linux-mainline/scripts
Miguel Ojeda 3ed03f4da0 rust: upgrade to Rust 1.68.2
This is the first upgrade to the Rust toolchain since the initial Rust
merge, from 1.62.0 to 1.68.2 (i.e. the latest).

# Context

The kernel currently supports only a single Rust version [1] (rather
than a minimum) given our usage of some "unstable" Rust features [2]
which do not promise backwards compatibility.

The goal is to reach a point where we can declare a minimum version for
the toolchain. For instance, by waiting for some of the features to be
stabilized. Therefore, the first minimum Rust version that the kernel
will support is "in the future".

# Upgrade policy

Given we will eventually need to reach that minimum version, it would be
ideal to upgrade the compiler from time to time to be as close as
possible to that goal and find any issues sooner. In the extreme, we
could upgrade as soon as a new Rust release is out. Of course, upgrading
so often is in stark contrast to what one normally would need for GCC
and LLVM, especially given the release schedule: 6 weeks for Rust vs.
half a year for LLVM and a year for GCC.

Having said that, there is no particular advantage to updating slowly
either: kernel developers in "stable" distributions are unlikely to be
able to use their distribution-provided Rust toolchain for the kernel
anyway [3]. Instead, by routinely upgrading to the latest instead,
kernel developers using Linux distributions that track the latest Rust
release may be able to use those rather than Rust-provided ones,
especially if their package manager allows to pin / hold back /
downgrade the version for some days during windows where the version may
not match. For instance, Arch, Fedora, Gentoo and openSUSE all provide
and track the latest version of Rust as they get released every 6 weeks.

Then, when the minimum version is reached, we will stop upgrading and
decide how wide the window of support will be. For instance, a year of
Rust versions. We will probably want to start small, and then widen it
over time, just like the kernel did originally for LLVM, see commit
3519c4d6e0 ("Documentation: add minimum clang/llvm version").

# Unstable features stabilized

This upgrade allows us to remove the following unstable features since
they were stabilized:

  - `feature(explicit_generic_args_with_impl_trait)` (1.63).
  - `feature(core_ffi_c)` (1.64).
  - `feature(generic_associated_types)` (1.65).
  - `feature(const_ptr_offset_from)` (1.65, *).
  - `feature(bench_black_box)` (1.66, *).
  - `feature(pin_macro)` (1.68).

The ones marked with `*` apply only to our old `rust` branch, not
mainline yet, i.e. only for code that we may potentially upstream.

With this patch applied, the only unstable feature allowed to be used
outside the `kernel` crate is `new_uninit`, though other code to be
upstreamed may increase the list.

Please see [2] for details.

# Other required changes

Since 1.63, `rustdoc` triggers the `broken_intra_doc_links` lint for
links pointing to exported (`#[macro_export]`) `macro_rules`. An issue
was opened upstream [4], but it turns out it is intended behavior. For
the moment, just add an explicit reference for each link. Later we can
revisit this if `rustdoc` removes the compatibility measure.

Nevertheless, this was helpful to discover a link that was pointing to
the wrong place unintentionally. Since that one was actually wrong, it
is fixed in a previous commit independently.

Another change was the addition of `cfg(no_rc)` and `cfg(no_sync)` in
upstream [5], thus remove our original changes for that.

Similarly, upstream now tests that it compiles successfully with
`#[cfg(not(no_global_oom_handling))]` [6], which allow us to get rid
of some changes, such as an `#[allow(dead_code)]`.

In addition, remove another `#[allow(dead_code)]` due to new uses
within the standard library.

Finally, add `try_extend_trusted` and move the code in `spec_extend.rs`
since upstream moved it for the infallible version.

# `alloc` upgrade and reviewing

There are a large amount of changes, but the vast majority of them are
due to our `alloc` fork being upgraded at once.

There are two kinds of changes to be aware of: the ones coming from
upstream, which we should follow as closely as possible, and the updates
needed in our added fallible APIs to keep them matching the newer
infallible APIs coming from upstream.

Instead of taking a look at the diff of this patch, an alternative
approach is reviewing a diff of the changes between upstream `alloc` and
the kernel's. This allows to easily inspect the kernel additions only,
especially to check if the fallible methods we already have still match
the infallible ones in the new version coming from upstream.

