From 555e595d74b2c863e33773c08a754fc9981fb1eb Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 1 May 2026 17:24:36 +0000
Subject: [PATCH 1/3] fix nio read/write iovec bugs causing deadlock and
 infinite loop

Agent-Logs-Url: https://github.com/acl-dev/open-coroutine/sessions/3ee10e36-26e4-49a6-88c3-bc465b166e2f

Co-authored-by: loongs-zhang <38336731+loongs-zhang@users.noreply.github.com>
---
 core/src/syscall/unix/mod.rs    | 12 +++++-------
 core/src/syscall/windows/mod.rs | 18 +++++++++---------
 2 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/core/src/syscall/unix/mod.rs b/core/src/syscall/unix/mod.rs
index f1198be4..1418d382 100644
--- a/core/src/syscall/unix/mod.rs
+++ b/core/src/syscall/unix/mod.rs
@@ -566,8 +566,8 @@ macro_rules! impl_nio_read_iovec {
                 let mut received = 0usize;
                 let mut r = -1;
                 let mut index = 0;
-                for iovec in &vec {
-                    let mut offset = received.saturating_sub(length);
+                'outer: for iovec in &vec {
+                    let offset = received.saturating_sub(length);
                     length += iovec.iov_len;
                     if received > length {
                         index += 1;
@@ -603,11 +603,9 @@ macro_rules! impl_nio_read_iovec {
                         } else if r != -1 {
                             $crate::syscall::reset_errno();
                             received += libc::size_t::try_from(r).expect("r overflow");
-                            if received >= length {
-                                r = received.try_into().expect("received overflow");
-                                break;
-                            }
-                            offset = received.saturating_sub(length);
+                            r = received.try_into().expect("received overflow");
+                            // readv returns as soon as any data is received
+                            break 'outer;
                         }
                         let error_kind = std::io::Error::last_os_error().kind();
                         if error_kind == std::io::ErrorKind::WouldBlock {
diff --git a/core/src/syscall/windows/mod.rs b/core/src/syscall/windows/mod.rs
index d3f418b8..bef7a8bc 100644
--- a/core/src/syscall/windows/mod.rs
+++ b/core/src/syscall/windows/mod.rs
@@ -533,7 +533,7 @@ macro_rules! impl_nio_read_iovec {
                 let mut received = 0usize;
                 let mut r = windows_sys::Win32::Networking::WinSock::SOCKET_ERROR;
                 let mut index = 0;
-                for iovec in &vec {
+                'outer: for iovec in &vec {
                     let mut offset = received.saturating_sub(length);
                     length += iovec.len as usize;
                     if received > length {
@@ -563,13 +563,12 @@ macro_rules! impl_nio_read_iovec {
                         );
                         if r != windows_sys::Win32::Networking::WinSock::SOCKET_ERROR {
                             $crate::syscall::reset_errno();
-                            received += usize::try_from(r).expect("overflow");
-                            if received >= length {
-                                r = 0;
-                                unsafe{ $recvd.write(received.try_into().expect("overflow")) };
-                                break;
-                            }
-                            offset = received.saturating_sub(length);
+                            // WSARecv returns 0 on success; actual byte count is in *$recvd
+                            received += unsafe { *$recvd } as usize;
+                            r = 0;
+                            unsafe{ $recvd.write(received.try_into().expect("overflow")) };
+                            // WSARecv returns as soon as any data is received
+                            break 'outer;
                         }
                         let error_kind = std::io::Error::last_os_error().kind();
                         if error_kind == std::io::ErrorKind::WouldBlock {
@@ -803,7 +802,8 @@ macro_rules! impl_nio_write_iovec {
                         );
                         if r != windows_sys::Win32::Networking::WinSock::SOCKET_ERROR {
                             $crate::syscall::reset_errno();
-                            sent += usize::try_from(r).expect("overflow");
+                            // WSASend returns 0 on success; actual byte count is in *$sent
+                            sent += unsafe { *$sent } as usize;
                             if sent >= length {
                                 r = 0;
                                 unsafe{ $sent.write(sent.try_into().expect("overflow")) };

