mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Benno Lossin](/assets/img/avatar_default.png)
This API is used to facilitate safe pinned initialization of structs. It replaces cumbersome `unsafe` manual initialization with elegant safe macro invocations. Due to the size of this change it has been split into six commits: 1. This commit introducing the basic public interface: traits and functions to represent and create initializers. 2. Adds the `#[pin_data]`, `pin_init!`, `try_pin_init!`, `init!` and `try_init!` macros along with their internal types. 3. Adds the `InPlaceInit` trait that allows using an initializer to create an object inside of a `Box<T>` and other smart pointers. 4. Adds the `PinnedDrop` trait and adds macro support for it in the `#[pin_data]` macro. 5. Adds the `stack_pin_init!` macro allowing to pin-initialize a struct on the stack. 6. Adds the `Zeroable` trait and `init::zeroed` function to initialize types that have `0x00` in all bytes as a valid bit pattern. -- In this section the problem that the new pin-init API solves is outlined. This message describes the entirety of the API, not just the parts introduced in this commit. For a more granular explanation and additional information on pinning and this issue, view [1]. Pinning is Rust's way of enforcing the address stability of a value. When a value gets pinned it will be impossible for safe code to move it to another location. This is done by wrapping pointers to said object with `Pin<P>`. This wrapper prevents safe code from creating mutable references to the object, preventing mutable access, which is needed to move the value. `Pin<P>` provides `unsafe` functions to circumvent this and allow modifications regardless. It is then the programmer's responsibility to uphold the pinning guarantee. Many kernel data structures require a stable address, because there are foreign pointers to them which would get invalidated by moving the structure. Since these data structures are usually embedded in structs to use them, this pinning property propagates to the container struct. Resulting in most structs in both Rust and C code needing to be pinned. So if we want to have a `mutex` field in a Rust struct, this struct also needs to be pinned, because a `mutex` contains a `list_head`. Additionally initializing a `list_head` requires already having the final memory location available, because it is initialized by pointing it to itself. But this presents another challenge in Rust: values have to be initialized at all times. There is the `MaybeUninit<T>` wrapper type, which allows handling uninitialized memory, but this requires using the `unsafe` raw pointers and a casting the type to the initialized variant. This problem gets exacerbated when considering encapsulation and the normal safety requirements of Rust code. The fields of the Rust `Mutex<T>` should not be accessible to normal driver code. After all if anyone can modify the fields, there is no way to ensure the invariants of the `Mutex<T>` are upheld. But if the fields are inaccessible, then initialization of a `Mutex<T>` needs to be somehow achieved via a function or a macro. Because the `Mutex<T>` must be pinned in memory, the function cannot return it by value. It also cannot allocate a `Box` to put the `Mutex<T>` into, because that is an unnecessary allocation and indirection which would hurt performance. The solution in the rust tree (e.g. this commit: [2]) that is replaced by this API is to split this function into two parts: 1. A `new` function that returns a partially initialized `Mutex<T>`, 2. An `init` function that requires the `Mutex<T>` to be pinned and that fully initializes the `Mutex<T>`. Both of these functions have to be marked `unsafe`, since a call to `new` needs to be accompanied with a call to `init`, otherwise using the `Mutex<T>` could result in UB. And because calling `init` twice also is not safe. While `Mutex<T>` initialization cannot fail, other structs might also have to allocate memory, which would result in conditional successful initialization requiring even more manual accommodation work. Combine this with the problem of pin-projections -- the way of accessing fields of a pinned struct -- which also have an `unsafe` API, pinned initialization is riddled with `unsafe` resulting in very poor ergonomics. Not only that, but also having to call two functions possibly multiple lines apart makes it very easy to forget it outright or during refactoring. Here is an example of the current way of initializing a struct with two synchronization primitives (see [3] for the full example): struct SharedState { state_changed: CondVar, inner: Mutex<SharedStateInner>, } impl SharedState { fn try_new() -> Result<Arc<Self>> { let mut state = Pin::from(UniqueArc::try_new(Self { // SAFETY: `condvar_init!