From c07fdc87e34d001c1c37819bd0cd991ee4964c8f Mon Sep 17 00:00:00 2001
From: LoveSy <shana@zju.edu.cn>
Date: Wed, 1 Oct 2025 19:30:15 +0800
Subject: [PATCH] Handle second splice() failure gracefully

---
 native/src/core/su/pts.rs | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/native/src/core/su/pts.rs b/native/src/core/su/pts.rs
index ba79094c3..b0d47450a 100644
--- a/native/src/core/su/pts.rs
+++ b/native/src/core/su/pts.rs
@@ -10,7 +10,7 @@ use nix::{
 };
 use std::fs::File;
 use std::io::{Read, Write};
-use std::mem::MaybeUninit;
+use std::mem::{ManuallyDrop, MaybeUninit};
 use std::os::fd::{AsFd, AsRawFd, FromRawFd, OwnedFd, RawFd};
 use std::sync::atomic::{AtomicBool, Ordering};
 
@@ -51,20 +51,24 @@ fn pump_via_copy(mut fd_in: &File, mut fd_out: &File) -> LoggedResult<()> {
 }
 
 fn pump_via_splice(fd_in: &File, fd_out: &File, pipe: &(OwnedFd, OwnedFd)) -> LoggedResult<()> {
-    if !SHOULD_USE_SPLICE.load(Ordering::Acquire) {
+    if !SHOULD_USE_SPLICE.load(Ordering::Relaxed) {
         return pump_via_copy(fd_in, fd_out);
     }
 
     // The pipe capacity is by default 16 pages, let's just use 65536
     let Ok(len) = splice(fd_in, &pipe.1, 65536) else {
         // If splice failed, stop using splice and fallback to userspace copy
-        SHOULD_USE_SPLICE.store(false, Ordering::Release);
+        SHOULD_USE_SPLICE.store(false, Ordering::Relaxed);
         return pump_via_copy(fd_in, fd_out);
     };
     if len == 0 {
         return Ok(());
     }
-    splice(&pipe.0, fd_out, len)?;
+    if let Err(_) = splice(&pipe.0, fd_out, len) {
+        // If splice failed, stop using splice and fallback to userspace copy
+        SHOULD_USE_SPLICE.store(false, Ordering::Relaxed);
+        return pump_via_copy(&ManuallyDrop::new(unsafe { File::from_raw_fd(pipe.0.as_raw_fd()) }), fd_out);
+    }
     Ok(())
 }