From 2affb3567dc7fb42e97da8d5bc7a6b89bdbceb8d Mon Sep 17 00:00:00 2001
From: Santo Cariotti <santo@dcariotti.me>
Date: Sun, 15 Oct 2023 18:46:35 +0200
Subject: Add docs
---
src/main.rs | 3 +++
src/trace.rs | 8 +++++++-
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/src/main.rs b/src/main.rs
index 0694aa5..1859606 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -8,9 +8,12 @@ use nix::unistd::Pid;
#[derive(Parser)]
#[command(author, version, about, long_about = None)]
struct Args {
+ /// Command to execute from ptrace
command: String,
}
+/// Create a fork of the program and execute the process in the child. Parent gets the pid
+/// value and trace it.
fn main() -> anyhow::Result<()> {
let args = Args::parse();
diff --git a/src/trace.rs b/src/trace.rs
index b00b9f9..04b3ecd 100644
--- a/src/trace.rs
+++ b/src/trace.rs
@@ -8,6 +8,7 @@ use nix::{
};
use std::{os::unix::process::CommandExt, process::Command};
+/// Exec the `command` value tracing it with `ptrace` lib
pub fn exec(command: &String) -> anyhow::Result<()> {
let params: Vec<&str> = command.split(' ').collect();
@@ -23,10 +24,13 @@ pub fn exec(command: &String) -> anyhow::Result<()> {
Ok(())
}
+/// Trace a process with `pid` ID
pub fn trace(pid: Pid) -> anyhow::Result<()> {
+ // Since you have to do 2 syscalls (start and end) you have to alternate the print value,
+ // because it could be equals except for the `rax` register.
let mut have_to_print = true;
- // First wait if for the parent process
+ // First wait for the parent process
_ = waitpid(pid, None)?;
loop {
@@ -35,9 +39,11 @@ pub fn trace(pid: Pid) -> anyhow::Result<()> {
let status = waitpid(pid, None)?;
match status {
+ // Break the loop if the process exists
WaitStatus::Exited(_pid, _) => {
break;
}
+ // Match the stopped value for a process
WaitStatus::Stopped(pid, signal) => {
match signal {
Signal::SIGTRAP => {
--
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