Implement /proc/PID/vm.

Refactored SyntheticFileSystem to maintain an arbitrary directory structure.
ProcFileSystem creates a directory entry in /proc for each new process.

AK/DoublyLinkedList.h

@@ -8,7 +8,7 @@ template<typename T>
 class DoublyLinkedList {
 private:
     struct Node {
-        explicit Node(T&& v) : value(v) { }
+        explicit Node(T&& v) : value(move(v)) { }
         T value;
         Node* next { nullptr };
         Node* prev { nullptr };
@@ -62,7 +62,8 @@ public:
 
     class Iterator {
     public:
-        bool operator!=(const Iterator& other) { return m_node != other.m_node; }
+        bool operator!=(const Iterator& other) const { return m_node != other.m_node; }
+        bool operator==(const Iterator& other) const { return m_node == other.m_node; }
         Iterator& operator++() { m_node = m_node->next; return *this; }
         T& operator*() { return m_node->value; }
         bool isEnd() const { return !m_node; }
@@ -78,7 +79,8 @@ public:
 
     class ConstIterator {
     public:
-        bool operator!=(const ConstIterator& other) { return m_node != other.m_node; }
+        bool operator!=(const ConstIterator& other) const { return m_node != other.m_node; }
+        bool operator==(const ConstIterator& other) const { return m_node == other.m_node; }
         ConstIterator& operator++() { m_node = m_node->next; return *this; }
         const T& operator*() const { return m_node->value; }
         bool isEnd() const { return !m_node; }

AK/HashTable.h

@@ -56,7 +56,7 @@ public:
 
     class Iterator {
     public:
-        bool operator!=(const Iterator& other)
+        bool operator!=(const Iterator& other) const
         {
             if (m_isEnd && other.m_isEnd)
                 return false;
@@ -65,6 +65,7 @@ public:
                 || m_bucketIndex != other.m_bucketIndex
                 || m_bucketIterator != other.m_bucketIterator;
         }
+        bool operator==(const Iterator& other) const { return !(*this != other); }
         T& operator*()
         {
 #ifdef HASHTABLE_DEBUG
@@ -126,12 +127,12 @@ public:
         typename DoublyLinkedList<T>::Iterator m_bucketIterator;
     };
 
-    Iterator begin() { return Iterator(*this, false); }
+    Iterator begin() { return Iterator(*this, isEmpty()); }
     Iterator end() { return Iterator(*this, true); }
 
     class ConstIterator {
     public:
-        bool operator!=(const ConstIterator& other)
+        bool operator!=(const ConstIterator& other) const
         {
             if (m_isEnd && other.m_isEnd)
                 return false;
@@ -140,6 +141,7 @@ public:
                 || m_bucketIndex != other.m_bucketIndex
                 || m_bucketIterator != other.m_bucketIterator;
         }
+        bool operator==(const ConstIterator& other) const { return !(*this != other); }
         const T& operator*() const
         {
 #ifdef HASHTABLE_DEBUG
@@ -203,7 +205,7 @@ public:
         typename DoublyLinkedList<T>::ConstIterator m_bucketIterator;
     };
 
-    ConstIterator begin() const { return ConstIterator(*this, false); }
+    ConstIterator begin() const { return ConstIterator(*this, isEmpty()); }
     ConstIterator end() const { return ConstIterator(*this, true); }
 
     Iterator find(const T&);

AK/OwnPtr.h

@@ -2,6 +2,7 @@
 
 #include "StdLib.h"
 #include "Types.h"
+#include "Traits.h"
 
 namespace AK {
 
@@ -96,6 +97,12 @@ make(Args&&... args)
     return OwnPtr<T>(new T(forward<Args>(args)...));
 }
 
+template<typename T>
+struct Traits<OwnPtr<T>> {
+    static unsigned hash(const OwnPtr<T>& p) { return (unsigned)p.ptr(); }
+    static void dump(const OwnPtr<T>& p) { kprintf("%p", p.ptr()); }
+};
+
 }
 
 using AK::OwnPtr;

