6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Masahiro Yamada masahiroy@kernel.org
[ Upstream commit 295d8398c67e314d99bb070f38883f83fe94a97a ]
In Kbuild, two different rules must not write to the same file, but it happens when compiling rust source files.
For example, set CONFIG_SAMPLE_RUST_MINIMAL=m and run the following:
$ make -j$(nproc) samples/rust/rust_minimal.o samples/rust/rust_minimal.rsi \ samples/rust/rust_minimal.s samples/rust/rust_minimal.ll [snip] RUSTC [M] samples/rust/rust_minimal.o RUSTC [M] samples/rust/rust_minimal.rsi RUSTC [M] samples/rust/rust_minimal.s RUSTC [M] samples/rust/rust_minimal.ll mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory make[3]: *** [scripts/Makefile.build:334: samples/rust/rust_minimal.ll] Error 1 make[3]: *** Waiting for unfinished jobs.... mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory make[3]: *** [scripts/Makefile.build:309: samples/rust/rust_minimal.o] Error 1 mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory make[3]: *** [scripts/Makefile.build:326: samples/rust/rust_minimal.s] Error 1 make[2]: *** [scripts/Makefile.build:504: samples/rust] Error 2 make[1]: *** [scripts/Makefile.build:504: samples] Error 2 make: *** [Makefile:2008: .] Error 2
The reason for the error is that 4 threads running in parallel renames the same file, samples/rust/rust_minimal.d.
This does not happen when compiling C or assembly files because -Wp,-MMD,$(depfile) explicitly specifies the dependency filepath. $(depfile) is a unique path for each target.
Currently, rustc is only given --out-dir and --emit=<list-of-types> So, all the rust build rules output the dep-info into the default <CRATE_NAME>.d, which causes the path conflict.
Fortunately, the --emit option is able to specify the output path individually, with the form --emit=<type>=<path>.
Add --emit=dep-info=$(depfile) to the common part. Also, remove the redundant --out-dir because the output path is specified for each type.
The code gets much cleaner because we do not need to rename *.d files.
Signed-off-by: Masahiro Yamada masahiroy@kernel.org Reviewed-by: Miguel Ojeda ojeda@kernel.org Tested-by: Miguel Ojeda ojeda@kernel.org Reviewed-by: Vincenzo Palazzo vincenzopalazzodev@gmail.com Stable-dep-of: ded103c7eb23 ("kbuild: rust: force `alloc` extern to allow "empty" Rust files") Signed-off-by: Sasha Levin sashal@kernel.org --- rust/Makefile | 11 +++++------ scripts/Makefile.build | 14 +++++++------- scripts/Makefile.host | 7 +++---- 3 files changed, 15 insertions(+), 17 deletions(-)
diff --git a/rust/Makefile b/rust/Makefile index 7700d3853404e..6d0c0e9757f21 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -322,10 +322,9 @@ $(obj)/exports_kernel_generated.h: $(obj)/kernel.o FORCE quiet_cmd_rustc_procmacro = $(RUSTC_OR_CLIPPY_QUIET) P $@ cmd_rustc_procmacro = \ $(RUSTC_OR_CLIPPY) $(rust_common_flags) \ - --emit=dep-info,link --extern proc_macro \ - --crate-type proc-macro --out-dir $(objtree)/$(obj) \ + --emit=dep-info=$(depfile) --emit=link=$@ --extern proc_macro \ + --crate-type proc-macro \ --crate-name $(patsubst lib%.so,%,$(notdir $@)) $<; \ - mv $(objtree)/$(obj)/$(patsubst lib%.so,%,$(notdir $@)).d $(depfile); \ sed -i '/^#/d' $(depfile)