` is called below. state_changed: unsafe { CondVar::new() }, // SAFETY: `mutex_init!` is called below. inner: unsafe { Mutex::new(SharedStateInner { token_count: 0 }) }, })?); // SAFETY: `state_changed` is pinned when `state` is. let pinned = unsafe { state.as_mut().map_unchecked_mut(|s| &mut s.state_changed) }; kernel::condvar_init!(pinned, "SharedState::state_changed"); // SAFETY: `inner` is pinned when `state` is. let pinned = unsafe { state.as_mut().map_unchecked_mut(|s| &mut s.inner) }; kernel::mutex_init!(pinned, "SharedState::inner"); Ok(state.into()) } } The pin-init API of this patch solves this issue by providing a comprehensive solution comprised of macros and traits. Here is the example from above using the pin-init API: #[pin_data] struct SharedState { #[pin] state_changed: CondVar, #[pin] inner: Mutex<SharedStateInner>, } impl SharedState { fn new() -> impl PinInit<Self> { pin_init!(Self { state_changed <- new_condvar!("SharedState::state_changed"), inner <- new_mutex!( SharedStateInner { token_count: 0 }, "SharedState::inner", ), }) } } Notably the way the macro is used here requires no `unsafe` and thus comes with the usual Rust promise of safe code not introducing any memory violations. Additionally it is now up to the caller of `new()` to decide the memory location of the `SharedState`. They can choose at the moment `Arc<T>`, `Box<T>` or the stack. -- The API has the following architecture: 1. Initializer traits `PinInit<T, E>` and `Init<T, E>` that act like closures. 2. Macros to create these initializer traits safely. 3. Functions to allow manually writing initializers. The initializers (an `impl PinInit<T, E>`) receive a raw pointer pointing to uninitialized memory and their job is to fully initialize a `T` at that location. If initialization fails, they return an error (`E`) by value. This way of initializing cannot be safely exposed to the user, since it relies upon these properties outside of the control of the trait: - the memory location (slot) needs to be valid memory, - if initialization fails, the slot should not be read from, - the value in the slot should be pinned, so it cannot move and the memory cannot be deallocated until the value is dropped. This is why using an initializer is facilitated by another trait that ensures these requirements. These initializers can be created manually by just supplying a closure that fulfills the same safety requirements as `PinInit<T, E>`. But this is an `unsafe` operation. To allow safe initializer creation, the `pin_init!` is provided along with three other variants: `try_pin_init!`, `try_init!` and `init!`. These take a modified struct initializer as a parameter and generate a closure that initializes the fields in sequence. The macros take great care in upholding the safety requirements: - A shadowed struct type is used as the return type of the closure instead of `()`. This is to prevent early returns, as these would prevent full initialization. - To ensure every field is only initialized once, a normal struct initializer is placed in unreachable code. The type checker will emit errors if a field is missing or specified multiple times. - When initializing a field fails, the whole initializer will fail and automatically drop fields that have been initialized earlier. - Only the correct initializer type is allowed for unpinned fields. You cannot use a `impl PinInit<T, E>` to initialize a structurally not pinned field. To ensure the last point, an additional macro `#[pin_data]` is needed. This macro annotates the struct itself and the user specifies structurally pinned and not pinned fields. Because dropping a pinned struct is also not allowed to break the pinning invariants, another macro attribute `#[pinned_drop]` is needed. This macro is introduced in a following commit. These two macros also have mechanisms to ensure the overall safety of the API. Additionally, they utilize a combined proc-macro, declarative macro design: first a proc-macro enables the outer attribute syntax `#[...]` and does some important pre-parsing. Notably this prepares the generics such that the declarative macro can handle them using token trees. Then the actual parsing of the structure and the emission of code is handled by a declarative macro. For pin-projections the crates `pin-project` [4] and `pin-project-lite` [5] had been considered, but were ultimately rejected: - `pin-project` depends on `syn` [6] which is a very big dependency, around 50k lines of code. - `pin-project-lite` is a more reasonable 5k lines of code, but contains a very complex declarative macro to parse generics. On top of that it would require modification that would need to be maintained independently. Link: https://rust-for-linux.com/the-safe-pinned-initialization-problem [1] Link:0a04dc4ddd
