From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ... --- rust/macros/concat_idents.rs | 23 ++++ rust/macros/helpers.rs | 63 ++++++++++ rust/macros/lib.rs | 168 ++++++++++++++++++++++++++ rust/macros/module.rs | 282 +++++++++++++++++++++++++++++++++++++++++++ rust/macros/vtable.rs | 95 +++++++++++++++ 5 files changed, 631 insertions(+) create mode 100644 rust/macros/concat_idents.rs create mode 100644 rust/macros/helpers.rs create mode 100644 rust/macros/lib.rs create mode 100644 rust/macros/module.rs create mode 100644 rust/macros/vtable.rs (limited to 'rust/macros') diff --git a/rust/macros/concat_idents.rs b/rust/macros/concat_idents.rs new file mode 100644 index 000000000..7e4b450f3 --- /dev/null +++ b/rust/macros/concat_idents.rs @@ -0,0 +1,23 @@ +// SPDX-License-Identifier: GPL-2.0 + +use proc_macro::{token_stream, Ident, TokenStream, TokenTree}; + +use crate::helpers::expect_punct; + +fn expect_ident(it: &mut token_stream::IntoIter) -> Ident { + if let Some(TokenTree::Ident(ident)) = it.next() { + ident + } else { + panic!("Expected Ident") + } +} + +pub(crate) fn concat_idents(ts: TokenStream) -> TokenStream { + let mut it = ts.into_iter(); + let a = expect_ident(&mut it); + assert_eq!(expect_punct(&mut it), ','); + let b = expect_ident(&mut it); + assert!(it.next().is_none(), "only two idents can be concatenated"); + let res = Ident::new(&format!("{a}{b}"), b.span()); + TokenStream::from_iter([TokenTree::Ident(res)]) +} diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs new file mode 100644 index 000000000..cf7ad950d --- /dev/null +++ b/rust/macros/helpers.rs @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0 + +use proc_macro::{token_stream, TokenTree}; + +pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option { + if let Some(TokenTree::Ident(ident)) = it.next() { + Some(ident.to_string()) + } else { + None + } +} + +pub(crate) fn try_literal(it: &mut token_stream::IntoIter) -> Option { + if let Some(TokenTree::Literal(literal)) = it.next() { + Some(literal.to_string()) + } else { + None + } +} + +pub(crate) fn try_string(it: &mut token_stream::IntoIter) -> Option { + try_literal(it).and_then(|string| { + if string.starts_with('\"') && string.ends_with('\"') { + let content = &string[1..string.len() - 1]; + if content.contains('\\') { + panic!("Escape sequences in string literals not yet handled"); + } + Some(content.to_string()) + } else if string.starts_with("r\"") { + panic!("Raw string literals are not yet handled"); + } else { + None + } + }) +} + +pub(crate) fn expect_ident(it: &mut token_stream::IntoIter) -> String { + try_ident(it).expect("Expected Ident") +} + +pub(crate) fn expect_punct(it: &mut token_stream::IntoIter) -> char { + if let TokenTree::Punct(punct) = it.next().expect("Reached end of token stream for Punct") { + punct.as_char() + } else { + panic!("Expected Punct"); + } +} + +pub(crate) fn expect_string(it: &mut token_stream::IntoIter) -> String { + try_string(it).expect("Expected string") +} + +pub(crate) fn expect_string_ascii(it: &mut token_stream::IntoIter) -> String { + let string = try_string(it).expect("Expected string"); + assert!(string.is_ascii(), "Expected ASCII string"); + string +} + +pub(crate) fn expect_end(it: &mut token_stream::IntoIter) { + if it.next().is_some() { + panic!