Migrate existing code to use `VmIo`

kernel/src/device/fb.rs

@@ -5,7 +5,7 @@ use alloc::sync::Arc;
 use aster_framebuffer::{ColorMapEntry, FrameBuffer, PixelFormat, FRAMEBUFFER, MAX_CMAP_SIZE};
 use device_id::{DeviceId, MajorId, MinorId};
 use ostd::{
-    mm::{io_util::HasVmReaderWriter, HasPaddr, HasSize},
+    mm::{io_util::HasVmReaderWriter, HasPaddr, HasSize, VmIo},
     Pod,
 };
 

kernel/src/device/pty/master.rs

@@ -2,7 +2,7 @@
 
 use alloc::format;
 
-use ostd::task::Task;
+use ostd::{mm::VmIo, task::Task};
 
 use super::{driver::PtyDriver, PtySlave};
 use crate::{

kernel/src/device/tty/mod.rs

@@ -6,7 +6,7 @@ use aster_console::{
     AnyConsoleDevice,
 };
 use device_id::{DeviceId, MajorId, MinorId};
-use ostd::sync::LocalIrqDisabled;
+use ostd::{mm::VmIo, sync::LocalIrqDisabled};
 
 use self::{line_discipline::LineDiscipline, termio::CFontOp};
 use crate::{
@@ -214,7 +214,7 @@ impl<D: TtyDriver> Tty<D> {
 
         let font_size = width.div_ceil(u8::BITS) * vpitch * charcount;
         let mut font_data = vec![0; font_size as usize];
-        current_userspace!().read_bytes(*data as Vaddr, &mut (&mut font_data[..]).into())?;
+        current_userspace!().read_bytes(*data as Vaddr, &mut font_data[..])?;
 
         // In Linux, the most significant bit represents the first pixel, but `BitmapFont` requires
         // the least significant bit to represent the first pixel. So now we reverse the bits.

kernel/src/fs/notify/inotify.rs

@@ -14,7 +14,7 @@ use core::{
 use bitflags::bitflags;
 use hashbrown::HashMap;
 use ostd::{
-    mm::VmWriter,
+    mm::{VmIo, VmWriter},
     sync::{Mutex, SpinLock},
 };
 

kernel/src/process/clone.rs

@@ -4,7 +4,8 @@ use alloc::borrow::Cow;
 use core::{num::NonZeroU64, sync::atomic::Ordering};
 
 use ostd::{
-    arch::cpu::context::UserContext, cpu::CpuId, sync::RwArc, task::Task, user::UserContextApi,
+    arch::cpu::context::UserContext, cpu::CpuId, mm::VmIo, sync::RwArc, task::Task,
+    user::UserContextApi,
 };
 
 use super::{
@@ -677,11 +678,11 @@ fn clone_pidfd(
     // FIXME: Should we remove the file from the file table if the write operation fails?
     match ctx.user_space().write_val(pidfd_addr, &fd) {
         Ok(()) => Ok(()),
-        Err(e) => {
+        Err(err) => {
             let file_table = ctx.thread_local.borrow_file_table();
             let mut file_table_locked = file_table.unwrap().write();
             file_table_locked.close_file(fd);
-            Err(e)
+            Err(err.into())
         }
     }
 }

kernel/src/process/execve.rs

@@ -3,6 +3,7 @@
 use aster_rights::WriteOp;
 use ostd::{
     arch::cpu::context::{FpuContext, GeneralRegs, UserContext},
+    mm::VmIo,
     sync::Waiter,
     user::UserContextApi,
 };

kernel/src/process/posix_thread/exit.rs

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MPL-2.0
 
-use ostd::task::Task;
+use ostd::{mm::VmIo, task::Task};
 
 use super::{
     futex::futex_wake, robust_list::wake_robust_futex, thread_table, AsPosixThread, AsThreadLocal,

kernel/src/process/posix_thread/robust_list.rs

@@ -2,7 +2,7 @@
 
 //! The implementation of robust list is from occlum.
 