AK/Vector.h

@@ -12,11 +12,12 @@ template<typename T>
 class VectorImpl {
 public:
     ~VectorImpl() { }
-    static OwnPtr<VectorImpl> create(size_t capacity)
+    static VectorImpl* create(size_t capacity)
     {
         size_t size = sizeof(VectorImpl) + sizeof(T) * capacity;
         void* slot = kmalloc(size);
-        return OwnPtr<VectorImpl>(new (slot) VectorImpl(capacity));
+        new (slot) VectorImpl(capacity);
+        return (VectorImpl*)slot;
     }
 
     size_t size() const { return m_size; }
@@ -59,14 +60,17 @@ public:
     ~Vector() { clear(); }
 
     Vector(Vector&& other)
-        : m_impl(move(other.m_impl))
+        : m_impl(other.m_impl)
     {
+        other.m_impl = nullptr;
     }
 
     Vector& operator=(Vector&& other)
     {
-        if (this != &other)
+        if (this != &other) {
-            m_impl = move(other.m_impl);
+            m_impl = other.m_impl;
+            other.m_impl = nullptr;
+        }
         return *this;
     }
 
@@ -75,6 +79,7 @@ public:
         for (size_t i = 0; i < size(); ++i) {
             at(i).~T();
         }
+        kfree(m_impl);
         m_impl = nullptr;
     }
 
@@ -134,8 +139,9 @@ public:
                 new (newImpl->slot(i)) T(move(m_impl->at(i)));
                 m_impl->at(i).~T();
             }
+            kfree(m_impl);
         }
-        m_impl = move(newImpl);
+        m_impl = newImpl;
     }
 
     class Iterator {
@@ -174,7 +180,7 @@ private:
         return max(size_t(4), capacity + (capacity / 4) + 4);
     }
 
-    OwnPtr<VectorImpl<T>> m_impl;
+    VectorImpl<T>* m_impl { nullptr };
 };
 
 }

AK/kmalloc.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "Compiler.h"
+
 #ifdef SERENITY
 #ifdef USERLAND
 #include <LibC/stdlib.h>

AK/test.cpp

@@ -16,6 +16,26 @@ static void testWeakPtr();
 int main(int, char**)
 {
     StringImpl::initializeGlobals();
+
+    {
+        struct entry {
+            String s;
+        };
+
+        HashMap<unsigned, entry> tab;
+        tab.set(1, { "one" });
+        tab.set(2, { "two" });
+        tab.set(3, { "three" });
+        tab.set(4, { "four" });
+        tab.remove(1);
+        tab.remove(2);
+        tab.remove(3);
+        for (auto& it : tab) {
+            printf("%s\n", it.value.s.characters());
+        }
+        return 0;
+    }
+
     {
         CircularQueue<int, 4> queue;
         queue.dump();

Kernel/ProcFileSystem.cpp

@@ -1,6 +1,14 @@
 #include "ProcFileSystem.h"
 #include "Task.h"
 
+static ProcFileSystem* s_the;
+
+ProcFileSystem& ProcFileSystem::the()
+{
+    ASSERT(s_the);
+    return *s_the;
+}
+
 RetainPtr<ProcFileSystem> ProcFileSystem::create()
 {
     return adopt(*new ProcFileSystem);
@@ -8,15 +16,56 @@ RetainPtr<ProcFileSystem> ProcFileSystem::create()
 
