pm24.git/scripts, branch rust-6.5

rust: upgrade to Rust 1.68.2

2023-05-31T15:35:03Z

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 3519c4d6e08e ("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 Reviewed-by: Gary Guo Reviewed-By: Martin Rodriguez Reboredo Tested-by: Ariel Miculas Tested-by: David Gow Tested-by: Boqun Feng Link: https://lore.kernel.org/r/20230418214347.324156-4-ojeda@kernel.org [ Removed `feature(core_ffi_c)` from `uapi` ] Signed-off-by: Miguel Ojeda

Merge tag 'locking-core-2023-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-05-05T19:56:55Z

Pull locking updates from Ingo Molnar: - Introduce local{,64}_try_cmpxchg() - a slightly more optimal primitive, which will be used in perf events ring-buffer code - Simplify/modify rwsems on PREEMPT_RT, to address writer starvation - Misc cleanups/fixes * tag 'locking-core-2023-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/atomic: Correct (cmp)xchg() instrumentation locking/x86: Define arch_try_cmpxchg_local() locking/arch: Wire up local_try_cmpxchg() locking/generic: Wire up local{,64}_try_cmpxchg() locking/atomic: Add generic try_cmpxchg{,64}_local() support locking/rwbase: Mitigate indefinite writer starvation locking/arch: Rename all internal __xchg() names to __arch_xchg()

sysctl: remove register_sysctl_paths()

2023-05-03T02:24:16Z

The deprecation for register_sysctl_paths() is over. We can rejoice as we nuke register_sysctl_paths(). The routine register_sysctl_table() was the only user left of register_sysctl_paths(), so we can now just open code and move the implementation over to what used to be to __register_sysctl_paths(). The old dynamic struct ctl_table_set *set is now the point to sysctl_table_root.default_set. The old dynamic const struct ctl_path *path was being used in the routine register_sysctl_paths() with a static: static const struct ctl_path null_path[] = { {} }; Since this is a null path we can now just simplfy the old routine and remove its use as its always empty. This saves us a total of 230 bytes. $ ./scripts/bloat-o-meter vmlinux.old vmlinux add/remove: 2/7 grow/shrink: 1/1 up/down: 1015/-1245 (-230) Function old new delta register_leaf_sysctl_tables.constprop - 524 +524 register_sysctl_table 22 497 +475 __pfx_register_leaf_sysctl_tables.constprop - 16 +16 null_path 8 - -8 __pfx_register_sysctl_paths 16 - -16 __pfx_register_leaf_sysctl_tables 16 - -16 __pfx___register_sysctl_paths 16 - -16 __register_sysctl_base 29 12 -17 register_sysctl_paths 18 - -18 register_leaf_sysctl_tables 534 - -534 __register_sysctl_paths 620 - -620 Total: Before=21259666, After=21259436, chg -0.00% Signed-off-by: Luis Chamberlain

Merge tag 'kbuild-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2023-04-30T18:32:53Z

Pull Kbuild updates from Masahiro Yamada: - Refactor scripts/kallsyms to make it faster and easier to maintain - Clean up menuconfig - Provide Clang with hard-coded target triple instead of CROSS_COMPILE - Use -z pack-relative-relocs flags instead of --use-android-relr-tags for arm64 CONFIG_RELR - Add srcdeb-pkg target to build only a Debian source package - Add KDEB_SOURCE_COMPRESS option to specify the compression for a Debian source package - Misc cleanups and fixes * tag 'kbuild-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: deb-pkg: specify targets in debian/rules as .PHONY sparc: unify sparc32/sparc64 archhelp kbuild: rpm-pkg: remove kernel-drm PROVIDES kbuild: deb-pkg: add KDEB_SOURCE_COMPRESS to specify source compression kbuild: add srcdeb-pkg target Makefile: use -z pack-relative-relocs kbuild: clang: do not use CROSS_COMPILE for target triple kconfig: menuconfig: reorder functions to remove forward declarations kconfig: menuconfig: remove unused M_EVENT macro kconfig: menuconfig: remove OLD_NCURSES macro kbuild: builddeb: Eliminate debian/arch use scripts/kallsyms: update the usage in the comment block scripts/kallsyms: decrease expand_symbol() / cleanup_symbol_name() calls scripts/kallsyms: change the output order scripts/kallsyms: move compiler-generated symbol patterns to mksysmap scripts/kallsyms: exclude symbols generated by itself dynamically scripts/mksysmap: use sed with in-line comments scripts/mksysmap: remove comments described in nm(1) scripts/kallsyms: remove redundant code for omitting U and N kallsyms: expand symbol name into comment for debugging