-use ostd::task::Task;
+use ostd::{mm::VmIo, task::Task};
 
 use crate::{current_userspace, prelude::*, process::posix_thread::futex::futex_wake, thread::Tid};
 

kernel/src/process/process/terminal.rs

@@ -2,6 +2,8 @@
 
 use alloc::sync::Arc;
 
+use ostd::mm::VmIo;
+
 use super::{session::SessionGuard, JobControl, Pgid, Process, Session, Sid};
 use crate::{
     current_userspace,
@@ -44,7 +46,7 @@ impl dyn Terminal {
                     self.is_control_and(&current!(), |_, _| Ok(operate()))?
                 };
 
-                current_userspace!().write_val::<Pgid>(arg, &pgid)
+                Ok(current_userspace!().write_val::<Pgid>(arg, &pgid)?)
             }
 
             // Commands about sessions
@@ -80,7 +82,7 @@ impl dyn Terminal {
                     self.is_control_and(&current!(), |session, _| Ok(session.sid()))?
                 };
 
-                current_userspace!().write_val::<Sid>(arg, &sid)
+                Ok(current_userspace!().write_val::<Sid>(arg, &sid)?)
             }
 
             // Commands that are invalid or not supported

kernel/src/process/signal/mod.rs

@@ -20,6 +20,7 @@ use c_types::{siginfo_t, ucontext_t};
 use constants::SIGSEGV;
 use ostd::{
     arch::cpu::context::{FpuContext, UserContext},
+    mm::VmIo,
     user::UserContextApi,
 };
 pub use pause::{with_sigmask_changed, Pause, PauseReason};
@@ -300,8 +301,7 @@ pub fn handle_user_signal(
         }
     }
 
-    let mut fpu_context_reader = VmReader::from(fpu_context_bytes);
-    user_space.write_bytes(fpu_context_addr as _, &mut fpu_context_reader)?;
+    user_space.write_bytes(fpu_context_addr as _, fpu_context_bytes)?;
 
     user_space.write_val(ucontext_addr as _, &ucontext)?;
     // Store the ucontext addr in sig context of current thread.

kernel/src/syscall/capget.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     prelude::*,

kernel/src/syscall/capset.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     prelude::*,

kernel/src/syscall/clock_gettime.rs

@@ -3,6 +3,7 @@
 use core::time::Duration;
 
 use int_to_c_enum::TryFromInt;
+use ostd::mm::VmIo;
 
 use super::SyscallReturn;
 use crate::{

kernel/src/syscall/clone.rs

@@ -2,7 +2,7 @@
 
 use core::num::NonZeroU64;
 
-use ostd::arch::cpu::context::UserContext;
+use ostd::{arch::cpu::context::UserContext, mm::VmIo};
 
 use super::SyscallReturn;
 use crate::{

kernel/src/syscall/epoll.rs

@@ -2,6 +2,8 @@
 
 use core::{sync::atomic::Ordering, time::Duration};
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     events::IoEvents,

kernel/src/syscall/fcntl.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::{

kernel/src/syscall/futex.rs

@@ -2,6 +2,8 @@
 
 use core::time::Duration;
 
+use ostd::mm::VmIo;
+
 use crate::{
     current_userspace,
     prelude::*,

kernel/src/syscall/getcpu.rs

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MPL-2.0
 
-use ostd::cpu::CpuId;
+use ostd::{cpu::CpuId, mm::VmIo};
 
 use super::SyscallReturn;
 use crate::prelude::*;

kernel/src/syscall/getcwd.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::prelude::*;
 
@@ -11,8 +13,7 @@ pub fn sys_getcwd(buf: Vaddr, len: usize, ctx: &Context) -> Result<SyscallReturn
     let cwd = CString::new(name)?;
     let bytes = cwd.as_bytes_with_nul();
     let write_len = len.min(bytes.len());
-    ctx.user_space()
-        .write_bytes(buf, &mut VmReader::from(&bytes[..write_len]))?;
+    ctx.user_space().write_bytes(buf, &bytes[..write_len])?;
 
