delay mapping file

crate/memory/src/memory_set/handler/delay.rs

@@ -40,9 +40,10 @@ impl<T: FrameAllocator> MemoryHandler for Delay<T> {
             let data = Vec::from(pt.get_page_slice_mut(addr));
             with(&mut || {
                 let target = self.allocator.alloc().expect("failed to alloc frame");
+                let target_data = pt.get_page_slice_mut(addr);
                 let entry = pt.map(addr, target);
+                target_data.copy_from_slice(&data);
                 attr.apply(entry);
-                pt.get_page_slice_mut(addr).copy_from_slice(&data);
             });
         } else {
             // delay map

crate/memory/src/memory_set/handler/file.rs

@@ -0,0 +1,108 @@
+use super::*;
+
+/// Delay mapping a page to an area of a file.
+#[derive(Clone)]
+pub struct File<F, T> {
+    pub file: F,
+    pub mem_start: usize,
+    pub file_start: usize,
+    pub file_end: usize,
+    pub allocator: T,
+}
+
+pub trait Read: Clone + Send + Sync + 'static {
+    fn read_at(&self, offset: usize, buf: &mut [u8]) -> usize;
+}
+
+impl<F: Read, T: FrameAllocator> MemoryHandler for File<F, T> {
+    fn box_clone(&self) -> Box<MemoryHandler> {
+        Box::new(self.clone())
+    }
+
+    fn map(&self, pt: &mut PageTable, addr: usize, attr: &MemoryAttr) {
+        let entry = pt.map(addr, 0);
+        entry.set_present(false);
+        attr.apply(entry);
+    }
+
+    fn unmap(&self, pt: &mut PageTable, addr: usize) {
+        let entry = pt.get_entry(addr).expect("failed to get entry");
+        if entry.present() {
+            self.allocator.dealloc(entry.target());
+        }
+
+        // PageTable::unmap requires page to be present
+        entry.set_present(true);
+        pt.unmap(addr);
+    }
+
+    fn clone_map(
+        &self,
+        pt: &mut PageTable,
+        with: &Fn(&mut FnMut()),
+        addr: usize,
+        attr: &MemoryAttr,
+    ) {
+        let entry = pt.get_entry(addr).expect("failed to get entry");
+        if entry.present() && !attr.readonly {
+            // eager map and copy data
+            let data = Vec::from(pt.get_page_slice_mut(addr));
+            with(&mut || {
+                let target = self.allocator.alloc().expect("failed to alloc frame");
+                let target_data = pt.get_page_slice_mut(addr);
+                let entry = pt.map(addr, target);
+                target_data.copy_from_slice(&data);
+                attr.apply(entry);
+            });
+        } else {
+            // delay map
+            with(&mut || self.map(pt, addr, attr));
+        }
+    }
+
+    fn handle_page_fault(&self, pt: &mut PageTable, addr: usize) -> bool {
+        let addr = addr & !(PAGE_SIZE - 1);
+        let entry = pt.get_entry(addr).expect("failed to get entry");
+        if entry.present() {
+            return false;
+        }
+        let frame = self.allocator.alloc().expect("failed to alloc frame");
+        entry.set_target(frame);
+        entry.set_present(true);
+        let writable = entry.writable();
+        entry.set_writable(true);
+        entry.update();
+
+        self.fill_data(pt, addr);
+
+        let entry = pt.get_entry(addr).expect("failed to get entry");
+        entry.set_writable(writable);
+        entry.update();
+
+        true
+    }
+}
+
+impl<F: Read, T: FrameAllocator> File<F, T> {
+    fn fill_data(&self, pt: &mut PageTable, addr: VirtAddr) {
+        let data = pt.get_page_slice_mut(addr);
+        let file_offset = addr + self.file_start - self.mem_start;
+        let read_size = (self.file_end as isize - file_offset as isize)
+            .min(PAGE_SIZE as isize)
+            .max(0) as usize;
+        let read_size = self.file.read_at(file_offset, &mut data[..read_size]);
+        if read_size != PAGE_SIZE {
+            data[read_size..].iter_mut().for_each(|x| *x = 0);
+        }
+    }
+}
+
+impl<F, T> Debug for File<F, T> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+        f.debug_struct("FileHandler")
+            .field("mem_start", &self.mem_start)
+            .field("file_start", &self.file_start)
+            .field("file_end", &self.file_end)
+            .finish()
+    }
+}

crate/memory/src/memory_set/handler/mod.rs

@@ -42,8 +42,10 @@ pub trait FrameAllocator: Debug + Clone + Send + Sync + 'static {
 mod byframe;
 mod delay;
 mod linear;
+mod file;
 //mod swap;
 
