finchie/HexOS - Change S2RR5DIKAB5T5J5LL6NJKNPOF3J7HJBPIS5KODP4RFQKRUB2MPDAC

Add tracing support to kernel

The main limitation of this simple implementation is that all events/spans are deliberately sinkholed by the MockSubscriber, as a most off-the-shelf subscribers depend on the standard library. In the future, it would be nice to get those to work properly, but this simple approach should work fine for now.

Created by finchie on December 29, 2023

S2RR5DIKAB5T5J5LL6NJKNPOF3J7HJBPIS5KODP4RFQKRUB2MPDAC

Dependencies

In channels

main

Change contents

File addition: tracing_serial (d--x------)
[3.1]
File addition: src (d--x------)
[0.26]

File addition: lib.rs (----------)

[0.43]

#![no_std]
extern crate alloc;
use alloc::string::{String, ToString};
use core::fmt::Write;
use lazy_static::lazy_static;
use tracing_core::Subscriber;
use tracing_subscriber::Layer;
use uart_16550::SerialPort;
use x86_64::instructions::interrupts;
lazy_static! {
    pub static ref SERIAL1: spin::Mutex<SerialPort> = {
        let mut serial_port = unsafe { SerialPort::new(0x3F8) };
        serial_port.init();
        spin::Mutex::new(serial_port)
    };
}
/// Tracing subscriber that does nothing
// TODO: figure out how to use standard library so can replace with actual subscribers
pub struct MockSubscriber;
/// A layer that prints all events to the serial console
pub struct SerialLayer;
/// Simple visitor that formats any fields attached to spans
struct PrintVisitor(String);
impl<S> Layer<S> for SerialLayer
where
    S: tracing_core::Subscriber,
{
    fn on_event(
        &self,
        event: &tracing_core::Event<'_>,
        _ctx: tracing_subscriber::layer::Context<'_, S>,
    ) {
        let metadata = event.metadata();
        let mut msg = metadata.level().to_string();
        // Attach any location context
        if let Some(location) = metadata.file().or(metadata.module_path()) {
            msg.push(' ');
            msg.push_str(location);
            if let Some(line) = metadata.line() {
                msg.push(':');
                msg.push_str(&line.to_string());
            }
        }
        let mut visitor = PrintVisitor(String::new());
        event.record(&mut visitor);
        msg.push_str(&visitor.0);
        msg.push('\n');
        interrupts::without_interrupts(|| {
            SERIAL1
                .lock()
                .write_str(&msg)
                .expect("Printing to serial failed");
        });
    }
}
impl tracing::field::Visit for PrintVisitor {
    fn record_debug(&mut self, field: &tracing_core::Field, value: &dyn core::fmt::Debug) {
        self.0.push(' ');
        if field.name() != "message" {
            self.0.push_str(field.name());
            self.0.push('=');
        }
        write!(self.0, "{:#?}", value).unwrap();
    }
}
impl Subscriber for MockSubscriber {
    fn enabled(&self, _metadata: &tracing_core::Metadata<'_>) -> bool {
        true
    }
    fn new_span(&self, _span: &tracing_core::span::Attributes<'_>) -> tracing_core::span::Id {
        tracing_core::span::Id::from_u64(0)
    }
    fn record(&self, _span: &tracing_core::span::Id, _values: &tracing_core::span::Record<'_>) {
        ()
    }
    fn record_follows_from(
        &self,
        _span: &tracing_core::span::Id,
        _follows: &tracing_core::span::Id,
    ) {
        ()
    }
    fn event(&self, _event: &tracing_core::Event<'_>) {
        ()
    }
    fn enter(&self, _span: &tracing_core::span::Id) {
        ()
    }
    fn exit(&self, _span: &tracing_core::span::Id) {
        ()
    }
}

File addition: Cargo.toml (----------)

[0.26]

[package]
name = "tracing_serial"
version = "0.1.0"
edition = "2021"
[dependencies]
lazy_static = { version = "1.4.0", features = ["spin_no_std"] }
spin = "0.9.8"
tracing = { version = "0.1.40", default-features = false }
tracing-core = { version = "0.1.32", default-features = false }
tracing-subscriber = { version = "0.3.18", default-features = false, features = [
    "alloc",
] }
uart_16550 = "0.3.0"
x86_64 = "0.14.11"