From b1a1896d40e6a4ffad433996a2c8eb49fa97aabb Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 1 May 2026 17:28:53 +0000
Subject: [PATCH 2/3] remove dead offset code from impl_nio_read_iovec (readv
 returns on first data)

Agent-Logs-Url: https://github.com/acl-dev/open-coroutine/sessions/3ee10e36-26e4-49a6-88c3-bc465b166e2f

Co-authored-by: loongs-zhang <38336731+loongs-zhang@users.noreply.github.com>
---
 core/src/syscall/unix/mod.rs | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/core/src/syscall/unix/mod.rs b/core/src/syscall/unix/mod.rs
index 1418d382..cab27a1d 100644
--- a/core/src/syscall/unix/mod.rs
+++ b/core/src/syscall/unix/mod.rs
@@ -567,7 +567,6 @@ macro_rules! impl_nio_read_iovec {
                 let mut r = -1;
                 let mut index = 0;
                 'outer: for iovec in &vec {
-                    let offset = received.saturating_sub(length);
                     length += iovec.iov_len;
                     if received > length {
                         index += 1;
@@ -578,12 +577,6 @@ macro_rules! impl_nio_read_iovec {
                         arg.push(*i);
                     }
                     while received < length && left_time > 0 {
-                        if 0 != offset {
-                            arg[0] = libc::iovec {
-                                iov_base: (arg[0].iov_base as usize + offset) as *mut std::ffi::c_void,
-                                iov_len: arg[0].iov_len - offset,
-                            };
-                        }
                         r = self.inner.$syscall(
                             fn_ptr,
                             $fd,

From fd44e970efaa8f6aeaa34f8d906c72d18b2fce7e Mon Sep 17 00:00:00 2001
From: loongs-zhang <1936978077@qq.com>
Date: Sat, 2 May 2026 17:07:53 +0800
Subject: [PATCH 3/3] fix impl_nio_read_iovec/impl_nio_write_iovec bug

---
 core/src/syscall/unix/mod.rs    | 24 ++++++++++++++++++------
 core/src/syscall/windows/mod.rs | 27 +++++++++++++++------------
 2 files changed, 33 insertions(+), 18 deletions(-)