("Expected end"); + } +} diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs new file mode 100644 index 000000000..c1d385e34 --- /dev/null +++ b/rust/macros/lib.rs @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Crate for all kernel procedural macros. + +mod concat_idents; +mod helpers; +mod module; +mod vtable; + +use proc_macro::TokenStream; + +/// Declares a kernel module. +/// +/// The `type` argument should be a type which implements the [`Module`] +/// trait. Also accepts various forms of kernel metadata. +/// +/// C header: [`include/linux/moduleparam.h`](../../../include/linux/moduleparam.h) +/// +/// [`Module`]: ../kernel/trait.Module.html +/// +/// # Examples +/// +/// ```ignore +/// use kernel::prelude::*; +/// +/// module!{ +/// type: MyModule, +/// name: "my_kernel_module", +/// author: "Rust for Linux Contributors", +/// description: "My very own kernel module!", +/// license: "GPL", +/// params: { +/// my_i32: i32 { +/// default: 42, +/// permissions: 0o000, +/// description: "Example of i32", +/// }, +/// writeable_i32: i32 { +/// default: 42, +/// permissions: 0o644, +/// description: "Example of i32", +/// }, +/// }, +/// } +/// +/// struct MyModule; +/// +/// impl kernel::Module for MyModule { +/// fn init() -> Result { +/// // If the parameter is writeable, then the kparam lock must be +/// // taken to read the parameter: +/// { +/// let lock = THIS_MODULE.kernel_param_lock(); +/// pr_info!("i32 param is: {}\n", writeable_i32.read(&lock)); +/// } +/// // If the parameter is read only, it can be read without locking +/// // the kernel parameters: +/// pr_info!("i32 param is: {}\n", my_i32.read()); +/// Ok(Self) +/// } +/// } +/// ``` +/// +/// # Supported argument types +/// - `type`: type which implements the [`Module`] trait (required). +/// - `name`: byte array of the name of the kernel module (required). +/// - `author`: byte array of the author of the kernel module. +/// - `description`: byte array of the description of the kernel module. +/// - `license`: byte array of the license of the kernel module (required). +/// - `alias`: byte array of alias name of the kernel module. +#[proc_macro] +pub fn module(ts: TokenStream) -> TokenStream { + module::module(ts) +} + +/// Declares or implements a vtable trait. +/// +/// Linux's use of pure vtables is very close to Rust traits, but they differ +/// in how unimplemented functions are represented. In Rust, traits can provide +/// default implementation for all non-required methods (and the default +/// implementation could just return `Error::EINVAL`); Linux typically use C +/// `NULL` pointers to represent these functions. +/// +/// This attribute is intended to close the gap. Traits can be declared and +/// implemented with the `#[vtable]` attribute, and a `HAS_*` associated constant +/// will be generated for each method in the trait, indicating if the implementor +/// has overridden a method. +/// +/// This attribute is not needed if all methods are required. +/// +/// # Examples +/// +/// ```ignore +/// use kernel::prelude::*; +/// +/// // Declares a `#[vtable]` trait +/// #[vtable] +/// pub trait Operations: Send + Sync + Sized { +/// fn foo(&self) -> Result<()> { +/// Err(EINVAL) +/// } +/// +/// fn bar(&self) -> Result<()> { +/// Err(EINVAL) +/// } +/// } +/// +/// struct Foo; +/// +/// // Implements the `#[vtable]` trait +/// #[vtable] +/// impl Operations for Foo { +/// fn foo(&self) -> Result<()> { +/// # Err(EINVAL) +/// // ... +/// } +/// } +/// +/// assert_eq!(::HAS_FOO, true); +/// assert_eq!