Merge tag 'rust-6.4' of https://github.com/Rust-for-Linux/linux

2023-04-30T18:20:22Z

Pull rust updates from Miguel Ojeda "More additions to the Rust core. Importantly, this adds the pin-init API, which will be used by other abstractions, such as the synchronization ones added here too: - pin-init API: a solution for the safe pinned initialization problem. This allows to reduce the need for 'unsafe' code in the kernel when dealing with data structures that require a stable address. Commit 90e53c5e70a6 ("rust: add pin-init API core") contains a nice introduction -- here is an example of how it looks like: #[pin_data] struct Example { #[pin] value: Mutex, #[pin] value_changed: CondVar, } impl Example { fn new() -> impl PinInit { pin_init!(Self { value <- new_mutex!(0), value_changed <- new_condvar!(), }) } } // In a `Box`. let b = Box::pin_init(Example::new())?; // In the stack. stack_pin_init!(let s = Example::new()); - 'sync' module: New types 'LockClassKey' ('struct lock_class_key'), 'Lock', 'Guard', 'Mutex' ('struct mutex'), 'SpinLock' ('spinlock_t'), 'LockedBy' and 'CondVar' (uses 'wait_queue_head_t'), plus macros such as 'static_lock_class!' and 'new_spinlock!'. In particular, 'Lock' and 'Guard' are generic implementations that contain code that is common to all locks. Then, different backends (the new 'Backend' trait) are implemented and used to define types like 'Mutex': type Mutex = Lock; In addition, new methods 'assume_init()', 'init_with()' and 'pin_init_with()' for 'UniqueArc>' and 'downcast()' for 'Arc'; as well as 'Debug' and 'Display' implementations for 'Arc' and 'UniqueArc'. Reduced stack usage of 'UniqueArc::try_new_uninit()', too. - 'types' module: New trait 'AlwaysRefCounted' and new type 'ARef' (an owned reference to an always-reference-counted object, meant to be used in wrappers for C types that have their own ref counting functions). Moreover, new associated functions 'raw_get()' and 'ffi_init()' for 'Opaque'. - New 'task' module with a new type 'Task' ('struct task_struct'), and a new macro 'current!' to safely get a reference to the current one. - New 'ioctl' module with new '_IOC*' const functions (equivalent to the C macros). - New 'uapi' crate, intended to be accessible by drivers directly. - 'macros' crate: new 'quote!' macro (similar to the one provided in userspace by the 'quote' crate); and the 'module!' macro now allows specifying multiple module aliases. - 'error' module: New associated functions for the 'Error' type, such as 'from_errno()' and new functions such as 'to_result()'. - 'alloc' crate: More fallible 'Vec' methods: 'try_resize` and 'try_extend_from_slice' and the infrastructure (imported from the Rust standard library) they need" * tag 'rust-6.4' of https://github.com/Rust-for-Linux/linux: (44 commits) rust: ioctl: Add ioctl number manipulation functions rust: uapi: Add UAPI crate rust: sync: introduce `CondVar` rust: lock: add `Guard::do_unlocked` rust: sync: introduce `LockedBy` rust: introduce `current` rust: add basic `Task` rust: introduce `ARef` rust: lock: introduce `SpinLock` rust: lock: introduce `Mutex` rust: sync: introduce `Lock` and `Guard` rust: sync: introduce `LockClassKey` MAINTAINERS: add Benno Lossin as Rust reviewer rust: init: broaden the blanket impl of `Init` rust: sync: add functions for initializing `UniqueArc>` rust: sync: reduce stack usage of `UniqueArc::try_new_uninit` rust: types: add `Opaque::ffi_init` rust: prelude: add `pin-init` API items to prelude rust: init: add `Zeroable` trait and `init::zeroed` function rust: init: add `stack_pin_init!` macro ...