Insertion in kernel/src/main.rs at line 13 [4.1937]
[2.2365]
[2.2365]
```
use tracing_subscriber::layer::SubscriberExt;
```

Insertion in kernel/src/main.rs at line 46 [4.1937]

[2.3133]

[5.125]


    let serial_layer = tracing_serial::SerialLayer {};
    let subscriber = tracing_serial::MockSubscriber;
    tracing::subscriber::set_global_default(subscriber.with(serial_layer)).unwrap();
    tracing::info!("Initialized kernel");

Insertion in kernel/src/main.rs at line 56 [4.1937]
[5.163]
[4.2192]
```
    tracing::error!(message = "Kernel panic", %info);
```

Insertion in kernel/Cargo.toml at line 10 [4.2242]

[2.4723]

[5.2393]

tracing = { version = "0.1.40", default-features = false }
tracing-subscriber = { version = "0.3.18", default-features = false, features = [
    "alloc",
] }

Insertion in kernel/Cargo.toml at line 15 [4.2242]
[5.2412]
```
tracing_serial = { path = "../tracing_serial" }
```
Replacement in Cargo.toml at line 3 [4.2386]
B:BD[4.2414] → [4.2414:2445]
```
members = ["kernel", "runner"]
```
[4.2414]
[4.2445]
```
members = ["kernel", "runner", "tracing_serial"]
```
Insertion in Cargo.lock at line 513 [4.2547]
[2.5146]
[5.2624]
```
 "tracing",
 "tracing-subscriber",
 "tracing_serial",
```
Replacement in Cargo.lock at line 560 [4.2547]
B:BD[5.2848] → [5.2848:2857]
```
 "spin",
```
[5.2848]
[5.2857]
```
 "spin 0.5.2",
```

Insertion in Cargo.lock at line 741 [4.2547]

[4.20217]

name = "raw-cpuid"
version = "10.7.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "6c297679cb867470fa8c9f67dbba74a78d78e3e98d7cf2b08d6d71540f797332"
dependencies = [
 "bitflags 1.3.2",
]
[[package]]

Insertion in Cargo.lock at line 882 [4.2547]

[5.3232]

[2.5923]


[[package]]
name = "spin"
version = "0.9.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
dependencies = [
 "lock_api",
]

Insertion in Cargo.lock at line 968 [4.2547]

[4.24742]

name = "tracing-subscriber"
version = "0.3.18"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ad0f048c97dbd9faa9b7df56362b8ebcaa52adb06b498c050d2f4e32f90a7a8b"
dependencies = [
 "tracing-core",
]
[[package]]
name = "tracing_serial"
version = "0.1.0"
dependencies = [
 "lazy_static",
 "spin 0.9.8",
 "tracing",
 "tracing-core",
 "tracing-subscriber",
 "uart_16550",
 "x86_64",
]
[[package]]
name = "uart_16550"
version = "0.3.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "6dc00444796f6c71f47c85397a35e9c4dbf9901902ac02386940d178e2b78687"
dependencies = [
 "bitflags 1.3.2",
 "rustversion",
 "x86",
]
[[package]]

Insertion in Cargo.lock at line 1194 [4.2547]

[4.30679]

]
[[package]]
name = "x86"
version = "0.52.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "2781db97787217ad2a2845c396a5efe286f87467a5810836db6d74926e94a385"
dependencies = [
 "bit_field",
 "bitflags 1.3.2",
 "raw-cpuid",

Add tracing support to kernel

Dependencies

In channels

Change contents

File addition: tracing_serial (d--x------)

File addition: src (d--x------)

File addition: lib.rs (----------)

File addition: Cargo.toml (----------)

Insertion in kernel/src/main.rs at line 13 [4.1937]

Insertion in kernel/src/main.rs at line 46 [4.1937]

Insertion in kernel/src/main.rs at line 56 [4.1937]

Insertion in kernel/Cargo.toml at line 10 [4.2242]

Insertion in kernel/Cargo.toml at line 15 [4.2242]

Replacement in Cargo.toml at line 3 [4.2386]

Insertion in Cargo.lock at line 513 [4.2547]

Replacement in Cargo.lock at line 560 [4.2547]

Insertion in Cargo.lock at line 741 [4.2547]

Insertion in Cargo.lock at line 882 [4.2547]

Insertion in Cargo.lock at line 968 [4.2547]

Insertion in Cargo.lock at line 1194 [4.2547]