Replace mem::zeroed with mem::MaybeUninit::uninit for large struct in unix

Signed-off-by: xizheyin <xizheyin@smail.nju.edu.cn>

2 files changed, 11 insertions, 5 deletions

diff --git a/library/std/src/sys/net/connection/socket.rs b/library/std/src/sys/net/connection/socket.rs
index b4f0a783680..ddd74b42615 100644
--- a/library/std/src/sys/net/connection/socket.rs
+++ b/library/std/src/sys/net/connection/socket.rs
@@ -557,10 +557,13 @@ impl TcpListener {
     }
 
     pub fn accept(&self) -> io::Result<(TcpStream, SocketAddr)> {
-        let mut storage: c::sockaddr_storage = unsafe { mem::zeroed() };
+        // The `accept` function will fill in the storage with the address,
+        // so we don't need to zero it here.
+        // reference: https://linux.die.net/man/2/accept4
+        let mut storage: mem::MaybeUninit<c::sockaddr_storage> = mem::MaybeUninit::uninit();
         let mut len = mem::size_of_val(&storage) as c::socklen_t;
-        let sock = self.inner.accept((&raw mut storage) as *mut _, &mut len)?;
-        let addr = unsafe { socket_addr_from_c(&storage, len as usize)? };
+        let sock = self.inner.accept(storage.as_mut_ptr() as *mut _, &mut len)?;
+        let addr = unsafe { socket_addr_from_c(storage.as_ptr(), len as usize)? };
         Ok((TcpStream { inner: sock }, addr))
     }
 
diff --git a/library/std/src/sys/net/connection/socket/unix.rs b/library/std/src/sys/net/connection/socket/unix.rs
index 34ab26bc117..29fb47ddca3 100644
--- a/library/std/src/sys/net/connection/socket/unix.rs
+++ b/library/std/src/sys/net/connection/socket/unix.rs
@@ -322,7 +322,10 @@ impl Socket {
         buf: &mut [u8],
         flags: c_int,
     ) -> io::Result<(usize, SocketAddr)> {
-        let mut storage: libc::sockaddr_storage = unsafe { mem::zeroed() };
+        // The `recvfrom` function will fill in the storage with the address,
+        // so we don't need to zero it here.
+        // reference: https://linux.die.net/man/2/recvfrom
+        let mut storage: mem::MaybeUninit<libc::sockaddr_storage> = mem::MaybeUninit::uninit();
         let mut addrlen = mem::size_of_val(&storage) as libc::socklen_t;
 
         let n = cvt(unsafe {
@@ -335,7 +338,7 @@ impl Socket {
                 &mut addrlen,
             )
         })?;
-        Ok((n as usize, unsafe { socket_addr_from_c(&storage, addrlen as usize)? }))
+        Ok((n as usize, unsafe { socket_addr_from_c(storage.as_ptr(), addrlen as usize)? }))
     }
 
     pub fn recv_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {