diff --git a/kernel/aster-nix/src/syscall/access.rs b/kernel/aster-nix/src/syscall/access.rs
index c0889bebe..1962dfea2 100644
--- a/kernel/aster-nix/src/syscall/access.rs
+++ b/kernel/aster-nix/src/syscall/access.rs
@@ -60,7 +60,7 @@ pub fn do_faccessat(
     let flags = FaccessatFlags::from_bits(flags)
         .ok_or_else(|| Error::with_message(Errno::EINVAL, "Invalid flags"))?;
 
-    let path = CurrentUserSpace::get().read_cstring(path_ptr, PATH_MAX)?;
+    let path = ctx.get_user_space().read_cstring(path_ptr, PATH_MAX)?;
     debug!(
         "dirfd = {}, path = {:?}, mode = {:o}, flags = {:?}",
         dirfd, path, mode, flags
diff --git a/kernel/aster-nix/src/syscall/capget.rs b/kernel/aster-nix/src/syscall/capget.rs
index 5c28a3b9b..7e20462ac 100644
--- a/kernel/aster-nix/src/syscall/capget.rs
+++ b/kernel/aster-nix/src/syscall/capget.rs
@@ -13,7 +13,7 @@ pub fn sys_capget(
     cap_user_data_addr: Vaddr,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let cap_user_header: cap_user_header_t =
         user_space.read_val::<cap_user_header_t>(cap_user_header_addr)?;
 
diff --git a/kernel/aster-nix/src/syscall/capset.rs b/kernel/aster-nix/src/syscall/capset.rs
index b92715c8b..224e9b25e 100644
--- a/kernel/aster-nix/src/syscall/capset.rs
+++ b/kernel/aster-nix/src/syscall/capset.rs
@@ -18,7 +18,7 @@ pub fn sys_capset(
     cap_user_data_addr: Vaddr,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let cap_user_header: cap_user_header_t =
         user_space.read_val::<cap_user_header_t>(cap_user_header_addr)?;
 
diff --git a/kernel/aster-nix/src/syscall/chdir.rs b/kernel/aster-nix/src/syscall/chdir.rs
index 730f9594b..8e9050029 100644
--- a/kernel/aster-nix/src/syscall/chdir.rs
+++ b/kernel/aster-nix/src/syscall/chdir.rs
@@ -8,7 +8,9 @@ use crate::{
 };
 
 pub fn sys_chdir(path_ptr: Vaddr, ctx: &Context) -> Result<SyscallReturn> {
-    let path = CurrentUserSpace::get().read_cstring(path_ptr, MAX_FILENAME_LEN)?;
+    let path = ctx
+        .get_user_space()
+        .read_cstring(path_ptr, MAX_FILENAME_LEN)?;
     debug!("path = {:?}", path);
 
     let mut fs = ctx.process.fs().write();
diff --git a/kernel/aster-nix/src/syscall/chmod.rs b/kernel/aster-nix/src/syscall/chmod.rs
index 476ce3468..d8ede284f 100644
--- a/kernel/aster-nix/src/syscall/chmod.rs
+++ b/kernel/aster-nix/src/syscall/chmod.rs
@@ -31,7 +31,7 @@ pub fn sys_fchmodat(
     /* flags: u32, */
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let path = CurrentUserSpace::get().read_cstring(path_ptr, PATH_MAX)?;
+    let path = ctx.get_user_space().read_cstring(path_ptr, PATH_MAX)?;
     debug!("dirfd = {}, path = {:?}, mode = 0o{:o}", dirfd, path, mode,);
 
     let dentry = {
diff --git a/kernel/aster-nix/src/syscall/chown.rs b/kernel/aster-nix/src/syscall/chown.rs
index 9c08fc3d9..55ba1559f 100644
--- a/kernel/aster-nix/src/syscall/chown.rs
+++ b/kernel/aster-nix/src/syscall/chown.rs
@@ -54,7 +54,7 @@ pub fn sys_fchownat(
     flags: u32,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let path = CurrentUserSpace::get().read_cstring(path_ptr, PATH_MAX)?;
+    let path = ctx.get_user_space().read_cstring(path_ptr, PATH_MAX)?;
     let flags = ChownFlags::from_bits(flags)
         .ok_or_else(|| Error::with_message(Errno::EINVAL, "invalid flags"))?;
     debug!(
diff --git a/kernel/aster-nix/src/syscall/chroot.rs b/kernel/aster-nix/src/syscall/chroot.rs
index 5417ab0f6..d208e1bc2 100644
--- a/kernel/aster-nix/src/syscall/chroot.rs
+++ b/kernel/aster-nix/src/syscall/chroot.rs
@@ -8,7 +8,9 @@ use crate::{
 };
 
 pub fn sys_chroot(path_ptr: Vaddr, ctx: &Context) -> Result<SyscallReturn> {
-    let path = CurrentUserSpace::get().read_cstring(path_ptr, MAX_FILENAME_LEN)?;
+    let path = ctx
+        .get_user_space()
+        .read_cstring(path_ptr, MAX_FILENAME_LEN)?;
     debug!("path = {:?}", path);
 
     let mut fs = ctx.process.fs().write();
diff --git a/kernel/aster-nix/src/syscall/clock_gettime.rs b/kernel/aster-nix/src/syscall/clock_gettime.rs
index 20574f5e6..c4a6031df 100644
--- a/kernel/aster-nix/src/syscall/clock_gettime.rs
+++ b/kernel/aster-nix/src/syscall/clock_gettime.rs
@@ -29,7 +29,7 @@ pub fn sys_clock_gettime(
     let time_duration = read_clock(clockid, ctx)?;
 
     let timespec = timespec_t::from(time_duration);
-    CurrentUserSpace::get().write_val(timespec_addr, &timespec)?;
+    ctx.get_user_space().write_val(timespec_addr, &timespec)?;
 
     Ok(SyscallReturn::Return(0))
 }
diff --git a/kernel/aster-nix/src/syscall/clone.rs b/kernel/aster-nix/src/syscall/clone.rs
index 45cb7ea72..3a3c62576 100644
--- a/kernel/aster-nix/src/syscall/clone.rs
+++ b/kernel/aster-nix/src/syscall/clone.rs
@@ -42,7 +42,7 @@ pub fn sys_clone3(
     }
 
     let clone_args = {
-        let args: Clone3Args = CurrentUserSpace::get().read_val(clong_args_addr)?;
+        let args: Clone3Args = ctx.get_user_space().read_val(clong_args_addr)?;
         trace!("clone3 args = {:x?}", args);
         CloneArgs::from(args)
     };
diff --git a/kernel/aster-nix/src/syscall/epoll.rs b/kernel/aster-nix/src/syscall/epoll.rs
index e11d849dd..a32afefb5 100644
--- a/kernel/aster-nix/src/syscall/epoll.rs
+++ b/kernel/aster-nix/src/syscall/epoll.rs
@@ -61,14 +61,14 @@ pub fn sys_epoll_ctl(
 
     let cmd = match op {
         EPOLL_CTL_ADD => {
-            let c_epoll_event = CurrentUserSpace::get().read_val::<c_epoll_event>(event_addr)?;
+            let c_epoll_event = ctx.get_user_space().read_val::<c_epoll_event>(event_addr)?;
             let event = EpollEvent::from(&c_epoll_event);
             let flags = EpollFlags::from_bits_truncate(c_epoll_event.events);
             EpollCtl::Add(fd, event, flags)
         }
         EPOLL_CTL_DEL => EpollCtl::Del(fd),
         EPOLL_CTL_MOD => {
-            let c_epoll_event = CurrentUserSpace::get().read_val::<c_epoll_event>(event_addr)?;
+            let c_epoll_event = ctx.get_user_space().read_val::<c_epoll_event>(event_addr)?;
             let event = EpollEvent::from(&c_epoll_event);
             let flags = EpollFlags::from_bits_truncate(c_epoll_event.events);
             EpollCtl::Mod(fd, event, flags)
@@ -142,7 +142,7 @@ pub fn sys_epoll_wait(
 
     // Write back
     let mut write_addr = events_addr;
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     for epoll_event in epoll_events.iter() {
         let c_epoll_event = c_epoll_event::from(epoll_event);
         user_space.write_val(write_addr, &c_epoll_event)?;
@@ -154,7 +154,7 @@ pub fn sys_epoll_wait(
 
 fn set_signal_mask(set_ptr: Vaddr, ctx: &Context) -> Result<SigMask> {
     let new_mask: Option<SigMask> = if set_ptr != 0 {
-        Some(CurrentUserSpace::get().read_val::<u64>(set_ptr)?.into())
+        Some(ctx.get_user_space().read_val::<u64>(set_ptr)?.into())
     } else {
         None
     };
@@ -210,7 +210,7 @@ pub fn sys_epoll_pwait(
 
