diff --git a/Makefile b/Makefile index 4425d87dd2face2c76ddf8099886b95d3f2ed5e4..4382cdb38fba5fe746e810bae2818b5262da374b 100644 --- a/Makefile +++ b/Makefile @@ -563,14 +563,6 @@ KBUILD_CFLAGS += -funsigned-char KBUILD_CFLAGS += -fno-common KBUILD_CFLAGS += -fno-PIE KBUILD_CFLAGS += -fno-strict-aliasing -KBUILD_CFLAGS += -Wall -KBUILD_CFLAGS += -Wundef -KBUILD_CFLAGS += -Werror=implicit-function-declaration -KBUILD_CFLAGS += -Werror=implicit-int -KBUILD_CFLAGS += -Werror=return-type -KBUILD_CFLAGS += -Werror=strict-prototypes -KBUILD_CFLAGS += -Wno-format-security -KBUILD_CFLAGS += -Wno-trigraphs KBUILD_CPPFLAGS := -D__KERNEL__ KBUILD_RUSTFLAGS := $(rust_common_flags) \ @@ -823,10 +815,6 @@ endif # may-sync-config endif # need-config KBUILD_CFLAGS += -fno-delete-null-pointer-checks -KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,) -KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation) -KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow) -KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE KBUILD_CFLAGS += -O2 @@ -857,40 +845,15 @@ ifdef CONFIG_READABLE_ASM KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining endif -ifneq ($(CONFIG_FRAME_WARN),0) -KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN) -endif - stackp-flags-y := -fno-stack-protector stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong KBUILD_CFLAGS += $(stackp-flags-y) -KBUILD_CPPFLAGS-$(CONFIG_WERROR) += -Werror -KBUILD_CPPFLAGS += $(KBUILD_CPPFLAGS-y) -KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds - KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y) -ifdef CONFIG_CC_IS_CLANG -# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable. -KBUILD_CFLAGS += -Wno-gnu -else - -# gcc inanely warns about local variables called 'main' -KBUILD_CFLAGS += -Wno-main -endif - -# These warnings generated too much noise in a regular build. -# Use make W=1 to enable them (see scripts/Makefile.extrawarn) -KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable) -KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable) - -# These result in bogus false positives -KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer) - ifdef CONFIG_FRAME_POINTER KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y @@ -1025,51 +988,12 @@ endif # arch Makefile may override CC so keep this after arch Makefile is included NOSTDINC_FLAGS += -nostdinc -# Variable Length Arrays (VLAs) should not be used anywhere in the kernel -KBUILD_CFLAGS += -Wvla - -# disable pointer signed / unsigned warnings in gcc 4.0 -KBUILD_CFLAGS += -Wno-pointer-sign - -# In order to make sure new function cast mismatches are not introduced -# in the kernel (to avoid tripping CFI checking), the kernel should be -# globally built with -Wcast-function-type. -KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type) - # To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE, # the kernel uses only C99 flexible arrays for dynamically sized trailing # arrays. Enforce this for everything that may examine structure sizes and # perform bounds checking. KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3) -# disable stringop warnings in gcc 8+ -KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation) - -# We'll want to enable this eventually, but it's not going away for 5.7 at least -KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow) - -# Another good warning that we'll want to enable eventually -KBUILD_CFLAGS += $(call cc-disable-warning, restrict) - -# Enabled with W=2, disabled by default as noisy -ifdef CONFIG_CC_IS_GCC -KBUILD_CFLAGS += -Wno-maybe-uninitialized -endif - -# The allocators already balk at large sizes, so silence the compiler -# warnings for bounds checks involving those possible values. While -# -Wno-alloc-size-larger-than would normally be used here, earlier versions -# of gcc (<9.1) weirdly don't handle the option correctly when _other_ -# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX -# doesn't work (as it is documented to), silently resolving to "0" prior to -# version 9.1 (and producing an error more recently). Numeric values larger -# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently -# ignored, continuing to default to PTRDIFF_MAX. So, left with no other -# choice, we must perform a versioned check to disable this warning. -# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au -KBUILD_CFLAGS-$(call 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 @@ -1081,18 +1005,6 @@ ifdef CONFIG_CC_IS_GCC KBUILD_CFLAGS += -fconserve-stack endif -# Prohibit date/time