diff --git a/src/process/fd_table/select.rs b/src/process/fd_table/select.rs
index 38036eb0..e5758e3b 100644
--- a/src/process/fd_table/select.rs
+++ b/src/process/fd_table/select.rs
@@ -1,10 +1,11 @@
 use alloc::{boxed::Box, vec::Vec};
-use core::{future::poll_fn, iter, pin::pin, task::Poll, time::Duration};
+use core::{future::poll_fn, iter, pin::pin, task::Poll};
 use libkernel::{
     error::{KernelError, Result},
     memory::address::TUA,
 };
 
+use super::Fd;
 use crate::{
     clock::timespec::TimeSpec,
     drivers::timer::sleep,
@@ -15,8 +16,6 @@ use crate::{
     sched::syscall_ctx::ProcessCtx,
 };
 
-use super::Fd;
-
 const SET_SIZE: usize = 1024;
 
 #[derive(Clone, Copy, Debug)]
@@ -59,15 +58,15 @@ impl FdSet {
 
 unsafe impl UserCopyable for FdSet {}
 
-// TODO: writefds, exceptfds, timeout.
+// TODO: handle exceptfds
 pub async fn sys_pselect6(
     ctx: &ProcessCtx,
     max: i32,
     readfds: TUA<FdSet>,
-    _writefds: TUA<FdSet>,
+    writefds: TUA<FdSet>,
     _exceptfds: TUA<FdSet>,
     timeout: TUA<TimeSpec>,
-    _mask: TUA<SigSet>,
+    mask: TUA<SigSet>,
 ) -> Result<usize> {
     let task = ctx.shared();
 
@@ -75,10 +74,15 @@ pub async fn sys_pselect6(
 
     let mut read_fds = Vec::new();
 
-    let timeout: Option<Duration> = if timeout.is_null() {
+    let mut write_fd_set = copy_from_user(writefds).await?;
+
+    let mut write_fds = Vec::new();
+
+    let mut timeout_fut = if timeout.is_null() {
         None
     } else {
-        Some(copy_from_user(timeout).await?.into())
+        let duration = copy_from_user(timeout).await?.into();
+        Some(pin!(sleep(duration)))
     };
 
     for fd in read_fd_set.iter_fds(max) {
@@ -98,7 +102,37 @@ pub async fn sys_pselect6(
         ));
     }
 
+    for fd in write_fd_set.iter_fds(max) {
+        let file = task
+            .fd_table
+            .lock_save_irq()
+            .get(fd)
+            .ok_or(KernelError::BadFd)?;
+
+        write_fds.push((
+            Box::pin(async move {
+                let (ops, _) = &mut *file.lock().await;
+
+                ops.poll_write_ready().await
+            }),
+            fd,
+        ));
+    }
+
+    let mask = if mask.is_null() {
+        None
+    } else {
+        Some(copy_from_user(mask).await?)
+    };
+    let old_sigmask = task.sig_mask.load();
+    if let Some(mask) = mask {
+        let mut new_sigmask = mask;
+        new_sigmask.remove(SigSet::UNMASKABLE_SIGNALS);
+        task.sig_mask.store(new_sigmask);
+    }
+
     read_fd_set.zero();
+    write_fd_set.zero();
 
     let n = poll_fn(|cx| {
         let mut num_ready: usize = 0;
@@ -112,15 +146,17 @@ pub async fn sys_pselect6(
             }
         }
 
+        for (fut, fd) in write_fds.iter_mut() {
+            if fut.as_mut().poll(cx).is_ready() {
+                write_fd_set.set_fd(*fd);
+                num_ready += 1;
+            }
+        }
+
         if num_ready == 0 {
-            // Check for the case where both timeout fields are zero:
-            //
-            // If both fields of the timeval structure are zero, then select()
-            // returns immediately.
-            if let Some(timeout) = timeout
-                && timeout.is_zero()
-            {
-                Poll::Ready(0)
+            // Check if done
+            if let Some(ref mut timeout) = timeout_fut {
+                timeout.as_mut().poll(cx).map(|_| 0)
             } else {
                 Poll::Pending
             }
@@ -131,6 +167,10 @@ pub async fn sys_pselect6(
     .await;
 
     copy_to_user(readfds, read_fd_set).await?;
+    copy_to_user(writefds, write_fd_set).await?;
+    if mask.is_some() {
+        task.sig_mask.store(old_sigmask);
+    }
 
     Ok(n)
 }
diff --git a/src/process/thread_group/signal.rs b/src/process/thread_group/signal.rs
index c2289bee..bbf68e51 100644
--- a/src/process/thread_group/signal.rs
+++ b/src/process/thread_group/signal.rs
@@ -54,6 +54,7 @@ bitflags! {
        const SIGIO      = 1 << 28;
        const SIGPWR     = 1 << 29;
        const SIGUNUSED  = 1 << 30;
+       const UNMASKABLE_SIGNALS = Self::SIGKILL.bits() | Self::SIGSTOP.bits();
     }
 }
 
@@ -213,9 +214,6 @@ impl Display for SigId {
     }
 }
 
-// SIGKILL and SIGSTOP
-const UNMASKABLE_SIGNALS: SigSet = SigSet::SIGKILL.union(SigSet::SIGSTOP);
-
 #[derive(Clone, Copy, Debug)]
 pub enum SigActionState {
     Ignore,
diff --git a/src/process/thread_group/signal/sigprocmask.rs b/src/process/thread_group/signal/sigprocmask.rs
index c06d4a55..dc757f72 100644
--- a/src/process/thread_group/signal/sigprocmask.rs
+++ b/src/process/thread_group/signal/sigprocmask.rs
@@ -3,7 +3,7 @@ use crate::sched::syscall_ctx::ProcessCtx;
 use libkernel::error::{KernelError, Result};
 use libkernel::memory::address::TUA;
 
-use super::{SigSet, UNMASKABLE_SIGNALS};
+use super::SigSet;
 
 pub const SIG_BLOCK: u32 = 0;
 pub const SIG_UNBLOCK: u32 = 1;
@@ -39,7 +39,7 @@ pub async fn sys_rt_sigprocmask(
             };
 
             // SIGSTOP and SIGKILL can never be masked.
-            new_sigmask.remove(UNMASKABLE_SIGNALS);
+            new_sigmask.remove(SigSet::UNMASKABLE_SIGNALS);
 
             task.sig_mask.store(new_sigmask);
         }