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authorLinus Torvalds <torvalds@linux-foundation.org>2022-10-03 16:39:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-10-03 16:39:37 -0700
commit8aebac82933ff1a7c8eede18cab11e1115e2062b (patch)
tree8305fe6437fe1db1a5dedf218d53a6bd21120793 /Documentation/kbuild
parenta5088ee7251e5106a4efa9588a73866eb4b4154e (diff)
parent615131b8e9bcd88e2d3ef78a4954ff4abfbb1fb7 (diff)
Merge tag 'rust-v6.1-rc1' of https://github.com/Rust-for-Linux/linux
Pull Rust introductory support from Kees Cook: "The tree has a recent base, but has fundamentally been in linux-next for a year and a half[1]. It's been updated based on feedback from the Kernel Maintainer's Summit, and to gain recent Reviewed-by: tags. Miguel is the primary maintainer, with me helping where needed/wanted. Our plan is for the tree to switch to the standard non-rebasing practice once this initial infrastructure series lands. The contents are the absolute minimum to get Rust code building in the kernel, with many more interfaces[2] (and drivers - NVMe[3], 9p[4], M1 GPU[5]) on the way. The initial support of Rust-for-Linux comes in roughly 4 areas: - Kernel internals (kallsyms expansion for Rust symbols, %pA format) - Kbuild infrastructure (Rust build rules and support scripts) - Rust crates and bindings for initial minimum viable build - Rust kernel documentation and samples Rust support has been in linux-next for a year and a half now, and the short log doesn't do justice to the number of people who have contributed both to the Linux kernel side but also to the upstream Rust side to support the kernel's needs. Thanks to these 173 people, and many more, who have been involved in all kinds of ways: Miguel Ojeda, Wedson Almeida Filho, Alex Gaynor, Boqun Feng, Gary Guo, Björn Roy Baron, Andreas Hindborg, Adam Bratschi-Kaye, Benno Lossin, Maciej Falkowski, Finn Behrens, Sven Van Asbroeck, Asahi Lina, FUJITA Tomonori, John Baublitz, Wei Liu, Geoffrey Thomas, Philip Herron, Arthur Cohen, David Faust, Antoni Boucher, Philip Li, Yujie Liu, Jonathan Corbet, Greg Kroah-Hartman, Paul E. McKenney, Josh Triplett, Kent Overstreet, David Gow, Alice Ryhl, Robin Randhawa, Kees Cook, Nick Desaulniers, Matthew Wilcox, Linus Walleij, Joe Perches, Michael Ellerman, Petr Mladek, Masahiro Yamada, Arnaldo Carvalho de Melo, Andrii Nakryiko, Konstantin Shelekhin, Rasmus Villemoes, Konstantin Ryabitsev, Stephen Rothwell, Andy Shevchenko, Sergey Senozhatsky, John Paul Adrian Glaubitz, David Laight, Nathan Chancellor, Jonathan Cameron, Daniel Latypov, Shuah Khan, Brendan Higgins, Julia Lawall, Laurent Pinchart, Geert Uytterhoeven, Akira Yokosawa, Pavel Machek, David S. Miller, John Hawley, James Bottomley, Arnd Bergmann, Christian Brauner, Dan Robertson, Nicholas Piggin, Zhouyi Zhou, Elena Zannoni, Jose E. Marchesi, Leon Romanovsky, Will Deacon, Richard Weinberger, Randy Dunlap, Paolo Bonzini, Roland Dreier, Mark Brown, Sasha Levin, Ted Ts'o, Steven Rostedt, Jarkko Sakkinen, Michal Kubecek, Marco Elver, Al Viro, Keith Busch, Johannes Berg, Jan Kara, David Sterba, Connor Kuehl, Andy Lutomirski, Andrew Lunn, Alexandre