     Ok(SyscallReturn::Return(write_len as _))
 }

kernel/src/syscall/getdents64.rs

@@ -2,6 +2,8 @@
 
 use core::marker::PhantomData;
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs,
@@ -34,7 +36,7 @@ pub fn sys_getdents(
     let _ = inode_handle.readdir(&mut reader)?;
     let read_len = reader.read_len();
     ctx.user_space()
-        .write_bytes(buf_addr, &mut VmReader::from(&buffer[..read_len]))?;
+        .write_bytes(buf_addr, &buffer[..read_len])?;
     fs::notify::on_access(&file);
     Ok(SyscallReturn::Return(read_len as _))
 }
@@ -61,7 +63,7 @@ pub fn sys_getdents64(
     let _ = inode_handle.readdir(&mut reader)?;
     let read_len = reader.read_len();
     ctx.user_space()
-        .write_bytes(buf_addr, &mut VmReader::from(&buffer[..read_len]))?;
+        .write_bytes(buf_addr, &buffer[..read_len])?;
     fs::notify::on_access(&file);
     Ok(SyscallReturn::Return(read_len as _))
 }

kernel/src/syscall/getgroups.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::prelude::*;
 

kernel/src/syscall/getresgid.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::prelude::*;
 

kernel/src/syscall/getresuid.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::prelude::*;
 

kernel/src/syscall/getrusage.rs

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
 use int_to_c_enum::TryFromInt;
+use ostd::mm::VmIo;
 
 use super::SyscallReturn;
 use crate::{prelude::*, time::timeval_t};

kernel/src/syscall/getsockopt.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::file_table::{get_file_fast, FileDesc},

kernel/src/syscall/gettimeofday.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     prelude::*,

kernel/src/syscall/ioctl.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::{

kernel/src/syscall/madvise.rs

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
 use align_ext::AlignExt;
+use ostd::mm::VmIo;
 
 use super::SyscallReturn;
 use crate::prelude::*;
@@ -38,8 +39,7 @@ pub fn sys_madvise(
         | MadviseBehavior::MADV_WILLNEED => {
             // perform a read at first
             let mut buffer = vec![0u8; len];
-            ctx.user_space()
-                .read_bytes(start, &mut VmWriter::from(buffer.as_mut_slice()))?;
+            ctx.user_space().read_bytes(start, buffer.as_mut_slice())?;
         }
         MadviseBehavior::MADV_DONTNEED => {
             warn!("MADV_DONTNEED isn't implemented, do nothing for now.");

kernel/src/syscall/nanosleep.rs

@@ -2,7 +2,7 @@
 
 use core::time::Duration;
 
-use ostd::sync::Waiter;
+use ostd::{mm::VmIo, sync::Waiter};
 
 use super::{clock_gettime::read_clock, ClockId, SyscallReturn};
 use crate::{

kernel/src/syscall/pipe.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::{
@@ -33,7 +35,7 @@ pub fn sys_pipe2(fds: Vaddr, flags: u32, ctx: &Context) -> Result<SyscallReturn>
     if let Err(err) = ctx.user_space().write_val(fds, &pipe_fds) {
         file_table_locked.close_file(pipe_fds.reader_fd).unwrap();
         file_table_locked.close_file(pipe_fds.writer_fd).unwrap();
-        return Err(err);
+        return Err(err.into());
     }
 
     Ok(SyscallReturn::Return(0))

kernel/src/syscall/poll.rs

@@ -2,6 +2,8 @@
 
 use core::{cell::Cell, time::Duration};
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     events::IoEvents,

kernel/src/syscall/ppoll.rs

@@ -2,6 +2,8 @@
 
 use core::time::Duration;
 
+use ostd::mm::VmIo;
+
 use super::{poll::do_sys_poll, SyscallReturn};
 use crate::{
     prelude::*,

kernel/src/syscall/prctl.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     prelude::*,
@@ -64,10 +66,8 @@ pub fn sys_prctl(
         }
         PrctlCmd::PR_GET_NAME(write_to_addr) => {
             let thread_name = ctx.posix_thread.thread_name().lock();
-            ctx.user_space().write_bytes(
-                write_to_addr,
-                &mut VmReader::from(thread_name.name().to_bytes_with_nul()),
-            )?;
+            ctx.user_space()
+                .write_bytes(write_to_addr, thread_name.name().to_bytes_with_nul())?;
         }
         PrctlCmd::PR_SET_NAME(read_addr) => {
             let new_thread_name = ctx

kernel/src/syscall/prlimit64.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     prelude::*,

kernel/src/syscall/pselect6.rs

@@ -2,6 +2,8 @@
 
 use core::time::Duration;
 
