| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20241011131316.5d6e5d10@eugeo>
Date: Fri, 11 Oct 2024 13:13:16 +0100
From: Gary Guo <gary@...yguo.net>
To: Alice Ryhl <aliceryhl@...gle.com>
Cc: Steven Rostedt <rostedt@...dmis.org>, Masami Hiramatsu
<mhiramat@...nel.org>, Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
Peter Zijlstra <peterz@...radead.org>, Josh Poimboeuf
<jpoimboe@...nel.org>, Jason Baron <jbaron@...mai.com>, Ard Biesheuvel
<ardb@...nel.org>, Miguel Ojeda <ojeda@...nel.org>, Alex Gaynor
<alex.gaynor@...il.com>, Wedson Almeida Filho <wedsonaf@...il.com>, Boqun
Feng <boqun.feng@...il.com>, "Björn Roy Baron"
<bjorn3_gh@...tonmail.com>, Benno Lossin <benno.lossin@...ton.me>, Andreas
Hindborg <a.hindborg@...nel.org>, linux-trace-kernel@...r.kernel.org,
rust-for-linux@...r.kernel.org, linux-kernel@...r.kernel.org, Arnd Bergmann
<arnd@...db.de>, linux-arch@...r.kernel.org, Thomas Gleixner
<tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, Borislav Petkov
<bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
"H. Peter Anvin" <hpa@...or.com>, Sean Christopherson <seanjc@...gle.com>,
Uros Bizjak <ubizjak@...il.com>, Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will@...nel.org>, Marc Zyngier <maz@...nel.org>, Oliver Upton
<oliver.upton@...ux.dev>, Mark Rutland <mark.rutland@....com>, Ryan Roberts
<ryan.roberts@....com>, Fuad Tabba <tabba@...gle.com>,
linux-arm-kernel@...ts.infradead.org, Paul Walmsley
<paul.walmsley@...ive.com>, Palmer Dabbelt <palmer@...belt.com>, Albert Ou
<aou@...s.berkeley.edu>, Anup Patel <apatel@...tanamicro.com>, Andrew Jones
<ajones@...tanamicro.com>, Alexandre Ghiti <alexghiti@...osinc.com>, Conor
Dooley <conor.dooley@...rochip.com>, Samuel Holland
<samuel.holland@...ive.com>, linux-riscv@...ts.infradead.org, Huacai Chen
<chenhuacai@...nel.org>, WANG Xuerui <kernel@...0n.name>, Bibo Mao
<maobibo@...ngson.cn>, Tiezhu Yang <yangtiezhu@...ngson.cn>, Andrew Morton
<akpm@...ux-foundation.org>, Tianrui Zhao <zhaotianrui@...ngson.cn>,
loongarch@...ts.linux.dev
Subject: Re: [PATCH v10 1/5] rust: add static_branch_unlikely for
static_key_false
On Fri, 11 Oct 2024 10:13:34 +0000
Alice Ryhl <aliceryhl@...gle.com> wrote:
> Add just enough support for static key so that we can use it from
> tracepoints. Tracepoints rely on `static_branch_unlikely` with a `struct
> static_key_false`, so we add the same functionality to Rust.
>
> This patch only provides a generic implementation without code patching
> (matching the one used when CONFIG_JUMP_LABEL is disabled). Later
> patches add support for inline asm implementations that use runtime
> patching.
>
> When CONFIG_JUMP_LABEL is unset, `static_key_count` is a static inline
> function, so a Rust helper is defined for `static_key_count` in this
> case. If Rust is compiled with LTO, this call should get inlined. The
> helper can be eliminated once we have the necessary inline asm to make
> atomic operations from Rust.