Belloni, Peter Zijlstra, Russell King, Eric W. Biederman, Willy Tarreau, Christoph Hellwig, Emilio Cobos Álvarez, Christian Poveda, Mark Rousskov, John Ericson, TennyZhuang, Xuanwo, Daniel Paoliello, Manish Goregaokar, comex, Josh Stone, Stephan Sokolow, Philipp Krones, Guillaume Gomez, Joshua Nelson, Mats Larsen, Marc Poulhiès, Samantha Miller, Esteban Blanc, Martin Schmidt, Martin Rodriguez Reboredo, Daniel Xu, Viresh Kumar, Bartosz Golaszewski, Vegard Nossum, Milan Landaverde, Dariusz Sosnowski, Yuki Okushi, Matthew Bakhtiari, Wu XiangCheng, Tiago Lam, Boris-Chengbiao Zhou, Sumera Priyadarsini, Viktor Garske, Niklas Mohrin, Nándor István Krácser, Morgan Bartlett, Miguel Cano, Léo Lanteri Thauvin, Julian Merkle, Andreas Reindl, Jiapeng Chong, Fox Chen, Douglas Su, Antonio Terceiro, SeongJae Park, Sergio González Collado, Ngo Iok Ui (Wu Yu Wei), Joshua Abraham, Milan, Daniel Kolsoi, ahomescu, Manas, Luis Gerhorst, Li Hongyu, Philipp Gesang, Russell Currey, Jalil David Salamé Messina, Jon Olson, Raghvender, Angelos, Kaviraj Kanagaraj, Paul Römer, Sladyn Nunes, Mauro Baladés, Hsiang-Cheng Yang, Abhik Jain, Hongyu Li, Sean Nash, Yuheng Su, Peng Hao, Anhad Singh, Roel Kluin, Sara Saa, Geert Stappers, Garrett LeSage, IFo Hancroft, and Linus Torvalds" Link: https://lwn.net/Articles/849849/ [1] Link: https://github.com/Rust-for-Linux/linux/commits/rust [2] Link: https://github.com/metaspace/rust-linux/commit/d88c3744d6cbdf11767e08bad56cbfb67c4c96d0 [3] Link: https://github.com/wedsonaf/linux/commit/9367032607f7670de0ba1537cf09ab0f4365a338 [4] Link: https://github.com/AsahiLinux/linux/commits/gpu/rust-wip [5] * tag 'rust-v6.1-rc1' of https://github.com/Rust-for-Linux/linux: (27 commits) MAINTAINERS: Rust samples: add first Rust examples x86: enable initial Rust support docs: add Rust documentation Kbuild: add Rust support rust: add `.rustfmt.toml` scripts: add `is_rust_module.sh` scripts: add `rust_is_available.sh` scripts: add `generate_rust_target.rs` scripts: add `generate_rust_analyzer.py` scripts: decode_stacktrace: demangle Rust symbols scripts: checkpatch: enable language-independent checks for Rust scripts: checkpatch: diagnose uses of `%pA` in the C side as errors vsprintf: add new `%pA` format specifier rust: export generated symbols rust: add `kernel` crate rust: add `bindings` crate rust: add `macros` crate rust: add `compiler_builtins` crate rust: adapt `alloc` crate to the kernel ...
Diffstat (limited to 'Documentation/kbuild')
-rw-r--r--Documentation/kbuild/kbuild.rst17
-rw-r--r--Documentation/kbuild/makefiles.rst50
2 files changed, 63 insertions, 4 deletions
diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst
index ef19b9c13523..08f575e6236c 100644
--- a/Documentation/kbuild/kbuild.rst
+++ b/Documentation/kbuild/kbuild.rst
@@ -48,6 +48,10 @@ KCFLAGS
-------
Additional options to the C compiler (for built-in and modules).
+KRUSTFLAGS
+----------
+Additional options to the Rust compiler (for built-in and modules).
+
CFLAGS_KERNEL
-------------
Additional options for $(CC) when used to compile
@@ -57,6 +61,15 @@ CFLAGS_MODULE
-------------
Additional module specific options to use for $(CC).
