remoteprocess

This crate provides a cross platform way of querying information about other processes running on the system. This let's you build profiling and debugging tools.

Features:

• Suspending the execution of the process
• Getting the process executable name and current working directory
• Listing all the threads in the process
• Getting a stack trace for a thread in the target process
• Resolve symbols for an address in the other process
• Figure out if a thread is active or not

This crate provides implementations for Linux, OSX and Windows.

Usage

To show a stack trace from each thread in a program

fn get_backtrace(pid: remoteprocess::Pid) -> Result<(), remoteprocess::Error> {
    // Create a new handle to the process
    let process = remoteprocess::Process::new(pid)?;

    // lock the process to get a consistent snapshot. Unwinding will fail otherwise
    let _lock = process.lock()?;

    // Create a stack unwind object, and use it to get the stack for each thread
    let unwinder = process.unwinder()?;
    for thread in process.threads()?.iter() {
        println!("Thread {}", thread);

        // Iterate over the callstack for the current thread
        for ip in unwinder.cursor(thread)? {
            let ip = ip?;

            // Lookup the current stack frame containing a filename/function/linenumber etc
            // for the current address
            unwinder.symbolicate(ip, &mut |sf| {
                println!("{}", sf);
            })?;
        }
    }
    Ok(())
}

A complete program with this code can be found in the examples folder.

Credits

This crate heavily relies on the gimli project. Gimli is an amazing tool for parsing DWARF debugging information, and we are using it here for getting stack traces and looking up filename and line numbers given an instruction pointeer.

This crate includes code that was originally written as part of backtrace-rs. In particular, we are using the OSX symbolication code from backtrace-rs, which was modified here to support working with remote processes. This also requires a utility module (dylib.rs) from backtrace-rs to dynamically load the core symbolication framework on OSX, and which is also being used on linux to load libunwind-ptrace if it is installed for a fallback stack unwinder. backtrace-rs is licensed under the MIT license, a copy of which is included in the relevant files here.