locking/atomic: Correct (cmp)xchg() instrumentation

2023-04-29T07:09:31Z

All xchg() and cmpxchg() ops are atomic RMWs, but currently we instrument these with instrument_atomic_write() rather than instrument_atomic_read_write(), missing the read aspect. Similarly, all try_cmpxchg() ops are non-atomic RMWs on *oldp, but we instrument these accesses with instrument_atomic_write() rather than instrument_read_write(), missing the read aspect and erroneously marking these as atomic. Fix the instrumentation for both points. Signed-off-by: Mark Rutland Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lkml.kernel.org/r/20230413160644.490976-1-mark.rutland@arm.com Cc: Linus Torvalds

locking/atomic: Add generic try_cmpxchg{,64}_local() support

2023-04-29T07:09:02Z

Add generic support for try_cmpxchg{,64}_local() and their falbacks. These provides the generic try_cmpxchg_local family of functions from the arch_ prefixed version, also adding explicit instrumentation. Signed-off-by: Uros Bizjak Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20230405141710.3551-2-ubizjak@gmail.com Cc: Linus Torvalds

Merge tag 'riscv-for-linus-6.4-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2023-04-28T23:55:39Z

Pull RISC-V updates from Palmer Dabbelt: - Support for runtime detection of the Svnapot extension - Support for Zicboz when clearing pages - We've moved to GENERIC_ENTRY - Support for !MMU on rv32 systems - The linear region is now mapped via huge pages - Support for building relocatable kernels - Support for the hwprobe interface - Various fixes and cleanups throughout the tree * tag 'riscv-for-linus-6.4-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (57 commits) RISC-V: hwprobe: Explicity check for -1 in vdso init RISC-V: hwprobe: There can only be one first riscv: Allow to downgrade paging mode from the command line dt-bindings: riscv: add sv57 mmu-type RISC-V: hwprobe: Remove __init on probe_vendor_features() riscv: Use --emit-relocs in order to move .rela.dyn in init riscv: Check relocations at compile time powerpc: Move script to check relocations at compile time in scripts/ riscv: Introduce CONFIG_RELOCATABLE riscv: Move .rela.dyn outside of init to avoid empty relocations riscv: Prepare EFI header for relocatable kernels riscv: Unconditionnally select KASAN_VMALLOC if KASAN riscv: Fix ptdump when KASAN is enabled riscv: Fix EFI stub usage of KASAN instrumented strcmp function riscv: Move DTB_EARLY_BASE_VA to the kernel address space riscv: Rework kasan population functions riscv: Split early and final KASAN population functions riscv: Use PUD/P4D/PGD pages for the linear mapping riscv: Move the linear mapping creation in its own function riscv: Get rid of riscv_pfn_base variable ...

