From f1673e85e57f6d628cafdc2d59e6a999a4a93212 Mon Sep 17 00:00:00 2001 From: Aakash Sen Sharma Date: Tue, 13 Jun 2023 01:13:11 +0530 Subject: [PATCH] rust: bindgen: upgrade to 0.65.1 In LLVM 16, anonymous items may return names like `(unnamed union at ..)` rather than empty names [1], which breaks Rust-enabled builds because bindgen assumed an empty name instead of detecting them via `clang_Cursor_isAnonymous` [2]: $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... This was fixed in bindgen 0.62.0. Therefore, upgrade bindgen to a more recent version, 0.65.1, to support LLVM 16. Since bindgen 0.58.0 changed the `--{white,black}list-*` flags to `--{allow,block}list-*` [3], update them on our side too. In addition, bindgen 0.61.0 moved its CLI utility into a binary crate called `bindgen-cli` [4]. Thus update the installation command in the Quick Start guide. Moreover, bindgen 0.61.0 changed the default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` flag to not bind `size_t` as `usize`. Then bindgen 0.65.0 removed the `--size_t-is-usize` flag [6]. Thus stop passing the flag to bindgen. Finally, bindgen 0.61.0 added support for the `noreturn` attribute (in its different forms) [7]. Thus remove the infinite loop in our Rust panic handler after calling `BUG()`, since bindgen now correctly generates a `BUG()` binding that returns `!` instead of `()`. Link: https://github.com/llvm/llvm-project/commit/19e984ef8f49bc3ccced15621989fa9703b2cd5b [1] Link: https://github.com/rust-lang/rust-bindgen/pull/2319 [2] Link: https://github.com/rust-lang/rust-bindgen/pull/1990 [3] Link: https://github.com/rust-lang/rust-bindgen/pull/2284 [4] Link: https://github.com/rust-lang/rust-bindgen/commit/cc78b6fdb6e829e5fb8fa1639f2182cb49333569 [5] Link: https://github.com/rust-lang/rust-bindgen/pull/2408 [6] Link: https://github.com/rust-lang/rust-bindgen/issues/2094 [7] Signed-off-by: Aakash Sen Sharma Closes: https://github.com/Rust-for-Linux/linux/issues/1013 Tested-by: Ariel Miculas Reviewed-by: Gary Guo Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [ Reworded commit message. Mentioned the `bindgen-cli` binary crate change, linked to it and updated the Quick Start guide. Re-added a deleted "as" word in a code comment and reflowed comment to respect the maximum length. ] Signed-off-by: Miguel Ojeda --- rust/Makefile | 6 +++--- rust/helpers.c | 15 +++++++-------- rust/kernel/lib.rs | 3 --- scripts/min-tool-version.sh | 2 +- 4 files changed, 11 insertions(+), 15 deletions(-) diff --git a/rust/Makefile b/rust/Makefile index 7c9d9f11aec505..fc8cdcfcc9e598 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -300,7 +300,7 @@ quiet_cmd_bindgen = BINDGEN $@ $(BINDGEN) $< $(bindgen_target_flags) \ --use-core --with-derive-default --ctypes-prefix core::ffi --no-layout-tests \ --no-debug '.*' \ - --size_t-is-usize -o $@ -- $(bindgen_c_flags_final) -DMODULE \ + -o $@ -- $(bindgen_c_flags_final) -DMODULE \ $(bindgen_target_cflags) $(bindgen_target_extra) $(obj)/bindings/bindings_generated.rs: private bindgen_target_flags = \ @@ -320,8 +320,8 @@ $(obj)/uapi/uapi_generated.rs: $(src)/uapi/uapi_helper.h \ # given it is `libclang`; but for consistency, future Clang changes and/or # a potential future GCC backend for `bindgen`, we disable it too. $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_flags = \ - --blacklist-type '.*' --whitelist-var '' \ - --whitelist-function 'rust_helper_.*' + --blocklist-type '.*' --allowlist-var '' \ + --allowlist-function 'rust_helper_.*' $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_cflags = \ -I$(objtree)/$(obj) -Wno-missing-prototypes -Wno-missing-declarations $(obj)/bindings/bindings_helpers_generated.rs: private bindgen_target_extra = ; \ diff --git a/rust/helpers.c b/rust/helpers.c index 81e80261d597c6..05ad112b938293 100644 --- a/rust/helpers.c +++ b/rust/helpers.c @@ -129,19 +129,18 @@ void rust_helper_put_task_struct(struct task_struct *t) EXPORT_SYMBOL_GPL(rust_helper_put_task_struct); /* - * We use `bindgen`'s `--size_t-is-usize` option to bind the C `size_t` type - * as the Rust `usize` type, so we can use it in contexts where Rust - * expects a `usize` like slice (array) indices. `usize` is defined to be - * the same as C's `uintptr_t` type (can hold any pointer) but not - * necessarily the same as `size_t` (can hold the size of any single - * object). Most modern platforms use the same concrete integer type for + * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can + * use it in contexts where Rust expects a `usize` like slice (array) indices. + * `usize` is defined to be the same as C's `uintptr_t` type (can hold any + * pointer) but not necessarily the same as `size_t` (can hold the size of any + * single object). Most modern platforms use the same concrete integer type for * both of them, but in case we find ourselves on a platform where * that's not true, fail early instead of risking ABI or * integer-overflow issues. * * If your platform fails this assertion, it means that you are in - * danger of integer-overflow bugs (even if you attempt to remove - * `--size_t-is-usize`). It may be easiest to change the kernel ABI on + * danger of integer-overflow bugs (even if you attempt to add + * `--no-size_t-is-usize`). It may be easiest to change the kernel ABI on * your platform such that `size_t` matches `uintptr_t` (i.e., to increase * `size_t`, because `uintptr_t` has to be at least as big as `size_t`). */ diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 676995d4e46038..b043a8fc49d8e7 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -97,7 +97,4 @@ fn panic(info: &core::panic::PanicInfo<'_>) -> ! { pr_emerg!("{}\n", info); // SAFETY: FFI call. unsafe { bindings::BUG() }; - // Bindgen currently does not recognize `__noreturn` so `BUG` returns `()` - // instead of `!`. See . - loop {} } diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh index 20d483ec6f5fca..5b80c5d3a9f85a 100755 --- a/scripts/min-tool-version.sh +++ b/scripts/min-tool-version.sh @@ -30,7 +30,7 @@ rustc) echo 1.62.0 ;; bindgen) - echo 0.56.0 + echo 0.65.1 ;; *) echo "$1: unknown tool" >&2