler version check

In reply to Nathan Chancellor

The minimum supported version of LLVM has been raised to 11.0.0, meaning this check is always true, so it can be dropped.

Signed-off-by Nathan Chancellor <[email protected]>

---
 kernel/gcov/Kconfig | 1 -
 1 file changed, 1 deletion(-)

kernel/gcov/Kconfig +0 -1

index 053447183ac5..04f4ebdc3cf5 100644
@@ -4,7 +4,6 @@ menu "GCOV-based kernel profiling"
 config GCOV_KERNEL
 	bool "Enable gcov-based kernel profiling"
 	depends on DEBUG_FS
-	depends on !CC_IS_CLANG || CLANG_VERSION >= 110000
 	depends on !ARCH_WANTS_NO_INSTR || CC_HAS_NO_PROFILE_FN_ATTR
 	select CONSTRUCTORS
 	default n

Signature · 1 line

2.34.1

Nathan Chancellor

author maintainer

2021-11-29 16:58 UTC #6 lore raw

RFC PATCH 6/6 init/Kconfig: Drop linker version check for LD_ORPHAN_WARN

In reply to Nathan Chancellor

The minimum supported version of LLVM has been raised to 11.0.0, meaning this check is always true, so it can be dropped.

Signed-off-by Nathan Chancellor <[email protected]>

---
 init/Kconfig | 1 -
 1 file changed, 1 deletion(-)

init/Kconfig +0 -1

index 4b7bac10c72d..e40f967dee3f 100644
@@ -1414,7 +1414,6 @@ config LD_DEAD_CODE_DATA_ELIMINATION
 config LD_ORPHAN_WARN
 	def_bool y
 	depends on ARCH_WANT_LD_ORPHAN_WARN
-	depends on !LD_IS_LLD || LLD_VERSION >= 110000
 	depends on $(ld-option,--orphan-handling=warn)
 
 config SYSCTL

Signature · 1 line

2.34.1

Miguel Ojeda

Reviewed-by on the v1 series

2021-11-29 17:27 UTC #7 lore raw

In reply to Nathan Chancellor

Quoted 2 lines · Nathan Chancellor

tree. If that is not true, scream so that we can see what can be done

The patches themselves look good to me. Let's see if somebody screams! :)

Reviewed-by Miguel Ojeda <[email protected]>

Cheers,
Miguel

Mark Brown

Reviewed-by on the v1 series

2021-11-29 17:56 UTC #8 lore raw

In reply to Nathan Chancellor

Quoted 6 lines · Nathan Chancellor

This patch series raises the minimum supported version of LLVM to 11.0.0.
Patch #1 outlines the issue, goes over the potential impact of the change, and does the actual bump. Subsequent patches clean up the various checks that are always true after the bump.

Reviewed-by Mark Brown <[email protected]>

Nick Desaulniers

Reviewed-by on the v1 series

2021-11-29 18:30 UTC #9 lore raw

In reply to Nathan Chancellor

Quoted 19 lines · Nathan Chancellor

This patch series raises the minimum supported version of LLVM to 11.0.0.
Patch #1 outlines the issue, goes over the potential impact of the change, and does the actual bump. Subsequent patches clean up the various checks that are always true after the bump.
I have marked this revision as RFC to give various parties the option to comment on this bump before it is done, namely KernelCI and Linaro's LKFT, who are still testing clang-10. I have added some other folks to CC that I know are testing with clang to see if this impacts them in any way (as I would like to impact as few people as possible) but as far as I am aware, most other CIs and developers are testing closer to tip of tree. If that is not true, scream so that we can see what can be done about that. If I missed anyone who is actively testing with clang, please key them in and I will make sure to include them in future revisions (if any are needed).

Quoted 1 line

It probably makes sense for this series to live in -mm.

Series looks good to me. Thanks for the patch, and cleanups!

Reviewed-by Nick Desaulniers <[email protected]>

Quoted 25 lines

Nathan Chancellor (6):
Documentation: Raise the minimum supported version of LLVM to 11.0.0 mm, slab: Remove compiler check in __kmalloc_index arch/Kconfig: Remove CLANG_VERSION check in HAS_LTO_CLANG Revert "ARM: 9070/1: Make UNWINDER_ARM depend on ld.bfd or ld.lld
    11.0.0+"
gcov: Remove compiler version check init/Kconfig: Drop linker version check for LD_ORPHAN_WARN
 Documentation/process/changes.rst | 2 +-
 arch/Kconfig                      | 3 +--
 arch/arm/Kconfig.debug            | 2 --
 include/linux/slab.h              | 3 +--
 init/Kconfig                      | 1 -
 kernel/gcov/Kconfig               | 1 -
 scripts/min-tool-version.sh       | 2 +-
 7 files changed, 4 insertions(+), 10 deletions(-)
base-commit: d58071a8a76d779eedab38033ae4c821c30295a5 --
2.34.1

Signature · 2 lines

Thanks,
~Nick Desaulniers

Kees Cook

Reviewed-by on the v1 series

2021-12-01 19:41 UTC #10 lore raw

In reply to Nathan Chancellor

Quoted 18 lines · Nathan Chancellor

This patch series raises the minimum supported version of LLVM to 11.0.0.
Patch #1 outlines the issue, goes over the potential impact of the change, and does the actual bump. Subsequent patches clean up the various checks that are always true after the bump.
I have marked this revision as RFC to give various parties the option to comment on this bump before it is done, namely KernelCI and Linaro's LKFT, who are still testing clang-10. I have added some other folks to CC that I know are testing with clang to see if this impacts them in any way (as I would like to impact as few people as possible) but as far as I am aware, most other CIs and developers are testing closer to tip of tree. If that is not true, scream so that we can see what can be done about that. If I missed anyone who is actively testing with clang, please key them in and I will make sure to include them in future revisions (if any are needed).