     // Write back
     let mut write_addr = events_addr;
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     for event in ready_events.iter() {
         let c_event = c_epoll_event::from(event);
         user_space.write_val(write_addr, &c_event)?;
diff --git a/kernel/aster-nix/src/syscall/execve.rs b/kernel/aster-nix/src/syscall/execve.rs
index ffc937f17..dc4566c33 100644
--- a/kernel/aster-nix/src/syscall/execve.rs
+++ b/kernel/aster-nix/src/syscall/execve.rs
@@ -24,14 +24,14 @@ pub fn sys_execve(
     argv_ptr_ptr: Vaddr,
     envp_ptr_ptr: Vaddr,
     ctx: &Context,
-    user_ctx: &mut UserContext,
+    user_context: &mut UserContext,
 ) -> Result<SyscallReturn> {
     let elf_file = {
-        let executable_path = read_filename(filename_ptr)?;
+        let executable_path = read_filename(filename_ptr, ctx)?;
         lookup_executable_file(AT_FDCWD, executable_path, OpenFlags::empty(), ctx)?
     };
 
-    do_execve(elf_file, argv_ptr_ptr, envp_ptr_ptr, ctx, user_ctx)?;
+    do_execve(elf_file, argv_ptr_ptr, envp_ptr_ptr, ctx, user_context)?;
     Ok(SyscallReturn::NoReturn)
 }
 
@@ -42,15 +42,15 @@ pub fn sys_execveat(
     envp_ptr_ptr: Vaddr,
     flags: u32,
     ctx: &Context,
-    user_ctx: &mut UserContext,
+    user_context: &mut UserContext,
 ) -> Result<SyscallReturn> {
     let elf_file = {
         let flags = OpenFlags::from_bits_truncate(flags);
-        let filename = read_filename(filename_ptr)?;
+        let filename = read_filename(filename_ptr, ctx)?;
         lookup_executable_file(dfd, filename, flags, ctx)?
     };
 
-    do_execve(elf_file, argv_ptr_ptr, envp_ptr_ptr, ctx, user_ctx)?;
+    do_execve(elf_file, argv_ptr_ptr, envp_ptr_ptr, ctx, user_context)?;
     Ok(SyscallReturn::NoReturn)
 }
 
@@ -84,7 +84,7 @@ fn do_execve(
     argv_ptr_ptr: Vaddr,
     envp_ptr_ptr: Vaddr,
     ctx: &Context,
-    user_ctx: &mut UserContext,
+    user_context: &mut UserContext,
 ) -> Result<()> {
     let Context {
         process,
@@ -94,8 +94,8 @@ fn do_execve(
     } = ctx;
 
     let executable_path = elf_file.abs_path();
-    let argv = read_cstring_vec(argv_ptr_ptr, MAX_ARGV_NUMBER, MAX_ARG_LEN)?;
-    let envp = read_cstring_vec(envp_ptr_ptr, MAX_ENVP_NUMBER, MAX_ENV_LEN)?;
+    let argv = read_cstring_vec(argv_ptr_ptr, MAX_ARGV_NUMBER, MAX_ARG_LEN, ctx)?;
+    let envp = read_cstring_vec(envp_ptr_ptr, MAX_ENVP_NUMBER, MAX_ENV_LEN, ctx)?;
     debug!(
         "filename: {:?}, argv = {:?}, envp = {:?}",
         executable_path, argv, envp
@@ -131,16 +131,16 @@ fn do_execve(
     process.set_executable_path(new_executable_path);
     // set signal disposition to default
     process.sig_dispositions().lock().inherit();
-    // set cpu ctx to default
+    // set cpu context to default
     let default_content = UserContext::default();
-    *user_ctx.general_regs_mut() = *default_content.general_regs();
-    user_ctx.set_tls_pointer(default_content.tls_pointer());
-    *user_ctx.fp_regs_mut() = *default_content.fp_regs();
+    *user_context.general_regs_mut() = *default_content.general_regs();
+    user_context.set_tls_pointer(default_content.tls_pointer());
+    *user_context.fp_regs_mut() = *default_content.fp_regs();
     // set new entry point
-    user_ctx.set_instruction_pointer(elf_load_info.entry_point() as _);
+    user_context.set_instruction_pointer(elf_load_info.entry_point() as _);
     debug!("entry_point: 0x{:x}", elf_load_info.entry_point());
     // set new user stack top
-    user_ctx.set_stack_pointer(elf_load_info.user_stack_top() as _);
+    user_context.set_stack_pointer(elf_load_info.user_stack_top() as _);
     debug!("user stack top: 0x{:x}", elf_load_info.user_stack_top());
     Ok(())
 }
@@ -152,8 +152,10 @@ bitflags::bitflags! {
     }
 }
 
-fn read_filename(filename_ptr: Vaddr) -> Result<String> {
-    let filename = CurrentUserSpace::get().read_cstring(filename_ptr, MAX_FILENAME_LEN)?;
+fn read_filename(filename_ptr: Vaddr, ctx: &Context) -> Result<String> {
+    let filename = ctx
+        .get_user_space()
+        .read_cstring(filename_ptr, MAX_FILENAME_LEN)?;
     Ok(filename.into_string().unwrap())
 }
 
@@ -161,6 +163,7 @@ fn read_cstring_vec(
     array_ptr: Vaddr,
     max_string_number: usize,
     max_string_len: usize,
+    ctx: &Context,
 ) -> Result<Vec<CString>> {
     let mut res = Vec::new();
     // On Linux, argv pointer and envp pointer can be specified as NULL.
@@ -169,7 +172,7 @@ fn read_cstring_vec(
     }
     let mut read_addr = array_ptr;
     let mut find_null = false;
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     for _ in 0..max_string_number {
         let cstring_ptr = user_space.read_val::<usize>(read_addr)?;
         read_addr += 8;
diff --git a/kernel/aster-nix/src/syscall/getcwd.rs b/kernel/aster-nix/src/syscall/getcwd.rs
index 8cace4d25..c1ef00ae8 100644
--- a/kernel/aster-nix/src/syscall/getcwd.rs
+++ b/kernel/aster-nix/src/syscall/getcwd.rs
@@ -3,11 +3,12 @@
 use super::SyscallReturn;
 use crate::prelude::*;
 
-pub fn sys_getcwd(buf: Vaddr, len: usize, _ctx: &Context) -> Result<SyscallReturn> {
+pub fn sys_getcwd(buf: Vaddr, len: usize, ctx: &Context) -> Result<SyscallReturn> {
     // TODO: getcwd only return a fake result now
     let fake_cwd = CString::new("/")?;
     let bytes = fake_cwd.as_bytes_with_nul();
     let write_len = len.min(bytes.len());
-    CurrentUserSpace::get().write_bytes(buf, &mut VmReader::from(&bytes[..write_len]))?;
+    ctx.get_user_space()
+        .write_bytes(buf, &mut VmReader::from(&bytes[..write_len]))?;
     Ok(SyscallReturn::Return(write_len as _))
 }
diff --git a/kernel/aster-nix/src/syscall/getdents64.rs b/kernel/aster-nix/src/syscall/getdents64.rs
index 8c354cee3..adb57c3f6 100644
--- a/kernel/aster-nix/src/syscall/getdents64.rs
+++ b/kernel/aster-nix/src/syscall/getdents64.rs
@@ -37,7 +37,8 @@ pub fn sys_getdents(
     let mut reader = DirentBufferReader::<Dirent>::new(&mut buffer); // Use the non-64-bit reader
     let _ = inode_handle.readdir(&mut reader)?;
     let read_len = reader.read_len();
-    CurrentUserSpace::get().write_bytes(buf_addr, &mut VmReader::from(&buffer[..read_len]))?;
+    ctx.get_user_space()
+        .write_bytes(buf_addr, &mut VmReader::from(&buffer[..read_len]))?;
     Ok(SyscallReturn::Return(read_len as _))
 }
 
@@ -66,7 +67,8 @@ pub fn sys_getdents64(
     let mut reader = DirentBufferReader::<Dirent64>::new(&mut buffer);
     let _ = inode_handle.readdir(&mut reader)?;
     let read_len = reader.read_len();
-    CurrentUserSpace::get().write_bytes(buf_addr, &mut VmReader::from(&buffer[..read_len]))?;
+    ctx.get_user_space()
+        .write_bytes(buf_addr, &mut VmReader::from(&buffer[..read_len]))?;
     Ok(SyscallReturn::Return(read_len as _))
 }
 
diff --git a/kernel/aster-nix/src/syscall/getgroups.rs b/kernel/aster-nix/src/syscall/getgroups.rs
index 4e959d85d..208bc6373 100644
--- a/kernel/aster-nix/src/syscall/getgroups.rs
+++ b/kernel/aster-nix/src/syscall/getgroups.rs
@@ -24,7 +24,7 @@ pub fn sys_getgroups(size: i32, group_list_addr: Vaddr, ctx: &Context) -> Result
         );
     }
 
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     for (idx, gid) in groups.iter().enumerate() {
         let addr = group_list_addr + idx * core::mem::size_of_val(gid);
         user_space.write_val(addr, gid)?;
diff --git a/kernel/aster-nix/src/syscall/getrandom.rs b/kernel/aster-nix/src/syscall/getrandom.rs
index 4857718b1..02a4bfa1e 100644
--- a/kernel/aster-nix/src/syscall/getrandom.rs
+++ b/kernel/aster-nix/src/syscall/getrandom.rs
@@ -3,12 +3,7 @@
 use super::SyscallReturn;
 use crate::{device, prelude::*};
 
