From patchwork Fri Jun 28 13:23:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alice Ryhl X-Patchwork-Id: 13716139 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A8771BE86E for ; Fri, 28 Jun 2024 13:24:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719581051; cv=none; b=TblbRVSF2UYBpci/kpoBZ82L03H1fS1YWz+3fSsR7DF4YRSU6IqgyFNj42B2Kr2PgS/32VE4VRxdmAPH84Asvr+87MhCUQYLhmKIOTZrNeyPJOA75i34DhShm+zom2QFxcGLFLZS8jsb7I2Ji5EXsNp6q4Ua1ZszDRMLTHRPMHI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719581051; c=relaxed/simple; bh=smlzFG650Bjyj/G17d9Nx6uQENcjy/0hVqprbqaAZSk=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=EzaBfxpifUhTWu1tXvckJmaBbZP0Wjpr0a7DcV1GLlxcSno6Wyq134wrt2A8BaMDFQsP708E5TyVR803/Oi8/SA/z/Dg7x9E2HxJ4Cj1FR2xwyv4RsCNtFaIom3EfEFQ4D3jyrPlbwOjMI9EPGW6fOxst0A3Nq43Wl39caP5VuQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=EQGuf6YD; arc=none smtp.client-ip=209.85.219.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="EQGuf6YD" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-dfdff0a9f26so1131959276.1 for ; Fri, 28 Jun 2024 06:24:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1719581048; x=1720185848; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=/a2ZCUdqZnx3gcLssluxRqmW7oZjQjPUNJsEztKYUiU=; b=EQGuf6YDaIc1yCZjuh9ZPQaCDH0boIuy00WO0StqDMFQNLXsb5TEqX6GxCPsYCyisu 84hmNU3WSiMlr71+ldF3NxMI/z/u1dvowTxUK2cg2I05vr8mvjbqBHwL2lb1iNY3Zoyt SK7R2lZ064jqifNwSngsBNF0AEi9++HJGWsW6c1LXxfHRE06WLCmW4/qC2wLutaHd6UX XmZsQa01DOWGedpqAHaVo1/c8hD7ooEQ3UbKUireP5ffhsdC9Q1rQYMQTtoUjygSQ8DB uY+rilsBbBbBLNZyX9YbY7ogcHik3H9dbAFxSK0yudaKpstnX6MgzCwmrlEahNLDMLGB zIvg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1719581048; x=1720185848; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=/a2ZCUdqZnx3gcLssluxRqmW7oZjQjPUNJsEztKYUiU=; b=utoUUyMxWe5pPK2UbbQCT1cUBda3dMvKrhHcWkGAAtxo3pav2qHqEv6yBmnnwbllfL JH8mabVEi32GZn4c6qazpMsO1/jRsNDMfbklBFGWo+IBGXpqsLsVO3pt5Cpfoyjhy+zx ZIvzxg0BT7OD+tkUA1y0FbkiWNsRUHATGjbo/GRyjxehwsg/Y7H40iwwjJtGdP8CyqM3 FyHMxytoZERCoMXjB3/jkoEjmepEOMxdtl+T8IMNLiWMN5rdyad3TJkHLKbBLXiiI2C+ KbiynfvyjRDDcTdWK9TWf83QYN6J+xaCzGm4fc8apqEW1naEyGGIGPU18Z/lCdvn5whI 9rpw== X-Gm-Message-State: AOJu0Yy/+NuhDPidmVex8uhsFX8kUBNmFud2SzFPxGR5qPP6bA+Sj0Bh K0LLnbT6RdM9KoKdY4v1hWG7yqASbT2s9MP6qBwx4jUBAfvU7KMYfTpUUazoe7a/CUaDNSNEUOl 2f6dgD4Uy2BIsYw== X-Google-Smtp-Source: AGHT+IGK2JbrDPOIj4UtdPPGCRvHLr6NwiAv2YDbVcCcknMSROVSjrnV3BiQa7tDUYtaKr8A5oiO1msI8gMbuL0= X-Received: from aliceryhl2.c.googlers.com ([fda3:e722:ac3:cc00:68:949d:c0a8:572]) (user=aliceryhl job=sendgmr) by 2002:a05:6902:1009:b0:e03:252a:f931 with SMTP id 3f1490d57ef6-e03252afca1mr21180276.1.1719581048085; Fri, 28 Jun 2024 06:24:08 -0700 (PDT) Date: Fri, 28 Jun 2024 13:23:31 +0000 In-Reply-To: <20240628-tracepoint-v4-0-353d523a9c15@google.