(::HAS_BAR, false); +/// ``` +#[proc_macro_attribute] +pub fn vtable(attr: TokenStream, ts: TokenStream) -> TokenStream { + vtable::vtable(attr, ts) +} + +/// Concatenate two identifiers. +/// +/// This is useful in macros that need to declare or reference items with names +/// starting with a fixed prefix and ending in a user specified name. The resulting +/// identifier has the span of the second argument. +/// +/// # Examples +/// +/// ```ignore +/// use kernel::macro::concat_idents; +/// +/// macro_rules! pub_no_prefix { +/// ($prefix:ident, $($newname:ident),+) => { +/// $(pub(crate) const $newname: u32 = kernel::macros::concat_idents!($prefix, $newname);)+ +/// }; +/// } +/// +/// pub_no_prefix!( +/// binder_driver_return_protocol_, +/// BR_OK, +/// BR_ERROR, +/// BR_TRANSACTION, +/// BR_REPLY, +/// BR_DEAD_REPLY, +/// BR_TRANSACTION_COMPLETE, +/// BR_INCREFS, +/// BR_ACQUIRE, +/// BR_RELEASE, +/// BR_DECREFS, +/// BR_NOOP, +/// BR_SPAWN_LOOPER, +/// BR_DEAD_BINDER, +/// BR_CLEAR_DEATH_NOTIFICATION_DONE, +/// BR_FAILED_REPLY +/// ); +/// +/// assert_eq!(BR_OK, binder_driver_return_protocol_BR_OK); +/// ``` +#[proc_macro] +pub fn concat_idents(ts: TokenStream) -> TokenStream { + concat_idents::concat_idents(ts) +} diff --git a/rust/macros/module.rs b/rust/macros/module.rs new file mode 100644 index 000000000..a7e363c2b --- /dev/null +++ b/rust/macros/module.rs @@ -0,0 +1,282 @@ +// SPDX-License-Identifier: GPL-2.0 + +use crate::helpers::*; +use proc_macro::{token_stream, Literal, TokenStream, TokenTree}; +use std::fmt::Write; + +struct ModInfoBuilder<'a> { + module: &'a str, + counter: usize, + buffer: String, +} + +impl<'a> ModInfoBuilder<'a> { + fn new(module: &'a str) -> Self { + ModInfoBuilder { + module, + counter: 0, + buffer: String::new(), + } + } + + fn emit_base(&mut self, field: &str, content: &str, builtin: bool) { + let string = if builtin { + // Built-in modules prefix their modinfo strings by `module.`. + format!( + "{module}.{field}={content}\0", + module = self.module, + field = field, + content = content + ) + } else { + // Loadable modules' modinfo strings go as-is. + format!("{field}={content}\0", field = field, content = content) + }; + + write!( + &mut self.buffer, + " + {cfg} + #[doc(hidden)] + #[link_section = \".modinfo\"] + #[used] + pub static __{module}_{counter}: [u8; {length}] = *{string}; + ", + cfg = if builtin { + "#[cfg(not(MODULE))]" + } else { + "#[cfg(MODULE)]" + }, + module = self.module.to_uppercase(), + counter = self.counter, + length = string.len(), + string = Literal::byte_string(string.as_bytes()), + ) + .unwrap(); + + self.counter += 1; + } + + fn emit_only_builtin(&mut self, field: &str, content: &str) { + self.emit_base(field, content, true) + } + + fn emit_only_loadable(&mut self, field: &str, content: &str) { + self.emit_base(field, content, false) + } + + fn emit(&mut self, field: &str, content: &str) { + self.emit_only_builtin(field, content); + self.emit_only_loadable(field, content); + } +} + +#[derive(Debug, Default)] +struct ModuleInfo { + type_: String, + license: String, + name: String, + author: Option, + description: Option, + alias: Option, +} + +impl ModuleInfo { + fn parse(it: &mut token_stream::IntoIter) -> Self { + let mut info = ModuleInfo::default(); + + const EXPECTED_KEYS: &[&str] = + &["type", "name", "author", "description", "license", "alias"]; + const REQUIRED_KEYS: &[&str] = &["type", "name", "license"]; + let mut seen_keys = Vec::new(); + + loop { + let key = match it.next() { + Some(TokenTree::Ident(ident)) => ident.to_string(), + Some(_) => panic!("Expected Ident or end"), + None => break, + }; + + if seen_keys.contains(&key) { + panic!( + "Duplicated key \"{}\". Keys can only be specified once.", + key + ); + } + + assert_eq!