fiedzia/rust-usdt

Inject USDT probes into rust code

rust-usdt

Inject USDT probes into rust code. Requires nightly.

Based on work done by Josh Stone [https://github.com/cuviper/rust-libprobe]

For more details, see documentation

Usage:

Cargo.toml:

[dependencies.rust-usdt]
git = "https://github.com/Fiedzia/rust-usdt"

in src/main.rs (as example, but you can insert probes in any place in your code)

#![feature(asm)]
#![feature(plugin)]
#![plugin(rust_usdt)]


fn main() {
    let a = 0i64;
	let b = 1i64;
    static_probe!(provider="foo", name="bar"; a,  i64, b, i64);
}

compile:

cargo build

Make sure probes were generated:

readelf -n ./target/debug/demo | grep NT_STAPSDT -A 4
  stapsdt              0x00000048       NT_STAPSDT (SystemTap probe descriptors)
    Provider: foo
    Name: bar
    Location: 0x000000000000741b, Base: 0x000000000003dc21, Semaphore: 0x0000000000000000
    Arguments: 8@-281(%rbp) 8@-289(%rbp)

Run bcc trace to trace them:

sudo /usr/share/bcc/tools/trace 'u:/home/maciej/git/rust-usdt/demo/demo1/target/debug/usdt_demo:bar "%d", arg1' 

PID    TID    COMM         FUNC             -
8163   8163   demo         bar              0

(you will need to run your app in separate terminal window to see the results)

rust-usdt's Issues

failed to build the demo

I got two errors when tried to build the demo and rust-usdt

error[E0557]: feature has been removed
  --> /root/src/github.com/rust-usdt/src/lib.rs:26:12
   |
26 | #![feature(quote, plugin_registrar, rustc_private)]
   |            ^^^^^ feature has been removed

error[E0463]: can't find crate for `syntax`
  --> /root/src/github.com/rust-usdt/src/lib.rs:29:1
   |
29 | extern crate syntax;
   | ^^^^^^^^^^^^^^^^^^^^ can't find crate

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0463, E0557.
For more information about an error, try `rustc --explain E0463`.
error: could not compile `rust-usdt`.

the version of rustc and cargo I'm using

# rustc --version
rustc 1.46.0-nightly (346aec9b0 2020-07-11)
# cargo --version
cargo 1.46.0-nightly (4f74d9b2a 2020-07-08)

All I did is following the instruction in the Readme, can anyone help?

Publish on crates.io

This doesn't seem to be available on crates.io yet -- is that intentional? It'd be awesome to publish this as, say, usdt, so that people could start using it in their applications :)

Q: Is the platform target really correct?

In mod platform, this is using #[cfg(target_os = "...)] to select the appropriate probe implementation.

However, AIUI compiler plugins are compiled for the host platform, since they have to be loaded in rustc, so this code will see target_os of the host. But this may be different than the target platform that you're generating code for, set by cargo build --target ....

So I suspect this is incorrect for cross-compilation. It probably should use some runtime condition to detect the target and select the probe implementation.

Use driver instead of plugin

Holyjit had the same problem of mir passes being removed. They fixed in nbp/holyjit@bfb32d6. Pay attention to nbp/holyjit@bfb32d6#diff-6bcbac5af87775052ff08ef59d5e1a07R89.