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240628-tracepoint-v4-0-353d523a9c15@google.com> X-Developer-Key: i=aliceryhl@google.com; a=openpgp; fpr=49F6C1FAA74960F43A5B86A1EE7A392FDE96209F X-Developer-Signature: v=1; a=openpgp-sha256; l=9288; i=aliceryhl@google.com; h=from:subject:message-id; bh=smlzFG650Bjyj/G17d9Nx6uQENcjy/0hVqprbqaAZSk=; b=owEBbQKS/ZANAwAKAQRYvu5YxjlGAcsmYgBmfrlw3bHKyORe0dE0EbrR0xejztmzSskCkdb1q 8YpniSF/amJAjMEAAEKAB0WIQSDkqKUTWQHCvFIvbIEWL7uWMY5RgUCZn65cAAKCRAEWL7uWMY5 RmF6D/4s+/xnuVSiUlgtEsduacVpUm4pE1jcx/Do8fGJ9OQfkiODdmUNe7KHShGgcJff1bKG5jr J0ZxJr/GVN2vslbojoTLkBHwhCEfY/aXJcT6/dmCWylHIKd1Z8xSA4Uf0fVDCph0gmr0+3fDl+3 ND1WW57X9ZfVHYrNw53br5PavOcA/zTYzyyqoXKzUwHYXuRfPlWF+KGCAh5vHSPp+xJMUNJ9/rd xe6DRQ2I6mNjE14bZDgjixPJMnYetZDsn7OHtfGhTcxWNCeOCO+AtkETX+DPb1YywcwJQkbpBSC HT0GMYoa4klrOEj/1IL5aAtIQJjaWuqgOHYOS9+TvHqhfxBq8Zx6n4zibWP23zxPcTOyJect/An uVR+SRz9sbdH0HI2vVszXlm51cx5gNGxIFRYc81pbGbPGO6jLOvkEqPEeYUCCY5nnguSgWDqpjA 9TYpro/ubpYC45Ry9XzS2m2iHQPBaaj4QPYiKO86g1vpdUlp0+FLAoJqyu1WZNk08i8+smeXe7U 3mLF114P0UL1tpd1dwL8eOsFkoHg02AAy6IvTvcCxOR/fDqaT0blCbsr7FFTCyhuuF9EkQrNCW7 xzvTGAOLliUGNSDFfoW/wnVuxKy4GxlwizdVQnlf3CvIZug0MGICixjVL8aALVEQDDweYf5BJGG DAULc4DNwd64I9Q== X-Mailer: b4 0.13-dev-26615 Message-ID: <20240628-tracepoint-v4-1-353d523a9c15@google.com> Subject: [PATCH v4 1/2] rust: add static_key_false From: Alice Ryhl To: Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Peter Zijlstra , Josh Poimboeuf , Jason Baron , Ard Biesheuvel , Miguel Ojeda , Alex Gaynor , Wedson Almeida Filho , Boqun Feng , Gary Guo , " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " , Benno Lossin , Andreas Hindborg Cc: linux-trace-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Arnd Bergmann , linux-arch@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , "Peter Zijlstra (Intel)" , Sean Christopherson , Uros Bizjak , Catalin Marinas , Will Deacon , Marc Zyngier , Oliver Upton , Mark Rutland , Ryan Roberts , Fuad Tabba , linux-arm-kernel@lists.infradead.org, Paul Walmsley , Palmer Dabbelt , Albert Ou , Anup Patel , Andrew Jones , Alexandre Ghiti , Conor Dooley , Samuel Holland , linux-riscv@lists.infradead.org, Huacai Chen , WANG Xuerui , Bibo Mao , Tiezhu Yang , Andrew Morton , Tianrui Zhao , loongarch@lists.linux.dev, Alice Ryhl Add just enough support for static key so that we can use it from tracepoints. Tracepoints rely on `static_key_false` even though it is deprecated, so we add the same functionality to Rust. It is not possible to use the existing C implementation of arch_static_branch because it passes the argument `key` to inline assembly as an 'i' parameter, so any attempt to add a C helper for this function will fail to compile because the value of `key` must be known at compile-time. Signed-off-by: Alice Ryhl Tested-by: WANG Rui Reviewed-by: Gary Guo --- rust/kernel/arch/arm64/jump_label.rs | 34 ++++++++++++++++++++++++++++ rust/kernel/arch/loongarch/jump_label.rs | 35 +++++++++++++++++++++++++++++ rust/kernel/arch/mod.rs | 24 ++++++++++++++++++++ rust/kernel/arch/riscv/jump_label.rs | 38 ++++++++++++++++++++++++++++++++ rust/kernel/arch/x86/jump_label.rs | 35 +++++++++++++++++++++++++++++ rust/kernel/lib.rs | 2 ++ rust/kernel/static_key.rs | 32 +++++++++++++++++++++++++++ scripts/Makefile.build | 2 +- 8 files changed, 201 insertions(+), 1 deletion(-) diff --git a/rust/kernel/arch/arm64/jump_label.rs b/rust/kernel/arch/arm64/jump_label.rs new file mode 100644 index 000000000000..5eede2245718 --- /dev/null +++ b/rust/kernel/arch/arm64/jump_label.rs @@ -0,0 +1,34 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2024 Google LLC. + +//! Arm64 Rust implementation of jump_label.h + +/// arm64 implementation of arch_static_branch +#[macro_export] +#[cfg(target_arch = "aarch64")] +macro_rules! arch_static_branch { + ($key:path, $keytyp:ty, $field:ident, $branch:expr) => {'my_label: { + core::arch::asm!