Another approach is reviewing the changes introduced in the additions in
the kernel fork between the two versions. This is useful to spot
potentially unintended changes to our additions.

To apply these approaches, one may follow steps similar to the following
to generate a pair of patches that show the differences between upstream
Rust and the kernel (for the subset of `alloc` we use) before and after
applying this patch:

    # Get the difference with respect to the old version.
    git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
    git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
        cut -d/ -f3- |
        grep -Fv README.md |
        xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
    git -C linux diff --patch-with-stat --summary -R > old.patch
    git -C linux restore rust/alloc

    # Apply this patch.
    git -C linux am rust-upgrade.patch

    # Get the difference with respect to the new version.
    git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
    git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
        cut -d/ -f3- |
        grep -Fv README.md |
        xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
    git -C linux diff --patch-with-stat --summary -R > new.patch
    git -C linux restore rust/alloc

Now one may check the `new.patch` to take a look at the additions (first
approach) or at the difference between those two patches (second
approach). For the latter, a side-by-side tool is recommended.

Link: https://rust-for-linux.com/rust-version-policy [1]
Link: https://github.com/Rust-for-Linux/linux/issues/2 [2]
Link: https://lore.kernel.org/rust-for-linux/CANiq72mT3bVDKdHgaea-6WiZazd8Mvurqmqegbe5JZxVyLR8Yg@mail.gmail.com/ [3]
Link: https://github.com/rust-lang/rust/issues/106142 [4]
Link: https://github.com/rust-lang/rust/pull/89891 [5]
Link: https://github.com/rust-lang/rust/pull/98652 [6]
Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-By: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Tested-by: Ariel Miculas <amiculas@cisco.com>
Tested-by: David Gow <davidgow@google.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20230418214347.324156-4-ojeda@kernel.org
[ Removed `feature(core_ffi_c)` from `uapi` ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31 17:35:03 +02:00
..
atomic locking/atomic: Correct (cmp)xchg() instrumentation 2023-04-29 09:09:31 +02:00
basic fixdep: do not parse *.rlib, *.rmeta, *.so 2023-01-22 23:43:33 +09:00
clang-tools scripts: handle BrokenPipeError for python scripts 2023-01-26 12:43:33 +09:00
coccinelle coccinelle: api/atomic_as_refcounter: include message type in output 2022-12-26 21:47:12 +01:00
dtc dts: add riscv include prefix link 2023-03-27 22:45:22 +02:00
dummy-tools
gcc-plugins Merge branch 'for-linus/hardening' into for-next/hardening 2023-02-02 18:43:28 +00:00
gdb Mainly singleton patches all over the place. Series of note are: 2023-04-27 19:57:00 -07:00
genksyms
kconfig kconfig: menuconfig: reorder functions to remove forward declarations 2023-04-17 11:03:56 +09:00
ksymoops
mod modules-6.4-rc1 2023-04-27 16:36:55 -07:00
package Kbuild updates for v6.4 2023-04-30 11:32:53 -07:00
selinux
tracing tracing: Always use canonical ftrace path 2023-02-18 14:34:09 -05:00
.gitignore kbuild: use git-archive for source package creation 2023-03-16 22:46:12 +09:00
adjust_autoksyms.sh
as-version.sh kbuild: Update assembler calls to use proper flags and language target 2023-01-26 12:41:38 +09:00