-pub fn sys_getrandom(
-    buf: Vaddr,
-    count: usize,
-    flags: u32,
-    _ctx: &Context,
-) -> Result<SyscallReturn> {
+pub fn sys_getrandom(buf: Vaddr, count: usize, flags: u32, ctx: &Context) -> Result<SyscallReturn> {
     let flags = GetRandomFlags::from_bits_truncate(flags);
     debug!(
         "buf = 0x{:x}, count = 0x{:x}, flags = {:?}",
@@ -22,7 +17,8 @@ pub fn sys_getrandom(
     } else {
         device::Urandom::getrandom(&mut buffer)?
     };
-    CurrentUserSpace::get().write_bytes(buf, &mut VmReader::from(buffer.as_slice()))?;
+    ctx.get_user_space()
+        .write_bytes(buf, &mut VmReader::from(buffer.as_slice()))?;
     Ok(SyscallReturn::Return(read_len as isize))
 }
 
diff --git a/kernel/aster-nix/src/syscall/getresgid.rs b/kernel/aster-nix/src/syscall/getresgid.rs
index ba90a4557..4863d0cc7 100644
--- a/kernel/aster-nix/src/syscall/getresgid.rs
+++ b/kernel/aster-nix/src/syscall/getresgid.rs
@@ -12,7 +12,7 @@ pub fn sys_getresgid(
     debug!("rgid_ptr = 0x{rgid_ptr:x}, egid_ptr = 0x{egid_ptr:x}, sgid_ptr = 0x{sgid_ptr:x}");
 
     let credentials = ctx.posix_thread.credentials();
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
 
     let rgid = credentials.rgid();
     user_space.write_val(rgid_ptr, &rgid)?;
diff --git a/kernel/aster-nix/src/syscall/getresuid.rs b/kernel/aster-nix/src/syscall/getresuid.rs
index 519a09af4..dfd2670f0 100644
--- a/kernel/aster-nix/src/syscall/getresuid.rs
+++ b/kernel/aster-nix/src/syscall/getresuid.rs
@@ -12,7 +12,7 @@ pub fn sys_getresuid(
     debug!("ruid_ptr = 0x{ruid_ptr:x}, euid_ptr = 0x{euid_ptr:x}, suid_ptr = 0x{suid_ptr:x}");
 
     let credentials = ctx.posix_thread.credentials();
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
 
     let ruid = credentials.ruid();
     user_space.write_val(ruid_ptr, &ruid)?;
diff --git a/kernel/aster-nix/src/syscall/getrusage.rs b/kernel/aster-nix/src/syscall/getrusage.rs
index b82df6d51..dbe2e96ae 100644
--- a/kernel/aster-nix/src/syscall/getrusage.rs
+++ b/kernel/aster-nix/src/syscall/getrusage.rs
@@ -48,7 +48,7 @@ pub fn sys_getrusage(target: i32, rusage_addr: Vaddr, ctx: &Context) -> Result<S
             }
         };
 
-        CurrentUserSpace::get().write_val(rusage_addr, &rusage)?;
+        ctx.get_user_space().write_val(rusage_addr, &rusage)?;
     }
 
     Ok(SyscallReturn::Return(0))
diff --git a/kernel/aster-nix/src/syscall/getsockopt.rs b/kernel/aster-nix/src/syscall/getsockopt.rs
index 9b2f797e2..1f9925470 100644
--- a/kernel/aster-nix/src/syscall/getsockopt.rs
+++ b/kernel/aster-nix/src/syscall/getsockopt.rs
@@ -13,13 +13,13 @@ pub fn sys_getsockopt(
     optname: i32,
     optval: Vaddr,
     optlen_addr: Vaddr,
-    _ctx: &Context,
+    ctx: &Context,
 ) -> Result<SyscallReturn> {
     let level = CSocketOptionLevel::try_from(level)?;
     if optval == 0 || optlen_addr == 0 {
         return_errno_with_message!(Errno::EINVAL, "optval or optlen_addr is null pointer");
     }
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
 
     let optlen: u32 = user_space.read_val(optlen_addr)?;
     debug!("level = {level:?}, sockfd = {sockfd}, optname = {optname:?}, optlen = {optlen}");
diff --git a/kernel/aster-nix/src/syscall/gettimeofday.rs b/kernel/aster-nix/src/syscall/gettimeofday.rs
index f30204e56..43e566576 100644
--- a/kernel/aster-nix/src/syscall/gettimeofday.rs
+++ b/kernel/aster-nix/src/syscall/gettimeofday.rs
@@ -10,7 +10,7 @@ use crate::{
 // Glibc sets the timezone_addr argument to NULL, so just ignore it.
 pub fn sys_gettimeofday(
     timeval_addr: Vaddr,
-    /* timezone_addr: Vaddr */ _ctx: &Context,
+    /* timezone_addr: Vaddr, */ ctx: &Context,
 ) -> Result<SyscallReturn> {
     if timeval_addr == 0 {
         return Ok(SyscallReturn::Return(0));
@@ -21,7 +21,7 @@ pub fn sys_gettimeofday(
         let time_duration = now.duration_since(&SystemTime::UNIX_EPOCH)?;
         timeval_t::from(time_duration)
     };
-    CurrentUserSpace::get().write_val(timeval_addr, &time_val)?;
+    ctx.get_user_space().write_val(timeval_addr, &time_val)?;
 
     Ok(SyscallReturn::Return(0))
 }
diff --git a/kernel/aster-nix/src/syscall/ioctl.rs b/kernel/aster-nix/src/syscall/ioctl.rs
index 4a36a122e..15ae801ac 100644
--- a/kernel/aster-nix/src/syscall/ioctl.rs
+++ b/kernel/aster-nix/src/syscall/ioctl.rs
@@ -19,14 +19,14 @@ pub fn sys_ioctl(fd: FileDesc, cmd: u32, arg: Vaddr, ctx: &Context) -> Result<Sy
     let file = file_table.get_file(fd)?;
     let res = match ioctl_cmd {
         IoctlCmd::FIONBIO => {
-            let is_nonblocking = CurrentUserSpace::get().read_val::<i32>(arg)? != 0;
+            let is_nonblocking = ctx.get_user_space().read_val::<i32>(arg)? != 0;
             let mut flags = file.status_flags();
             flags.set(StatusFlags::O_NONBLOCK, is_nonblocking);
             file.set_status_flags(flags)?;
             0
         }
         IoctlCmd::FIOASYNC => {
-            let is_async = CurrentUserSpace::get().read_val::<i32>(arg)? != 0;
+            let is_async = ctx.get_user_space().read_val::<i32>(arg)? != 0;
             let mut flags = file.status_flags();
 
             // Set `O_ASYNC` flags will send `SIGIO` signal to a process when
diff --git a/kernel/aster-nix/src/syscall/link.rs b/kernel/aster-nix/src/syscall/link.rs
index b8ad0fd0c..88d732eeb 100644
--- a/kernel/aster-nix/src/syscall/link.rs
+++ b/kernel/aster-nix/src/syscall/link.rs
@@ -18,7 +18,7 @@ pub fn sys_linkat(
     flags: u32,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
 
     let old_path = user_space.read_cstring(old_path_addr, MAX_FILENAME_LEN)?;
     let new_path = user_space.read_cstring(new_path_addr, MAX_FILENAME_LEN)?;
diff --git a/kernel/aster-nix/src/syscall/madvise.rs b/kernel/aster-nix/src/syscall/madvise.rs
index 34734eaaf..5b12bb7dc 100644
--- a/kernel/aster-nix/src/syscall/madvise.rs
+++ b/kernel/aster-nix/src/syscall/madvise.rs
@@ -20,7 +20,7 @@ pub fn sys_madvise(
         | MadviseBehavior::MADV_WILLNEED => {
             // perform a read at first
             let mut buffer = vec![0u8; len];
-            CurrentUserSpace::get()
+            ctx.get_user_space()
                 .read_bytes(start, &mut VmWriter::from(buffer.as_mut_slice()))?;
         }
         MadviseBehavior::MADV_DONTNEED => {
diff --git a/kernel/aster-nix/src/syscall/mkdir.rs b/kernel/aster-nix/src/syscall/mkdir.rs
index 844346462..77526c750 100644
--- a/kernel/aster-nix/src/syscall/mkdir.rs
+++ b/kernel/aster-nix/src/syscall/mkdir.rs
@@ -17,7 +17,9 @@ pub fn sys_mkdirat(
     mode: u16,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let path = CurrentUserSpace::get().read_cstring(path_addr, MAX_FILENAME_LEN)?;
+    let path = ctx
+        .get_user_space()
+        .read_cstring(path_addr, MAX_FILENAME_LEN)?;
     debug!("dirfd = {}, path = {:?}, mode = {}", dirfd, path, mode);
 