( + r#" + 1: nop + + .pushsection __jump_table, "aw" + .align 3 + .long 1b - ., {0} - . + .quad {1} + {2} + {3} - . + .popsection + "#, + label { + break 'my_label true; + }, + sym $key, + const ::core::mem::offset_of!($keytyp, $field), + const $crate::arch::bool_to_int($branch), + ); + + break 'my_label false; + }}; +} + +pub use arch_static_branch; diff --git a/rust/kernel/arch/loongarch/jump_label.rs b/rust/kernel/arch/loongarch/jump_label.rs new file mode 100644 index 000000000000..8d31318aeb11 --- /dev/null +++ b/rust/kernel/arch/loongarch/jump_label.rs @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2024 Google LLC. + +//! Loongarch Rust implementation of jump_label.h + +/// loongarch implementation of arch_static_branch +#[doc(hidden)] +#[macro_export] +#[cfg(target_arch = "loongarch64")] +macro_rules! arch_static_branch { + ($key:path, $keytyp:ty, $field:ident, $branch:expr) => {'my_label: { + core::arch::asm!( + r#" + 1: nop + + .pushsection __jump_table, "aw" + .align 3 + .long 1b - ., {0} - . + .quad {1} + {2} + {3} - . + .popsection + "#, + label { + break 'my_label true; + }, + sym $key, + const ::core::mem::offset_of!($keytyp, $field), + const $crate::arch::bool_to_int($branch), + ); + + break 'my_label false; + }}; +} + +pub use arch_static_branch; diff --git a/rust/kernel/arch/mod.rs b/rust/kernel/arch/mod.rs new file mode 100644 index 000000000000..14271d2530e9 --- /dev/null +++ b/rust/kernel/arch/mod.rs @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2024 Google LLC. + +//! Architecture specific code. + +#[cfg_attr(target_arch = "aarch64", path = "arm64")] +#[cfg_attr(target_arch = "x86_64", path = "x86")] +#[cfg_attr(target_arch = "loongarch64", path = "loongarch")] +#[cfg_attr(target_arch = "riscv64", path = "riscv")] +mod inner { + pub mod jump_label; +} + +pub use self::inner::*; + +/// A helper used by inline assembly to pass a boolean to as a `const` parameter. +/// +/// Using this function instead of a cast lets you assert that the input is a boolean, rather than +/// some other type that can be cast to an integer. +#[doc(hidden)] +pub const fn bool_to_int(b: bool) -> i32 { + b as i32 +} diff --git a/rust/kernel/arch/riscv/jump_label.rs b/rust/kernel/arch/riscv/jump_label.rs new file mode 100644 index 000000000000..2672e0c6f033 --- /dev/null +++ b/rust/kernel/arch/riscv/jump_label.rs @@ -0,0 +1,38 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2024 Google LLC. + +//! RiscV Rust implementation of jump_label.h + +/// riscv implementation of arch_static_branch +#[macro_export] +#[cfg(target_arch = "riscv64")] +macro_rules! arch_static_branch { + ($key:path, $keytyp:ty, $field:ident, $branch:expr) => {'my_label: { + core::arch::asm!( + r#" + .align 2 + .option push + .option norelax + .option norvc + 1: nop + .option pop + .pushsection __jump_table, "aw" + .align 3 + .long 1b - ., {0} - . + .dword {1} + {2} + {3} - . + .popsection + "#, + label { + break 'my_label true; + }, + sym $key, + const ::core::mem::offset_of!