asn1_compiler.c ASN.1: Fix check for strdup() success 2023-04-21 08:58:00 -07:00
bloat-o-meter scripts/bloat-o-meter: use the reverse flag for sort 2023-02-02 22:50:03 -08:00
bootgraph.pl
bpf_doc.py bpf: Remove extra whitespace in SPDX tag for syscall/helpers man pages 2023-04-11 17:45:57 +02:00
cc-can-link.sh
cc-version.sh scripts: Remove ICC-related dead code 2023-04-24 10:18:32 -07:00
check_extable.sh
check-git kbuild: use git-archive for source package creation 2023-03-16 22:46:12 +09:00
check-local-export
check-sysctl-docs sysctl: remove register_sysctl_paths() 2023-05-02 19:24:16 -07:00
checkdeclares.pl
checkincludes.pl
checkkconfigsymbols.py scripts: handle BrokenPipeError for python scripts 2023-01-26 12:43:33 +09:00
checkpatch.pl Mainly singleton patches all over the place. Series of note are: 2023-04-27 19:57:00 -07:00
checkstack.pl sh: remove sh5/sh64 last fragments 2023-03-23 10:02:02 +01:00
checksyscalls.sh checksyscalls: ignore fstat to silence build warning on LoongArch 2023-03-23 17:18:32 -07:00
checkversion.pl
cleanfile
cleanpatch
coccicheck scripts: coccicheck: Use /usr/bin/env 2023-02-25 20:11:06 +01:00
config
const_structs.checkpatch const_structs.checkpatch.pl: add kobj_type 2023-02-08 13:33:29 +01:00
decode_stacktrace.sh
decodecode scripts/decodecode: Add support for RISC-V 2023-02-21 16:53:54 -08:00
depmod.sh
dev-needs.sh
diffconfig scripts: handle BrokenPipeError for python scripts 2023-01-26 12:43:33 +09:00
documentation-file-ref-check
export_report.pl
extract_xc3028.pl
extract-ikconfig
extract-module-sig.pl
extract-sys-certs.pl
extract-vmlinux
faddr2line scripts/faddr2line: Fix regression in name resolution on ppc64le 2022-11-16 10:42:10 +01:00
file-size.sh
find-unused-docs.sh
gcc-x86_32-has-stack-protector.sh
gcc-x86_64-has-stack-protector.sh
gen_autoksyms.sh kbuild: change module.order to list *.o instead of *.ko 2022-12-14 15:42:40 +09:00
gen_ksymdeps.sh
gen-randstruct-seed.sh
generate_initcall_order.pl
generate_rust_analyzer.py scripts: generate_rust_analyzer: Handle sub-modules with no Makefile 2023-04-07 00:53:34 +02:00
generate_rust_target.rs
get_abi.pl
get_dvb_firmware
get_feat.pl
get_maintainer.pl
gfp-translate
head-object-list.txt scripts/head-object-list: Remove x86 from the list 2023-01-09 18:22:21 +01:00
headerdep.pl
headers_install.sh scripts: Update the CONFIG_* ignore list in headers_install.sh 2023-03-10 21:05:16 +01:00
insert-sys-cert.c
install.sh
is_rust_module.sh rust: fix regexp in scripts/is_rust_module.sh 2023-04-19 19:28:49 +02:00
jobserver-exec scripts: support GNU make 4.4 in jobserver-exec 2023-01-16 20:15:20 +09:00
kallsyms.c scripts/kallsyms: update the usage in the comment block 2023-04-17 11:03:56 +09:00
Kbuild.include kbuild: replace $(dot-target).tmp in filechk with $(tmp-target) 2023-01-22 23:43:33 +09:00
Kconfig.include kbuild: Update assembler calls to use proper flags and language target 2023-01-26 12:41:38 +09:00
kernel-doc Kbuild updates for v6.3 2023-02-26 11:53:25 -08:00
ld-version.sh
leaking_addresses.pl leaking_addresses: also skip canonical ftrace path 2023-03-29 06:52:08 -04:00
Lindent
link-vmlinux.sh Kbuild updates for v6.4 2023-04-30 11:32:53 -07:00
Makefile kbuild: use git-archive for source package creation 2023-03-16 22:46:12 +09:00
Makefile.asm-generic kbuild: add kbuild-file macro 2022-11-22 23:40:02 +09:00
Makefile.build rust: upgrade to Rust 1.68.2 2023-05-31 17:35:03 +02:00
Makefile.clang kbuild: clang: do not use CROSS_COMPILE for target triple 2023-04-17 11:23:06 +09:00