+use ostd::mm::VmIo;
+
 use super::{select::do_sys_select, SyscallReturn};
 use crate::{
     fs::file_table::FileDesc,

kernel/src/syscall/readlink.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::{
@@ -37,7 +39,7 @@ pub fn sys_readlinkat(
     let linkpath = path.inode().read_link()?.to_string();
     let bytes = linkpath.as_bytes();
     let write_len = bytes.len().min(usr_buf_len);
-    user_space.write_bytes(usr_buf_addr, &mut VmReader::from(&bytes[..write_len]))?;
+    user_space.write_bytes(usr_buf_addr, &bytes[..write_len])?;
     Ok(SyscallReturn::Return(write_len as _))
 }
 

kernel/src/syscall/recvmsg.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::file_table::{get_file_fast, FileDesc},

kernel/src/syscall/rt_sigaction.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     prelude::*,

kernel/src/syscall/rt_sigpending.rs

@@ -2,6 +2,8 @@
 
 use core::sync::atomic::Ordering;
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{prelude::*, process::signal::HandlePendingSignal};
 

kernel/src/syscall/rt_sigprocmask.rs

@@ -2,6 +2,8 @@
 
 use core::sync::atomic::Ordering;
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     prelude::*,

kernel/src/syscall/rt_sigreturn.rs

@@ -4,6 +4,7 @@ use core::sync::atomic::Ordering;
 
 use ostd::{
     arch::cpu::context::{FpuContext, UserContext},
+    mm::VmIo,
     user::UserContextApi,
 };
 
@@ -59,9 +60,8 @@ pub fn sys_rt_sigreturn(ctx: &Context, user_ctx: &mut UserContext) -> Result<Sys
         }
     }
     let mut fpu_context = FpuContext::new();
-    let mut fpu_context_writer = VmWriter::from(fpu_context.as_bytes_mut());
     ctx.user_space()
-        .read_bytes(fpu_context_addr, &mut fpu_context_writer)?;
+        .read_bytes(fpu_context_addr, fpu_context.as_bytes_mut())?;
     ctx.thread_local.fpu().set_context(fpu_context);
 
     // unblock sig mask

kernel/src/syscall/rt_sigsuspend.rs

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MPL-2.0
 
-use ostd::sync::Waiter;
+use ostd::{mm::VmIo, sync::Waiter};
 
 use super::SyscallReturn;
 use crate::{

kernel/src/syscall/sched_affinity.rs

@@ -4,6 +4,7 @@ use core::{cmp, sync::atomic::Ordering};
 
 use ostd::{
     cpu::{num_cpus, CpuId, CpuSet},
+    mm::VmIo,
     util::id_set::Id,
 };
 

kernel/src/syscall/sched_getattr.rs

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MPL-2.0
 
-use ostd::const_assert;
+use ostd::{const_assert, mm::VmIo};
 
 use super::{
     sched_get_priority_max::{rt_to_static, static_to_rt, SCHED_PRIORITY_RANGE},

kernel/src/syscall/sched_getparam.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::{sched_getattr::access_sched_attr_with, SyscallReturn};
 use crate::{prelude::*, sched::SchedPolicy, thread::Tid};
 

kernel/src/syscall/sched_setparam.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::{sched_getattr::access_sched_attr_with, SyscallReturn};
 use crate::{prelude::*, sched::SchedPolicy, thread::Tid};
 

kernel/src/syscall/sched_setscheduler.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::{
     sched_getattr::{access_sched_attr_with, LinuxSchedAttr},
     SyscallReturn,

kernel/src/syscall/select.rs

@@ -2,6 +2,8 @@
 
 use core::time::Duration;
 