 ProcFileSystem::ProcFileSystem()
 {
+    s_the = this;
 }
 
 ProcFileSystem::~ProcFileSystem()
 {
 }
 
+void ProcFileSystem::addProcess(Task& task)
+{
+    ASSERT_INTERRUPTS_DISABLED();
+    char buf[16];
+    ksprintf(buf, "%d", task.pid());
+    auto dir = addFile(createDirectory(buf));
+    m_pid2inode.set(task.pid(), dir.index());
+    addFile(createGeneratedFile("vm", [&task] {
+        InterruptDisabler disabler;
+        char* buffer;
+        auto stringImpl = StringImpl::createUninitialized(80 + task.regionCount() * 80, buffer);
+        memset(buffer, 0, stringImpl->length());
+        char* ptr = buffer;
+        ptr += ksprintf(ptr, "BEGIN       END         SIZE        NAME\n");
+        for (auto& region : task.regions()) {
+            ptr += ksprintf(ptr, "%x -- %x    %x    %s\n",
+                region->linearAddress.get(),
+                region->linearAddress.offset(region->size - 1).get(),
+                region->size,
+                region->name.characters());
+        }
+        *ptr = '\0';
+        return ByteBuffer::copy((byte*)buffer, ptr - buffer);
+    }), dir.index());
+}
+
+void ProcFileSystem::removeProcess(Task& task)
+{
+    ASSERT_INTERRUPTS_DISABLED();
+    auto pid = task.pid();
+    auto it = m_pid2inode.find(pid);
+    ASSERT(it != m_pid2inode.end());
+    bool success = removeFile((*it).value);
+    ASSERT(success);
+    m_pid2inode.remove(pid);
+}
+
 bool ProcFileSystem::initialize()
 {
     SyntheticFileSystem::initialize();
+
+    auto d = addFile(createDirectory("sys"));
+
     addFile(createGeneratedFile("summary", [] {
         InterruptDisabler disabler;
         auto tasks = Task::allTasks();

Kernel/ProcFileSystem.h

@@ -3,15 +3,24 @@
 #include <AK/Types.h>
 #include <VirtualFileSystem/SyntheticFileSystem.h>
 
+class Task;
+
 class ProcFileSystem final : public SyntheticFileSystem {
 public:
+    static ProcFileSystem& the();
+
     virtual ~ProcFileSystem() override;
     static RetainPtr<ProcFileSystem> create();
 
     virtual bool initialize() override;
     virtual const char* className() const override;
 
+    void addProcess(Task&);
+    void removeProcess(Task&);
+
 private:
     ProcFileSystem();
+
+    HashMap<pid_t, InodeIndex> m_pid2inode;
 };
 

Kernel/Task.cpp

@@ -12,6 +12,7 @@
 #include "errno.h"
 #include "i8253.h"
 #include "RTC.h"
+#include "ProcFileSystem.h"
 
 //#define DEBUG_IO
 //#define TASK_DEBUG
@@ -397,11 +398,14 @@ Task::Task(String&& name, uid_t uid, gid_t gid, pid_t parentPID, RingLevel ring)
     // HACK: Ring2 SS in the TSS is the current PID.
     m_tss.ss2 = m_pid;
     m_farPtr.offset = 0x98765432;
+
+    ProcFileSystem::the().addProcess(*this);
 }
 
 Task::~Task()
 {
     InterruptDisabler disabler;
+    ProcFileSystem::the().removeProcess(*this);
     system.nprocess--;
     delete [] m_ldtEntries;
     m_ldtEntries = nullptr;

Kernel/Task.h

@@ -15,6 +15,7 @@ class Zone;
 
 class Task : public InlineLinkedListNode<Task> {
     friend class InlineLinkedListNode<Task>;
+    class Region;
 public:
     static Task* createKernelTask(void (*entry)(), String&& name);
     static Task* createUserTask(const String& path, uid_t, gid_t, pid_t parentPID, int& error, const char** args = nullptr);
@@ -110,6 +111,8 @@ public:
 
     static void taskDidCrash(Task*);
 
+    size_t regionCount() const { return m_regions.size(); }
+    const Vector<OwnPtr<Region>>& regions() const { return m_regions; }
     void dumpRegions();
 
     void didSchedule() { ++m_timesScheduled; }

Kernel/init.cpp

@@ -108,9 +108,7 @@ static void init_stage2()
 
     vfs->mountRoot(e2fs.copyRef());
 
