From 1cf5f151d25fcca94689efd91afa0253621fb33a Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 2 Feb 2022 16:05:16 -0700 Subject: Makefile.extrawarn: Move -Wunaligned-access to W=1 -Wunaligned-access is a new warning in clang that is default enabled for arm and arm64 under certain circumstances within the clang frontend (see LLVM commit below). On v5.17-rc2, an ARCH=arm allmodconfig build shows 1284 total/70 unique instances of this warning (most of the instances are in header files), which is quite noisy. To keep a normal build green through CONFIG_WERROR, only show this warning with W=1, which will allow automated build systems to catch new instances of the warning so that the total number can be driven down to zero eventually since catching unaligned accesses at compile time would be generally useful. Cc: stable@vger.kernel.org Link: https://github.com/llvm/llvm-project/commit/35737df4dcd28534bd3090157c224c19b501278a Link: https://github.com/ClangBuiltLinux/linux/issues/1569 Link: https://github.com/ClangBuiltLinux/linux/issues/1576 Signed-off-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Signed-off-by: Masahiro Yamada --- scripts/Makefile.extrawarn | 1 + 1 file changed, 1 insertion(+) (limited to 'scripts/Makefile.extrawarn') diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index d53825503874..8be892887d71 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -51,6 +51,7 @@ KBUILD_CFLAGS += -Wno-sign-compare KBUILD_CFLAGS += -Wno-format-zero-length KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare +KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access) endif endif -- cgit v1.2.3 From 1344794a59db2bd44b4919d2d75300fd3b1c2cd7 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 8 Mar 2022 22:56:12 +0100 Subject: Kbuild: add -Wno-shift-negative-value where -Wextra is used As a preparation for moving to -std=gnu11, turn off the -Wshift-negative-value option. This warning is enabled by gcc when building with -Wextra for c99 or higher, but not for c89. Since the kernel already relies on well-defined overflow behavior, the warning is not helpful and can simply be disabled in all locations that use -Wextra. Signed-off-by: Arnd Bergmann Acked-by: Jani Nikula Reviewed-by: Nathan Chancellor Tested-by: Sedat Dilek # LLVM/Clang v13.0.0 (x86-64) Signed-off-by: Masahiro Yamada --- drivers/gpu/drm/i915/Makefile | 1 + drivers/staging/greybus/tools/Makefile | 3 ++- fs/btrfs/Makefile | 1 + scripts/Makefile.extrawarn | 1 + 4 files changed, 5 insertions(+), 1 deletion(-) (limited to 'scripts/Makefile.extrawarn') diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index 1b62b9f65196..1618a6e0af4e 100644 --- a/drivers/gpu/drm/i915/Makefile +++ b/drivers/gpu/drm/i915/Makefile @@ -17,6 +17,7 @@ subdir-ccflags-y += -Wno-unused-parameter subdir-ccflags-y += -Wno-type-limits subdir-ccflags-y += -Wno-missing-field-initializers subdir-ccflags-y += -Wno-sign-compare +subdir-ccflags-y += -Wno-shift-negative-value subdir-ccflags-y += $(call cc-disable-warning, unused-but-set-variable) subdir-ccflags-y += $(call cc-disable-warning, frame-address) subdir-ccflags-$(CONFIG_DRM_I915_WERROR) += -Werror diff --git a/drivers/staging/greybus/tools/Makefile b/drivers/staging/greybus/tools/Makefile index ad0ae8053b79..a3bbd73171f2 100644 --- a/drivers/staging/greybus/tools/Makefile +++ b/drivers/staging/greybus/tools/Makefile @@ -12,7 +12,8 @@ CFLAGS += -std=gnu99 -Wall -Wextra -g \ -Wredundant-decls \ -Wcast-align \ -Wsign-compare \ - -Wno-missing-field-initializers + -Wno-missing-field-initializers \ + -Wno-shift-negative-value CC := $(CROSS_COMPILE)gcc diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index 4188ba3fd8c3..99f9995670ea 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -17,6 +17,7 @@ subdir-ccflags-y += $(condflags) subdir-ccflags-y += -Wno-missing-field-initializers subdir-ccflags-y += -Wno-sign-compare subdir-ccflags-y += -Wno-type-limits +subdir-ccflags-y += -Wno-shift-negative-value obj-$(CONFIG_BTRFS_FS) := btrfs.o diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 8be892887d71..650d0b8ceec3 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -36,6 +36,7 @@ KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation) KBUILD_CFLAGS += -Wno-missing-field-initializers KBUILD_CFLAGS += -Wno-sign-compare KBUILD_CFLAGS += -Wno-type-limits +KBUILD_CFLAGS += -Wno-shift-negative-value KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1 -- cgit v1.2.3 From c77d06e70d59cbc6e3c22bf644bb0b197a5fc182 Mon Sep 17 00:00:00 2001 From: Yann Droneaud Date: Fri, 8 Apr 2022 10:46:07 +0200 Subject: kbuild: support W=e to make build abort in case of warning When developing new code/feature, CONFIG_WERROR is most often turned off, especially for people using make W=12 to get more warnings. In such case, turning on -Werror temporarily would require switching on CONFIG_WERROR in the configuration, building, then switching off CONFIG_WERROR. For this use case, this patch introduces a new 'e' modifier to W= as a short hand for KCFLAGS+=-Werror" so that -Werror got added to the kernel (built-in) and modules' CFLAGS. Signed-off-by: Yann Droneaud Signed-off-by: Masahiro Yamada --- Makefile | 1 + scripts/Makefile.extrawarn | 13 +++++++++++-- 2 files changed, 12 insertions(+), 2 deletions(-) (limited to 'scripts/Makefile.extrawarn') diff --git a/Makefile b/Makefile index e915aacd02b0..235d68fa1470 100644 --- a/Makefile +++ b/Makefile @@ -1650,6 +1650,7 @@ help: @echo ' 1: warnings which may be relevant and do not occur too often' @echo ' 2: warnings which occur quite often but may still be relevant' @echo ' 3: more obscure warnings, can most likely be ignored' + @echo ' e: warnings are being treated as errors' @echo ' Multiple levels can be combined with W=12 or W=123' @echo '' @echo 'Execute "make" or "make all" to build all targets marked with [*] ' diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 650d0b8ceec3..f5f0d6f09053 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -2,8 +2,8 @@ # ========================================================================== # make W=... settings # -# There are three warning groups enabled by W=1, W=2, W=3. -# They are independent, and can be combined like W=12 or W=123. +# There are four warning groups enabled by W=1, W=2, W=3, and W=e +# They are independent, and can be combined like W=12 or W=123e. # ========================================================================== KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned) @@ -94,3 +94,12 @@ KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat) KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3 endif + +# +# W=e - error out on warnings +# +ifneq ($(findstring e, $(KBUILD_EXTRA_WARN)),) + +KBUILD_CFLAGS += -Werror + +endif -- cgit v1.2.3 From 258fafcd0683d9ccfa524129d489948ab3ddc24c Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Wed, 20 Jul 2022 16:23:32 -0700 Subject: Makefile.extrawarn: re-enable -Wformat for clang There's been an ongoing mission to re-enable the -Wformat warning for Clang. A previous attempt at enabling the warning showed that there were many instances of this warning throughout the codebase. The sheer amount of these warnings really polluted builds and thus -Wno-format was added to _temporarily_ toggle them off. After many patches the warning has largely been eradicated for x86, x86_64, arm, and arm64 on a variety of configs. The time to enable the warning has never been better as it seems for the first time we are ahead of them and can now solve them as they appear rather than tackling from a backlog. As to the root cause of this large backlog of warnings, Clang seems to pickup on some more nuanced cases of format warnings caused by implicit integer conversion as well as default argument promotions from printf-like functions. Link: https://github.com/ClangBuiltLinux/linux/issues/378 Suggested-by: Nick Desaulniers Signed-off-by: Justin Stitt Signed-off-by: Masahiro Yamada --- scripts/Makefile.extrawarn | 1 - 1 file changed, 1 deletion(-) (limited to 'scripts/Makefile.extrawarn') diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index f5f0d6f09053..9bbaf7112a9b 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -47,7 +47,6 @@ else ifdef CONFIG_CC_IS_CLANG KBUILD_CFLAGS += -Wno-initializer-overrides -KBUILD_CFLAGS += -Wno-format KBUILD_CFLAGS += -Wno-sign-compare KBUILD_CFLAGS += -Wno-format-zero-length KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) -- cgit v1.2.3 From 21f9c8a13bb2a0c24d9c6b86bc0896542a28c197 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 11 Aug 2022 08:40:01 -0700 Subject: Revert "Makefile.extrawarn: re-enable -Wformat for clang" This reverts commit 258fafcd0683d9ccfa524129d489948ab3ddc24c. The clang -Wformat warning is terminally broken, and the clang people can't seem to get their act together. This test program causes a warning with clang: #include int main(int argc, char **argv) { printf("%hhu\n", 'a'); } resulting in t.c:5:19: warning: format specifies type 'unsigned char' but the argument has type 'int' [-Wformat] printf("%hhu\n", 'a'); ~~~~ ^~~ %d and apparently clang people consider that a feature, because they don't want to face the reality of how either C character constants, C arithmetic, and C varargs functions work. The rest of the world just shakes their head at that kind of incompetence, and turns off -Wformat for clang again. And no, the "you should use a pointless cast to shut this up" is not a valid answer. That warning should not exist in the first place, or at least be optinal with some "-Wformat-me-harder" kind of option. [ Admittedly, there's also very little reason to *ever* use '%hh[ud]' in C, but what little reason there is is entirely about 'I want to see only the low 8 bits of the argument'. So I would suggest nobody ever use that format in the first place, but if they do, the clang behavious is simply always wrong. Because '%hhu' takes an 'int'. It's that simple. ] Reported-by: Sudip Mukherjee (Codethink) Cc: Nick Desaulniers Signed-off-by: Linus Torvalds --- scripts/Makefile.extrawarn | 1 + 1 file changed, 1 insertion(+) (limited to 'scripts/Makefile.extrawarn') diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 9bbaf7112a9b..f5f0d6f09053 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -47,6 +47,7 @@ else ifdef CONFIG_CC_IS_CLANG KBUILD_CFLAGS += -Wno-initializer-overrides +KBUILD_CFLAGS += -Wno-format KBUILD_CFLAGS += -Wno-sign-compare KBUILD_CFLAGS += -Wno-format-zero-length KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) -- cgit v1.2.3 From 370655bc183b1824ba623e621b58e8c2616c839c Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 10 Aug 2022 16:01:33 -0700 Subject: scripts/Makefile.extrawarn: Do not disable clang's -Wformat-zero-length There are no instances of this warning in the tree across several difference architectures and configurations. This was added by commit 26ea6bb1fef0 ("kbuild, LLVMLinux: Supress warnings unless W=1-3") back in 2014, where it might have been necessary, but there are no instances of it now so stop disabling it to increase warning coverage for clang. Signed-off-by: Nathan Chancellor Signed-off-by: Masahiro Yamada --- scripts/Makefile.extrawarn | 1 - 1 file changed, 1 deletion(-) (limited to 'scripts/Makefile.extrawarn') diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index f5f0d6f09053..0621c39a3955 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -49,7 +49,6 @@ ifdef CONFIG_CC_IS_CLANG KBUILD_CFLAGS += -Wno-initializer-overrides KBUILD_CFLAGS += -Wno-format KBUILD_CFLAGS += -Wno-sign-compare -KBUILD_CFLAGS += -Wno-format-zero-length KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access) -- cgit v1.2.3 From b0839b281c427e844143dba3893e25c83cdd6c17 Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Thu, 1 Sep 2022 10:59:13 -0700 Subject: Makefile.extrawarn: re-enable -Wformat for clang; take 2 -Wformat was recently re-enabled for builds with clang, then quickly re-disabled, due to concerns stemming from the frequency of default argument promotion related warning instances. commit 258fafcd0683 ("Makefile.extrawarn: re-enable -Wformat for clang") commit 21f9c8a13bb2 ("Revert "Makefile.extrawarn: re-enable -Wformat for clang"") ISO WG14 has ratified N2562 to address default argument promotion explicitly for printf, as part of the upcoming ISO C2X standard. The behavior of clang was changed in clang-16 to not warn for the cited cases in all language modes. Add a version check, so that users of clang-16 now get the full effect of -Wformat. For older clang versions, re-enable flags under the -Wformat group that way users still get some useful checks related to format strings, without noisy default argument promotion warnings. I intentionally omitted -Wformat-y2k and -Wformat-security from being re-enabled, which are also part of -Wformat in clang-16. Link: https://github.com/ClangBuiltLinux/linux/issues/378 Link: https://github.com/llvm/llvm-project/issues/57102 