test(crasht): fix CentOS SIGPIPE tests (#1233)

Co-authored-by: morrisonlevi <[email protected]>

Author: gyuheon0h

bin_tests/src/modes/unix/test_001_sigpipe.rs

@@ -25,8 +25,7 @@ use crate::modes::behavior::{
 use datadog_crashtracker::CrashtrackerConfiguration;
 use libc;
 use nix::sys::socket;
-use std::io::prelude::*;
-use std::os::unix::net::UnixStream;
+use std::os::unix::io::AsRawFd;
 use std::path::{Path, PathBuf};
 use std::sync::atomic::AtomicPtr;
 
@@ -81,17 +80,22 @@ fn inner(output_dir: &Path, filename: &str) -> anyhow::Result<()> {
     let ofile = atom_to_clone(&OUTPUT_FILE)?;
 
     // Cause a SIGPIPE to occur by opening a socketpair, closing the read side, and writing into
-    // the write side.
+    // the write side. Use raw write() syscall to bypass Rust's MSG_NOSIGNAL protection.
     let (reader_fd, writer_fd) = socket::socketpair(
         socket::AddressFamily::Unix,
         socket::SockType::Stream,
         None,
         socket::SockFlag::empty(),
     )?;
     drop(reader_fd);
-    let mut writer = UnixStream::from(writer_fd);
-    if writer.write_all(b"Hello").is_ok() {
-        anyhow::bail!("Expected write to fail, but it succeeded");
+
+    // Use raw write() syscall instead of Rust's write_all() to avoid MSG_NOSIGNAL
+    let writer_raw_fd = writer_fd.as_raw_fd();
+    let write_result =
+        unsafe { libc::write(writer_raw_fd, b"Hello".as_ptr() as *const libc::c_void, 5) };
+
+    if write_result != -1 {
+        anyhow::bail!("Expected write to fail with SIGPIPE, but it succeeded");
     }
 
     // Now check the output file.  Strongly assumes that nothing happened to change the value of

bin_tests/src/modes/unix/test_005_sigpipe_sigstack.rs

@@ -16,8 +16,7 @@ use crate::modes::behavior::{
 use datadog_crashtracker::CrashtrackerConfiguration;
 use libc;
 use nix::sys::socket;
-use std::io::prelude::*;
-use std::os::unix::net::UnixStream;
+use std::os::unix::io::AsRawFd;
 use std::path::{Path, PathBuf};
 use std::sync::atomic::AtomicPtr;
 
@@ -72,17 +71,22 @@ fn inner(output_dir: &Path, filename: &str) -> anyhow::Result<()> {
     let ofile = atom_to_clone(&OUTPUT_FILE)?;
 
     // Cause a SIGPIPE to occur by opening a socketpair, closing the read side, and writing into
-    // the write side.
+    // the write side. Use raw write() syscall to bypass Rust's MSG_NOSIGNAL protection.
     let (reader_fd, writer_fd) = socket::socketpair(
         socket::AddressFamily::Unix,
         socket::SockType::Stream,
         None,
         socket::SockFlag::empty(),
     )?;
     drop(reader_fd);
-    let mut writer = UnixStream::from(writer_fd);
-    if writer.write_all(b"Hello").is_ok() {
-        anyhow::bail!("Expected write to fail, but it succeeded");
+
+    // Use raw write() syscall instead of Rust's write_all() to avoid MSG_NOSIGNAL
+    let writer_raw_fd = writer_fd.as_raw_fd();
+    let write_result =
+        unsafe { libc::write(writer_raw_fd, b"Hello".as_ptr() as *const libc::c_void, 5) };
+
+    if write_result != -1 {
+        anyhow::bail!("Expected write to fail with SIGPIPE, but it succeeded");
     }
 
     // Now check the output file.  Strongly assumes that nothing happened to change the value of