[2] Link:f509ede33f/samples/rust/rust_miscdev.rs
[3] Link: https://crates.io/crates/pin-project [4] Link: https://crates.io/crates/pin-project-lite [5] Link: https://crates.io/crates/syn [6] Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Wedson Almeida Filho <wedsonaf@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-7-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
527 lines
18 KiB
Makefile
527 lines
18 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
|
|
# ==========================================================================
|
|
# Building
|
|
# ==========================================================================
|
|
|
|
src := $(obj)
|
|
|
|
PHONY := $(obj)/
|
|
$(obj)/:
|
|
|
|
# Init all relevant variables used in kbuild files so
|
|
# 1) they have correct type
|
|
# 2) they do not inherit any value from the environment
|
|
obj-y :=
|
|
obj-m :=
|
|
lib-y :=
|
|
lib-m :=
|
|
always-y :=
|
|
always-m :=
|
|
targets :=
|
|
subdir-y :=
|
|
subdir-m :=
|
|
EXTRA_AFLAGS :=
|
|
EXTRA_CFLAGS :=
|
|
EXTRA_CPPFLAGS :=
|
|
EXTRA_LDFLAGS :=
|
|
asflags-y :=
|
|
ccflags-y :=
|
|
rustflags-y :=
|
|
cppflags-y :=
|
|
ldflags-y :=
|
|
|
|
subdir-asflags-y :=
|
|
subdir-ccflags-y :=
|
|
|
|
# Read auto.conf if it exists, otherwise ignore
|
|
-include include/config/auto.conf
|
|
|
|
include $(srctree)/scripts/Kbuild.include
|
|
include $(srctree)/scripts/Makefile.compiler
|
|
include $(kbuild-file)
|
|
include $(srctree)/scripts/Makefile.lib
|
|
|
|
# Do not include hostprogs rules unless needed.
|
|
# $(sort ...) is used here to remove duplicated words and excessive spaces.
|
|
hostprogs := $(sort $(hostprogs))
|
|
ifneq ($(hostprogs),)
|
|
include $(srctree)/scripts/Makefile.host
|
|
endif
|
|
|
|
# Do not include userprogs rules unless needed.
|
|
# $(sort ...) is used here to remove duplicated words and excessive spaces.
|
|
userprogs := $(sort $(userprogs))
|
|
ifneq ($(userprogs),)
|
|
include $(srctree)/scripts/Makefile.userprogs
|
|
endif
|
|
|
|
ifndef obj
|
|
$(warning kbuild: Makefile.build is included improperly)
|
|
endif
|
|
|
|
ifeq ($(need-modorder),)
|
|
ifneq ($(obj-m),)
|
|
$(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
|
|
$(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
|
|
endif
|
|
endif
|
|
|
|
# ===========================================================================
|
|
|
|
# subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
|
|
subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
|
|
subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
|
|
|
|
targets-for-builtin := $(extra-y)
|
|
|
|
ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
|
|
targets-for-builtin += $(obj)/lib.a
|
|
endif
|
|
|
|
ifdef need-builtin
|
|
targets-for-builtin += $(obj)/built-in.a
|
|
endif
|
|
|
|
targets-for-modules := $(foreach x, o mod $(if $(CONFIG_TRIM_UNUSED_KSYMS), usyms), \
|
|
$(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
|
|
|
|
ifdef need-modorder
|
|
targets-for-modules += $(obj)/modules.order
|
|
endif
|
|
|
|
targets += $(targets-for-builtin) $(targets-for-modules)
|
|
|
|
# Linus' kernel sanity checking tool
|
|
ifeq ($(KBUILD_CHECKSRC),1)
|
|
quiet_cmd_checksrc = CHECK $<
|
|
cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
|
|
else ifeq ($(KBUILD_CHECKSRC),2)
|
|
quiet_cmd_force_checksrc = CHECK $<
|
|
cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
|
|
endif
|
|
|
|
ifneq ($(KBUILD_EXTRA_WARN),)
|
|
cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
|
|
endif
|
|
|
|
# Compile C sources (.c)
|
|
# ---------------------------------------------------------------------------
|
|
|
|
quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
|
|
cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
|
|
|
|
$(obj)/%.s: $(src)/%.c FORCE
|
|
$(call if_changed_dep,cc_s_c)
|
|
|
|
quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
|
|
cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
|
|
|
|
$(obj)/%.i: $(src)/%.c FORCE
|
|
$(call if_changed_dep,cpp_i_c)
|
|
|
|
genksyms = scripts/genksyms/genksyms \
|
|
$(if $(1), -T $(2)) \
|
|
$(if $(KBUILD_PRESERVE), -p) \
|
|
-r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null)
|
|
|
|
# These mirror gensymtypes_S and co below, keep them in synch.
|
|
cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
|
|
|
|
quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
|
|
cmd_cc_symtypes_c = $(call cmd_gensymtypes_c,true,$@) >/dev/null
|
|
|
|
$(obj)/%.symtypes : $(src)/%.c FORCE
|
|
$(call cmd,cc_symtypes_c)
|
|
|
|
# LLVM assembly
|
|
# Generate .ll files from .c
|
|
quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
|
|
cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -fno-discard-value-names -o $@ $<
|
|
|
|
$(obj)/%.ll: $(src)/%.c FORCE
|
|
$(call if_changed_dep,cc_ll_c)
|
|
|
|
# C (.c) files
|
|
# The C file is compiled and updated dependency information is generated.
|
|
# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
|
|
|
|
is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)
|
|
|
|
# When a module consists of a single object, there is no reason to keep LLVM IR.
|
|
# Make $(LD) covert LLVM IR to ELF here.
|
|
ifdef CONFIG_LTO_CLANG
|
|
cmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
|
|
endif
|
|
|
|
quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
|
|
cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \
|
|
$(cmd_ld_single_m) \
|
|
$(cmd_objtool)
|
|
|
|
ifdef CONFIG_MODVERSIONS
|
|
# When module versioning is enabled the following steps are executed:
|
|
# o compile a <file>.o from <file>.c
|
|
# o if <file>.o doesn't contain a __ksymtab version, i.e. does
|
|
# not export symbols, it's done.
|
|
# o otherwise, we calculate symbol versions using the good old
|
|
# genksyms on the preprocessed source and dump them into the .cmd file.
|
|
# o modpost will extract versions from that file and create *.c files that will
|
|
# be compiled and linked to the kernel and/or modules.
|
|
|
|
gen_symversions = \
|
|
if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \
|
|
$(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
|
|
>> $(dot-target).cmd; \
|
|
fi
|
|
|
|
cmd_gen_symversions_c = $(call gen_symversions,c)
|
|
|
|
endif
|
|
|
|
ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
|
|
# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
|
|
ifdef BUILD_C_RECORDMCOUNT
|
|
ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
|
|
RECORDMCOUNT_FLAGS = -w
|
|
endif
|
|
# Due to recursion, we must skip empty.o.
|
|
# The empty.o file is created in the make process in order to determine
|
|
# the target endianness and word size. It is made before all other C
|
|
# files, including recordmcount.
|
|
sub_cmd_record_mcount = \
|
|
if [ $(@) != "scripts/mod/empty.o" ]; then \
|
|
$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
|
|
fi;
|
|
recordmcount_source := $(srctree)/scripts/recordmcount.c \
|
|
$(srctree)/scripts/recordmcount.h
|
|
else
|
|
sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
|
|
"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
|
|
"$(if $(CONFIG_64BIT),64,32)" \
|
|
"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
|
|
"$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
|
|
"$(if $(part-of-module),1,0)" "$(@)";
|
|
recordmcount_source := $(srctree)/scripts/recordmcount.pl
|
|
endif # BUILD_C_RECORDMCOUNT
|
|
cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
|
|
$(sub_cmd_record_mcount))
|
|
endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
|
|
|
|
# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
|
|
# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
|
|
# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
|
|
|
|
is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
|
|
|
|
$(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
|
|
|
|
ifdef CONFIG_TRIM_UNUSED_KSYMS
|
|
cmd_gen_ksymdeps = \
|
|
$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
|
|
endif
|
|
|
|
cmd_check_local_export = $(srctree)/scripts/check-local-export $@
|
|
|
|
ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
|
|
cmd_warn_shared_object = $(if $(word 2, $(modname-multi)),$(warning $(kbuild-file): $*.o is added to multiple modules: $(modname-multi)))
|
|
endif
|
|
|
|
define rule_cc_o_c
|
|
$(call cmd_and_fixdep,cc_o_c)
|
|
$(call cmd,gen_ksymdeps)
|
|
$(call cmd,check_local_export)
|
|
$(call cmd,checksrc)
|
|
$(call cmd,checkdoc)
|
|
$(call cmd,gen_objtooldep)
|
|
$(call cmd,gen_symversions_c)
|
|
$(call cmd,record_mcount)
|
|
$(call cmd,warn_shared_object)
|
|
endef
|
|
|
|
define rule_as_o_S
|
|
$(call cmd_and_fixdep,as_o_S)
|
|
$(call cmd,gen_ksymdeps)
|
|
$(call cmd,check_local_export)
|
|
$(call cmd,gen_objtooldep)
|
|
$(call cmd,gen_symversions_S)
|
|
$(call cmd,warn_shared_object)
|
|
endef
|
|
|
|
# Built-in and composite module parts
|
|
$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
|
|
$(call if_changed_rule,cc_o_c)
|
|
$(call cmd,force_checksrc)