 pub use self::byframe::ByFrame;
 pub use self::delay::Delay;
 pub use self::linear::Linear;
+pub use self::file::{File, Read};

kernel/src/fs/file.rs

@@ -116,4 +116,8 @@ impl FileHandle {
     pub fn io_control(&self, cmd: u32, arg: usize) -> Result<()> {
         self.inode.io_control(cmd, arg)
     }
+
+    pub fn inode(&self) -> Arc<INode> {
+        self.inode.clone()
+    }
 }

kernel/src/process/structs.rs

@@ -14,10 +14,13 @@ use xmas_elf::{
 
 use crate::arch::interrupt::{Context, TrapFrame};
 use crate::fs::{FileHandle, FileLike, INodeExt, OpenOptions, FOLLOW_MAX_DEPTH};
-use crate::memory::{ByFrame, Delay, GlobalFrameAlloc, KernelStack, MemoryAttr, MemorySet};
+use crate::memory::{
+    ByFrame, Delay, File, GlobalFrameAlloc, KernelStack, MemoryAttr, MemorySet, Read,
+};
 use crate::sync::{Condvar, SpinNoIrqLock as Mutex};
 
 use super::abi::{self, ProcInitInfo};
+use rcore_fs::vfs::INode;
 
 // TODO: avoid pub
 pub struct Thread {
@@ -128,19 +131,25 @@ impl Thread {
     /// Construct virtual memory of a new user process from ELF `data`.
     /// Return `(MemorySet, entry_point, ustack_top)`
     pub fn new_user_vm(
-        data: &[u8],
+        inode: &Arc<INode>,
         exec_path: &str,
         mut args: Vec<String>,
         envs: Vec<String>,
-    ) -> (MemorySet, usize, usize) {
+    ) -> Result<(MemorySet, usize, usize), &'static str> {
+        // Read data
+        use crate::fs::INodeExt;
+        let data = inode
+            .read_as_vec()
+            .map_err(|_| "failed to read from INode")?;
+
         // Parse ELF
-        let elf = ElfFile::new(data).expect("failed to read elf");
+        let elf = ElfFile::new(&data)?;
 
         // Check ELF type
         match elf.header.pt2.type_().as_type() {
             header::Type::Executable => {}
             header::Type::SharedObject => {}
-            _ => panic!("ELF is not executable or shared object"),
+            _ => return Err("ELF is not executable or shared object"),
         }
 
         // Check ELF arch
@@ -153,7 +162,7 @@ impl Thread {
             header::Machine::Other(243) => {}
             #[cfg(target_arch = "mips")]
             header::Machine::Mips => {}
-            machine @ _ => panic!("invalid elf arch: {:?}", machine),
+            machine @ _ => return Err("invalid ELF arch"),
         }
 
         // Check interpreter (for dynamic link)
@@ -161,18 +170,17 @@ impl Thread {
             // assuming absolute path
             let inode = crate::fs::ROOT_INODE
                 .lookup_follow(loader_path, FOLLOW_MAX_DEPTH)
-                .expect("interpreter not found");
-            let buf = inode.read_as_vec().expect("failed to load interpreter");
+                .map_err(|_| "interpreter not found")?;
             // modify args for loader
             args[0] = exec_path.into();
             args.insert(0, loader_path.into());
             // Elf loader should not have INTERP
             // No infinite loop
-            return Thread::new_user_vm(buf.as_slice(), exec_path, args, envs);
+            return Thread::new_user_vm(&inode, exec_path, args, envs);
         }
 
         // Make page table
-        let mut vm = elf.make_memory_set();
+        let mut vm = elf.make_memory_set(inode);
 
         // User stack
         use crate::consts::{USER_STACK_OFFSET, USER_STACK_SIZE};
@@ -219,17 +227,17 @@ impl Thread {
         trace!("{:#x?}", vm);
 
         let entry_addr = elf.header.pt2.entry_point() as usize;
-        (vm, entry_addr, ustack_top)
+        Ok((vm, entry_addr, ustack_top))
     }
 
     /// Make a new user process from ELF `data`
     pub fn new_user(
-        data: &[u8],
+        inode: &Arc<INode>,
         exec_path: &str,
         mut args: Vec<String>,
         envs: Vec<String>,
     ) -> Box<Thread> {
-        let (vm, entry_addr, ustack_top) = Self::new_user_vm(data, exec_path, args, envs);
+        let (vm, entry_addr, ustack_top) = Self::new_user_vm(inode, exec_path, args, envs).unwrap();
 
         let kstack = KernelStack::new();
 