     let current = ctx.process;
diff --git a/kernel/aster-nix/src/syscall/mknod.rs b/kernel/aster-nix/src/syscall/mknod.rs
index cddbc886b..a673014de 100644
--- a/kernel/aster-nix/src/syscall/mknod.rs
+++ b/kernel/aster-nix/src/syscall/mknod.rs
@@ -19,7 +19,9 @@ pub fn sys_mknodat(
     dev: usize,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let path = CurrentUserSpace::get().read_cstring(path_addr, MAX_FILENAME_LEN)?;
+    let path = ctx
+        .get_user_space()
+        .read_cstring(path_addr, MAX_FILENAME_LEN)?;
     let current = ctx.process;
     let inode_mode = {
         let mask_mode = mode & !current.umask().read().get();
diff --git a/kernel/aster-nix/src/syscall/mount.rs b/kernel/aster-nix/src/syscall/mount.rs
index 89fc6c0f4..606203d24 100644
--- a/kernel/aster-nix/src/syscall/mount.rs
+++ b/kernel/aster-nix/src/syscall/mount.rs
@@ -25,7 +25,7 @@ pub fn sys_mount(
     data: Vaddr,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let devname = user_space.read_cstring(devname_addr, MAX_FILENAME_LEN)?;
     let dirname = user_space.read_cstring(dirname_addr, MAX_FILENAME_LEN)?;
     let mount_flags = MountFlags::from_bits_truncate(flags as u32);
@@ -63,7 +63,7 @@ pub fn sys_mount(
     } else if mount_flags.contains(MountFlags::MS_MOVE) {
         do_move_mount_old(devname, dst_dentry, ctx)?;
     } else {
-        do_new_mount(devname, fstype_addr, dst_dentry)?;
+        do_new_mount(devname, fstype_addr, dst_dentry, ctx)?;
     }
 
     Ok(SyscallReturn::Return(0))
@@ -132,12 +132,19 @@ fn do_move_mount_old(src_name: CString, dst_dentry: Arc<Dentry>, ctx: &Context)
 }
 
 /// Mount a new filesystem.
-fn do_new_mount(devname: CString, fs_type: Vaddr, target_dentry: Arc<Dentry>) -> Result<()> {
+fn do_new_mount(
+    devname: CString,
+    fs_type: Vaddr,
+    target_dentry: Arc<Dentry>,
+    ctx: &Context,
+) -> Result<()> {
     if target_dentry.type_() != InodeType::Dir {
         return_errno_with_message!(Errno::ENOTDIR, "mountpoint must be directory");
     };
 
-    let fs_type = CurrentUserSpace::get().read_cstring(fs_type, MAX_FILENAME_LEN)?;
+    let fs_type = ctx
+        .get_user_space()
+        .read_cstring(fs_type, MAX_FILENAME_LEN)?;
     if fs_type.is_empty() {
         return_errno_with_message!(Errno::EINVAL, "fs_type is empty");
     }
diff --git a/kernel/aster-nix/src/syscall/nanosleep.rs b/kernel/aster-nix/src/syscall/nanosleep.rs
index f430ade23..241b94420 100644
--- a/kernel/aster-nix/src/syscall/nanosleep.rs
+++ b/kernel/aster-nix/src/syscall/nanosleep.rs
@@ -57,7 +57,9 @@ fn do_clock_nanosleep(
     ctx: &Context,
 ) -> Result<SyscallReturn> {
     let request_time = {
-        let timespec = CurrentUserSpace::get().read_val::<timespec_t>(request_timespec_addr)?;
+        let timespec = ctx
+            .get_user_space()
+            .read_val::<timespec_t>(request_timespec_addr)?;
         Duration::try_from(timespec)?
     };
 
@@ -94,7 +96,8 @@ fn do_clock_nanosleep(
             if remain_timespec_addr != 0 && !is_abs_time {
                 let remaining_duration = (start_time + timeout) - end_time;
                 let remaining_timespec = timespec_t::from(remaining_duration);
-                CurrentUserSpace::get().write_val(remain_timespec_addr, &remaining_timespec)?;
+                ctx.get_user_space()
+                    .write_val(remain_timespec_addr, &remaining_timespec)?;
             }
 
             return_errno_with_message!(Errno::EINTR, "sleep was interrupted");
diff --git a/kernel/aster-nix/src/syscall/open.rs b/kernel/aster-nix/src/syscall/open.rs
index f66ade271..6c323e9d0 100644
--- a/kernel/aster-nix/src/syscall/open.rs
+++ b/kernel/aster-nix/src/syscall/open.rs
@@ -18,7 +18,9 @@ pub fn sys_openat(
     mode: u16,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let path = CurrentUserSpace::get().read_cstring(path_addr, MAX_FILENAME_LEN)?;
+    let path = ctx
+        .get_user_space()
+        .read_cstring(path_addr, MAX_FILENAME_LEN)?;
     debug!(
         "dirfd = {}, path = {:?}, flags = {}, mode = {}",
         dirfd, path, flags, mode
diff --git a/kernel/aster-nix/src/syscall/pipe.rs b/kernel/aster-nix/src/syscall/pipe.rs
index a3556620e..223008e26 100644
--- a/kernel/aster-nix/src/syscall/pipe.rs
+++ b/kernel/aster-nix/src/syscall/pipe.rs
@@ -38,7 +38,7 @@ pub fn sys_pipe2(fds: Vaddr, flags: u32, ctx: &Context) -> Result<SyscallReturn>
     };
     debug!("pipe_fds: {:?}", pipe_fds);
 
-    if let Err(err) = CurrentUserSpace::get().write_val(fds, &pipe_fds) {
+    if let Err(err) = ctx.get_user_space().write_val(fds, &pipe_fds) {
         file_table.close_file(pipe_fds.reader_fd).unwrap();
         file_table.close_file(pipe_fds.writer_fd).unwrap();
         return Err(err);
diff --git a/kernel/aster-nix/src/syscall/poll.rs b/kernel/aster-nix/src/syscall/poll.rs
index 929c1a4cc..a1166e76f 100644
--- a/kernel/aster-nix/src/syscall/poll.rs
+++ b/kernel/aster-nix/src/syscall/poll.rs
@@ -6,7 +6,7 @@ use super::SyscallReturn;
 use crate::{events::IoEvents, fs::file_table::FileDesc, prelude::*, process::signal::Poller};
 
 pub fn sys_poll(fds: Vaddr, nfds: u64, timeout: i32, ctx: &Context) -> Result<SyscallReturn> {
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let poll_fds = {
         let mut read_addr = fds;
         let mut poll_fds = Vec::with_capacity(nfds as _);
diff --git a/kernel/aster-nix/src/syscall/prctl.rs b/kernel/aster-nix/src/syscall/prctl.rs
index dea978f33..90f3db039 100644
--- a/kernel/aster-nix/src/syscall/prctl.rs
+++ b/kernel/aster-nix/src/syscall/prctl.rs
@@ -28,7 +28,7 @@ pub fn sys_prctl(
                 }
             };
 
-            CurrentUserSpace::get().write_val(write_to_addr, &write_val)?;
+            ctx.get_user_space().write_val(write_to_addr, &write_val)?;
         }
         PrctlCmd::PR_GET_DUMPABLE => {
             // TODO: when coredump is supported, return the actual value
@@ -45,7 +45,7 @@ pub fn sys_prctl(
             let thread_name = ctx.posix_thread.thread_name().lock();
             if let Some(thread_name) = &*thread_name {
                 if let Some(thread_name) = thread_name.name()? {
-                    CurrentUserSpace::get().write_bytes(
+                    ctx.get_user_space().write_bytes(
                         write_to_addr,
                         &mut VmReader::from(thread_name.to_bytes_with_nul()),
                     )?;
@@ -55,8 +55,9 @@ pub fn sys_prctl(
         PrctlCmd::PR_SET_NAME(read_addr) => {
             let mut thread_name = ctx.posix_thread.thread_name().lock();
             if let Some(thread_name) = &mut *thread_name {
-                let new_thread_name =
-                    CurrentUserSpace::get().read_cstring(read_addr, MAX_THREAD_NAME_LEN)?;
+                let new_thread_name = ctx
+                    .get_user_space()
+                    .read_cstring(read_addr, MAX_THREAD_NAME_LEN)?;
                 thread_name.set_name(&new_thread_name)?;
             }
         }
diff --git a/kernel/aster-nix/src/syscall/pread64.rs b/kernel/aster-nix/src/syscall/pread64.rs
index 9c058bd25..0ba295db9 100644
--- a/kernel/aster-nix/src/syscall/pread64.rs
+++ b/kernel/aster-nix/src/syscall/pread64.rs
@@ -33,7 +33,7 @@ pub fn sys_pread64(
     let read_len = {
         let mut buffer = vec![0u8; user_buf_len];
         let read_len = file.read_at(offset as usize, &mut buffer)?;
-        CurrentUserSpace::get()
+        ctx.get_user_space()
             .write_bytes(user_buf_ptr, &mut VmReader::from(buffer.as_slice()))?;
         read_len
     };
diff --git a/kernel/aster-nix/src/syscall/prlimit64.rs b/kernel/aster-nix/src/syscall/prlimit64.rs
index d83b5e180..62c02082a 100644
--- a/kernel/aster-nix/src/syscall/prlimit64.rs
+++ b/kernel/aster-nix/src/syscall/prlimit64.rs
@@ -21,10 +21,10 @@ pub fn sys_prlimit64(
     let mut resource_limits = ctx.process.resource_limits().lock();
     if old_rlim_addr != 0 {
         let rlimit = resource_limits.get_rlimit(resource);
-        CurrentUserSpace::get().write_val(old_rlim_addr, rlimit)?;
+        ctx.get_user_space().write_val(old_rlim_addr, rlimit)?;
     }
     if new_rlim_addr != 0 {
-        let new_rlimit = CurrentUserSpace::get().read_val(new_rlim_addr)?;
+        let new_rlimit = ctx.get_user_space().read_val(new_rlim_addr)?;
         *resource_limits.get_rlimit_mut(resource) = new_rlimit;
     }
     Ok(SyscallReturn::Return(0))
diff --git a/kernel/aster-nix/src/syscall/pselect6.rs b/kernel/aster-nix/src/syscall/pselect6.rs
index c409babcc..9402f48ac 100644
--- a/kernel/aster-nix/src/syscall/pselect6.rs
+++ b/kernel/aster-nix/src/syscall/pselect6.rs
@@ -16,7 +16,7 @@ pub fn sys_pselect6(
     sigmask_addr: Vaddr,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let old_simask = if sigmask_addr != 0 {
         let sigmask_with_size: SigMaskWithSize = user_space.read_val(sigmask_addr)?;
 
