add support for mmap shared memory. passed compilation.

crate/memory/Cargo.toml

@@ -6,3 +6,4 @@ edition = "2018"
 
 [dependencies]
 log = "0.4"
+spin = "0.5"

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

@@ -40,9 +40,11 @@ mod byframe;
 mod delay;
 mod file;
 mod linear;
+mod shared;
 //mod swap;
 
 pub use self::byframe::ByFrame;
 pub use self::delay::Delay;
 pub use self::file::{File, Read};
 pub use self::linear::Linear;
+pub use self::shared::Shared;

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

@@ -0,0 +1,130 @@
+use super::*;
+use alloc::sync::Arc;
+use alloc::collections::BTreeMap;
+use spin::Mutex;
+
+#[derive(Debug)]
+struct SharedGuard<T: FrameAllocator> {
+    allocator: T,
+    // direct mapping now. only work for mmap
+    target: BTreeMap<usize, usize> 
+}
+
+impl<T: FrameAllocator> SharedGuard<T> {
+    pub fn new(allocator: T) -> Self {
+        SharedGuard { 
+            allocator: allocator,
+            target: BTreeMap::new()
+        } // delayed allocated now
+    }
+    pub fn alloc(&mut self, virtAddr: usize) -> Option<usize> {
+        let physAddr = self.allocator.alloc().expect("failed to allocate frame");
+        self.target.insert(virtAddr, physAddr);
+        Some(physAddr)
+    }
+    pub fn dealloc(&mut self, virtAddr: usize) {
+        let physAddr = self.target.get(&virtAddr).unwrap().clone();
+        self.allocator.dealloc(physAddr);
+        self.target.remove(&virtAddr);
+    }
+    pub fn get(&self, addr: usize) -> Option<usize> {
+        Some(self.target.get(&addr).unwrap().clone())
+    }
+}
+
+impl<T: FrameAllocator> Drop for SharedGuard<T> {
+    fn drop(&mut self) {
+        let mut freeList = Vec::new();
+        for (virtAddr, _physAddr) in self.target.iter() {
+            freeList.push(virtAddr.clone());
+        }
+        for virtAddr in freeList.iter() {
+            self.dealloc(virtAddr.clone());
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Shared<T: FrameAllocator> {
+    allocator: T,
+    guard: Option<Arc<Mutex<SharedGuard<T>>>>
+}
+
+impl<T: FrameAllocator> MemoryHandler for Shared<T> {
+    fn box_clone(&self) -> Box<dyn MemoryHandler> {
+        Box::new(self.clone())
+    }
+
+    fn map(&self, pt: &mut dyn PageTable, addr: VirtAddr, attr: &MemoryAttr) {
+        //assert!(self.guard.is_some(), "remapping memory area")
+        let guard = self.guard.clone();
+        let physAddrOpt = guard.unwrap().lock().get(addr);
+        if physAddrOpt.is_none() { // not mapped yet
+            let entry = pt.map(addr, 0);
+            entry.set_present(false);
+            attr.apply(entry);
+        } else  { // physical memory already allocated by other process
+            let physAddr = physAddrOpt.unwrap().clone();
+            let entry = pt.map(addr, physAddr);
+            attr.apply(entry)
+        }
+    }
+
+    fn unmap(&self, pt: &mut dyn PageTable, addr: VirtAddr) {
+        // free physical memory done when guard destroyed
+        pt.unmap(addr);
+    }
+
+    fn clone_map(
+        &self,
+        pt: &mut dyn PageTable,
+        _src_pt: &mut dyn PageTable,
+        addr: VirtAddr,
+        attr: &MemoryAttr,
+    ) {
+        // actual map done when handling page fault, since guard are copied.
+        let entry = pt.map(addr, 0);
+        entry.set_present(false);
+        attr.apply(entry);
+    }
+
+    fn handle_page_fault(&self, pt: &mut dyn PageTable, addr: VirtAddr) -> bool {
+        let entry = pt.get_entry(addr).expect("failed to get entry");
+        let guard = self.guard.clone();
+        let physAddrOpt = guard.clone().unwrap().lock().get(addr);
+        if entry.present() {
+            // not a delay case
+            return false;
+        } else if physAddrOpt.is_none() {
+            // physical memory not alloced.
+            let frame = guard.clone().unwrap().lock().alloc(addr).unwrap();
+            entry.set_target(frame);
+            entry.set_present(true);
+            entry.update();
+
+            //init with zero for delay mmap mode
+            let data = pt.get_page_slice_mut(addr);
+            let len = data.len();
+            for x in data {
+                *x = 0;
+            }
+            pt.flush_cache_copy_user(addr, addr + len, false);
+        } else {
+            // physical memory alloced. update page table
+            let frame = physAddrOpt.unwrap().clone();
+            entry.set_target(frame);
+            entry.set_present(true);
+            entry.update();
+        }
+        true
+    }
+}
+
+impl<T: FrameAllocator> Shared<T> {
+    pub fn new(allocator: T) -> Self {
+        Shared {
+            allocator: allocator.clone(),
+            guard: Some(Arc::new(Mutex::new(SharedGuard::new(allocator))))
+        }
+    }
+}