(expect_punct(it), ':'); + + match key.as_str() { + "type" => info.type_ = expect_ident(it), + "name" => info.name = expect_string_ascii(it), + "author" => info.author = Some(expect_string(it)), + "description" => info.description = Some(expect_string(it)), + "license" => info.license = expect_string_ascii(it), + "alias" => info.alias = Some(expect_string_ascii(it)), + _ => panic!( + "Unknown key \"{}\". Valid keys are: {:?}.", + key, EXPECTED_KEYS + ), + } + + assert_eq!(expect_punct(it), ','); + + seen_keys.push(key); + } + + expect_end(it); + + for key in REQUIRED_KEYS { + if !seen_keys.iter().any(|e| e == key) { + panic!("Missing required key \"{}\".", key); + } + } + + let mut ordered_keys: Vec<&str> = Vec::new(); + for key in EXPECTED_KEYS { + if seen_keys.iter().any(|e| e == key) { + ordered_keys.push(key); + } + } + + if seen_keys != ordered_keys { + panic!( + "Keys are not ordered as expected. Order them like: {:?}.", + ordered_keys + ); + } + + info + } +} + +pub(crate) fn module(ts: TokenStream) -> TokenStream { + let mut it = ts.into_iter(); + + let info = ModuleInfo::parse(&mut it); + + let mut modinfo = ModInfoBuilder::new(info.name.as_ref()); + if let Some(author) = info.author { + modinfo.emit("author", &author); + } + if let Some(description) = info.description { + modinfo.emit("description", &description); + } + modinfo.emit("license", &info.license); + if let Some(alias) = info.alias { + modinfo.emit("alias", &alias); + } + + // Built-in modules also export the `file` modinfo string. + let file = + std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable"); + modinfo.emit_only_builtin("file", &file); + + format!( + " + /// The module name. + /// + /// Used by the printing macros, e.g. [`info!`]. + const __LOG_PREFIX: &[u8] = b\"{name}\\0\"; + + /// The \"Rust loadable module\" mark, for `scripts/is_rust_module.sh`. + // + // This may be best done another way later on, e.g. as a new modinfo + // key or a new section. For the moment, keep it simple. + #[cfg(MODULE)] + #[doc(hidden)] + #[used] + static __IS_RUST_MODULE: () = (); + + static mut __MOD: Option<{type_}> = None; + + // SAFETY: `__this_module` is constructed by the kernel at load time and will not be + // freed until the module is unloaded. + #[cfg(MODULE)] + static THIS_MODULE: kernel::ThisModule = unsafe {{ + kernel::ThisModule::from_ptr(&kernel::bindings::__this_module as *const _ as *mut _) + }}; + #[cfg(not(MODULE))] + static THIS_MODULE: kernel::ThisModule = unsafe {{ + kernel::ThisModule::from_ptr(core::ptr::null_mut()) + }}; + + // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. + #[cfg(MODULE)] + #[doc(hidden)] + #[no_mangle] + pub extern \"C\" fn init_module() -> core::ffi::c_int {{ + __init() + }} + + #[cfg(MODULE)] + #[doc(hidden)] + #[no_mangle] + pub extern \"C\" fn cleanup_module() {{ + __exit() + }} + + // Built-in modules are initialized through an initcall pointer + // and the identifiers need to be unique. + #[cfg(not(MODULE))] + #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))] + #[doc(hidden)] + #[link_section = \"{initcall_section}\"] + #[used] + pub static __{name}_initcall: extern \"C\" fn() -> core::ffi::c_int = __{name}_init; + + #[cfg(not(MODULE))] + #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)] + core::arch::global_asm!