($keytyp, $field), + const $crate::arch::bool_to_int($branch), + ); + + break 'my_label false; + }}; +} + +pub use arch_static_branch; diff --git a/rust/kernel/arch/x86/jump_label.rs b/rust/kernel/arch/x86/jump_label.rs new file mode 100644 index 000000000000..383bed273c50 --- /dev/null +++ b/rust/kernel/arch/x86/jump_label.rs @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2024 Google LLC. + +//! X86 Rust implementation of jump_label.h + +/// x86 implementation of arch_static_branch +#[macro_export] +#[cfg(target_arch = "x86_64")] +macro_rules! arch_static_branch { + ($key:path, $keytyp:ty, $field:ident, $branch:expr) => {'my_label: { + core::arch::asm!( + r#" + 1: .byte 0x0f,0x1f,0x44,0x00,0x00 + + .pushsection __jump_table, "aw" + .balign 8 + .long 1b - . + .long {0} - . + .quad {1} + {2} + {3} - . + .popsection + "#, + label { + break 'my_label true; + }, + sym $key, + const ::core::mem::offset_of!($keytyp, $field), + const $crate::arch::bool_to_int($branch), + ); + + break 'my_label false; + }}; +} + +pub use arch_static_branch; diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index fbd91a48ff8b..fffd4e1dd1c1 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -27,6 +27,7 @@ extern crate self as kernel; pub mod alloc; +pub mod arch; mod build_assert; pub mod error; pub mod init; @@ -38,6 +39,7 @@ pub mod prelude; pub mod print; mod static_assert; +pub mod static_key; #[doc(hidden)] pub mod std_vendor; pub mod str; diff --git a/rust/kernel/static_key.rs b/rust/kernel/static_key.rs new file mode 100644 index 000000000000..32cf027ef091 --- /dev/null +++ b/rust/kernel/static_key.rs @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2024 Google LLC. + +//! Logic for static keys. + +use crate::bindings::*; + +/// 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`. +#[macro_export] +macro_rules! static_key_false { + ($key:path, $keytyp:ty, $field:ident) => {{ + // Assert that `$key` has type `$keytyp` and that `$key.$field` has type `static_key`. + // + // SAFETY: We know that `$key` is a static because otherwise the inline assembly will not + // compile. The raw pointers created in this block are in-bounds of `$key`. + static _TY_ASSERT: () = unsafe { + let key: *const $keytyp = ::core::ptr::addr_of!($key); + let _: *const $crate::bindings::static_key = ::core::ptr::addr_of!((*key).$field); + }; + + $crate::arch::jump_label::arch_static_branch! { $key, $keytyp, $field, false } + }}; +} + +pub use static_key_false; diff --git a/scripts/Makefile.build b/scripts/Makefile.build index efacca63c897..60197c1c063f 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -263,7 +263,7 @@ $(obj)/%.lst: $(obj)/%.c FORCE # Compile Rust sources (.rs) # --------------------------------------------------------------------------- -rust_allowed_features := new_uninit +rust_allowed_features := asm_const,asm_goto,new_uninit # `--out-dir` is required to avoid temporaries being created by `rustc` in the # current working directory, which may be not accessible in the out-of-tree From patchwork Fri Jun 28 13:23:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alice Ryhl X-Patchwork-Id: 13716140 Received: from mail-lf1-f73.google.com (mail-lf1-f73.google.com [209.85.167.