Merge tag 'trace-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2023-04-28T22:57:53Z

Pull tracing updates from Steven Rostedt: - User events are finally ready! After lots of collaboration between various parties, we finally locked down on a stable interface for user events that can also work with user space only tracing. This is implemented by telling the kernel (or user space library, but that part is user space only and not part of this patch set), where the variable is that the application uses to know if something is listening to the trace. There's also an interface to tell the kernel about these events, which will show up in the /sys/kernel/tracing/events/user_events/ directory, where it can be enabled. When it's enabled, the kernel will update the variable, to tell the application to start writing to the kernel. See https://lwn.net/Articles/927595/ - Cleaned up the direct trampolines code to simplify arm64 addition of direct trampolines. Direct trampolines use the ftrace interface but instead of jumping to the ftrace trampoline, applications (mostly BPF) can register their own trampoline for performance reasons. - Some updates to the fprobe infrastructure. fprobes are more efficient than kprobes, as it does not need to save all the registers that kprobes on ftrace do. More work needs to be done before the fprobes will be exposed as dynamic events. - More updates to references to the obsolete path of /sys/kernel/debug/tracing for the new /sys/kernel/tracing path. - Add a seq_buf_do_printk() helper to seq_bufs, to print a large buffer line by line instead of all at once. There are users in production kernels that have a large data dump that originally used printk() directly, but the data dump was larger than what printk() allowed as a single print. Using seq_buf() to do the printing fixes that. - Add /sys/kernel/tracing/touched_functions that shows all functions that was every traced by ftrace or a direct trampoline. This is used for debugging issues where a traced function could have caused a crash by a bpf program or live patching. - Add a "fields" option that is similar to "raw" but outputs the fields of the events. It's easier to read by humans. - Some minor fixes and clean ups. * tag 'trace-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (41 commits) ring-buffer: Sync IRQ works before buffer destruction tracing: Add missing spaces in trace_print_hex_seq() ring-buffer: Ensure proper resetting of atomic variables in ring_buffer_reset_online_cpus recordmcount: Fix memory leaks in the uwrite function tracing/user_events: Limit max fault-in attempts tracing/user_events: Prevent same address and bit per process tracing/user_events: Ensure bit is cleared on unregister tracing/user_events: Ensure write index cannot be negative seq_buf: Add seq_buf_do_printk() helper tracing: Fix print_fields() for __dyn_loc/__rel_loc tracing/user_events: Set event filter_type from type ring-buffer: Clearly check null ptr returned by rb_set_head_page() tracing: Unbreak user events tracing/user_events: Use print_format_fields() for trace output tracing/user_events: Align structs with tabs for readability tracing/user_events: Limit global user_event count tracing/user_events: Charge event allocs to cgroups tracing/user_events: Update documentation for ABI tracing/user_events: Use write ABI in example tracing/user_events: Add ABI self-test ...

Merge tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-04-28T21:02:54Z

Pull objtool updates from Ingo Molnar: - Mark arch_cpu_idle_dead() __noreturn, make all architectures & drivers that did this inconsistently follow this new, common convention, and fix all the fallout that objtool can now detect statically - Fix/improve the ORC unwinder becoming unreliable due to UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK and UNWIND_HINT_UNDEFINED to resolve it - Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code - Generate ORC data for __pfx code - Add more __noreturn annotations to various kernel startup/shutdown and panic functions - Misc improvements & fixes * tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) x86/hyperv: Mark hv_ghcb_terminate() as noreturn scsi: message: fusion: Mark mpt_halt_firmware() __noreturn x86/cpu: Mark {hlt,resume}_play_dead() __noreturn btrfs: Mark btrfs_assertfail() __noreturn objtool: Include weak functions in global_noreturns check cpu: Mark nmi_panic_self_stop() __noreturn cpu: Mark panic_smp_self_stop() __noreturn arm64/cpu: Mark cpu_park_loop() and friends __noreturn x86/head: Mark *_start_kernel() __noreturn init: Mark start_kernel() __noreturn init: Mark [arch_call_]rest_init() __noreturn objtool: Generate ORC data for __pfx code x86/linkage: Fix padding for typed functions objtool: Separate prefix code from stack validation code objtool: Remove superfluous dead_end_function() check objtool: Add symbol iteration helpers objtool: Add WARN_INSN() scripts/objdump-func: Support multiple functions context_tracking: Fix KCSAN noinstr violation objtool: Add stackleak instrumentation to uaccess safe list ...