+RUSTFLAGS_KERNEL
+----------------
+Additional options for $(RUSTC) when used to compile
+code that is compiled as built-in.
+
+RUSTFLAGS_MODULE
+----------------
+Additional module specific options to use for $(RUSTC).
+
LDFLAGS_MODULE
--------------
Additional options used for $(LD) when linking modules.
@@ -69,6 +82,10 @@ HOSTCXXFLAGS
------------
Additional flags to be passed to $(HOSTCXX) when building host programs.
+HOSTRUSTFLAGS
+-------------
+Additional flags to be passed to $(HOSTRUSTC) when building host programs.
+
HOSTLDFLAGS
-----------
Additional flags to be passed when linking host programs.
diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index 11a296e52d68..5ea1e72d89c8 100644
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -29,8 +29,9 @@ This document describes the Linux kernel Makefiles.
--- 4.1 Simple Host Program
--- 4.2 Composite Host Programs
--- 4.3 Using C++ for host programs
- --- 4.4 Controlling compiler options for host programs
- --- 4.5 When host programs are actually built
+ --- 4.4 Using Rust for host programs
+ --- 4.5 Controlling compiler options for host programs
+ --- 4.6 When host programs are actually built
=== 5 Userspace Program support
--- 5.1 Simple Userspace Program
@@ -835,7 +836,24 @@ Both possibilities are described in the following.
qconf-cxxobjs := qconf.o
qconf-objs := check.o
-4.4 Controlling compiler options for host programs
+4.4 Using Rust for host programs
+--------------------------------
+
+ Kbuild offers support for host programs written in Rust. However,
+ since a Rust toolchain is not mandatory for kernel compilation,
+ it may only be used in scenarios where Rust is required to be
+ available (e.g. when ``CONFIG_RUST`` is enabled).
+
+ Example::
+
+ hostprogs := target
+ target-rust := y
+
+ Kbuild will compile ``target`` using ``target.rs`` as the crate root,
+ located in the same directory as the ``Makefile``. The crate may
+ consist of several source files (see ``samples/rust/hostprogs``).
+
+4.5 Controlling compiler options for host programs
--------------------------------------------------
When compiling host programs, it is possible to set specific flags.
@@ -867,7 +885,7 @@ Both possibilities are described in the following.
When linking qconf, it will be passed the extra option
"-L$(QTDIR)/lib".
-4.5 When host programs are actually built
+4.6 When host programs are actually built
-----------------------------------------
Kbuild will only build host-programs when they are referenced
@@ -1181,6 +1199,17 @@ When kbuild executes, the following steps are followed (roughly):
The first example utilises the trick that a config option expands
to 'y' when selected.
+ KBUILD_RUSTFLAGS
+ $(RUSTC) compiler flags
+
+ Default value - see top level Makefile
+ Append or modify as required per architecture.
+
+ Often, the KBUILD_RUSTFLAGS variable depends on the configuration.
+
+ Note that target specification file generation (for ``--target``)
+ is handled in ``scripts/generate_rust_target.rs``.
+
KBUILD_AFLAGS_KERNEL
Assembler options specific for built-in
@@ -1208,6 +1237,19 @@ When kbuild executes, the following steps are followed (roughly):
are used for $(CC).
From commandline CFLAGS_MODULE shall be used (see kbuild.rst).
+ KBUILD_RUSTFLAGS_KERNEL
+ $(RUSTC) options specific for built-in
+
+ $(KBUILD_RUSTFLAGS_KERNEL) contains extra Rust compiler flags used to
+ compile resident kernel code.
+
+ KBUILD_RUSTFLAGS_MODULE
+ Options for $(RUSTC) when building modules
+
+ $(KBUILD_RUSTFLAGS_MODULE) is used to add arch-specific options that
+ are used for $(RUSTC).
+ From commandline RUSTFLAGS_MODULE shall be used (see kbuild.rst).
+
KBUILD_LDFLAGS_MODULE
Options for $(LD) when linking modules