-    auto procfs = ProcFileSystem::create();
+    vfs->mount(ProcFileSystem::the(), "/proc");
-    procfs->initialize();
-    vfs->mount(procfs.copyRef(), "/proc");
 
 #endif
 
@@ -200,6 +198,9 @@ void init()
     kprintf("%u kB base memory\n", base_memory);
     kprintf("%u kB extended memory\n", ext_memory);
 
+    auto procfs = ProcFileSystem::create();
+    procfs->initialize();
+
     Task::initialize();
 
     Task::createKernelTask(undertaker_main, "undertaker");

VirtualFileSystem/FileHandle.cpp

@@ -133,7 +133,7 @@ bool FileHandle::isDirectory() const
     return m_vnode->metadata().isDirectory();
 }
 
-ssize_t FileHandle::get_dir_entries(byte* buffer, size_t size)
+ssize_t FileHandle::get_dir_entries(byte* buffer, Unix::size_t size)
 {
     Locker locker(VirtualFileSystem::lock());
 

VirtualFileSystem/SyntheticFileSystem.cpp

@@ -21,21 +21,36 @@ bool SyntheticFileSystem::initialize()
     // Add a File for the root directory.
     // FIXME: This needs work.
     auto rootDir = make<File>();
-    rootDir->metadata.inode = { id(), 1 };
+    rootDir->metadata.inode = { id(), RootInodeIndex };
+    rootDir->parent = { id(), RootInodeIndex };
     rootDir->metadata.mode = 0040555;
     rootDir->metadata.uid = 0;
     rootDir->metadata.gid = 0;
     rootDir->metadata.size = 0;
     rootDir->metadata.mtime = mepoch;
-    m_files.append(move(rootDir));
+    m_inodes.set(RootInodeIndex, move(rootDir));
 
+#if 0
 #ifndef SERENITY
     addFile(createTextFile("file", "I'm a synthetic file!\n"));
     addFile(createTextFile("message", "Hey! This isn't my bottle!\n"));
+#endif
 #endif
     return true;
 }
 
+auto SyntheticFileSystem::createDirectory(String&& name) -> OwnPtr<File>
+{
+    auto file = make<File>();
+    file->name = move(name);
+    file->metadata.size = 0;
+    file->metadata.uid = 0;
+    file->metadata.gid = 0;
+    file->metadata.mode = 0040555;
+    file->metadata.mtime = mepoch;
+    return file;
+}
+
 auto SyntheticFileSystem::createTextFile(String&& name, String&& text) -> OwnPtr<File>
 {
     auto file = make<File>();
@@ -44,7 +59,7 @@ auto SyntheticFileSystem::createTextFile(String&& name, String&& text) -> OwnPtr
     file->metadata.size = file->data.size();
     file->metadata.uid = 100;
     file->metadata.gid = 200;
-    file->metadata.mode = 0100644;
+    file->metadata.mode = 04;
     file->metadata.mtime = mepoch;
     return file;
 }
@@ -62,11 +77,42 @@ auto SyntheticFileSystem::createGeneratedFile(String&& name, Function<ByteBuffer
     return file;
 }
 