( + r#\".section \"{initcall_section}\", \"a\" + __{name}_initcall: + .long __{name}_init - . + .previous + \"# + ); + + #[cfg(not(MODULE))] + #[doc(hidden)] + #[no_mangle] + pub extern \"C\" fn __{name}_init() -> core::ffi::c_int {{ + __init() + }} + + #[cfg(not(MODULE))] + #[doc(hidden)] + #[no_mangle] + pub extern \"C\" fn __{name}_exit() {{ + __exit() + }} + + fn __init() -> core::ffi::c_int {{ + match <{type_} as kernel::Module>::init(&THIS_MODULE) {{ + Ok(m) => {{ + unsafe {{ + __MOD = Some(m); + }} + return 0; + }} + Err(e) => {{ + return e.to_kernel_errno(); + }} + }} + }} + + fn __exit() {{ + unsafe {{ + // Invokes `drop()` on `__MOD`, which should be used for cleanup. + __MOD = None; + }} + }} + + {modinfo} + ", + type_ = info.type_, + name = info.name, + modinfo = modinfo.buffer, + initcall_section = ".initcall6.init" + ) + .parse() + .expect("Error parsing formatted string into token stream.") +} diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs new file mode 100644 index 000000000..34d5e7fb5 --- /dev/null +++ b/rust/macros/vtable.rs @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0 + +use proc_macro::{Delimiter, Group, TokenStream, TokenTree}; +use std::collections::HashSet; +use std::fmt::Write; + +pub(crate) fn vtable(_attr: TokenStream, ts: TokenStream) -> TokenStream { + let mut tokens: Vec<_> = ts.into_iter().collect(); + + // Scan for the `trait` or `impl` keyword. + let is_trait = tokens + .iter() + .find_map(|token| match token { + TokenTree::Ident(ident) => match ident.to_string().as_str() { + "trait" => Some(true), + "impl" => Some(false), + _ => None, + }, + _ => None, + }) + .expect("#[vtable] attribute should only be applied to trait or impl block"); + + // Retrieve the main body. The main body should be the last token tree. + let body = match tokens.pop() { + Some(TokenTree::Group(group)) if group.delimiter() == Delimiter::Brace => group, + _ => panic!("cannot locate main body of trait or impl block"), + }; + + let mut body_it = body.stream().into_iter(); + let mut functions = Vec::new(); + let mut consts = HashSet::new(); + while let Some(token) = body_it.next() { + match token { + TokenTree::Ident(ident) if ident.to_string() == "fn" => { + let fn_name = match body_it.next() { + Some(TokenTree::Ident(ident)) => ident.to_string(), + // Possibly we've encountered a fn pointer type instead. + _ => continue, + }; + functions.push(fn_name); + } + TokenTree::Ident(ident) if ident.to_string() == "const" => { + let const_name = match body_it.next() { + Some(TokenTree::Ident(ident)) => ident.to_string(), + // Possibly we've encountered an inline const block instead. + _ => continue, + }; + consts.insert(const_name); + } + _ => (), + } + } + + let mut const_items; + if is_trait { + const_items = " + /// A marker to prevent implementors from forgetting to use [`#[vtable]`](vtable) + /// attribute when implementing this trait. + const USE_VTABLE_ATTR: (); + " + .to_owned(); + + for f in functions { + let gen_const_name = format!("HAS_{}", f.to_uppercase()); + // Skip if it's declared already -- this allows user override. + if consts.contains(&gen_const_name) { + continue; + } + // We don't know on the implementation-site whether a method is required or provided + // so we have to generate a const for all methods. + write!( + const_items, + "/// Indicates if the `{f}` method is overridden by the implementor. + const {gen_const_name}: bool = false;", + ) + .unwrap(); + } + } else { + const_items = "const USE_VTABLE_ATTR: () = ();".to_owned(); + + for f in functions { + let gen_const_name = format!("HAS_{}", f.to_uppercase()); + if consts.contains(&gen_const_name) { + continue; + } + write!(const_items, "const {gen_const_name}: bool = true;").unwrap(); + } + } + + let new_body = vec![const_items.parse().unwrap(), body.stream()] + .into_iter() + .collect(); + tokens.push(TokenTree::Group(Group::new(Delimiter::Brace, new_body))); + tokens.into_iter().collect() +} -- cgit v1.2.3