@@ -307,7 +315,8 @@ impl Thread {
             threads: Vec::new(),
             child_exit: Arc::new(Condvar::new()),
             child_exit_code: BTreeMap::new(),
-        }.add_to_table();
+        }
+        .add_to_table();
         // link to parent
         proc.children.push(Arc::downgrade(&new_proc));
 
@@ -382,10 +391,12 @@ trait ToMemoryAttr {
 impl ToMemoryAttr for Flags {
     fn to_attr(&self) -> MemoryAttr {
         let mut flags = MemoryAttr::default().user();
-        // FIXME: handle readonly
         if self.is_execute() {
             flags = flags.execute();
         }
+        if !self.is_write() {
+            flags = flags.readonly();
+        }
         flags
     }
 }
@@ -393,7 +404,7 @@ impl ToMemoryAttr for Flags {
 /// Helper functions to process ELF file
 trait ElfExt {
     /// Generate a MemorySet according to the ELF file.
-    fn make_memory_set(&self) -> MemorySet;
+    fn make_memory_set(&self, inode: &Arc<INode>) -> MemorySet;
 
     /// Get interpreter string if it has.
     fn get_interpreter(&self) -> Result<&str, &str>;
@@ -403,7 +414,7 @@ trait ElfExt {
 }
 
 impl ElfExt for ElfFile<'_> {
-    fn make_memory_set(&self) -> MemorySet {
+    fn make_memory_set(&self, inode: &Arc<INode>) -> MemorySet {
         debug!("creating MemorySet from ELF");
         let mut ms = MemorySet::new();
 
@@ -411,33 +422,19 @@ impl ElfExt for ElfFile<'_> {
             if ph.get_type() != Ok(Type::Load) {
                 continue;
             }
-            let virt_addr = ph.virtual_addr() as usize;
-            let mem_size = ph.mem_size() as usize;
-            let data = match ph.get_data(self).unwrap() {
-                SegmentData::Undefined(data) => data,
-                _ => unreachable!(),
-            };
-
-            // Get target slice
-            let target = {
             ms.push(
-                    virt_addr,
-                    virt_addr + mem_size,
+                ph.virtual_addr() as usize,
+                ph.virtual_addr() as usize + ph.mem_size() as usize,
                 ph.flags().to_attr(),
-                    ByFrame::new(GlobalFrameAlloc),
+                File {
+                    file: INodeForMap(inode.clone()),
+                    mem_start: ph.virtual_addr() as usize,
+                    file_start: ph.offset() as usize,
+                    file_end: ph.offset() as usize + ph.file_size() as usize,
+                    allocator: GlobalFrameAlloc,
+                },
                 "elf",
             );
-                unsafe { ::core::slice::from_raw_parts_mut(virt_addr as *mut u8, mem_size) }
-            };
-            // Copy data
-            unsafe {
-                ms.with(|| {
-                    if data.len() != 0 {
-                        target[..data.len()].copy_from_slice(data);
-                    }
-                    target[data.len()..].iter_mut().for_each(|x| *x = 0);
-                });
-            }
         }
         ms
     }
@@ -479,3 +476,12 @@ impl ElfExt for ElfFile<'_> {
         }
     }
 }
+
+#[derive(Clone)]
+pub struct INodeForMap(pub Arc<INode>);
+
+impl Read for INodeForMap {
+    fn read_at(&self, offset: usize, buf: &mut [u8]) -> usize {
+        self.0.read_at(offset, buf).unwrap()
+    }
+}

kernel/src/shell.rs

@@ -30,9 +30,8 @@ pub fn add_user_shell() {
     let init_args = vec!["busybox".into(), "ash".into()];
 
     if let Ok(inode) = ROOT_INODE.lookup(init_shell) {
-        let data = inode.read_as_vec().unwrap();
         processor().manager().add(Thread::new_user(
-            data.as_slice(),
+            &inode,
             init_shell,
             init_args,
             init_envs,
@@ -46,9 +45,8 @@ pub fn add_user_shell() {
 pub fn add_user_shell() {
     let cmdline = CMDLINE.read();
     let inode = ROOT_INODE.lookup(&cmdline).unwrap();
-    let data = inode.read_as_vec().unwrap();
     processor().manager().add(Thread::new_user(
-        data.as_slice(),
+        &inode,
         cmdline.split(' ').map(|s| s.into()).collect(),
         Vec::new(),
     ));
@@ -66,16 +64,14 @@ pub extern "C" fn shell(_arg: usize) -> ! {
             continue;
         }
         let name = cmd.trim().split(' ').next().unwrap();
-        if let Ok(file) = ROOT_INODE.lookup(name) {
-            let data = file.read_as_vec().unwrap();
-            let _pid = processor().manager().add(Thread::new_user(
-                data.as_slice(),
+        if let Ok(inode) = ROOT_INODE.lookup(name) {
+            let _tid = processor().manager().add(Thread::new_user(
+                &inode,
                 &cmd,
                 cmd.split(' ').map(|s| s.into()).collect(),
                 Vec::new(),
             ));
         // TODO: wait until process exits, or use user land shell completely
-        //unsafe { thread::JoinHandle::<()>::_of(pid) }.join().unwrap();
         } else {
             println!("Program not exist");
         }

