[PATCH 6.1 140/236] kbuild: rust: avoid creating temporary files

Greg Kroah-Hartman
2024-05-14T11:34:05Z

From: Miguel Ojeda <ojeda@kernel.org>

[ Upstream commit df01b7cfcef08bf3fdcac2909d0e1910781d6bfd ]

`rustc` outputs by default the temporary files (i.e. the ones saved
by `-Csave-temps`, such as `*.rcgu*` files) in the current working
directory when `-o` and `--out-dir` are not given (even if
`--emit=x=path` is given, i.e. it does not use those for temporaries).

Since out-of-tree modules are compiled from the `linux` tree,
`rustc` then tries to create them there, which may not be accessible.

Thus pass `--out-dir` explicitly, even if it is just for the temporary
files.

Similarly, do so for Rust host programs too.

Reported-by: Raphael Nestler <raphael.nestler@gmail.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/1015
Reported-by: Andrea Righi <andrea.righi@canonical.com>
Tested-by: Raphael Nestler <raphael.nestler@gmail.com> # non-hostprogs
Tested-by: Andrea Righi <andrea.righi@canonical.com> # non-hostprogs
Fixes: 295d8398c67e ("kbuild: specify output names separately for each emission type from rustc")
Cc: stable@vger.kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
scripts/Makefile.build | 5 ++++-
scripts/Makefile.host | 6 +++++-
2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 9ae02542b9389..1827bc1db1e98 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -277,6 +277,9 @@ $(obj)/%.lst: $(src)/%.c FORCE

rust_allowed_features := core_ffi_c

+# `--out-dir` is required to avoid temporaries being created by `rustc` in the
+# current working directory, which may be not accessible in the out-of-tree
+# modules case.
rust_common_cmd = \
RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
-Zallow-features=$(rust_allowed_features) \
@@ -285,7 +288,7 @@ rust_common_cmd = \
--extern alloc --extern kernel \
--crate-type rlib -L $(objtree)/rust/ \
--crate-name $(basename $(notdir $@)) \
- --emit=dep-info=$(depfile)
+ --out-dir $(dir $@) --emit=dep-info=$(depfile)

rust_handle_depfile = \
sed -i '/^\#/d' $(depfile)
diff --git a/scripts/Makefile.host b/scripts/Makefile.host
index d812241144d44..a447c91893de6 100644
--- a/scripts/Makefile.host
+++ b/scripts/Makefile.host
@@ -86,7 +86,11 @@ hostc_flags = -Wp,-MMD,$(depfile) \
hostcxx_flags = -Wp,-MMD,$(depfile) \
$(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
$(HOSTCXXFLAGS_$(target-stem).o)
-hostrust_flags = --emit=dep-info=$(depfile) \
+
+# `--out-dir` is required to avoid temporaries being created by `rustc` in the
+# current working directory, which may be not accessible in the out-of-tree
+# modules case.
+hostrust_flags = --out-dir $(dir $@) --emit=dep-info=$(depfile) \
$(KBUILD_HOSTRUSTFLAGS) $(HOST_EXTRARUSTFLAGS) \
$(HOSTRUSTFLAGS_$(target-stem))

--
2.43.0