Link: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2562.pdf Suggested-by: Justin Stitt Suggested-by: Nathan Chancellor Suggested-by: Youngmin Nam Signed-off-by: Nick Desaulniers Reviewed-by: Masahiro Yamada Reviewed-by: Nathan Chancellor Signed-off-by: Linus Torvalds --- scripts/Makefile.extrawarn | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'scripts/Makefile.extrawarn') diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 0621c39a3955..6ae482158bc4 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -47,7 +47,19 @@ else ifdef CONFIG_CC_IS_CLANG KBUILD_CFLAGS += -Wno-initializer-overrides +# Clang before clang-16 would warn on default argument promotions. +ifeq ($(shell [ $(CONFIG_CLANG_VERSION) -lt 160000 ] && echo y),y) +# Disable -Wformat KBUILD_CFLAGS += -Wno-format +# Then re-enable flags that were part of the -Wformat group that aren't +# problematic. +KBUILD_CFLAGS += -Wformat-extra-args -Wformat-invalid-specifier +KBUILD_CFLAGS += -Wformat-zero-length -Wnonnull +# Requires clang-12+. +ifeq ($(shell [ $(CONFIG_CLANG_VERSION) -ge 120000 ] && echo y),y) +KBUILD_CFLAGS += -Wformat-insufficient-args +endif +endif KBUILD_CFLAGS += -Wno-sign-compare KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare -- cgit v1.2.3 From 88b61e3bff93f99712718db785b4aa0c1165f35c Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Mon, 19 Sep 2022 10:08:28 -0700 Subject: Makefile.compiler: replace cc-ifversion with compiler-specific macros cc-ifversion is GCC specific. Replace it with compiler specific variants. Update the users of cc-ifversion to use these new macros. Link: https://github.com/ClangBuiltLinux/linux/issues/350 Link: https://lore.kernel.org/llvm/CAGG=3QWSAUakO42kubrCap8fp-gm1ERJJAYXTnP1iHk_wrH=BQ@mail.gmail.com/ Suggested-by: Bill Wendling Reviewed-by: Nathan Chancellor Signed-off-by: Nick Desaulniers Signed-off-by: Masahiro Yamada --- Documentation/kbuild/makefiles.rst | 29 +++++++++++++++++------------ Makefile | 6 ++---- drivers/gpu/drm/amd/display/dc/dml/Makefile | 2 +- scripts/Makefile.compiler | 10 +++++++--- scripts/Makefile.extrawarn | 4 ++-- 5 files changed, 29 insertions(+), 22 deletions(-) (limited to 'scripts/Makefile.extrawarn') diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst index 11a296e52d68..ee7e3ea1fbe1 100644 --- a/Documentation/kbuild/makefiles.rst +++ b/Documentation/kbuild/makefiles.rst @@ -682,22 +682,27 @@ more details, with real examples. In the above example, -Wno-unused-but-set-variable will be added to KBUILD_CFLAGS only if gcc really accepts it. - cc-ifversion - cc-ifversion tests the version of $(CC) and equals the fourth parameter - if version expression is true, or the fifth (if given) if the version - expression is false. + gcc-min-version + gcc-min-version tests if the value of $(CONFIG_GCC_VERSION) is greater than + or equal to the provided value and evaluates to y if so. Example:: - #fs/reiserfs/Makefile - ccflags-y := $(call cc-ifversion, -lt, 0402, -O1) + cflags-$(call gcc-min-version, 70100) := -foo - In this example, ccflags-y will be assigned the value -O1 if the - $(CC) version is less than 4.2. - cc-ifversion takes all the shell operators: - -eq, -ne, -lt, -le, -gt, and -ge - The third parameter may be a text as in this example, but it may also - be an expanded variable or a macro. + In this example, cflags-y will be assigned the value -foo if $(CC) is gcc and + $(CONFIG_GCC_VERSION) is >= 7.1. + + clang-min-version + clang-min-version tests if the value of $(CONFIG_CLANG_VERSION) is greater + than or equal to the provided value and evaluates to y if so. + + Example:: + + cflags-$(call clang-min-version, 110000) := -foo + + In this example, cflags-y will be assigned the value -foo if $(CC) is clang + and $(CONFIG_CLANG_VERSION) is >= 11.0.0. cc-cross-prefix cc-cross-prefix is used to check if there exists a $(CC) in path with diff --git a/Makefile b/Makefile index b0a3cba5af94..09c9d9a005bd 100644 --- a/Makefile +++ b/Makefile @@ -790,7 +790,6 @@ KBUILD_CFLAGS += $(stackp-flags-y) KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds -KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH) ifdef CONFIG_CC_IS_CLANG KBUILD_CPPFLAGS += -Qunused-arguments @@ -972,7 +971,6 @@ ifdef CONFIG_CC_IS_GCC KBUILD_CFLAGS += -Wno-maybe-uninitialized endif -ifdef CONFIG_CC_IS_GCC # The allocators already balk at large sizes, so silence the compiler # warnings for bounds checks involving those possible values. While # -Wno-alloc-size-larger-than would normally be used here, earlier versions @@ -984,8 +982,8 @@ ifdef CONFIG_CC_IS_GCC # ignored, continuing to default to PTRDIFF_MAX. So, left with no other # choice, we must perform a versioned check to disable this warning. # https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au -KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0901, -Wno-alloc-size-larger-than) -endif +KBUILD_CFLAGS-$(call gcc-min-version, 90100) += -Wno-alloc-size-larger-than +KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH) # disable invalid "can't wrap" optimizations for signed / pointers KBUILD_CFLAGS += -fno-strict-overflow diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile b/drivers/gpu/drm/amd/display/dc/dml/Makefile index cb81ed2fbd53..d70838edba80 100644 --- a/drivers/gpu/drm/amd/display/dc/dml/Makefile +++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile @@ -34,7 +34,7 @@ dml_ccflags := -mhard-float -maltivec endif ifdef CONFIG_CC_IS_GCC -ifeq ($(call cc-ifversion, -lt, 0701, y), y) +ifneq ($(call gcc-min-version, 70100),y) IS_OLD_GCC = 1 endif endif diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler index 94d0d40cddb3..20d353dcabfb 100644 --- a/scripts/Makefile.compiler +++ b/scripts/Makefile.compiler @@ -61,9 +61,13 @@ cc-option-yn = $(call try-run,\ cc-disable-warning = $(call try-run,\ $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) -# cc-ifversion -# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1) -cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4)) +# gcc-min-version +# Usage: cflags-$(call gcc-min-version, 70100) += -foo +gcc-min-version = $(shell [ $(CONFIG_GCC_VERSION)0 -ge $(1)0 ] && echo y) + +# clang-min-version +# Usage: cflags-$(call clang-min-version, 110000) += -foo +clang-min-version = $(shell [ $(CONFIG_CLANG_VERSION)0 -ge $(1)0 ] && echo y) # ld-option # Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y) diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 6ae482158bc4..5769c1939d40 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -48,7 +48,7 @@ else ifdef CONFIG_CC_IS_CLANG KBUILD_CFLAGS += -Wno-initializer-overrides # Clang before clang-16 would warn on default argument promotions. -ifeq ($(shell [ $(CONFIG_CLANG_VERSION) -lt 160000 ] && echo y),y) +ifneq ($(call clang-min-version, 160000),y) # Disable -Wformat KBUILD_CFLAGS += -Wno-format # Then re-enable flags that were part of the -Wformat group that aren't @@ -56,7 +56,7 @@ KBUILD_CFLAGS += -Wno-format KBUILD_CFLAGS += -Wformat-extra-args -Wformat-invalid-specifier KBUILD_CFLAGS += -Wformat-zero-length -Wnonnull # Requires clang-12+. -ifeq ($(shell [ $(CONFIG_CLANG_VERSION) -ge 120000 ] && echo y),y) +ifeq ($(call clang-min-version, 120000),y) KBUILD_CFLAGS += -Wformat-insufficient-args endif endif -- cgit v1.2.3 From 2120635108b35ecad9c59c8b44f6cbdf4f98214e Mon Sep 17 00:00:00 2001 From: Sami Tolvanen Date: Fri, 30 Sep 2022 20:33:10 +0000 Subject: Makefile.extrawarn: Move -Wcast-function-type-strict to W=1 We enable -Wcast-function-type globally in the kernel to warn about mismatching types in function pointer casts. Compilers currently warn only about ABI incompability with this flag, but Clang 16 will enable a stricter version of the check by default that checks for an exact type match. This will be very noisy in the kernel, so disable -Wcast-function-type-strict without W=1 until the new warnings have been addressed. Cc: stable@vger.kernel.org Link: https://reviews.llvm.org/D134831 Link: https://github.com/ClangBuiltLinux/linux/issues/1724 Suggested-by: Nathan Chancellor Signed-off-by: Sami Tolvanen Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220930203310.4010564-1-samitolvanen@google.com --- scripts/Makefile.extrawarn | 1 + 1 file changed, 1 insertion(+) (limited to 'scripts/Makefile.extrawarn') diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 0621c39a3955..20df48637373 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -52,6 +52,7 @@ KBUILD_CFLAGS += -Wno-sign-compare KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access) +KBUILD_CFLAGS += $(call cc-disable-warning, cast-function-type-strict) endif endif -- cgit v1.2.3