kernel/src/syscall/mem.rs

@@ -1,4 +1,4 @@
-use rcore_memory::memory_set::handler::{ByFrame, Delay};
+use rcore_memory::memory_set::handler::{ByFrame, Delay, File};
 use rcore_memory::memory_set::MemoryAttr;
 use rcore_memory::paging::PageTable;
 use rcore_memory::Page;
@@ -46,35 +46,25 @@ pub fn sys_mmap(
             addr,
             addr + len,
             prot.to_attr(),
-            //            ByFrame::new(GlobalFrameAlloc),   //eagle mmap mode
             Delay::new(GlobalFrameAlloc),
             "mmap_anon",
         );
-        //init with zero for eagle mmap mode
-        //        let data = unsafe { slice::from_raw_parts_mut(addr as *mut u8, len) };
-        //        for x in data {
-        //            *x = 0;
-        //        }
         return Ok(addr);
     } else {
-        // only check
-        let _ = proc.get_file(fd)?;
-
-        // TODO: delay mmap file
+        let inode = proc.get_file(fd)?.inode();
         proc.vm.push(
             addr,
             addr + len,
             prot.to_attr(),
-            ByFrame::new(GlobalFrameAlloc),
+            File {
+                file: INodeForMap(inode),
+                mem_start: addr,
+                file_start: offset,
+                file_end: offset + len,
+                allocator: GlobalFrameAlloc,
+            },
             "mmap_file",
         );
-        let data = unsafe { slice::from_raw_parts_mut(addr as *mut u8, len) };
-        let file = proc.get_file(fd)?;
-        let read_len = file.read_at(offset, data)?;
-        if read_len != data.len() {
-            // use count() to consume the iterator
-            data[read_len..].iter_mut().map(|x| *x = 0).count();
-        }
         return Ok(addr);
     }
 }

kernel/src/syscall/mod.rs

@@ -329,7 +329,7 @@ fn x86_64_syscall(id: usize, args: [usize; 6], tf: &mut TrapFrame) -> Option<Sys
         SYS_DUP2 => sys_dup2(args[0], args[1]),
         SYS_ALARM => unimplemented("alarm", Ok(0)),
         SYS_FORK => sys_fork(tf),
-        SYS_VFORK => sys_fork(tf), // use fork for vfork
+        SYS_VFORK => sys_vfork(tf),
         SYS_RENAME => sys_rename(args[0] as *const u8, args[1] as *const u8),
         SYS_MKDIR => sys_mkdir(args[0] as *const u8, args[1]),
         SYS_RMDIR => sys_rmdir(args[0] as *const u8),

kernel/src/syscall/proc.rs

@@ -13,6 +13,10 @@ pub fn sys_fork(tf: &TrapFrame) -> SysResult {
     Ok(pid)
 }
 
+pub fn sys_vfork(tf: &TrapFrame) -> SysResult {
+    sys_fork(tf)
+}
+
 /// Create a new thread in the current process.
 /// The new thread's stack pointer will be set to `newsp`,
 /// and thread pointer will be set to `newtls`.
@@ -168,16 +172,15 @@ pub fn sys_exec(
 
     // Read program file
     let inode = proc.lookup_inode(&path)?;
-    let data = inode.read_as_vec()?;
 
     // Make new Thread
-    let (mut vm, entry_addr, ustack_top) = Thread::new_user_vm(data.as_slice(), &path, args, envs);
+    let (mut vm, entry_addr, ustack_top) = Thread::new_user_vm(&inode, &path, args, envs).unwrap();
 
     // Activate new page table
-    unsafe {
-        vm.activate();
-    }
     core::mem::swap(&mut proc.vm, &mut vm);
+    unsafe {
+        proc.vm.activate();
+    }
 
     // Modify the TrapFrame
     *tf = TrapFrame::new_user_thread(entry_addr, ustack_top);