diff --git a/kernel/aster-nix/src/syscall/pwrite64.rs b/kernel/aster-nix/src/syscall/pwrite64.rs
index 335545b7a..0779af3d7 100644
--- a/kernel/aster-nix/src/syscall/pwrite64.rs
+++ b/kernel/aster-nix/src/syscall/pwrite64.rs
@@ -30,7 +30,8 @@ pub fn sys_pwrite64(
     }
 
     let mut buffer = vec![0u8; user_buf_len];
-    CurrentUserSpace::get().read_bytes(user_buf_ptr, &mut VmWriter::from(buffer.as_mut_slice()))?;
+    ctx.get_user_space()
+        .read_bytes(user_buf_ptr, &mut VmWriter::from(buffer.as_mut_slice()))?;
     let write_len = file.write_at(offset as _, &buffer)?;
     Ok(SyscallReturn::Return(write_len as _))
 }
diff --git a/kernel/aster-nix/src/syscall/read.rs b/kernel/aster-nix/src/syscall/read.rs
index 502bc2aa8..da7e2dd22 100644
--- a/kernel/aster-nix/src/syscall/read.rs
+++ b/kernel/aster-nix/src/syscall/read.rs
@@ -27,7 +27,7 @@ pub fn sys_read(
     let read_len = if buf_len != 0 {
         let mut read_buf = vec![0u8; buf_len];
         let read_len = file.read(&mut read_buf)?;
-        CurrentUserSpace::get().write_bytes(
+        ctx.get_user_space().write_bytes(
             user_buf_addr,
             &mut VmReader::from(&read_buf[..min(read_len, buf_len)]),
         )?;
diff --git a/kernel/aster-nix/src/syscall/readlink.rs b/kernel/aster-nix/src/syscall/readlink.rs
index 365f743f5..a654d4084 100644
--- a/kernel/aster-nix/src/syscall/readlink.rs
+++ b/kernel/aster-nix/src/syscall/readlink.rs
@@ -17,7 +17,7 @@ pub fn sys_readlinkat(
     usr_buf_len: usize,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let path = user_space.read_cstring(path_addr, MAX_FILENAME_LEN)?;
     debug!(
         "dirfd = {}, path = {:?}, usr_buf_addr = 0x{:x}, usr_buf_len = 0x{:x}",
diff --git a/kernel/aster-nix/src/syscall/recvmsg.rs b/kernel/aster-nix/src/syscall/recvmsg.rs
index 57a3a0aa1..3901bc543 100644
--- a/kernel/aster-nix/src/syscall/recvmsg.rs
+++ b/kernel/aster-nix/src/syscall/recvmsg.rs
@@ -12,9 +12,9 @@ pub fn sys_recvmsg(
     sockfd: FileDesc,
     user_msghdr_ptr: Vaddr,
     flags: i32,
-    _ctx: &Context,
+    ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let c_user_msghdr: CUserMsgHdr = CurrentUserSpace::get().read_val(user_msghdr_ptr)?;
+    let c_user_msghdr: CUserMsgHdr = ctx.get_user_space().read_val(user_msghdr_ptr)?;
     let flags = SendRecvFlags::from_bits_truncate(flags);
 
     debug!(
diff --git a/kernel/aster-nix/src/syscall/rename.rs b/kernel/aster-nix/src/syscall/rename.rs
index 5a117d604..ad99bfb0a 100644
--- a/kernel/aster-nix/src/syscall/rename.rs
+++ b/kernel/aster-nix/src/syscall/rename.rs
@@ -18,7 +18,7 @@ pub fn sys_renameat(
     new_path_addr: Vaddr,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let old_path = user_space.read_cstring(old_path_addr, MAX_FILENAME_LEN)?;
     let new_path = user_space.read_cstring(new_path_addr, MAX_FILENAME_LEN)?;
     debug!(
diff --git a/kernel/aster-nix/src/syscall/rmdir.rs b/kernel/aster-nix/src/syscall/rmdir.rs
index f3c3af86b..596f67b51 100644
--- a/kernel/aster-nix/src/syscall/rmdir.rs
+++ b/kernel/aster-nix/src/syscall/rmdir.rs
@@ -19,7 +19,9 @@ pub(super) fn sys_rmdirat(
     path_addr: Vaddr,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let path_addr = CurrentUserSpace::get().read_cstring(path_addr, MAX_FILENAME_LEN)?;
+    let path_addr = ctx
+        .get_user_space()
+        .read_cstring(path_addr, MAX_FILENAME_LEN)?;
     debug!("dirfd = {}, path_addr = {:?}", dirfd, path_addr);
 
     let (dir_dentry, name) = {
diff --git a/kernel/aster-nix/src/syscall/rt_sigaction.rs b/kernel/aster-nix/src/syscall/rt_sigaction.rs
index 30ed34078..547269940 100644
--- a/kernel/aster-nix/src/syscall/rt_sigaction.rs
+++ b/kernel/aster-nix/src/syscall/rt_sigaction.rs
@@ -25,10 +25,13 @@ pub fn sys_rt_sigaction(
     let old_action = sig_dispositions.get(sig_num);
     let old_action_c = old_action.as_c_type();
     if old_sig_action_addr != 0 {
-        CurrentUserSpace::get().write_val(old_sig_action_addr, &old_action_c)?;
+        ctx.get_user_space()
+            .write_val(old_sig_action_addr, &old_action_c)?;
     }
     if sig_action_addr != 0 {
-        let sig_action_c = CurrentUserSpace::get().read_val::<sigaction_t>(sig_action_addr)?;
+        let sig_action_c = ctx
+            .get_user_space()
+            .read_val::<sigaction_t>(sig_action_addr)?;
         let sig_action = SigAction::try_from(sig_action_c).unwrap();
         trace!("sig action = {:?}", sig_action);
         sig_dispositions.set(sig_num, sig_action);
diff --git a/kernel/aster-nix/src/syscall/rt_sigpending.rs b/kernel/aster-nix/src/syscall/rt_sigpending.rs
index cd7b95823..e02d99ab1 100644
--- a/kernel/aster-nix/src/syscall/rt_sigpending.rs
+++ b/kernel/aster-nix/src/syscall/rt_sigpending.rs
@@ -28,6 +28,7 @@ fn do_rt_sigpending(set_ptr: Vaddr, ctx: &Context) -> Result<()> {
         sig_mask_value & sig_pending_value
     };
 
-    CurrentUserSpace::get().write_val(set_ptr, &u64::from(combined_signals))?;
+    ctx.get_user_space()
+        .write_val(set_ptr, &u64::from(combined_signals))?;
     Ok(())
 }
diff --git a/kernel/aster-nix/src/syscall/rt_sigprocmask.rs b/kernel/aster-nix/src/syscall/rt_sigprocmask.rs
index 35c541e18..8292d2fe3 100644
--- a/kernel/aster-nix/src/syscall/rt_sigprocmask.rs
+++ b/kernel/aster-nix/src/syscall/rt_sigprocmask.rs
@@ -39,12 +39,13 @@ fn do_rt_sigprocmask(
     let old_sig_mask_value = ctx.posix_thread.sig_mask().load(Ordering::Relaxed);
     debug!("old sig mask value: 0x{:x}", old_sig_mask_value);
     if oldset_ptr != 0 {
-        CurrentUserSpace::get().write_val(oldset_ptr, &old_sig_mask_value)?;
+        ctx.get_user_space()
+            .write_val(oldset_ptr, &old_sig_mask_value)?;
     }
 
     let sig_mask_ref = ctx.posix_thread.sig_mask();
     if set_ptr != 0 {
-        let mut read_mask = CurrentUserSpace::get().read_val::<SigMask>(set_ptr)?;
+        let mut read_mask = ctx.get_user_space().read_val::<SigMask>(set_ptr)?;
         match mask_op {
             MaskOp::Block => {
                 // According to man pages, "it is not possible to block SIGKILL or SIGSTOP.
diff --git a/kernel/aster-nix/src/syscall/rt_sigreturn.rs b/kernel/aster-nix/src/syscall/rt_sigreturn.rs
index f9900ac6c..517e0213c 100644
--- a/kernel/aster-nix/src/syscall/rt_sigreturn.rs
+++ b/kernel/aster-nix/src/syscall/rt_sigreturn.rs
@@ -24,7 +24,9 @@ pub fn sys_rt_sigreturn(ctx: &Context, user_ctx: &mut UserContext) -> Result<Sys
     // However, for most glibc applications, the restorer codes is provided by glibc and RESTORER flag is set.
     debug_assert!(sig_context_addr == user_ctx.stack_pointer() as Vaddr);
 