Quoted 1 line

It probably makes sense for this series to live in -mm.

Sounds good to me. Thanks!

Reviewed-by Kees Cook <[email protected]>

Signature · 1 line

Kees Cook

Masahiro Yamada

2021-12-02 08:26 UTC #11 lore raw

Quoted 20 lines · Kees Cook

Quoted 18 lines · Nathan Chancellor
This patch series raises the minimum supported version of LLVM to 11.0.0.
Patch #1 outlines the issue, goes over the potential impact of the change, and does the actual bump. Subsequent patches clean up the various checks that are always true after the bump.
I have marked this revision as RFC to give various parties the option to comment on this bump before it is done, namely KernelCI and Linaro's LKFT, who are still testing clang-10. I have added some other folks to CC that I know are testing with clang to see if this impacts them in any way (as I would like to impact as few people as possible) but as far as I am aware, most other CIs and developers are testing closer to tip of tree. If that is not true, scream so that we can see what can be done about that. If I missed anyone who is actively testing with clang, please key them in and I will make sure to include them in future revisions (if any are needed).

Quoted 8 lines

Quoted 1 line
It probably makes sense for this series to live in -mm.
Sounds good to me. Thanks!
Reviewed-by Kees Cook <[email protected]>
--
Kees Cook

Only positive feedback so far.

All applied to linux-kbuild.

Signature · 2 lines

Best Regards
Masahiro Yamada

Marco Elver

maintainer Acked-by

2021-12-03 13:38 UTC #12 lore raw

Quoted 5 lines · Masahiro Yamada

Quoted 4 lines · Kees Cook
Quoted 2 lines · Nathan Chancellor
This patch series raises the minimum supported version of LLVM to 11.0.0.

[...]

Quoted 3 lines

Only positive feedback so far.
All applied to linux-kbuild.

Some of the "dynamic" checks for compiler support unfortunately aren't as easily grepable -- as far as I can tell, we can also include the below, which would save us 2 cc-option invocations for all clang builds.

And just in case:

Acked-by Marco Elver <[email protected]>

for the rest as well.

Thanks,
-- Marco

------ >8 ------

From: Marco Elver <[email protected]>
Date: Fri, 3 Dec 2021 14:18:44 +0100
Subject: [PATCH] Revert "ubsan, kcsan: Don't combine sanitizer with kcov on
clang"

This reverts commit ea91a1d45d19469001a4955583187b0d75915759.

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

Signed-off-by Marco Elver <[email protected]>

---
 lib/Kconfig.kcsan | 11 -----------
 lib/Kconfig.ubsan | 12 ------------
 2 files changed, 23 deletions(-)

lib/Kconfig.kcsan +0 ~~-11~~

index e0a93ffdef30..b81454b2a0d0 100644
@@ -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

lib/Kconfig.ubsan +0 ~~-12~~

index e5372a13511d..31f38e7fe948 100644
@@ -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

Signature · 1 line

2.34.0.384.gca35af8252-goog

Nathan Chancellor

author maintainer Reviewed-by

2021-12-03 15:51 UTC #13 lore raw

Quoted 31 lines · Marco Elver

Quoted 5 lines · Masahiro Yamada
Quoted 4 lines · Kees Cook
Quoted 2 lines · Nathan Chancellor
This patch series raises the minimum supported version of LLVM to 11.0.0.
[...]
Quoted 3 lines
Only positive feedback so far.
All applied to linux-kbuild.
Some of the "dynamic" checks for compiler support unfortunately aren't as easily grepable -- as far as I can tell, we can also include the below, which would save us 2 cc-option invocations for all clang builds.
And just in case:
Acked-by Marco Elver <[email protected]>
for the rest as well.
Thanks,
-- Marco
------ >8 ------
From: Marco Elver <[email protected]>
Date: Fri, 3 Dec 2021 14:18:44 +0100
Subject: [PATCH] Revert "ubsan, kcsan: Don't combine sanitizer with kcov on
clang"

Quoted 7 lines

This reverts commit ea91a1d45d19469001a4955583187b0d75915759.
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
Signed-off-by Marco Elver <[email protected]>

Thanks!

Reviewed-by Nathan Chancellor <[email protected]>

Quoted 71 lines

---
 lib/Kconfig.kcsan | 11 -----------
 lib/Kconfig.ubsan | 12 ------------
 2 files changed, 23 deletions(-)

lib/Kconfig.kcsan +0 ~~-11~~

index e0a93ffdef30..b81454b2a0d0 100644
@@ -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

lib/Kconfig.ubsan +0 ~~-12~~

index e5372a13511d..31f38e7fe948 100644
@@ -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

Signature · 1 line

2.34.0.384.gca35af8252-goog