+use ostd::mm::VmIo;
+
 use super::{
     poll::{do_poll, PollFd},
     SyscallReturn,

kernel/src/syscall/semctl.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     ipc::{
@@ -95,7 +97,7 @@ pub fn sys_semctl(
         IpcControlCmd::IPC_STAT => {
             check_and_ctl(semid, PermissionMode::READ, |sem_set| {
                 let semid_ds = sem_set.semid_ds();
-                ctx.user_space().write_val(arg as Vaddr, &semid_ds)
+                Ok(ctx.user_space().write_val(arg as Vaddr, &semid_ds)?)
             })?;
         }
         _ => todo!("Need to support {:?} in SYS_SEMCTL", cmd),

kernel/src/syscall/semop.rs

@@ -2,6 +2,8 @@
 
 use core::time::Duration;
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     ipc::semaphore::system_v::{

kernel/src/syscall/sendfile.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs,

kernel/src/syscall/sendmmsg.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use crate::{
     fs::file_table::FileDesc,
     net::socket::{util::SendRecvFlags, Socket},

kernel/src/syscall/sendmsg.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::file_table::FileDesc,

kernel/src/syscall/set_robust_list.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{prelude::*, process::posix_thread::RobustListHead};
 

kernel/src/syscall/setgroups.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{prelude::*, process::Gid};
 

kernel/src/syscall/setitimer.rs

@@ -2,6 +2,8 @@
 
 use core::time::Duration;
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     prelude::*,

kernel/src/syscall/sigaltstack.rs

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MPL-2.0
 
-use ostd::{arch::cpu::context::UserContext, user::UserContextApi};
+use ostd::{arch::cpu::context::UserContext, mm::VmIo, user::UserContextApi};
 
 use super::SyscallReturn;
 use crate::{

kernel/src/syscall/signalfd.rs

@@ -12,6 +12,7 @@ use core::{
 };
 
 use bitflags::bitflags;
+use ostd::mm::VmIo;
 
 use super::SyscallReturn;
 use crate::{

kernel/src/syscall/socketpair.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::{

kernel/src/syscall/stat.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::{

kernel/src/syscall/statfs.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::{

kernel/src/syscall/statx.rs

@@ -2,6 +2,8 @@
 
 use core::time::Duration;
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::{file_table::FileDesc, fs_resolver::FsPath, path::Path},

kernel/src/syscall/sysinfo.rs

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
 use aster_time::read_monotonic_time;
+use ostd::mm::VmIo;
 
 use super::SyscallReturn;
 use crate::{prelude::*, process::process_table};

kernel/src/syscall/time.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{prelude::*, time::SystemTime};
 

kernel/src/syscall/timer_create.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::{
     clock_gettime::{DynamicClockIdInfo, DynamicClockType},
     SyscallReturn,

kernel/src/syscall/timer_settime.rs

@@ -2,6 +2,8 @@
 
 use core::time::Duration;
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     prelude::*,

kernel/src/syscall/timerfd_gettime.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::file_table::FileDesc,

kernel/src/syscall/timerfd_settime.rs

@@ -2,6 +2,8 @@
 
 use core::time::Duration;
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     fs::file_table::FileDesc,

kernel/src/syscall/uname.rs

@@ -1,4 +1,6 @@
 // SPDX-License-Identifier: MPL-2.0
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::prelude::*;
 

kernel/src/syscall/utimens.rs

@@ -2,6 +2,8 @@
 
 use core::time::Duration;
 
+use ostd::mm::VmIo;
+
 use super::{constants::MAX_FILENAME_LEN, SyscallReturn};
 use crate::{
     fs,

kernel/src/syscall/wait4.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::{getrusage::rusage_t, SyscallReturn};
 use crate::{
     prelude::*,

kernel/src/syscall/waitid.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::SyscallReturn;
 use crate::{
     prelude::*,

kernel/src/thread/task.rs

@@ -2,6 +2,7 @@
 
 use ostd::{
     arch::cpu::context::UserContext,
+    mm::VmIo,
     sync::Waiter,
     task::{Task, TaskOptions},
     user::{ReturnReason, UserContextApi, UserMode},

kernel/src/util/net/addr/family.rs

@@ -2,7 +2,7 @@
 
 use core::cmp::min;
 
