Kernel: Move SharedMemory.{cpp,h} into FileSystem/

Kernel/FileSystem/FileDescription.cpp

@@ -6,9 +6,9 @@
 #include <Kernel/FileSystem/FileDescription.h>
 #include <Kernel/FileSystem/FileSystem.h>
 #include <Kernel/FileSystem/InodeFile.h>
+#include <Kernel/FileSystem/SharedMemory.h>
 #include <Kernel/Net/Socket.h>
 #include <Kernel/Process.h>
-#include <Kernel/SharedMemory.h>
 #include <Kernel/TTY/MasterPTY.h>
 #include <Kernel/TTY/TTY.h>
 #include <Kernel/UnixTypes.h>

Kernel/FileSystem/SharedMemory.cpp

@@ -0,0 +1,97 @@
+#include <AK/HashMap.h>
+#include <Kernel/FileSystem/SharedMemory.h>
+#include <Kernel/Lock.h>
+#include <Kernel/Process.h>
+#include <Kernel/VM/VMObject.h>
+
+Lockable<HashMap<String, RefPtr<SharedMemory>>>& shared_memories()
+{
+    static Lockable<HashMap<String, RefPtr<SharedMemory>>>* map;
+    if (!map)
+        map = new Lockable<HashMap<String, RefPtr<SharedMemory>>>;
+    return *map;
+}
+
+KResultOr<NonnullRefPtr<SharedMemory>> SharedMemory::open(const String& name, int flags, mode_t mode)
+{
+    UNUSED_PARAM(flags);
+    LOCKER(shared_memories().lock());
+    auto it = shared_memories().resource().find(name);
+    if (it != shared_memories().resource().end()) {
+        auto shared_memory = it->value;
+        // FIXME: Improved access checking.
+        if (shared_memory->uid() != current->process().uid())
+            return KResult(-EACCES);
+        return *shared_memory;
+    }
+    auto shared_memory = adopt(*new SharedMemory(name, current->process().uid(), current->process().gid(), mode));
+    shared_memories().resource().set(name, shared_memory.ptr());
+    return shared_memory;
+}
+
+KResult SharedMemory::unlink(const String& name)
+{
+    LOCKER(shared_memories().lock());
+    auto it = shared_memories().resource().find(name);
+    if (it == shared_memories().resource().end())
+        return KResult(-ENOENT);
+    shared_memories().resource().remove(it);
+    return KSuccess;
+}
+
+SharedMemory::SharedMemory(const String& name, uid_t uid, gid_t gid, mode_t mode)
+    : m_name(name)
+    , m_uid(uid)
+    , m_gid(gid)
+    , m_mode(mode)
+{
+}
+
+SharedMemory::~SharedMemory()
+{
+}
+
+KResult SharedMemory::truncate(int length)
+{
+    if (!length) {
+        m_vmo = nullptr;
+        return KSuccess;
+    }
+
+    if (!m_vmo) {
+        m_vmo = VMObject::create_anonymous(length);
+        return KSuccess;
+    }
+
+    // FIXME: Support truncation.
+    ASSERT_NOT_REACHED();
+    return KResult(-ENOTIMPL);
+}
+
+String SharedMemory::absolute_path(const FileDescription&) const
+{
+    return String::format("shm:%u", this);
+}
+
+int SharedMemory::read(FileDescription&, u8* buffer, int buffer_size)
+{
+    UNUSED_PARAM(buffer);
+    UNUSED_PARAM(buffer_size);
+    // FIXME: Implement.
+    ASSERT_NOT_REACHED();
+}
+
+int SharedMemory::write(FileDescription&, const u8* data, int data_size)
+{
+    UNUSED_PARAM(data);
+    UNUSED_PARAM(data_size);
+    // FIXME: Implement.
+    ASSERT_NOT_REACHED();
+}
+
+KResultOr<Region*> SharedMemory::mmap(Process& process, FileDescription&, VirtualAddress vaddr, size_t offset, size_t size, int prot)
+{
+    if (!vmo())
+        return KResult(-ENODEV);
+    return process.allocate_region_with_vmo(vaddr, size, *vmo(), offset, name(), prot);
+}

Kernel/FileSystem/SharedMemory.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <AK/RefPtr.h>
+#include <AK/RefCounted.h>
+#include <Kernel/FileSystem/File.h>
+#include <Kernel/KResult.h>
+#include <Kernel/UnixTypes.h>
+
+class VMObject;
+
+class SharedMemory : public File {
+public:
+    static KResultOr<NonnullRefPtr<SharedMemory>> open(const String& name, int flags, mode_t);
+    static KResult unlink(const String& name);
+    virtual ~SharedMemory() override;
+
+    const String& name() const { return m_name; }
+    virtual KResult truncate(off_t) override;
+    VMObject* vmo() { return m_vmo.ptr(); }
+    const VMObject* vmo() const { return m_vmo.ptr(); }
+    uid_t uid() const { return m_uid; }
+    gid_t gid() const { return m_gid; }
+
+private:
+    // ^File
+    virtual bool can_read(FileDescription&) const override { return true; }
+    virtual bool can_write(FileDescription&) const override { return true; }
+    virtual int read(FileDescription&, u8*, int) override;
+    virtual int write(FileDescription&, const u8*, int) override;
+    virtual String absolute_path(const FileDescription&) const override;
+    virtual const char* class_name() const override { return "SharedMemory"; }
+    virtual bool is_shared_memory() const override { return true; }
+    virtual KResultOr<Region*> mmap(Process&, FileDescription&, VirtualAddress, size_t offset, size_t size, int prot) override;
+
+    SharedMemory(const String& name, uid_t, gid_t, mode_t);
+
+    String m_name;
+    uid_t m_uid { 0 };
+    gid_t m_gid { 0 };
+    mode_t m_mode { 0 };
+    RefPtr<VMObject> m_vmo;
+};