kernel/Cargo.lock

@@ -429,6 +429,7 @@ name = "rcore-memory"
 version = "0.1.0"
 dependencies = [
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "spin 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]

kernel/src/ipc/shared_mem.rs

@@ -0,0 +1,81 @@
+use crate::sync::Semaphore;
+use crate::sync::SpinLock as Mutex;
+use alloc::{boxed::Box, collections::BTreeMap, string::String, sync::Arc, sync::Weak, vec::Vec};
+use core::cell::UnsafeCell;
+use lazy_static::lazy_static;
+use spin::RwLock;
+use rcore_memory::{VirtAddr, PhysAddr};
+
+pub struct shmid {
+    key: usize,
+    size: usize,
+    target: PhysAddr
+}
+
+pub struct shmid_local {
+    key: usize,
+    size: usize,
+    addr: VirtAddr,
+    target: PhysAddr
+}
+
+impl shmid {
+    pub fn new(key: usize, size: usize, target: PhysAddr) -> shmid {
+        shmid {
+            key,
+            size,
+            target
+        }
+    }
+}
+
+impl shmid_local {
+    pub fn new(key: usize, size: usize, addr: VirtAddr, target: PhysAddr) -> shmid {
+        shmid_local {
+            key,
+            size,
+            addr,
+            target
+        }
+    } 
+}
+
+lazy_static! {
+    pub static ref KEY2SHM: RwLock<BTreeMap<usize, Arc<shmid>>> =
+        RwLock::new(BTreeMap::new());                                                   // between ARC & WEAK
+}
+
+/*pub fn new_shm(key: usize, size: usize, shmflg: usize) -> shmid_local {
+    let mut key2shm_table = KEY2SHM.write();
+    let mut shmid_ref: shmid;
+    let mut key_shmid_ref = key2shm_table.get(&key);
+    if (key_shmid_ref.is_none() || key_shmid_ref.unwrap().upgrade().is_none()) {
+        proc.
+    } else {
+        shmid_ref = key2shm_table.get(&key).unwrap().unwrap();
+
+    }
+
+    shmid_ref
+}
+
+pub fn new_semary(key: usize, nsems: usize, semflg: usize) -> Arc<SemArray> {
+    let mut key2sem_table = KEY2SEM.write();
+    let mut sem_array_ref: Arc<SemArray>;
+
+    let mut key_sem_array_ref = key2sem_table.get(&key);
+    if (key_sem_array_ref.is_none() || key_sem_array_ref.unwrap().upgrade().is_none()) {
+        let mut semaphores: Vec<Semaphore> = Vec::new();
+        for i in 0..nsems {
+            semaphores.push(Semaphore::new(0));
+        }
+
+        let mut sem_array = SemArray::new(key, semaphores);
+        sem_array_ref = Arc::new(sem_array);
+        key2sem_table.insert(key, Arc::downgrade(&sem_array_ref));
+    } else {
+        sem_array_ref = key2sem_table.get(&key).unwrap().upgrade().unwrap(); // no security check
+    }
+
+    sem_array_ref
+}*/

kernel/src/syscall/ipc.rs

@@ -11,6 +11,10 @@ pub use crate::ipc::SemArray;
 pub use crate::ipc::SemBuf;
 pub use crate::ipc::SemctlUnion;
 