# Procedural macros can only be used with the `rustc` that compiled it. @@ -339,10 +338,10 @@ quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L OBJTREE=$(abspath $(objtree)) \ $(if $(skip_clippy),$(RUSTC),$(RUSTC_OR_CLIPPY)) \ $(filter-out $(skip_flags),$(rust_flags) $(rustc_target_flags)) \ - --emit=dep-info,obj,metadata --crate-type rlib \ - --out-dir $(objtree)/$(obj) -L$(objtree)/$(obj) \ + --emit=dep-info=$(depfile) --emit=obj=$@ \ + --emit=metadata=$(dir $@)$(patsubst %.o,lib%.rmeta,$(notdir $@)) \ + --crate-type rlib -L$(objtree)/$(obj) \ --crate-name $(patsubst %.o,%,$(notdir $@)) $<; \ - mv $(objtree)/$(obj)/$(patsubst %.o,%,$(notdir $@)).d $(depfile); \ sed -i '/^#/d' $(depfile) \ $(if $(rustc_objcopy),;$(OBJCOPY) $(rustc_objcopy) $@)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 41f3602fc8de7..9ae02542b9389 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -283,11 +283,11 @@ rust_common_cmd = \ -Zcrate-attr=no_std \ -Zcrate-attr='feature($(rust_allowed_features))' \ --extern alloc --extern kernel \ - --crate-type rlib --out-dir $(obj) -L $(objtree)/rust/ \ - --crate-name $(basename $(notdir $@)) + --crate-type rlib -L $(objtree)/rust/ \ + --crate-name $(basename $(notdir $@)) \ + --emit=dep-info=$(depfile)
rust_handle_depfile = \ - mv $(obj)/$(basename $(notdir $@)).d $(depfile); \ sed -i '/^#/d' $(depfile)
# `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit @@ -300,7 +300,7 @@ rust_handle_depfile = \
quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@ cmd_rustc_o_rs = \ - $(rust_common_cmd) --emit=dep-info,obj $<; \ + $(rust_common_cmd) --emit=obj=$@ $<; \ $(rust_handle_depfile)
$(obj)/%.o: $(src)/%.rs FORCE @@ -308,7 +308,7 @@ $(obj)/%.o: $(src)/%.rs FORCE
quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@ cmd_rustc_rsi_rs = \ - $(rust_common_cmd) --emit=dep-info -Zunpretty=expanded $< >$@; \ + $(rust_common_cmd) -Zunpretty=expanded $< >$@; \ command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@; \ $(rust_handle_depfile)
@@ -317,7 +317,7 @@ $(obj)/%.rsi: $(src)/%.rs FORCE
quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@ cmd_rustc_s_rs = \ - $(rust_common_cmd) --emit=dep-info,asm $<; \ + $(rust_common_cmd) --emit=asm=$@ $<; \ $(rust_handle_depfile)
$(obj)/%.s: $(src)/%.rs FORCE @@ -325,7 +325,7 @@ $(obj)/%.s: $(src)/%.rs FORCE
quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@ cmd_rustc_ll_rs = \ - $(rust_common_cmd) --emit=dep-info,llvm-ir $<; \ + $(rust_common_cmd) --emit=llvm-ir=$@ $<; \ $(rust_handle_depfile)
$(obj)/%.ll: $(src)/%.rs FORCE diff --git a/scripts/Makefile.host b/scripts/Makefile.host index 4a02b31cd1029..d812241144d44 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -86,7 +86,8 @@ hostc_flags = -Wp,-MMD,$(depfile) \ hostcxx_flags = -Wp,-MMD,$(depfile) \ $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \ $(HOSTCXXFLAGS_$(target-stem).o) -hostrust_flags = $(KBUILD_HOSTRUSTFLAGS) $(HOST_EXTRARUSTFLAGS) \ +hostrust_flags = --emit=dep-info=$(depfile) \ + $(KBUILD_HOSTRUSTFLAGS) $(HOST_EXTRARUSTFLAGS) \ $(HOSTRUSTFLAGS_$(target-stem))
# $(objtree)/$(obj) for including generated headers from checkin source files @@ -147,9 +148,7 @@ $(host-cxxobjs): $(obj)/%.o: $(src)/%.cc FORCE # host-rust -> Executable quiet_cmd_host-rust = HOSTRUSTC $@ cmd_host-rust = \ - $(HOSTRUSTC) $(hostrust_flags) --emit=dep-info,link \ - --out-dir=$(obj)/ $<; \ - mv $(obj)/$(target-stem).d $(depfile); \ + $(HOSTRUSTC) $(hostrust_flags) --emit=link=$@ $<; \ sed -i '/^#/d' $(depfile) $(host-rust): $(obj)/%: $(src)/%.rs FORCE $(call if_changed_dep,host-rust)