rust/src/test/ui/command/command-pre-exec.rs
Dominik Stolz 12fbabd27f Do not call getpid wrapper after fork in tests
The test calls libc::getpid() in the pre_exec hook and asserts that the returned value is different from the PID of the parent.
However, libc::getpid() returns the wrong value.
Before version 2.25, glibc caches the PID of the current process with the goal of avoiding additional syscalls.
The cached value is only updated when the wrapper functions for fork or clone are called.
In PR #81825 we switch to directly using the clone3 syscall.
Thus, the cache is not updated and getpid returns the PID of the parent.
source: https://man7.org/linux/man-pages/man2/getpid.2.html#NOTES
2021-08-01 09:45:00 +02:00

118 lines
3.1 KiB
Rust

// run-pass
// revisions: mir thir
// [thir]compile-flags: -Zthir-unsafeck
#![allow(stable_features)]
// ignore-windows - this is a unix-specific test
// ignore-emscripten no processes
// ignore-sgx no processes
#![feature(process_exec, rustc_private)]
use std::env;
use std::io::Error;
use std::os::unix::process::CommandExt;
use std::process::Command;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Arc;
#[cfg(not(target_os = "linux"))]
fn getpid() -> u32 {
use std::process;
process::id()
}
/// We need to directly use the getpid syscall instead of using `process::id()`
/// because the libc wrapper might return incorrect values after a process was
/// forked.
#[cfg(target_os = "linux")]
fn getpid() -> u32 {
extern crate libc;
unsafe {
libc::syscall(libc::SYS_getpid) as _
}
}
fn main() {
if let Some(arg) = env::args().nth(1) {
match &arg[..] {
"test1" => println!("hello2"),
"test2" => assert_eq!(env::var("FOO").unwrap(), "BAR"),
"test3" => assert_eq!(env::current_dir().unwrap().to_str().unwrap(), "/"),
"empty" => {}
_ => panic!("unknown argument: {}", arg),
}
return;
}
let me = env::current_exe().unwrap();
let output = unsafe {
Command::new(&me)
.arg("test1")
.pre_exec(|| {
println!("hello");
Ok(())
})
.output()
.unwrap()
};
assert!(output.status.success());
assert!(output.stderr.is_empty());
assert_eq!(output.stdout, b"hello\nhello2\n");
let output = unsafe {
Command::new(&me)
.arg("test3")
.pre_exec(|| {
env::set_current_dir("/").unwrap();
Ok(())
})
.output()
.unwrap()
};
assert!(output.status.success());
assert!(output.stderr.is_empty());
assert!(output.stdout.is_empty());
let output = unsafe {
Command::new(&me)
.arg("bad")
.pre_exec(|| Err(Error::from_raw_os_error(102)))
.output()
.unwrap_err()
};
assert_eq!(output.raw_os_error(), Some(102));
let pid = getpid();
let output = unsafe {
Command::new(&me)
.arg("empty")
.pre_exec(move || {
let child = getpid();
assert!(pid != child);
Ok(())
})
.output()
.unwrap()
};
assert!(output.status.success());
assert!(output.stderr.is_empty());
assert!(output.stdout.is_empty());
let mem = Arc::new(AtomicUsize::new(0));
let mem2 = mem.clone();
let output = unsafe {
Command::new(&me)
.arg("empty")
.pre_exec(move || {
assert_eq!(mem2.fetch_add(1, Ordering::SeqCst), 0);
Ok(())
})
.output()
.unwrap()
};
assert!(output.status.success());
assert!(output.stderr.is_empty());
assert!(output.stdout.is_empty());
assert_eq!(mem.load(Ordering::SeqCst), 0);
}