mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-03-22 07:27:12 +08:00
977c4308ee
Currently rust on arm fails to compile due to '-mno-fdpic'. This flag
disables a GCC feature that we don't want for kernel builds, so let's
skip it as it doesn't apply to Clang.
UPD include/generated/asm-offsets.h
CALL scripts/checksyscalls.sh
RUSTC L rust/core.o
BINDGEN rust/bindings/bindings_generated.rs
BINDGEN rust/bindings/bindings_helpers_generated.rs
CC rust/helpers/helpers.o
Unable to generate bindings: clang diagnosed error: error: unknown argument: '-mno-fdpic'
make[2]: *** [rust/Makefile:369: rust/bindings/bindings_helpers_generated.rs] Error 1
make[2]: *** Deleting file 'rust/bindings/bindings_helpers_generated.rs'
make[2]: *** Waiting for unfinished jobs....
Unable to generate bindings: clang diagnosed error: error: unknown argument: '-mno-fdpic'
make[2]: *** [rust/Makefile:349: rust/bindings/bindings_generated.rs] Error 1
make[2]: *** Deleting file 'rust/bindings/bindings_generated.rs'
make[1]: *** [/home/pmos/build/src/linux-next-next-20250521/Makefile:1285: prepare] Error 2
make: *** [Makefile:248: __sub-make] Error 2
[ Naresh provided the draft diff [1].
Ben explained [2]:
FDPIC is only relevant with no-MMU targets, and then only for userspace.
When configured for the arm-*-uclinuxfdpiceabi target, GCC enables FDPIC
by default to facilitate compiling userspace programs. FDPIC is never
used for the kernel, and we pass -mno-fdpic when building the kernel to
override the default and make sure FDPIC is disabled.
and [3]:
-mno-fdpic disables a GCC feature that we don't want for kernel builds.
clang does not support this feature, so it always behaves as though
-mno-fdpic is passed. Therefore, it should be fine to mix the two, at
least as far as FDPIC is concerned.
[1] https://lore.kernel.org/rust-for-linux/CA+G9fYt4otQK4pHv8pJBW9e28yHSGCDncKquwuJiJ_1ou0pq0w@mail.gmail.com/
[2] https://lore.kernel.org/rust-for-linux/aAKrq2InExQk7f_k@dell-precision-5540/
[3] https://lore.kernel.org/rust-for-linux/aAo_F_UP1Gd4jHlZ@dell-precision-5540/
- Miguel ]
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/all/CA+G9fYvOanQBYXKSg7C6EU30k8sTRC0JRPJXYu7wWK51w38QUQ@mail.gmail.com/
Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
Link: https://lore.kernel.org/r/20250522-rust-mno-fdpic-arm-fix-v2-1-a6f691d9c198@gmail.com
[ Reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.