|
|
|
|
# To make this rule robust against "Argument list too long" error,
|
|
# ensure to add $(obj)/ prefix by a shell command.
|
|
cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \
|
|
$(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
|
|
|
|
$(obj)/%.mod: FORCE
|
|
$(call if_changed,mod)
|
|
|
|
# List module undefined symbols
|
|
cmd_undefined_syms = $(NM) $< | sed -n 's/^ *U //p' > $@
|
|
|
|
$(obj)/%.usyms: $(obj)/%.o FORCE
|
|
$(call if_changed,undefined_syms)
|
|
|
|
quiet_cmd_cc_lst_c = MKLST $@
|
|
cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
|
|
$(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
|
|
System.map $(OBJDUMP) > $@
|
|
|
|
$(obj)/%.lst: $(src)/%.c FORCE
|
|
$(call if_changed_dep,cc_lst_c)
|
|
|
|
# Compile Rust sources (.rs)
|
|
# ---------------------------------------------------------------------------
|
|
|
|
rust_allowed_features := core_ffi_c,explicit_generic_args_with_impl_trait,new_uninit,pin_macro
|
|
|
|
rust_common_cmd = \
|
|
RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
|
|
-Zallow-features=$(rust_allowed_features) \
|
|
-Zcrate-attr=no_std \
|
|
-Zcrate-attr='feature($(rust_allowed_features))' \
|
|
--extern alloc --extern kernel \
|
|
--crate-type rlib -L $(objtree)/rust/ \
|
|
--crate-name $(basename $(notdir $@)) \
|
|
--emit=dep-info=$(depfile)
|
|
|
|
# `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
|
|
# will be used. We explicitly request `-Ccodegen-units=1` in any case, and
|
|
# the compiler shows a warning if it is not 1. However, if we ever stop
|
|
# requesting it explicitly and we start using some other `--emit` that does not
|
|
# imply it (and for which codegen is performed), then we would be out of sync,
|
|
# i.e. the outputs we would get for the different single targets (e.g. `.ll`)
|
|
# would not match each other.
|
|
|
|
quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
|
|
cmd_rustc_o_rs = $(rust_common_cmd) --emit=obj=$@ $<
|
|
|
|
$(obj)/%.o: $(src)/%.rs FORCE
|
|
$(call if_changed_dep,rustc_o_rs)
|
|
|
|
quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
|
|
cmd_rustc_rsi_rs = \
|
|
$(rust_common_cmd) -Zunpretty=expanded $< >$@; \
|
|
command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@
|
|
|
|
$(obj)/%.rsi: $(src)/%.rs FORCE
|
|
$(call if_changed_dep,rustc_rsi_rs)
|
|
|
|
quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
|
|
cmd_rustc_s_rs = $(rust_common_cmd) --emit=asm=$@ $<
|
|
|
|
$(obj)/%.s: $(src)/%.rs FORCE
|
|
$(call if_changed_dep,rustc_s_rs)
|
|
|
|
quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
|
|
cmd_rustc_ll_rs = $(rust_common_cmd) --emit=llvm-ir=$@ $<
|
|
|
|
$(obj)/%.ll: $(src)/%.rs FORCE
|
|
$(call if_changed_dep,rustc_ll_rs)