>
> Reviewed-by: Boqun Feng <boqun.feng@...il.com>
> Signed-off-by: Alice Ryhl <aliceryhl@...gle.com>
> ---
> rust/bindings/bindings_helper.h | 1 +
> rust/helpers/helpers.c | 1 +
> rust/helpers/jump_label.c | 15 +++++++++++++++
> rust/kernel/jump_label.rs | 30 ++++++++++++++++++++++++++++++
> rust/kernel/lib.rs | 1 +
> 5 files changed, 48 insertions(+)
>
> diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
> index ae82e9c941af..e0846e7e93e6 100644
> --- a/rust/bindings/bindings_helper.h
> +++ b/rust/bindings/bindings_helper.h
> @@ -14,6 +14,7 @@
> #include <linux/ethtool.h>
> #include <linux/firmware.h>
> #include <linux/jiffies.h>
> +#include <linux/jump_label.h>
> #include <linux/mdio.h>
> #include <linux/phy.h>
> #include <linux/refcount.h>
> diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
> index 30f40149f3a9..17e1b60d178f 100644
> --- a/rust/helpers/helpers.c
> +++ b/rust/helpers/helpers.c
> @@ -12,6 +12,7 @@
> #include "build_assert.c"
> #include "build_bug.c"
> #include "err.c"
> +#include "jump_label.c"
> #include "kunit.c"
> #include "mutex.c"
> #include "page.c"
> diff --git a/rust/helpers/jump_label.c b/rust/helpers/jump_label.c
> new file mode 100644
> index 000000000000..6948cae5738f
> --- /dev/null
> +++ b/rust/helpers/jump_label.c
> @@ -0,0 +1,15 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +/*
> + * Copyright (C) 2024 Google LLC.
> + */
> +
> +#include <linux/jump_label.h>
> +
> +#ifndef CONFIG_JUMP_LABEL
> +int rust_helper_static_key_count(struct static_key *key)
> +{
> + return static_key_count(key);
> +}
> +EXPORT_SYMBOL_GPL(rust_helper_static_key_count);
^ Explicit export should be removed. This only works because we didn't
remove export.h from all helpers.c yet, but there's a patch to do
that and this will stop working.
You can add a Reviewed-by from me with this fixed.
> +#endif
> diff --git a/rust/kernel/jump_label.rs b/rust/kernel/jump_label.rs
> new file mode 100644
> index 000000000000..4b7655b2a022
> --- /dev/null
> +++ b/rust/kernel/jump_label.rs
> @@ -0,0 +1,30 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +// Copyright (C) 2024 Google LLC.
> +
> +//! Logic for static keys.
> +//!
> +//! C header: [`include/linux/jump_label.h`](srctree/include/linux/jump_label.h).
> +
> +/// Branch based on a static key.
> +///
> +/// Takes three arguments:
> +///
> +/// * `key` - the path to the static variable containing the `static_key`.
> +/// * `keytyp` - the type of `key`.
> +/// * `field` - the name of the field of `key` that contains the `static_key`.
> +///
> +/// # Safety
> +///
> +/// The macro must be used with a real static key defined by C.
> +#[macro_export]
> +macro_rules! static_branch_unlikely {
> + ($key:path, $keytyp:ty, $field:ident) => {{
> + let _key: *const $keytyp = ::core::ptr::addr_of!($key);
> + let _key: *const $crate::bindings::static_key_false = ::core::ptr::addr_of!((*_key).$field);
> + let _key: *const $crate::bindings::static_key = _key.cast();
> +
> + $crate::bindings::static_key_count(_key.cast_mut()) > 0
> + }};
> +}
> +pub use static_branch_unlikely;
> diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
> index b5f4b3ce6b48..708ff817ccc3 100644
> --- a/rust/kernel/lib.rs
> +++ b/rust/kernel/lib.rs
> @@ -36,6 +36,7 @@
> pub mod firmware;
> pub mod init;
> pub mod ioctl;
> +pub mod jump_label;
> #[cfg(CONFIG_KUNIT)]
> pub mod kunit;
> pub mod list;
>
Powered by blists - more mailing lists