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A700F1BF318 for ; Fri, 28 Jun 2024 13:24:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719581055; cv=none; b=rYT8Hd3YxFlsW8HvjsbTZk2oblbKhIsoz9ZsPBquNgHQWGLJ+EWor/1P0RixlEvbK70HgPu65iVeci56S6+7emBqia+iLSPCHWz/cGFSOCVeLPlCEf7GSokcHz14y6tQQRFPYonZUJ8vFN9x5CcwG++pKoQyEKUXg5sGPQriULc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719581055; c=relaxed/simple; bh=v/CwpANb/enEE59VpWuqO+vG2Bs6iq8UapwpRJZ9hQA=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ZfUVqqoNkBH/AlGlv5Ajwan9TbMdmfkatoMTWI7QIFAcbft961L6rXD9gSKIluerVGj1XvzJpPNJ2B9afUn7ROV8G6sJT39ICerygS2BR2EfLWTSmIVtytlcitYZLBLIhvFgUi/8jqTaGVvsiQubol3Ju/QUiwUWb/jNUhQZVhU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=mhCPbRl+; arc=none smtp.client-ip=209.85.167.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="mhCPbRl+" Received: by mail-lf1-f73.google.com with SMTP id 2adb3069b0e04-52ce1688931so566467e87.2 for ; Fri, 28 Jun 2024 06:24:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1719581051; x=1720185851; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=969O3CWF12Jm+ipcoNEWf7U/TfwGyBpHNp6wtcZC710=; b=mhCPbRl+Q865Z4rS0BVo2alLn8Ijd2NW7qi0Ohjy9K/4NCPei3/bDQ959AisXBRXac 67guRJeMdwLpM1La3/1LJHLYHtZ7RS+rz1WM+IPhhTenJEr1MMSbwB4euciSv1b+n2Tt oikN3iEiWBlCegO26ysEbjcEKDGvpDYrqLfT8xVklH3sjCcWvCKiFgmmoNNUjLp4IWUp jJgcHqESwe3n2ugC1xbVqsThkku4iMjHxG/UEO/S6bvI+dR/LrdNyV6QEpTn/vjzzphh ginY2lcAaZg/FF216qEwZsvYzOiwUA3m1X83yU8IyfHsXmkSn0+9cBoLMLQzgeqbEJnV R82A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1719581051; x=1720185851; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=969O3CWF12Jm+ipcoNEWf7U/TfwGyBpHNp6wtcZC710=; b=IKh6uR6caaAZ5YLm/GdzDhEA/xwLkTUUYumW5MP3pZBhkv9Eulzffex0o9v6NOS/Zq 3r4rLHXChwjwZGOobS6Ebq2RoDxJZGcjkooCXvigi+EX1tLHtcnAxZk/yGJeozqSKS0t XXaU18X6ezEutsGFvKK+m7aU162gT+zpG5gr2692vot1q3EbXEBMusUsrRFLihnzh1GD m6IDXSDiLTQWAcYzYswSC5OWaeMKmRz6CVz4Z4rks+nGl5YyA6ZBE+u5lFa1T1gwo6WL GNMNdd3kqE/7F3HNAxuNvgAqLlRU0JJet4nD7kq+bJ8WZak+oocKzD9O6OoWxCBeLzLz p49g== X-Gm-Message-State: AOJu0YzZFYJIL1YSI0l637wPbrU3oDoGqhaAdXaecSJj5hAzXHFGvcYY tZYBsF4cBAKyGOZW7RrgLgbta7tq+fnw9ROFmN7vv4qrkBOpNp5cryeQ5drU0wK/1DV2ofrk8Bt ud2sEj+B8FpOoUg== X-Google-Smtp-Source: AGHT+IHOuhMH8lCZyqgPZo0IUCZguSKcNbXCdaWjj3cdEvBVq1Q+0LN7WSNqoq7E7NvkH+V+nQUqXL0VRBCHifE= X-Received: from aliceryhl2.c.googlers.com ([fda3:e722:ac3:cc00:68:949d:c0a8:572]) (user=aliceryhl job=sendgmr) by 2002:a05:6512:3e28:b0:52c:7f96:81d1 with SMTP id 2adb3069b0e04-52ce061ab41mr20614e87.6.1719581050857; Fri, 28 Jun 2024 06:24:10 -0700 (PDT) Date: Fri, 28 Jun 2024 13:23:32 +0000 In-Reply-To: <20240628-tracepoint-v4-0-353d523a9c15@google.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240628-tracepoint-v4-0-353d523a9c15@google.com> X-Developer-Key: i=aliceryhl@google.com; a=openpgp; fpr=49F6C1FAA74960F43A5B86A1EE7A392FDE96209F X-Developer-Signature: v=1; a=openpgp-sha256; l=5954; i=aliceryhl@google.com; h=from:subject:message-id; bh=v/CwpANb/enEE59VpWuqO+vG2Bs6iq8UapwpRJZ9hQA=; b=owEBbQKS/ZANAwAKAQRYvu5YxjlGAcsmYgBmfrlxFoRsS4nKuM5f791HMS0zaizWUN/GuWPSF 5DmAsQIie+JAjMEAAEKAB0WIQSDkqKUTWQHCvFIvbIEWL7uWMY5RgUCZn65cQAKCRAEWL7uWMY5 Rnn4D/9tLGOpO3gm1Mdg7+V3aBKPndVvoDIfPVKiSkD+ATgpOSjsralpHwXujxhx1IqP3lYgOdz