-    let ucontext = CurrentUserSpace::get().read_val::<ucontext_t>(sig_context_addr)?;
+    let ucontext = ctx
+        .get_user_space()
+        .read_val::<ucontext_t>(sig_context_addr)?;
 
     // If the sig stack is active and used by current handler, decrease handler counter.
     if let Some(sig_stack) = posix_thread.sig_stack().lock().as_mut() {
diff --git a/kernel/aster-nix/src/syscall/rt_sigsuspend.rs b/kernel/aster-nix/src/syscall/rt_sigsuspend.rs
index 1a864f613..29cd75373 100644
--- a/kernel/aster-nix/src/syscall/rt_sigsuspend.rs
+++ b/kernel/aster-nix/src/syscall/rt_sigsuspend.rs
@@ -13,7 +13,7 @@ use crate::{
 pub fn sys_rt_sigsuspend(
     sigmask_addr: Vaddr,
     sigmask_size: usize,
-    _ctx: &Context,
+    ctx: &Context,
 ) -> Result<SyscallReturn> {
     debug!(
         "sigmask_addr = 0x{:x}, sigmask_size = {}",
@@ -26,7 +26,7 @@ pub fn sys_rt_sigsuspend(
     }
 
     let sigmask = {
-        let mut mask: SigMask = CurrentUserSpace::get().read_val(sigmask_addr)?;
+        let mut mask: SigMask = ctx.get_user_space().read_val(sigmask_addr)?;
         // It is not possible to block SIGKILL or SIGSTOP,
         // specifying these signals in mask has no effect.
         mask -= SIGKILL;
diff --git a/kernel/aster-nix/src/syscall/sched_getaffinity.rs b/kernel/aster-nix/src/syscall/sched_getaffinity.rs
index 086d2d108..78e389e93 100644
--- a/kernel/aster-nix/src/syscall/sched_getaffinity.rs
+++ b/kernel/aster-nix/src/syscall/sched_getaffinity.rs
@@ -18,7 +18,7 @@ pub fn sys_sched_getaffinity(
     pid: Pid,
     cpuset_size: usize,
     cpu_set_ptr: Vaddr,
-    _ctx: &Context,
+    ctx: &Context,
 ) -> Result<SyscallReturn> {
     let num_cpus = get_num_cpus();
 
@@ -41,7 +41,8 @@ pub fn sys_sched_getaffinity(
 
     let dummy_cpu_set = cpu_set_t::new(num_cpus);
 
-    CurrentUserSpace::get().write_val(cpu_set_ptr, &dummy_cpu_set)?;
+    ctx.get_user_space()
+        .write_val(cpu_set_ptr, &dummy_cpu_set)?;
 
     Ok(SyscallReturn::Return(0))
 }
diff --git a/kernel/aster-nix/src/syscall/select.rs b/kernel/aster-nix/src/syscall/select.rs
index f708c5e75..db2d84f1c 100644
--- a/kernel/aster-nix/src/syscall/select.rs
+++ b/kernel/aster-nix/src/syscall/select.rs
@@ -19,7 +19,7 @@ pub fn sys_select(
     let timeout = if timeval_addr == 0 {
         None
     } else {
-        let timeval = CurrentUserSpace::get().read_val::<timeval_t>(timeval_addr)?;
+        let timeval = ctx.get_user_space().read_val::<timeval_t>(timeval_addr)?;
         Some(Duration::from(timeval))
     };
 
@@ -45,7 +45,7 @@ pub fn do_sys_select(
         return_errno_with_message!(Errno::EINVAL, "nfds is negative or exceeds the FD_SETSIZE");
     }
 
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let get_fdset = |fdset_addr: Vaddr| -> Result<Option<FdSet>> {
         let fdset = if fdset_addr == 0 {
             None
diff --git a/kernel/aster-nix/src/syscall/sendfile.rs b/kernel/aster-nix/src/syscall/sendfile.rs
index 74de7fa41..bcb8137ec 100644
--- a/kernel/aster-nix/src/syscall/sendfile.rs
+++ b/kernel/aster-nix/src/syscall/sendfile.rs
@@ -15,7 +15,7 @@ pub fn sys_sendfile(
     let offset = if offset_ptr == 0 {
         None
     } else {
-        let offset: isize = CurrentUserSpace::get().read_val(offset_ptr)?;
+        let offset: isize = ctx.get_user_space().read_val(offset_ptr)?;
         if offset < 0 {
             return_errno_with_message!(Errno::EINVAL, "offset cannot be negative");
         }
@@ -109,7 +109,8 @@ pub fn sys_sendfile(
     }
 
     if let Some(offset) = offset {
-        CurrentUserSpace::get().write_val(offset_ptr, &(offset as isize))?;
+        ctx.get_user_space()
+            .write_val(offset_ptr, &(offset as isize))?;
     }
 
     Ok(SyscallReturn::Return(total_len as _))
diff --git a/kernel/aster-nix/src/syscall/sendmsg.rs b/kernel/aster-nix/src/syscall/sendmsg.rs
index 675e8bb3a..ce4fdc6cb 100644
--- a/kernel/aster-nix/src/syscall/sendmsg.rs
+++ b/kernel/aster-nix/src/syscall/sendmsg.rs
@@ -12,9 +12,9 @@ pub fn sys_sendmsg(
     sockfd: FileDesc,
     user_msghdr_ptr: Vaddr,
     flags: i32,
-    _ctx: &Context,
+    ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let c_user_msghdr: CUserMsgHdr = CurrentUserSpace::get().read_val(user_msghdr_ptr)?;
+    let c_user_msghdr: CUserMsgHdr = ctx.get_user_space().read_val(user_msghdr_ptr)?;
     let flags = SendRecvFlags::from_bits_truncate(flags);
 
     debug!(
diff --git a/kernel/aster-nix/src/syscall/set_robust_list.rs b/kernel/aster-nix/src/syscall/set_robust_list.rs
index 791220bc3..58f838fce 100644
--- a/kernel/aster-nix/src/syscall/set_robust_list.rs
+++ b/kernel/aster-nix/src/syscall/set_robust_list.rs
@@ -18,8 +18,7 @@ pub fn sys_set_robust_list(
             "The len is not equal to the size of robust list head"
         );
     }
-    let robust_list_head: RobustListHead =
-        CurrentUserSpace::get().read_val(robust_list_head_ptr)?;
+    let robust_list_head: RobustListHead = ctx.get_user_space().read_val(robust_list_head_ptr)?;
     debug!("{:x?}", robust_list_head);
     let mut robust_list = ctx.posix_thread.robust_list().lock();
     *robust_list = Some(robust_list_head);
diff --git a/kernel/aster-nix/src/syscall/setgroups.rs b/kernel/aster-nix/src/syscall/setgroups.rs
index c8f73c8cb..875c81b55 100644
--- a/kernel/aster-nix/src/syscall/setgroups.rs
+++ b/kernel/aster-nix/src/syscall/setgroups.rs
@@ -15,7 +15,7 @@ pub fn sys_setgroups(size: usize, group_list_addr: Vaddr, ctx: &Context) -> Resu
     let mut new_groups = BTreeSet::new();
     for idx in 0..size {
         let addr = group_list_addr + idx * core::mem::size_of::<Gid>();
-        let gid = CurrentUserSpace::get().read_val(addr)?;
+        let gid = ctx.get_user_space().read_val(addr)?;
         new_groups.insert(gid);
     }
 
diff --git a/kernel/aster-nix/src/syscall/setitimer.rs b/kernel/aster-nix/src/syscall/setitimer.rs
index 0b1ea7d72..d572eee08 100644
--- a/kernel/aster-nix/src/syscall/setitimer.rs
+++ b/kernel/aster-nix/src/syscall/setitimer.rs
@@ -32,7 +32,7 @@ pub fn sys_setitimer(
     if new_itimerval_addr == 0 {
         return_errno_with_message!(Errno::EINVAL, "invalid pointer to new value");
     }
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let new_itimerval = user_space.read_val::<itimerval_t>(new_itimerval_addr)?;
     let interval = Duration::from(new_itimerval.it_interval);
     let expire_time = Duration::from(new_itimerval.it_value);
@@ -92,7 +92,7 @@ pub fn sys_getitimer(
         it_interval: interval,
         it_value: remain,
     };
-    CurrentUserSpace::get().write_val(itimerval_addr, &itimerval)?;
+    ctx.get_user_space().write_val(itimerval_addr, &itimerval)?;
 
