Refine System-V shared memory

src/libos/src/ipc/mod.rs

@@ -3,5 +3,5 @@ use super::*;
 mod shm;
 mod syscalls;
 
-pub use self::shm::{key_t, shmids_t, SHM_MANAGER};
+pub use self::shm::{key_t, shmids_t, SYSTEM_V_SHM_MANAGER};
 pub use self::syscalls::{do_shmat, do_shmctl, do_shmdt, do_shmget};

src/libos/src/ipc/shm.rs

@@ -144,7 +144,6 @@ impl ShmSegment {
             .size(size)
             // Currently, Occlum only support shared memory segment with rw permission
             .perms(VMPerms::READ | VMPerms::WRITE)
-            .initializer(VMInitializer::FillZeros())
             .build()?;
         let chunk = USER_SPACE_VM_MANAGER.internal().mmap_chunk(&vm_option)?;
 
@@ -204,6 +203,14 @@ impl ShmSegment {
         self.process_set.remove(&pid);
         Ok(())
     }
+
+    fn chunk(&self) -> &ChunkRef {
+        &self.chunk
+    }
+
+    fn process_set(&self) -> &HashSet<pid_t> {
+        &self.process_set
+    }
 }
 
 impl Drop for ShmSegment {
@@ -265,7 +272,7 @@ impl ShmIdManager {
 }
 
 lazy_static! {
-    pub static ref SHM_MANAGER: ShmManager = ShmManager::new();
+    pub static ref SYSTEM_V_SHM_MANAGER: ShmManager = ShmManager::new();
 }
 
 #[derive(Debug)]
@@ -282,6 +289,16 @@ impl ShmManager {
         }
     }
 
+    pub fn get_shm_chunk_containing_addr(&self, addr: usize, pid: pid_t) -> Option<ChunkRef> {
+        let shm_segments = self.shm_segments.read().unwrap();
+        shm_segments
+            .iter()
+            .find(|(_, shm_segment)| {
+                shm_segment.chunk().range().contains(addr) && shm_segment.process_set.contains(&pid)
+            })
+            .map(|(_, shm_segment)| shm_segment.chunk().clone())
+    }
+
     fn current_time() -> time_t {
         do_gettimeofday().sec()
     }

src/libos/src/ipc/syscalls.rs

@@ -2,24 +2,24 @@ use super::*;
 
 use util::mem_util::from_user;
 
-use super::shm::{shmids_t, CmdId, ShmFlags, ShmId, SHM_MANAGER};
+use super::shm::{shmids_t, CmdId, ShmFlags, ShmId, SYSTEM_V_SHM_MANAGER};
 
 pub fn do_shmget(key: key_t, size: size_t, shmflg: i32) -> Result<isize> {
     let shmflg =
         ShmFlags::from_bits(shmflg as u32).ok_or_else(|| errno!(EINVAL, "invalid flags"))?;
-    let shmid = SHM_MANAGER.do_shmget(key, size, shmflg)?;
+    let shmid = SYSTEM_V_SHM_MANAGER.do_shmget(key, size, shmflg)?;
     Ok(shmid as isize)
 }
 
 pub fn do_shmat(shmid: i32, shmaddr: usize, shmflg: i32) -> Result<isize> {
     let shmflg =
         ShmFlags::from_bits(shmflg as u32).ok_or_else(|| errno!(EINVAL, "invalid flags"))?;
-    let addr = SHM_MANAGER.do_shmat(shmid as ShmId, shmaddr, shmflg)?;
+    let addr = SYSTEM_V_SHM_MANAGER.do_shmat(shmid as ShmId, shmaddr, shmflg)?;
     Ok(addr as isize)
 }
 
 pub fn do_shmdt(shmaddr: usize) -> Result<isize> {
-    SHM_MANAGER.do_shmdt(shmaddr)?;
+    SYSTEM_V_SHM_MANAGER.do_shmdt(shmaddr)?;
     Ok(0)
 }
 
@@ -31,6 +31,6 @@ pub fn do_shmctl(shmid: i32, cmd: i32, buf_u: *mut shmids_t) -> Result<isize> {
     } else {
         None
     };
-    SHM_MANAGER.do_shmctl(shmid as ShmId, cmd as CmdId, buf)?;
+    SYSTEM_V_SHM_MANAGER.do_shmctl(shmid as ShmId, cmd as CmdId, buf)?;
     Ok(0)
 }

src/libos/src/process/do_exit.rs

@@ -7,7 +7,7 @@ use super::do_vfork::{is_vforked_child_process, vfork_return_to_parent};
 use super::pgrp::clean_pgrp_when_exit;
 use super::process::{Process, ProcessFilter};
 use super::{table, ProcessRef, TermStatus, ThreadRef, ThreadStatus};
-use crate::ipc::SHM_MANAGER;
+use crate::ipc::SYSTEM_V_SHM_MANAGER;
 use crate::prelude::*;
 use crate::signal::{KernelSignal, SigNum};
 use crate::syscall::CpuContext;
@@ -120,7 +120,7 @@ fn exit_process(thread: &ThreadRef, term_status: TermStatus) {
     let mut process_inner = process.inner();
     // Clean used VM
     USER_SPACE_VM_MANAGER.free_chunks_when_exit(thread);
-    SHM_MANAGER.detach_shm_when_process_exit(thread);
+    SYSTEM_V_SHM_MANAGER.detach_shm_when_process_exit(thread);
 
     // The parent is the idle process
     if parent_inner.is_none() {

src/libos/src/vm/process_vm.rs

@@ -10,7 +10,6 @@ use super::vm_util::{
     VMRemapOptions,
 };
 use crate::config;
-use crate::ipc::SHM_MANAGER;
 use crate::process::elf_file::{ElfFile, ProgramHeaderExt};
 use crate::util::sync::rw_lock::RwLockWriteGuard;
 

src/libos/src/vm/vm_manager.rs

@@ -9,6 +9,7 @@ use super::vm_area::{VMAccess, VMArea};
 use super::vm_chunk_manager::ChunkManager;
 use super::vm_perms::VMPerms;
 use super::vm_util::*;
+use crate::ipc::SYSTEM_V_SHM_MANAGER;
 use crate::process::{ThreadRef, ThreadStatus};
 
 use std::collections::BTreeSet;