-use ostd::task::Task;
+use ostd::{mm::VmIo, task::Task};
 
 use super::{ip::CSocketAddrInet, netlink::CSocketAddrNetlink, unix, vsock::CSocketAddrVm};
 use crate::{current_userspace, net::socket::util::SocketAddr, prelude::*};
@@ -145,10 +145,7 @@ pub fn read_socket_addr_from_user(addr: Vaddr, addr_len: usize) -> Result<Socket
     }
 
     let mut storage = Storage::new_zeroed();
-    current_userspace!().read_bytes(
-        addr,
-        &mut VmWriter::from(&mut storage.as_bytes_mut()[..addr_len]),
-    )?;
+    current_userspace!().read_bytes(addr, &mut storage.as_bytes_mut()[..addr_len])?;
 
     let result = match CSocketAddrFamily::try_from(storage.sa_family as i32) {
         Ok(CSocketAddrFamily::AF_INET) => {
@@ -215,7 +212,7 @@ pub fn write_socket_addr_to_user(
 
     let actual_len = write_socket_addr_with_max_len(socket_addr, dest, max_len)?;
 
-    user_space.write_val(max_len_ptr, &actual_len)
+    Ok(user_space.write_val(max_len_ptr, &actual_len)?)
 }
 
 /// Writes a socket address to the user space.
@@ -253,7 +250,7 @@ pub fn write_socket_addr_with_max_len(
         )?,
         SocketAddr::Unix(addr) => unix::into_c_bytes_and(addr, |bytes| {
             let written_len = min(bytes.len(), max_len as _);
-            current_userspace!().write_bytes(dest, &mut VmReader::from(&bytes[..written_len]))?;
+            current_userspace!().write_bytes(dest, &bytes[..written_len])?;
             Ok::<usize, Error>(bytes.len())
         })?,
         SocketAddr::Netlink(addr) => {
@@ -280,10 +277,7 @@ where
     let actual_len = size_of::<TCSockAddr>();
     let written_len = min(actual_len, max_len);
 
-    current_userspace!().write_bytes(
-        dest,
-        &mut VmReader::from(&c_socket_addr.as_bytes()[..written_len]),
-    )?;
+    current_userspace!().write_bytes(dest, &c_socket_addr.as_bytes()[..written_len])?;
 
     Ok(actual_len)
 }

kernel/src/util/net/options/socket.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use ostd::mm::VmIo;
+
 use super::RawSocketOption;
 use crate::{
     current_userspace, impl_raw_sock_option_get_only, impl_raw_socket_option,

kernel/src/util/net/options/utils.rs

@@ -2,6 +2,8 @@
 
 use core::{num::NonZeroU8, time::Duration};
 
+use ostd::mm::VmIo;
+
 use crate::{
     current_userspace,
     net::socket::{
@@ -44,7 +46,7 @@ macro_rules! impl_read_write_for_32bit_type {
                 if (max_len as usize) < size_of::<$pod_ty>() {
                     return_errno_with_message!(Errno::EINVAL, "max_len is too short");
                 }
-                crate::current_userspace!().read_val::<$pod_ty>(addr)
+                Ok(crate::current_userspace!().read_val::<$pod_ty>(addr)?)
             }
         }
 
@@ -174,11 +176,7 @@ impl ReadFromUser for CongestionControl {
             &mut bytes[..read_len]
         };
 
-        // Clippy warns that `dst.as_mut` is redundant. However, using `dst` directly
-        // instead of `dst.as_mut` would take the ownership of `dst`. Consequently,
-        // the subsequent code that constructs `name` from `dst` would fail to compile.
-        #[expect(clippy::useless_asref)]
-        current_userspace!().read_bytes(addr, &mut VmWriter::from(dst.as_mut()))?;
+        current_userspace!().read_bytes(addr, dst.as_mut())?;
 
         let name = core::str::from_utf8(dst)
             .map_err(|_| Error::with_message(Errno::ENOENT, "non-UTF8 congestion name"))?;
@@ -196,7 +194,7 @@ impl WriteToUser for CongestionControl {
 
         let write_len = TCP_CONGESTION_NAME_MAX.min(max_len) as usize;
 
-        current_userspace!().write_bytes(addr, &mut VmReader::from(&bytes[..write_len]))?;
+        current_userspace!().write_bytes(addr, &bytes[..write_len])?;
 
         Ok(write_len)
     }