     Ok(SyscallReturn::Return(0))
 }
diff --git a/kernel/aster-nix/src/syscall/sigaltstack.rs b/kernel/aster-nix/src/syscall/sigaltstack.rs
index 48c11860e..97de99382 100644
--- a/kernel/aster-nix/src/syscall/sigaltstack.rs
+++ b/kernel/aster-nix/src/syscall/sigaltstack.rs
@@ -21,13 +21,17 @@ pub fn sys_sigaltstack(
         sig_stack.clone()
     };
 
-    get_old_stack(old_sig_stack_addr, old_stack.as_ref())?;
+    get_old_stack(old_sig_stack_addr, old_stack.as_ref(), ctx)?;
     set_new_stack(sig_stack_addr, old_stack.as_ref(), ctx)?;
 
     Ok(SyscallReturn::Return(0))
 }
 
-fn get_old_stack(old_sig_stack_addr: Vaddr, old_stack: Option<&SigStack>) -> Result<()> {
+fn get_old_stack(
+    old_sig_stack_addr: Vaddr,
+    old_stack: Option<&SigStack>,
+    ctx: &Context,
+) -> Result<()> {
     if old_sig_stack_addr == 0 {
         return Ok(());
     }
@@ -39,7 +43,7 @@ fn get_old_stack(old_sig_stack_addr: Vaddr, old_stack: Option<&SigStack>) -> Res
     debug!("old stack = {:?}", old_stack);
 
     let stack = stack_t::from(old_stack.clone());
-    CurrentUserSpace::get().write_val(old_sig_stack_addr, &stack)
+    ctx.get_user_space().write_val(old_sig_stack_addr, &stack)
 }
 
 fn set_new_stack(sig_stack_addr: Vaddr, old_stack: Option<&SigStack>, ctx: &Context) -> Result<()> {
@@ -54,7 +58,7 @@ fn set_new_stack(sig_stack_addr: Vaddr, old_stack: Option<&SigStack>, ctx: &Cont
     }
 
     let new_stack = {
-        let stack = CurrentUserSpace::get().read_val::<stack_t>(sig_stack_addr)?;
+        let stack = ctx.get_user_space().read_val::<stack_t>(sig_stack_addr)?;
         SigStack::try_from(stack)?
     };
 
diff --git a/kernel/aster-nix/src/syscall/socketpair.rs b/kernel/aster-nix/src/syscall/socketpair.rs
index 9ec9fa272..fe531f496 100644
--- a/kernel/aster-nix/src/syscall/socketpair.rs
+++ b/kernel/aster-nix/src/syscall/socketpair.rs
@@ -48,7 +48,7 @@ pub fn sys_socketpair(
         SocketFds(fd_a, fd_b)
     };
 
-    CurrentUserSpace::get().write_val(sv, &socket_fds)?;
+    ctx.get_user_space().write_val(sv, &socket_fds)?;
     Ok(SyscallReturn::Return(0))
 }
 
diff --git a/kernel/aster-nix/src/syscall/stat.rs b/kernel/aster-nix/src/syscall/stat.rs
index 136c93e5f..29b5c265f 100644
--- a/kernel/aster-nix/src/syscall/stat.rs
+++ b/kernel/aster-nix/src/syscall/stat.rs
@@ -18,7 +18,7 @@ pub fn sys_fstat(fd: FileDesc, stat_buf_ptr: Vaddr, ctx: &Context) -> Result<Sys
     let file_table = ctx.process.file_table().lock();
     let file = file_table.get_file(fd)?;
     let stat = Stat::from(file.metadata());
-    CurrentUserSpace::get().write_val(stat_buf_ptr, &stat)?;
+    ctx.get_user_space().write_val(stat_buf_ptr, &stat)?;
     Ok(SyscallReturn::Return(0))
 }
 
@@ -43,7 +43,7 @@ pub fn sys_fstatat(
     flags: u32,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let filename = user_space.read_cstring(filename_ptr, MAX_FILENAME_LEN)?;
     let flags =
         StatFlags::from_bits(flags).ok_or(Error::with_message(Errno::EINVAL, "invalid flags"))?;
diff --git a/kernel/aster-nix/src/syscall/statfs.rs b/kernel/aster-nix/src/syscall/statfs.rs
index 65d5d2014..81b9bb4cc 100644
--- a/kernel/aster-nix/src/syscall/statfs.rs
+++ b/kernel/aster-nix/src/syscall/statfs.rs
@@ -12,7 +12,7 @@ use crate::{
 };
 
 pub fn sys_statfs(path_ptr: Vaddr, statfs_buf_ptr: Vaddr, ctx: &Context) -> Result<SyscallReturn> {
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let path = user_space.read_cstring(path_ptr, PATH_MAX)?;
     debug!("path = {:?}, statfs_buf_ptr = 0x{:x}", path, statfs_buf_ptr,);
 
@@ -36,7 +36,7 @@ pub fn sys_fstatfs(fd: FileDesc, statfs_buf_ptr: Vaddr, ctx: &Context) -> Result
         .ok_or(Error::with_message(Errno::EBADF, "not inode"))?;
     let dentry = inode_handle.dentry();
     let statfs = Statfs::from(dentry.fs().sb());
-    CurrentUserSpace::get().write_val(statfs_buf_ptr, &statfs)?;
+    ctx.get_user_space().write_val(statfs_buf_ptr, &statfs)?;
     Ok(SyscallReturn::Return(0))
 }
 
diff --git a/kernel/aster-nix/src/syscall/symlink.rs b/kernel/aster-nix/src/syscall/symlink.rs
index e020f698e..582845c91 100644
--- a/kernel/aster-nix/src/syscall/symlink.rs
+++ b/kernel/aster-nix/src/syscall/symlink.rs
@@ -17,7 +17,7 @@ pub fn sys_symlinkat(
     linkpath_addr: Vaddr,
     ctx: &Context,
 ) -> Result<SyscallReturn> {
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let target = user_space.read_cstring(target_addr, MAX_FILENAME_LEN)?;
     let linkpath = user_space.read_cstring(linkpath_addr, MAX_FILENAME_LEN)?;
     debug!(
diff --git a/kernel/aster-nix/src/syscall/time.rs b/kernel/aster-nix/src/syscall/time.rs
index 973cd36fa..f4346adec 100644
--- a/kernel/aster-nix/src/syscall/time.rs
+++ b/kernel/aster-nix/src/syscall/time.rs
@@ -3,7 +3,7 @@
 use super::SyscallReturn;
 use crate::{prelude::*, time::SystemTime};
 
-pub fn sys_time(tloc: Vaddr, _ctx: &Context) -> Result<SyscallReturn> {
+pub fn sys_time(tloc: Vaddr, ctx: &Context) -> Result<SyscallReturn> {
     debug!("tloc = 0x{tloc:x}");
 
     let now_as_secs = {
@@ -12,7 +12,7 @@ pub fn sys_time(tloc: Vaddr, _ctx: &Context) -> Result<SyscallReturn> {
     };
 
     if tloc != 0 {
-        CurrentUserSpace::get().write_val(tloc, &now_as_secs)?;
+        ctx.get_user_space().write_val(tloc, &now_as_secs)?;
     }
 
     Ok(SyscallReturn::Return(now_as_secs as _))
diff --git a/kernel/aster-nix/src/syscall/timer_create.rs b/kernel/aster-nix/src/syscall/timer_create.rs
index 26b1c6685..297567aaa 100644
--- a/kernel/aster-nix/src/syscall/timer_create.rs
+++ b/kernel/aster-nix/src/syscall/timer_create.rs
@@ -51,7 +51,7 @@ pub fn sys_timer_create(
             })
         // Determine the timeout action through `sigevent`.
         } else {
-            let sig_event = CurrentUserSpace::get().read_val::<sigevent_t>(sigevent_addr)?;
+            let sig_event = ctx.get_user_space().read_val::<sigevent_t>(sigevent_addr)?;
             let sigev_notify = SigNotify::try_from(sig_event.sigev_notify)?;
             let signo = sig_event.sigev_signo;
             match sigev_notify {
@@ -146,7 +146,7 @@ pub fn sys_timer_create(
     };
 
     let timer_id = process_timer_manager.add_posix_timer(timer);
-    CurrentUserSpace::get().write_val(timer_id_addr, &timer_id)?;
+    ctx.get_user_space().write_val(timer_id_addr, &timer_id)?;
     Ok(SyscallReturn::Return(0))
 }
 
diff --git a/kernel/aster-nix/src/syscall/timer_settime.rs b/kernel/aster-nix/src/syscall/timer_settime.rs
index 88034985d..03ed4751d 100644
--- a/kernel/aster-nix/src/syscall/timer_settime.rs
+++ b/kernel/aster-nix/src/syscall/timer_settime.rs
@@ -19,7 +19,7 @@ pub fn sys_timer_settime(
         return_errno_with_message!(Errno::EINVAL, "invalid pointer to new value");
     }
 