Makefile.clean kbuild: add kbuild-file macro 2022-11-22 23:40:02 +09:00
Makefile.compiler kbuild: Update assembler calls to use proper flags and language target 2023-01-26 12:41:38 +09:00
Makefile.debug Makefile.debug: support for -gz=zstd 2022-11-21 10:18:39 +09:00
Makefile.defconf kbuild: Provide a version of merge_into_defconfig without override warnings 2023-02-13 20:18:28 +01:00
Makefile.dtbinst kbuild: add kbuild-file macro 2022-11-22 23:40:02 +09:00
Makefile.extrawarn kbuild: add -Wundef to KBUILD_CPPFLAGS for W=1 builds 2022-12-11 17:28:32 +09:00
Makefile.gcc-plugins
Makefile.headersinst
Makefile.host kbuild: remove sed commands after rustc rules 2023-01-22 23:43:33 +09:00
Makefile.kasan kasan: remove hwasan-kernel-mem-intrinsic-prefix=1 for clang-14 2023-04-18 16:29:43 -07:00
Makefile.kcov
Makefile.kcsan
Makefile.kmsan
Makefile.lib kbuild: unify cmd_dt_S_dtb and cmd_dt_S_dtbo 2023-01-22 23:43:33 +09:00
Makefile.modfinal kbuild: rename cmd_$@ to savedcmd_$@ in *.cmd files 2023-01-22 23:43:33 +09:00
Makefile.modinst modules-6.3-rc1 2023-02-23 14:05:08 -08:00
Makefile.modpost kbuild: do not automatically add -w option to modpost 2023-02-05 18:51:22 +09:00
Makefile.package Kbuild updates for v6.4 2023-04-30 11:32:53 -07:00
Makefile.randstruct
Makefile.ubsan
Makefile.userprogs
Makefile.vmlinux kbuild: Fix CFI hash randomization with KASAN 2023-01-13 15:22:03 -08:00
Makefile.vmlinux_o
makelst
markup_oops.pl
min-tool-version.sh rust: upgrade to Rust 1.68.2 2023-05-31 17:35:03 +02:00
misc-check kbuild: make W=1 warn files that are tracked but ignored by git 2023-01-22 23:43:33 +09:00
mkcompile_h
mksysmap scripts/kallsyms: move compiler-generated symbol patterns to mksysmap 2023-04-17 11:03:56 +09:00
mkuboot.sh
module.lds.S arm64: unwind: add asynchronous unwind tables to kernel and modules 2022-11-09 18:06:35 +00:00
modules-check.sh kbuild: change module.order to list *.o instead of *.ko 2022-12-14 15:42:40 +09:00
nsdeps
objdiff
objdump-func scripts/objdump-func: Support multiple functions 2023-04-14 16:08:28 +02:00
pahole-flags.sh btf, scripts: Exclude Rust CUs with pahole 2023-01-17 17:29:42 +01:00
pahole-version.sh
parse-maintainers.pl
patch-kernel
profile2linkerlist.pl
prune-kernel
recordmcount.c recordmcount: Fix memory leaks in the uwrite function 2023-04-25 21:10:20 -04:00
recordmcount.h
recordmcount.pl
relocs_check.sh powerpc: Move script to check relocations at compile time in scripts/ 2023-04-19 07:46:31 -07:00
remove-stale-files kbuild: do not put .scmversion into the source tarball 2023-01-30 13:00:30 +09:00
rust_is_available_bindgen_libclang.h
rust_is_available.sh
setlocalversion kbuild: use git-archive for source package creation 2023-03-16 22:46:12 +09:00
show_delta
sign-file.c
sorttable.c LoongArch: extable: Add type and data fields 2022-12-14 08:36:11 +08:00
sorttable.h x86,objtool: Split UNWIND_HINT_EMPTY in two 2023-03-23 23:18:58 +01:00
spdxcheck-test.sh
spdxcheck.py
spdxexclude
spelling.txt scripts/spelling.txt: add "exsits" pattern and fix typo instances 2023-02-02 22:50:07 -08:00
sphinx-pre-install docs: sphinx-pre-install: don't require the RTD theme 2022-10-13 11:14:43 -06:00
split-man.pl
stackdelta
stackusage
subarch.include
syscallhdr.sh
syscallnr.sh
syscalltbl.sh
tags.sh Kbuild updates for v6.3 2023-02-26 11:53:25 -08:00
test_fortify.sh
tools-support-relr.sh Makefile: use -z pack-relative-relocs 2023-04-17 11:23:06 +09:00
unifdef.c
ver_linux
xen-hypercalls.sh
xz_wrap.sh