|
|
|
|
# Compile assembler sources (.S)
|
|
# ---------------------------------------------------------------------------
|
|
|
|
# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
|
|
# or a file that it includes, in order to get versioned symbols. We build a
|
|
# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
|
|
# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
|
|
#
|
|
# This is convoluted. The .S file must first be preprocessed to run guards and
|
|
# expand names, then the resulting exports must be constructed into plain
|
|
# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
|
|
# to make the genksyms input.
|
|
#
|
|
# These mirror gensymtypes_c and co above, keep them in synch.
|
|
cmd_gensymtypes_S = \
|
|
{ echo "\#include <linux/kernel.h>" ; \
|
|
echo "\#include <asm/asm-prototypes.h>" ; \
|
|
$(CPP) $(a_flags) $< | \
|
|
grep "\<___EXPORT_SYMBOL\>" | \
|
|
sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
|
|
$(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
|
|
|
|
quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
|
|
cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
|
|
|
|
$(obj)/%.symtypes : $(src)/%.S FORCE
|
|
$(call cmd,cc_symtypes_S)
|
|
|
|
|
|
quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
|
|
cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
|
|
|
|
$(obj)/%.s: $(src)/%.S FORCE
|
|
$(call if_changed_dep,cpp_s_S)
|
|
|
|
quiet_cmd_as_o_S = AS $(quiet_modtag) $@
|
|
cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
|
|
|
|
ifdef CONFIG_ASM_MODVERSIONS
|
|
|
|
# versioning matches the C process described above, with difference that
|
|
# we parse asm-prototypes.h C header to get function definitions.
|
|
|
|
cmd_gen_symversions_S = $(call gen_symversions,S)
|
|
|
|
endif
|
|
|
|
$(obj)/%.o: $(src)/%.S FORCE
|
|
$(call if_changed_rule,as_o_S)
|
|
|
|
targets += $(filter-out $(subdir-builtin), $(real-obj-y))
|
|
targets += $(filter-out $(subdir-modorder), $(real-obj-m))
|
|
targets += $(real-dtb-y) $(lib-y) $(always-y)
|
|
|
|
# Linker scripts preprocessor (.lds.S -> .lds)
|
|
# ---------------------------------------------------------------------------
|
|
quiet_cmd_cpp_lds_S = LDS $@
|
|
cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
|
|
-D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
|
|
|
|
$(obj)/%.lds: $(src)/%.lds.S FORCE
|
|
$(call if_changed_dep,cpp_lds_S)
|
|
|
|
# ASN.1 grammar
|
|
# ---------------------------------------------------------------------------
|
|
quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
|
|
cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
|
|
$(basename $@).c $(basename $@).h
|
|
|
|
$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
|
|
$(call cmd,asn1_compiler)
|
|
|
|
# Build the compiled-in targets
|
|
# ---------------------------------------------------------------------------
|
|
|
|
# To build objects in subdirs, we need to descend into the directories
|
|
$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
|
|
$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
|
|
|
|
#
|
|
# Rule to compile a set of .o files into one .a file (without symbol table)
|
|
#
|
|
# To make this rule robust against "Argument list too long" error,
|
|
# remove $(obj)/ prefix, and restore it by a shell command.
|
|
|
|
quiet_cmd_ar_builtin = AR $@
|
|
cmd_ar_builtin = rm -f $@; \
|
|
$(if $(real-prereqs), printf "$(obj)/%s " $(patsubst $(obj)/%,%,$(real-prereqs)) | xargs) \
|
|
$(AR) cDPrST $@
|
|
|
|
$(obj)/built-in.a: $(real-obj-y) FORCE
|
|
$(call if_changed,ar_builtin)