diff --git a/core/src/syscall/unix/mod.rs b/core/src/syscall/unix/mod.rs
index cab27a1d..ecb0e301 100644
--- a/core/src/syscall/unix/mod.rs
+++ b/core/src/syscall/unix/mod.rs
@@ -566,7 +566,9 @@ macro_rules! impl_nio_read_iovec {
                 let mut received = 0usize;
                 let mut r = -1;
                 let mut index = 0;
-                'outer: for iovec in &vec {
+                for iovec in &vec {
+                    let stage = length;
+                    let mut offset = received.saturating_sub(stage);
                     length += iovec.iov_len;
                     if received > length {
                         index += 1;
@@ -577,6 +579,13 @@ macro_rules! impl_nio_read_iovec {
                         arg.push(*i);
                     }
                     while received < length && left_time > 0 {
+                        // Assuming iov_len is 4, but only 1 is read, at this point we should continue trying to fill the current iovec
+                        if 0 != offset {
+                            arg[0] = libc::iovec {
+                                iov_base: (arg[0].iov_base as usize + offset) as *mut std::ffi::c_void,
+                                iov_len: arg[0].iov_len - offset,
+                            };
+                        }
                         r = self.inner.$syscall(
                             fn_ptr,
                             $fd,
@@ -596,9 +605,11 @@ macro_rules! impl_nio_read_iovec {
                         } else if r != -1 {
                             $crate::syscall::reset_errno();
                             received += libc::size_t::try_from(r).expect("r overflow");
-                            r = received.try_into().expect("received overflow");
-                            // readv returns as soon as any data is received
-                            break 'outer;
+                            if received >= length {
+                                r = received.try_into().expect("received overflow");
+                                break;
+                            }
+                            offset = received.saturating_sub(stage);
                         }
                         let error_kind = std::io::Error::last_os_error().kind();
                         if error_kind == std::io::ErrorKind::WouldBlock {
@@ -781,7 +792,8 @@ macro_rules! impl_nio_write_iovec {
                 let mut r = -1;
                 let mut index = 0;
                 for iovec in &vec {
-                    let mut offset = sent.saturating_sub(length);
+                    let stage = length;
+                    let mut offset = sent.saturating_sub(stage);
                     length += iovec.iov_len;
                     if sent > length {
                         index += 1;
@@ -814,7 +826,7 @@ macro_rules! impl_nio_write_iovec {
                                 r = sent.try_into().expect("sent overflow");
                                 break;
                             }
-                            offset = sent.saturating_sub(length);
+                            offset = sent.saturating_sub(stage);
                         }
                         let error_kind = std::io::Error::last_os_error().kind();
                         if error_kind == std::io::ErrorKind::WouldBlock {
diff --git a/core/src/syscall/windows/mod.rs b/core/src/syscall/windows/mod.rs
index bef7a8bc..9bf09376 100644
--- a/core/src/syscall/windows/mod.rs
+++ b/core/src/syscall/windows/mod.rs
@@ -533,8 +533,9 @@ macro_rules! impl_nio_read_iovec {
                 let mut received = 0usize;
                 let mut r = windows_sys::Win32::Networking::WinSock::SOCKET_ERROR;
                 let mut index = 0;
-                'outer: for iovec in &vec {
-                    let mut offset = received.saturating_sub(length);
+                for iovec in &vec {
+                    let stage = length;
+                    let mut offset = received.saturating_sub(stage);
                     length += iovec.len as usize;
                     if received > length {
                         index += 1;
@@ -545,6 +546,7 @@ macro_rules! impl_nio_read_iovec {
                         arg.push(*i);
                     }
                     while received < length && left_time > 0 {
+                        // Assuming len is 4, but only 1 is read, at this point we should continue trying to fill the current WSABUF
                         if 0 != offset {
                             arg[0] = windows_sys::Win32::Networking::WinSock::WSABUF {
                                 buf: (arg[0].buf as usize + offset) as windows_sys::core::PSTR,
@@ -563,12 +565,13 @@ macro_rules! impl_nio_read_iovec {
                         );
                         if r != windows_sys::Win32::Networking::WinSock::SOCKET_ERROR {
                             $crate::syscall::reset_errno();
-                            // WSARecv returns 0 on success; actual byte count is in *$recvd
-                            received += unsafe { *$recvd } as usize;
-                            r = 0;
-                            unsafe{ $recvd.write(received.try_into().expect("overflow")) };
-                            // WSARecv returns as soon as any data is received
-                            break 'outer;
+                            received += unsafe{ usize::try_from(*$recvd).expect("overflow") };
+                            if received >= length {
+                                r = 0;
+                                unsafe{ $recvd.write(received.try_into().expect("overflow")) };
+                                break;
+                            }
+                            offset = received.saturating_sub(stage);
                         }
                         let error_kind = std::io::Error::last_os_error().kind();
                         if error_kind == std::io::ErrorKind::WouldBlock {
@@ -773,7 +776,8 @@ macro_rules! impl_nio_write_iovec {
                 let mut r = windows_sys::Win32::Networking::WinSock::SOCKET_ERROR;
                 let mut index = 0;
                 for iovec in &vec {
-                    let mut offset = sent.saturating_sub(length);
+                    let stage = length;
+                    let mut offset = sent.saturating_sub(stage);
                     length += iovec.len as usize;
                     if sent > length {
                         index += 1;
@@ -802,14 +806,13 @@ macro_rules! impl_nio_write_iovec {
                         );
                         if r != windows_sys::Win32::Networking::WinSock::SOCKET_ERROR {
                             $crate::syscall::reset_errno();
-                            // WSASend returns 0 on success; actual byte count is in *$sent
-                            sent += unsafe { *$sent } as usize;
+                            sent += unsafe{ usize::try_from(*$sent).expect("overflow")};
                             if sent >= length {
                                 r = 0;
                                 unsafe{ $sent.write(sent.try_into().expect("overflow")) };
                                 break;
                             }
-                            offset = sent.saturating_sub(length);
+                            offset = sent.saturating_sub(stage);
                         }
                         let error_kind = std::io::Error::last_os_error().kind();
                         if error_kind == std::io::ErrorKind::WouldBlock {