+use rcore_memory::memory_set::handler::{Delay, File, Linear, Shared};
+use rcore_memory::memory_set::MemoryAttr;
+use rcore_memory::PAGE_SIZE;
+
 use super::*;
 
 impl Syscall<'_> {
@@ -98,6 +102,60 @@ impl Syscall<'_> {
             unimplemented!("Semaphore: Semctl.(Not setval)");
         }
     }
+
+    /*pub fn sys_shmget(&self, key: usize, size: usize, shmflg: usize) -> SysResult {
+        info!("sys_shmget: key: {}", key);
+
+        let mut size = size;
+
+        if ((size & (PAGE_SIZE - 1)) != 0) {
+            size = (size & !(PAGE_SIZE - 1)) + PAGE_SIZE;
+        }
+
+
+        let mut proc = self.process();
+
+        let mut key2shm_table = KEY2SHM.write();
+        let mut shmid_ref: shmid;
+        let mut shmid_local_ref: shmid_local;
+
+        let mut key_shmid_ref = key2shm_table.get(&key);
+        if (key_shmid_ref.is_none() || key_shmid_ref.unwrap().upgrade().is_none()) {
+            let addr = proc.vm().find_free_area(PAGE_SIZE, size);
+            proc.vm().push(
+                addr,
+                addr + size,
+                MemoryAttr {
+                    user: true,
+                    readonly: false,
+                    execute: true,
+                    mmio: 0
+                }
+                Shared::new(GlobalFrameAlloc),
+                "shmget",
+            );
+            let target = proc.vm().translate(addr);
+            shmid_ref = shmid::new(key, size, target);
+            shmid_local_ref = shmid_local::new(key, size, addr, target);
+        } else {
+            shmid_ref = key2shm_table.get(&key).unwrap().unwrap();
+
+        }
+
+        shmid_ref
+
+        /*let sem_id = (0..)
+            .find(|i| match semarray_table.get(i) {
+                Some(p) => false,
+                _ => true,
+            })
+            .unwrap();
+
+        let mut sem_array: Arc<SemArray> = new_semary(key, nsems, semflg);
+
+        semarray_table.insert(sem_id, sem_array);
+        Ok(sem_id)*/
+    }*/
 }
 
 bitflags! {

kernel/src/syscall/mem.rs

@@ -1,4 +1,4 @@
-use rcore_memory::memory_set::handler::{Delay, File, Linear};
+use rcore_memory::memory_set::handler::{Delay, File, Linear, Shared};
 use rcore_memory::memory_set::MemoryAttr;
 use rcore_memory::PAGE_SIZE;
 
@@ -40,16 +40,25 @@ impl Syscall<'_> {
 
         if flags.contains(MmapFlags::ANONYMOUS) {
             if flags.contains(MmapFlags::SHARED) {
-                return Err(SysError::EINVAL);
+                self.vm().push(
+                    addr,
+                    addr + len,
+                    prot.to_attr(),
+                    Shared::new(GlobalFrameAlloc),
+                    "mmap_anon_shared",
+                );
+                return Ok(addr);
+            } else {
+                self.vm().push(
+                    addr,
+                    addr + len,
+                    prot.to_attr(),
+                    Delay::new(GlobalFrameAlloc),
+                    "mmap_anon",
+                );
+                return Ok(addr);
             }
-            self.vm().push(
-                addr,
-                addr + len,
-                prot.to_attr(),
-                Delay::new(GlobalFrameAlloc),
-                "mmap_anon",
-            );
-            return Ok(addr);
+            
         } else {
             let file = proc.get_file(fd)?;
             info!("mmap path is {} ", &*file.path);

kernel/src/syscall/mod.rs

@@ -268,9 +268,19 @@ impl Syscall<'_> {
                 args[0],
                 args[1],
                 args[2],
-                args[3] as isize, /* as SemctlUnion*/
+                args[3] as isize, /* as SemctlUnion */
             ),
 
+            // shm
+            /*SYS_SHMGET => self.sys_shmget(args[0], args[1], args[2]),
+            SYS_SHMAT => self.sys_shmat(args[0], args[1], args[2]),
+            SYS_SHMDT => self.sys_shmdt(args[0], args[1], args[2]),
+            SYS_SHMCTL => self.sys_shmctl(
+                args[0],
+                args[1],
+                args[2] /* should be shmid_ds *buf */
+            ),*/
+
             // system
             SYS_GETPID => self.sys_getpid(),
             SYS_GETTID => self.sys_gettid(),