|
|
|
|
#
|
|
# Rule to create modules.order file
|
|
#
|
|
# Create commands to either record .ko file or cat modules.order from
|
|
# a subdirectory
|
|
# Add $(obj-m) as the prerequisite to avoid updating the timestamp of
|
|
# modules.order unless contained modules are updated.
|
|
|
|
cmd_modules_order = { $(foreach m, $(real-prereqs), \
|
|
$(if $(filter %/modules.order, $m), cat $m, echo $m);) :; } \
|
|
> $@
|
|
|
|
$(obj)/modules.order: $(obj-m) FORCE
|
|
$(call if_changed,modules_order)
|
|
|
|
#
|
|
# Rule to compile a set of .o files into one .a file (with symbol table)
|
|
#
|
|
|
|
$(obj)/lib.a: $(lib-y) FORCE
|
|
$(call if_changed,ar)
|
|
|
|
quiet_cmd_ld_multi_m = LD [M] $@
|
|
cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@) $(cmd_objtool)
|
|
|
|
define rule_ld_multi_m
|
|
$(call cmd_and_savecmd,ld_multi_m)
|
|
$(call cmd,gen_objtooldep)
|
|
endef
|
|
|
|
$(multi-obj-m): objtool-enabled := $(delay-objtool)
|
|
$(multi-obj-m): part-of-module := y
|
|
$(multi-obj-m): %.o: %.mod FORCE
|
|
$(call if_changed_rule,ld_multi_m)
|
|
$(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
|
|
|
|
# Add intermediate targets:
|
|
# When building objects with specific suffix patterns, add intermediate
|
|
# targets that the final targets are derived from.
|
|
intermediate_targets = $(foreach sfx, $(2), \
|
|
$(patsubst %$(strip $(1)),%$(sfx), \
|
|
$(filter %$(strip $(1)), $(targets))))
|
|
# %.asn1.o <- %.asn1.[ch] <- %.asn1
|
|
# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
|
|
# %.dtbo.o <- %.dtbo.S <- %.dtbo <- %.dtso
|
|
# %.lex.o <- %.lex.c <- %.l
|
|
# %.tab.o <- %.tab.[ch] <- %.y
|
|
targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
|
|
$(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
|
|
$(call intermediate_targets, .dtbo.o, .dtbo.S .dtbo) \
|
|
$(call intermediate_targets, .lex.o, .lex.c) \
|
|
$(call intermediate_targets, .tab.o, .tab.c .tab.h)
|
|
|
|
# Build
|
|
# ---------------------------------------------------------------------------
|
|
|
|
$(obj)/: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
|
|
$(if $(KBUILD_MODULES), $(targets-for-modules)) \
|
|
$(subdir-ym) $(always-y)
|
|
@:
|
|
|
|
# Single targets
|
|
# ---------------------------------------------------------------------------
|
|
|
|
single-subdirs := $(foreach d, $(subdir-ym), $(if $(filter $d/%, $(MAKECMDGOALS)), $d))
|
|
single-subdir-goals := $(filter $(addsuffix /%, $(single-subdirs)), $(MAKECMDGOALS))
|
|
|
|
$(single-subdir-goals): $(single-subdirs)
|
|
@:
|
|
|
|
# Descending
|
|
# ---------------------------------------------------------------------------
|
|
|
|
PHONY += $(subdir-ym)
|
|
$(subdir-ym):
|
|
$(Q)$(MAKE) $(build)=$@ \
|
|
need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
|
|
need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) \
|
|
$(filter $@/%, $(single-subdir-goals))
|
|
|
|
# Add FORCE to the prequisites of a target to force it to be always rebuilt.
|
|
# ---------------------------------------------------------------------------
|
|
|
|
PHONY += FORCE
|
|
|
|
FORCE:
|
|
|
|
targets += $(filter-out $(single-subdir-goals), $(MAKECMDGOALS))
|
|
targets := $(filter-out $(PHONY), $(targets))
|
|
|
|
# Read all saved command lines and dependencies for the $(targets) we
|
|
# may be building above, using $(if_changed{,_dep}). As an
|
|
# optimization, we don't need to read them if the target does not
|
|
# exist, we will rebuild anyway in that case.
|
|
|
|
existing-targets := $(wildcard $(sort $(targets)))
|
|
|
|
-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
|
|
|
|
# Create directories for object files if they do not exist
|
|
obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
|
|
# If targets exist, their directories apparently exist. Skip mkdir.
|
|
existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
|
|
obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
|
|
ifneq ($(obj-dirs),)
|
|
$(shell mkdir -p $(obj-dirs))
|
|
endif
|
|
|
|
.PHONY: $(PHONY)
|