From 0cecd37daef3d57e6656c0023978d5ec2d7409c1 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Sat, 3 May 2025 11:46:18 -0700 Subject: gcc-plugins: Force full rebuild when plugins change There was no dependency between the plugins changing and the rest of the kernel being built. This could cause strange behaviors as instrumentation could vary between targets depending on when they were built. Generate a new header file, gcc-plugins.h, any time the GCC plugins change. Include the header file in compiler-version.h when its associated feature name, GCC_PLUGINS, is defined. This will be picked up by fixdep and force rebuilds where needed. Add a generic "touch" kbuild command, which will be used again in a following patch. Add a "normalize_path" string helper to make the "TOUCH" output less ugly. Link: https://lore.kernel.org/r/20250503184623.2572355-1-kees@kernel.org Tested-by: Nicolas Schier Reviewed-by: Nicolas Schier Signed-off-by: Kees Cook --- scripts/Makefile.lib | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'scripts/Makefile.lib') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 2fe73cda0bdd..6fc2a82ee3bb 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -296,6 +296,19 @@ $(foreach m, $1, \ $(addprefix $(obj)/, $(call suffix-search, $(patsubst $(obj)/%,%,$m), $2, $3)))) endef +# Remove ".." and "." from a path, without using "realpath" +# Usage: +# $(call normalize_path,path/to/../file) +define normalize_path +$(strip $(eval elements :=) \ +$(foreach elem,$(subst /, ,$1), \ + $(if $(filter-out .,$(elem)), \ + $(if $(filter ..,$(elem)), \ + $(eval elements := $(wordlist 2,$(words $(elements)),x $(elements))), \ + $(eval elements := $(elements) $(elem))))) \ +$(subst $(space),/,$(elements))) +endef + # Build commands # =========================================================================== # These are shared by some Makefile.* files. @@ -343,6 +356,11 @@ quiet_cmd_copy = COPY $@ $(obj)/%: $(src)/%_shipped $(call cmd,copy) +# Touch a file +# =========================================================================== +quiet_cmd_touch = TOUCH $(call normalize_path,$@) + cmd_touch = touch $@ + # Commands useful for building a boot image # =========================================================================== # -- cgit v1.2.3 From 8f81d8529e19c84b014e4239d2012373274d138d Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 14 May 2025 14:46:33 +0900 Subject: kbuild: move kbuild syntax processing to scripts/Makefile.build scripts/Makefile.lib is included by the following Makefiles: scripts/Makefile.build scripts/Makefile.modfinal scripts/Makefile.package scripts/Makefile.vmlinux scripts/Makefile.vmlinux_o However, the last four do not need to process Kbuild syntax such as obj-*, lib-*, subdir-*, etc. Move the relevant code to scripts/Makefile.build. Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier --- scripts/Makefile.lib | 84 ---------------------------------------------------- 1 file changed, 84 deletions(-) (limited to 'scripts/Makefile.lib') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 2fe73cda0bdd..2d3a8470cf39 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -1,89 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -# flags that take effect in current and sub directories -KBUILD_AFLAGS += $(subdir-asflags-y) -KBUILD_CFLAGS += $(subdir-ccflags-y) -KBUILD_RUSTFLAGS += $(subdir-rustflags-y) - -# Figure out what we need to build from the various variables -# =========================================================================== - -# When an object is listed to be built compiled-in and modular, -# only build the compiled-in version -obj-m := $(filter-out $(obj-y),$(obj-m)) - -# Libraries are always collected in one lib file. -# Filter out objects already built-in -lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m))) - -# Subdirectories we need to descend into -subdir-ym := $(sort $(subdir-y) $(subdir-m) \ - $(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m)))) - -# Handle objects in subdirs: -# - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and -# foo/modules.order -# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order -# -# Generate modules.order to determine modorder. Unfortunately, we don't