macros, which would make the build non-deterministic -KBUILD_CFLAGS += -Werror=date-time - -# enforce correct pointer usage -KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types) - -# Require designated initializers for all marked structures -KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init) - -# Warn if there is an enum types mismatch -KBUILD_CFLAGS += $(call cc-option,-Wenum-conversion) - # change __FILE__ to the relative path from the srctree KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 40cd13eca82e80f6de41e8d273a739d28c9c8e49..9cc0e52ebd7ebd850bd9ac76c2c92d2925551e38 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -6,6 +6,96 @@ # They are independent, and can be combined like W=12 or W=123e. # ========================================================================== +# Default set of warnings, always enabled +KBUILD_CFLAGS += -Wall +KBUILD_CFLAGS += -Wundef +KBUILD_CFLAGS += -Werror=implicit-function-declaration +KBUILD_CFLAGS += -Werror=implicit-int +KBUILD_CFLAGS += -Werror=return-type +KBUILD_CFLAGS += -Werror=strict-prototypes +KBUILD_CFLAGS += -Wno-format-security +KBUILD_CFLAGS += -Wno-trigraphs +KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,) +KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation) +KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow) +KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) + +ifneq ($(CONFIG_FRAME_WARN),0) +KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN) +endif + +KBUILD_CPPFLAGS-$(CONFIG_WERROR) += -Werror +KBUILD_CPPFLAGS += $(KBUILD_CPPFLAGS-y) +KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds + +ifdef CONFIG_CC_IS_CLANG +# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable. +KBUILD_CFLAGS += -Wno-gnu +else + +# gcc inanely warns about local variables called 'main' +KBUILD_CFLAGS += -Wno-main +endif + +# These warnings generated too much noise in a regular build. +# Use make W=1 to enable them (see scripts/Makefile.extrawarn) +KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable) +KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable) + +# These result in bogus false positives +KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer) + +# Variable Length Arrays (VLAs) should not be used anywhere in the kernel +KBUILD_CFLAGS += -Wvla + +# disable pointer signed / unsigned warnings in gcc 4.0 +KBUILD_CFLAGS += -Wno-pointer-sign + +# In order to make sure new function cast mismatches are not introduced +# in the kernel (to avoid tripping CFI checking), the kernel should be +# globally built with -Wcast-function-type. +KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type) + +# disable stringop warnings in gcc 8+ +KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation) + +# We'll want to enable this eventually, but it's not going away for 5.7 at least +KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow) + +# Another good warning that we'll want to enable eventually +KBUILD_CFLAGS += $(call cc-disable-warning, restrict) + +# Enabled with W=2, disabled by default as noisy +ifdef CONFIG_CC_IS_GCC +KBUILD_CFLAGS += -Wno-maybe-uninitialized +endif + +# The allocators already balk at large sizes, so silence the compiler +# warnings for bounds checks involving those possible values. While +# -Wno-alloc-size-larger-than would normally be used here, earlier versions +# of gcc (<9.1) weirdly don't handle the option correctly when _other_ +# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX +# doesn't work (as it is documented to), silently resolving to "0" prior to +# version 9.1 (and producing an error more recently). Numeric values larger +# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently +# ignored, continuing to default to PTRDIFF_MAX. So, left with no other +# choice, we must perform a versioned check to disable this warning. +# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au +KBUILD_CFLAGS-$(call gcc-min-version, 90100) += -Wno-alloc-size-larger-than +KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH) + +# Prohibit date/time macros, which would make the build non-deterministic +KBUILD_CFLAGS += -Werror=date-time + +# enforce correct pointer usage +KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types) + +# Require designated initializers for all marked structures +KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init) + +# Warn if there is an enum types mismatch +KBUILD_CFLAGS += $(call cc-option,-Wenum-conversion) + KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned) # backward compatibility