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let new_itimerspec = user_space.read_val::<itimerspec_t>(new_itimerspec_addr)?;
     let interval = Duration::try_from(new_itimerspec.it_interval)?;
     let expire_time = Duration::try_from(new_itimerspec.it_value)?;
@@ -74,7 +74,8 @@ pub fn sys_timer_gettime(
         it_interval: interval,
         it_value: remain,
     };
-    CurrentUserSpace::get().write_val(itimerspec_addr, &itimerspec)?;
+    ctx.get_user_space()
+        .write_val(itimerspec_addr, &itimerspec)?;
 
     Ok(SyscallReturn::Return(0))
 }
diff --git a/kernel/aster-nix/src/syscall/truncate.rs b/kernel/aster-nix/src/syscall/truncate.rs
index 136f6a6ce..1b4fd0094 100644
--- a/kernel/aster-nix/src/syscall/truncate.rs
+++ b/kernel/aster-nix/src/syscall/truncate.rs
@@ -23,7 +23,7 @@ pub fn sys_ftruncate(fd: FileDesc, len: isize, ctx: &Context) -> Result<SyscallR
 }
 
 pub fn sys_truncate(path_ptr: Vaddr, len: isize, ctx: &Context) -> Result<SyscallReturn> {
-    let path = CurrentUserSpace::get().read_cstring(path_ptr, PATH_MAX)?;
+    let path = ctx.get_user_space().read_cstring(path_ptr, PATH_MAX)?;
     debug!("path = {:?}, length = {}", path, len);
 
     check_length(len, ctx)?;
diff --git a/kernel/aster-nix/src/syscall/umount.rs b/kernel/aster-nix/src/syscall/umount.rs
index 630b28460..9c3903473 100644
--- a/kernel/aster-nix/src/syscall/umount.rs
+++ b/kernel/aster-nix/src/syscall/umount.rs
@@ -8,7 +8,9 @@ use crate::{
 };
 
 pub fn sys_umount(path_addr: Vaddr, flags: u64, ctx: &Context) -> Result<SyscallReturn> {
-    let path = CurrentUserSpace::get().read_cstring(path_addr, MAX_FILENAME_LEN)?;
+    let path = ctx
+        .get_user_space()
+        .read_cstring(path_addr, MAX_FILENAME_LEN)?;
     let umount_flags = UmountFlags::from_bits_truncate(flags as u32);
     debug!("path = {:?}, flags = {:?}", path, umount_flags);
 
diff --git a/kernel/aster-nix/src/syscall/uname.rs b/kernel/aster-nix/src/syscall/uname.rs
index d3fcefac1..220a37788 100644
--- a/kernel/aster-nix/src/syscall/uname.rs
+++ b/kernel/aster-nix/src/syscall/uname.rs
@@ -57,8 +57,8 @@ fn copy_cstring_to_u8_slice(src: &CStr, dst: &mut [u8]) {
     dst[..len].copy_from_slice(&src[..len]);
 }
 
-pub fn sys_uname(old_uname_addr: Vaddr, _ctx: &Context) -> Result<SyscallReturn> {
+pub fn sys_uname(old_uname_addr: Vaddr, ctx: &Context) -> Result<SyscallReturn> {
     debug!("old uname addr = 0x{:x}", old_uname_addr);
-    CurrentUserSpace::get().write_val(old_uname_addr, &*UTS_NAME)?;
+    ctx.get_user_space().write_val(old_uname_addr, &*UTS_NAME)?;
     Ok(SyscallReturn::Return(0))
 }
diff --git a/kernel/aster-nix/src/syscall/unlink.rs b/kernel/aster-nix/src/syscall/unlink.rs
index 9a338ce62..af909f401 100644
--- a/kernel/aster-nix/src/syscall/unlink.rs
+++ b/kernel/aster-nix/src/syscall/unlink.rs
@@ -22,7 +22,9 @@ pub fn sys_unlinkat(
         return super::rmdir::sys_rmdirat(dirfd, path_addr, ctx);
     }
 
-    let path = CurrentUserSpace::get().read_cstring(path_addr, MAX_FILENAME_LEN)?;
+    let path = ctx
+        .get_user_space()
+        .read_cstring(path_addr, MAX_FILENAME_LEN)?;
     debug!("dirfd = {}, path = {:?}", dirfd, path);
 
     let (dir_dentry, name) = {
diff --git a/kernel/aster-nix/src/syscall/utimens.rs b/kernel/aster-nix/src/syscall/utimens.rs
index 9bb94947c..5540a4d73 100644
--- a/kernel/aster-nix/src/syscall/utimens.rs
+++ b/kernel/aster-nix/src/syscall/utimens.rs
@@ -30,7 +30,7 @@ pub fn sys_utimensat(
         dirfd, pathname_ptr, timespecs_ptr, flags
     );
     let times = if timespecs_ptr != 0 {
-        let (autime, mutime) = read_time_from_user::<timespec_t>(timespecs_ptr)?;
+        let (autime, mutime) = read_time_from_user::<timespec_t>(timespecs_ptr, ctx)?;
         if autime.is_utime_omit() && mutime.is_utime_omit() {
             return Ok(SyscallReturn::Return(0));
         }
@@ -78,7 +78,7 @@ pub fn sys_utime(pathname_ptr: Vaddr, utimbuf_ptr: Vaddr, ctx: &Context) -> Resu
         pathname_ptr, utimbuf_ptr
     );
     let times = if utimbuf_ptr != 0 {
-        let utimbuf = CurrentUserSpace::get().read_val::<Utimbuf>(utimbuf_ptr)?;
+        let utimbuf = ctx.get_user_space().read_val::<Utimbuf>(utimbuf_ptr)?;
         let atime = timespec_t {
             sec: utimbuf.actime,
             nsec: 0,
@@ -160,7 +160,9 @@ fn do_utimes(
     let pathname = if pathname_ptr == 0 {
         String::new()
     } else {
-        let cstring = CurrentUserSpace::get().read_cstring(pathname_ptr, MAX_FILENAME_LEN)?;
+        let cstring = ctx
+            .get_user_space()
+            .read_cstring(pathname_ptr, MAX_FILENAME_LEN)?;
         cstring.to_string_lossy().into_owned()
     };
     let dentry = {
@@ -186,7 +188,7 @@ fn do_futimesat(
     ctx: &Context,
 ) -> Result<SyscallReturn> {
     let times = if timeval_ptr != 0 {
-        let (autime, mutime) = read_time_from_user::<timeval_t>(timeval_ptr)?;
+        let (autime, mutime) = read_time_from_user::<timeval_t>(timeval_ptr, ctx)?;
         if autime.usec >= 1000000 || autime.usec < 0 || mutime.usec >= 1000000 || mutime.usec < 0 {
             return_errno_with_message!(Errno::EINVAL, "Invalid time");
         }
@@ -201,9 +203,9 @@ fn do_futimesat(
     do_utimes(dirfd, pathname_ptr, times, 0, ctx)
 }
 
-fn read_time_from_user<T: Pod>(time_ptr: Vaddr) -> Result<(T, T)> {
+fn read_time_from_user<T: Pod>(time_ptr: Vaddr, ctx: &Context) -> Result<(T, T)> {
     let mut time_addr = time_ptr;
-    let user_space = CurrentUserSpace::get();
+    let user_space = ctx.get_user_space();
     let autime = user_space.read_val::<T>(time_addr)?;
     time_addr += core::mem::size_of::<T>();
     let mutime = user_space.read_val::<T>(time_addr)?;
diff --git a/kernel/aster-nix/src/syscall/wait4.rs b/kernel/aster-nix/src/syscall/wait4.rs
index c0d4f413d..4fe02ff21 100644
--- a/kernel/aster-nix/src/syscall/wait4.rs
+++ b/kernel/aster-nix/src/syscall/wait4.rs
@@ -29,7 +29,8 @@ pub fn sys_wait4(
 
     let (return_pid, exit_code) = (process.pid(), process.exit_code().unwrap());
     if exit_status_ptr != 0 {
-        CurrentUserSpace::get().write_val(exit_status_ptr as _, &exit_code)?;
+        ctx.get_user_space()
+            .write_val(exit_status_ptr as _, &exit_code)?;
     }
 
     if rusage_addr != 0 {
@@ -39,7 +40,7 @@ pub fn sys_wait4(
             ..Default::default()
         };
 
-        CurrentUserSpace::get().write_val(rusage_addr, &rusage)?;
+        ctx.get_user_space().write_val(rusage_addr, &rusage)?;
     }
 
     Ok(SyscallReturn::Return(return_pid as _))
diff --git a/kernel/aster-nix/src/syscall/write.rs b/kernel/aster-nix/src/syscall/write.rs
index 992a6e240..c9818e08c 100644
--- a/kernel/aster-nix/src/syscall/write.rs
+++ b/kernel/aster-nix/src/syscall/write.rs
@@ -24,7 +24,7 @@ pub fn sys_write(
     // the file discriptor. If no errors detected, return 0 successfully.
     let write_len = if user_buf_len != 0 {
         let mut buffer = vec![0u8; user_buf_len];
-        CurrentUserSpace::get()
+        ctx.get_user_space()
             .read_bytes(user_buf_ptr, &mut VmWriter::from(buffer.as_mut_slice()))?;
         debug!("write content = {:?}", buffer);
         file.write(&buffer)?