have -# information about ordering between -y and -m subdirs. Just put -y's first. - -ifdef need-modorder -obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m)) -else -obj-m := $(filter-out %/, $(obj-m)) -endif - -ifdef need-builtin -obj-y := $(patsubst %/, %/built-in.a, $(obj-y)) -else -obj-y := $(filter-out %/, $(obj-y)) -endif - -# Expand $(foo-objs) $(foo-y) etc. by replacing their individuals -suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s)))) -# List composite targets that are constructed by combining other targets -multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $m))) -# List primitive targets that are compiled from source files -real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $(call suffix-search, $m, $2, $3), $m)) - -# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object -multi-obj-y := $(call multi-search, $(obj-y), .o, -objs -y) -multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m) -multi-obj-ym := $(multi-obj-y) $(multi-obj-m) - -# Replace multi-part objects by their individual parts, -# including built-in.a from subdirectories -real-obj-y := $(call real-search, $(obj-y), .o, -objs -y) -real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m) - -always-y += $(always-m) - -# hostprogs-always-y += foo -# ... is a shorthand for -# hostprogs += foo -# always-y += foo -hostprogs += $(hostprogs-always-y) $(hostprogs-always-m) -always-y += $(hostprogs-always-y) $(hostprogs-always-m) - -# userprogs-always-y is likewise. -userprogs += $(userprogs-always-y) $(userprogs-always-m) -always-y += $(userprogs-always-y) $(userprogs-always-m) - -# Add subdir path - -ifneq ($(obj),.) -extra-y := $(addprefix $(obj)/,$(extra-y)) -always-y := $(addprefix $(obj)/,$(always-y)) -targets := $(addprefix $(obj)/,$(targets)) -obj-m := $(addprefix $(obj)/,$(obj-m)) -lib-y := $(addprefix $(obj)/,$(lib-y)) -real-obj-y := $(addprefix $(obj)/,$(real-obj-y)) -real-obj-m := $(addprefix $(obj)/,$(real-obj-m)) -multi-obj-m := $(addprefix $(obj)/, $(multi-obj-m)) -subdir-ym := $(addprefix $(obj)/,$(subdir-ym)) -endif - # Finds the multi-part object the current object will be linked into. # If the object belongs to two or more multi-part objects, list them all. modname-multi = $(sort $(foreach m,$(multi-obj-ym),\ -- cgit v1.2.3 From 3bf67171e98272c918a41b899070e6e86741adc8 Mon Sep 17 00:00:00 2001 From: Alice Ryhl Date: Thu, 1 May 2025 12:16:16 +0000 Subject: kcov: rust: add flags for KCOV with Rust MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Rust code is currently not instrumented properly when KCOV is enabled. Thus, add the relevant flags to perform instrumentation correctly. This is necessary for efficient fuzzing of Rust code. The sanitizer-coverage features of LLVM have existed for long enough that they are available on any LLVM version supported by rustc, so we do not need any Kconfig feature detection. The coverage level is set to 3, as that is the level needed by trace-pc. We do not instrument `core` since when we fuzz the kernel, we are looking for bugs in the kernel, not the Rust stdlib. Link: https://lkml.kernel.org/r/20250501-rust-kcov-v2-1-b71e83e9779f@google.com Signed-off-by: Alice Ryhl Co-developed-by: Matthew Maurer Signed-off-by: Matthew Maurer Reviewed-by: Alexander Potapenko Tested-by: Aleksandr Nogikh Acked-by: Miguel Ojeda Cc: Andreas Hindborg Cc: Andrey Konovalov Cc: Benno Lossin Cc: Bill Wendling Cc: Björn Roy Baron Cc: Boqun Feng Cc: Danilo Krummrich Cc: Dmitriy Vyukov Cc: Gary Guo Cc: Justin Stitt Cc: Masahiro Yamada Cc: Nathan Chancellor Cc: Trevor Gross Signed-off-by: Andrew Morton --- scripts/Makefile.lib | 3 +++ 1 file changed, 3 insertions(+) (limited to 'scripts/Makefile.lib') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 2fe73cda0bdd..520905f19a9b 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -169,6 +169,9 @@ ifeq ($(CONFIG_KCOV),y) _c_flags += $(if $(patsubst n%,, \ $(KCOV_INSTRUMENT_$(target-stem).o)$(KCOV_INSTRUMENT)$(if $(is-kernel-object),$(CONFIG_KCOV_INSTRUMENT_ALL))), \ $(CFLAGS_KCOV)) +_rust_flags += $(if $(patsubst n%,, \ + $(KCOV_INSTRUMENT_$(target-stem).o)$(KCOV_INSTRUMENT)$(if $(is-kernel-object),$(CONFIG_KCOV_INSTRUMENT_ALL))), \ + $(RUSTFLAGS_KCOV)) endif # -- cgit v1.2.3