F4tE/qK42GPiG2qOTjpSpJDaMSQfw1d9ndqFJp3KG71VnpHJGL3k4nwnKr4SGu5BoznL6eyv+wX GMjXIqpL1Aml+w5cF+MMfEs4FjjCVM/HRlpM4z5A/gCBUEAQqixk+LexC5R/qvVJJYOxiqTALFu idNa0gDOJwenzkvtOUM8hu1iBrNFC9/7BtwnCQ6dY14wy+j1zXRNORSmO4KK7TqxLuqtVRpBRm+ +ZFo3ePJ2Cv3ppirCqmoxPx2ntkTkPSMtU32nFAWBumNIIUDyH+gG/XFzLYK3nFLghDsB8WjPpZ FpJDBtbmHzuGz4yQU3sNeN6piB8QumLbHKi3cHoLdujMGDkno25gVUSRCXe7h70q0g1x2RlEmjg sFElazH5qpsztWiLuPlFMNPJo7W6iijAV0RGTCLtTYg+NNrInG+xze+KV4I/vuK6GiZkTbR4X21 YDrhSxVEt4S5Kv0bycWgW7FOOGIlWo7tDcn61JvMW8f9acRFHeVsKElIdbwzOnt1ThoUpvUbw7I HwsSEBS9BKACnoLcUCP1aDFTlZqDkmUTMcefFdHWM/6jPz92m7LbDPq2vWSCFmM2u/rum1QCrjY 6gmxPd34WQQHtZA== X-Mailer: b4 0.13-dev-26615 Message-ID: <20240628-tracepoint-v4-2-353d523a9c15@google.com> Subject: [PATCH v4 2/2] rust: add tracepoint support From: Alice Ryhl To: Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Peter Zijlstra , Josh Poimboeuf , Jason Baron , Ard Biesheuvel , Miguel Ojeda , Alex Gaynor , Wedson Almeida Filho , Boqun Feng , Gary Guo , " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " , Benno Lossin , Andreas Hindborg Cc: linux-trace-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Arnd Bergmann , linux-arch@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , "Peter Zijlstra (Intel)" , Sean Christopherson , Uros Bizjak , Catalin Marinas , Will Deacon , Marc Zyngier , Oliver Upton , Mark Rutland , Ryan Roberts , Fuad Tabba , linux-arm-kernel@lists.infradead.org, Paul Walmsley , Palmer Dabbelt , Albert Ou , Anup Patel , Andrew Jones , Alexandre Ghiti , Conor Dooley , Samuel Holland , linux-riscv@lists.infradead.org, Huacai Chen , WANG Xuerui , Bibo Mao , Tiezhu Yang , Andrew Morton , Tianrui Zhao , loongarch@lists.linux.dev, Alice Ryhl Make it possible to have Rust code call into tracepoints defined by C code. It is still required that the tracepoint is declared in a C header, and that this header is included in the input to bindgen. Signed-off-by: Alice Ryhl Reviewed-by: Carlos Llamas --- include/linux/tracepoint.h | 18 +++++++++++++++- include/trace/define_trace.h | 12 +++++++++++ rust/bindings/bindings_helper.h | 1 + rust/kernel/lib.rs | 1 + rust/kernel/tracepoint.rs | 47 +++++++++++++++++++++++++++++++++++++++++ 5 files changed, 78 insertions(+), 1 deletion(-) diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 689b6d71590e..d82af4d77c9f 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -238,6 +238,20 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) #define __DECLARE_TRACE_RCU(name, proto, args, cond) #endif +/* + * Declare an exported function that Rust code can call to trigger this + * tracepoint. This function does not include the static branch; that is done + * in Rust to avoid a function call when the tracepoint is disabled. + */ +#define DEFINE_RUST_DO_TRACE(name, proto, args) +#define DEFINE_RUST_DO_TRACE_REAL(name, proto, args) \ + notrace void rust_do_trace_##name(proto) \ + { \ + __DO_TRACE(name, \ + TP_ARGS(args), \ + cpu_online(raw_smp_processor_id()), 0); \ + } + /* * Make sure the alignment of the structure in the __tracepoints section will * not add unwanted padding between the beginning of the section and the @@ -253,6 +267,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) extern int __traceiter_##name(data_proto); \ DECLARE_STATIC_CALL(tp_func_##name, __traceiter_##name); \ extern struct tracepoint __tracepoint_##name; \ + extern void rust_do_trace_##name(proto); \ static inline void trace_##name(proto) \ { \ if (static_key_false(&__tracepoint_##name.key)) \ @@ -337,7 +352,8 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) void __probestub_##_name(void *__data, proto) \ { \ } \ - DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name); + DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name); \ + DEFINE_RUST_DO_TRACE(_name, TP_PROTO(proto), TP_ARGS(args)) #define DEFINE_TRACE(name, proto, args) \ DEFINE_TRACE_FN(name, NULL, NULL, PARAMS(proto), PARAMS(args)); diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h index 00723935dcc7..08ed5ce63a96 100644 --- a/include/trace/define_trace.h +++ b/include/trace/define_trace.h @@ -72,6 +72,13 @@ #define DECLARE_TRACE(name, proto, args) \ DEFINE_TRACE(name, PARAMS(proto), PARAMS(args)) +/* If requested, create helpers for calling these tracepoints from Rust. */ +#ifdef CREATE_RUST_TRACE_POINTS +#undef DEFINE_RUST_DO_TRACE +#define DEFINE_RUST_DO_TRACE(name, proto, args) \ + DEFINE_RUST_DO_TRACE_REAL(name, PARAMS(proto), PARAMS(args)) +#endif + #undef TRACE_INCLUDE #undef __TRACE_INCLUDE @@ -129,6 +136,11 @@ # undef UNDEF_TRACE_INCLUDE_PATH #endif +#ifdef CREATE_RUST_TRACE_POINTS +# undef DEFINE_RUST_DO_TRACE +# define DEFINE_RUST_DO_TRACE(name, proto, args) +#endif + /* We may be processing more files */ #define CREATE_TRACE_POINTS diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index ddb5644d4fd9..d442f9ccfc2c 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -15,6 +15,7 @@ #include #include #include +#include #include #include diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index fffd4e1dd1c1..9ae90eb69020 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -46,6 +46,7 @@ pub mod sync; pub mod task; pub mod time; +pub mod tracepoint; pub mod types; pub mod workqueue; diff --git a/rust/kernel/tracepoint.rs b/rust/kernel/tracepoint.rs new file mode 100644 index 000000000000..1005f09e0330 --- /dev/null +++ b/rust/kernel/tracepoint.rs @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2024 Google LLC. + +//! Logic for tracepoints. + +/// Declare the Rust entry point for a tracepoint. +#[macro_export] +macro_rules! declare_trace { + ($($(#[$attr:meta])* $pub:vis fn $name:ident($($argname:ident : $argtyp:ty),* $(,)?);)*) => {$( + $( #[$attr] )* + #[inline(always)] + $pub unsafe fn $name($($argname : $argtyp),*) { + #[cfg(CONFIG_TRACEPOINTS)] + { + use $crate::bindings::*; + + // SAFETY: It's always okay to query the static key for a tracepoint. + let should_trace = unsafe { + $crate::macros::paste! { + $crate::static_key::static_key_false!( + [< __tracepoint_ $name >], + $crate::bindings::tracepoint, + key + ) + } + }; + + if should_trace { + $crate::macros::paste! { + // SAFETY: The caller guarantees that it is okay to call this tracepoint. + unsafe { [< rust_do_trace_ $name >]($($argname),*) }; + } + } + } + + #[cfg(not(CONFIG_TRACEPOINTS))] + { + // If tracepoints are disabled, insert a trivial use of each argument + // to avoid unused argument warnings. + $( let _unused = $argname; )* + } + } + )*} +} + +pub use declare_trace;