-void SyntheticFileSystem::addFile(OwnPtr<File>&& file)
+InodeIdentifier SyntheticFileSystem::addFile(OwnPtr<File>&& file, InodeIndex parent)
 {
     ASSERT(file);
-    file->metadata.inode = { id(), m_files.size() + 1 };
+    auto it = m_inodes.find(parent);
-    m_files.append(move(file));
+    ASSERT(it != m_inodes.end());
+    InodeIdentifier newInode { id(), generateInodeIndex() };
+    file->metadata.inode = newInode;
+    file->parent = { id(), parent };
+    (*it).value->children.append(file.ptr());
+    m_inodes.set(newInode.index(), move(file));
+    return newInode;
+}
+
+bool SyntheticFileSystem::removeFile(InodeIndex inode)
+{
+    auto it = m_inodes.find(inode);
+    if (it == m_inodes.end())
+        return false;
+    auto& file = *(*it).value;
+
+    auto pit = m_inodes.find(file.parent.index());
+    if (pit == m_inodes.end())
+        return false;
+    auto& parent = *(*pit).value;
+    for (size_t i = 0; i < parent.children.size(); ++i) {
+        if (parent.children[i]->metadata.inode.index() != inode) {
+            continue;
+        }
+        parent.children.remove(i);
+        break;
+    }
+
+    for (auto& child : file.children)
+        removeFile(child->metadata.inode.index());
+    m_inodes.remove(inode);
+    return true;
 }
 
 const char* SyntheticFileSystem::className() const
@@ -85,14 +131,20 @@ bool SyntheticFileSystem::enumerateDirectoryInode(InodeIdentifier inode, Functio
 #ifdef SYNTHFS_DEBUG
     kprintf("[synthfs] enumerateDirectoryInode %u\n", inode.index());
 #endif
-    if (inode.index() != 1)
+
+    auto it = m_inodes.find(inode.index());
+    if (it == m_inodes.end())
+        return false;
+    const File& synInode = *(*it).value;
+    if (!synInode.metadata.isDirectory())
         return false;
 
-    callback({ ".", m_files[0]->metadata.inode });
+    callback({ ".", synInode.metadata.inode });
-    callback({ "..", m_files[0]->metadata.inode });
+    callback({ "..", synInode.parent });
 
-    for (unsigned i = 1; i < m_files.size(); ++i)
+    for (auto& child : synInode.children) {
-        callback({ m_files[i]->name, m_files[i]->metadata.inode });
+        callback({ child->name, child->metadata.inode });
+    }
     return true;
 }
 
@@ -102,10 +154,11 @@ InodeMetadata SyntheticFileSystem::inodeMetadata(InodeIdentifier inode) const
 #ifdef SYNTHFS_DEBUG
     kprintf("[synthfs] inodeMetadata(%u)\n", inode.index());
 #endif
-    if (inode.index() == 0 || inode.index() > m_files.size())
+
-        return InodeMetadata();
+    auto it = m_inodes.find(inode.index());
-    auto& file = *m_files[inode.index() - 1];
+    if (it == m_inodes.end())
-    return file.metadata;
+        return { };
+    return (*it).value->metadata;
 }
 
 bool SyntheticFileSystem::setModificationTime(InodeIdentifier, dword timestamp)
@@ -120,6 +173,7 @@ InodeIdentifier SyntheticFileSystem::createInode(InodeIdentifier parentInode, co
     (void) parentInode;
     (void) name;
     (void) mode;
+    (void) size;
     kprintf("FIXME: Implement SyntheticFileSystem::createDirectoryInode().\n");
     return { };
 }
@@ -136,12 +190,13 @@ Unix::ssize_t SyntheticFileSystem::readInodeBytes(InodeIdentifier inode, Unix::o
 #ifdef SYNTHFS_DEBUG
     kprintf("[synthfs] readInode %u\n", inode.index());
 #endif
-    ASSERT(inode.index() != 1);
-    ASSERT(inode.index() <= m_files.size());
     ASSERT(offset >= 0);
     ASSERT(buffer);
-
+\
-    auto& file = *m_files[inode.index() - 1];
+    auto it = m_inodes.find(inode.index());
+    if (it == m_inodes.end())
+        return false;
+    const File& file = *(*it).value;
     ByteBuffer generatedData;
     if (file.generator)
         generatedData = file.generator();
@@ -154,6 +209,13 @@ Unix::ssize_t SyntheticFileSystem::readInodeBytes(InodeIdentifier inode, Unix::o
 
 InodeIdentifier SyntheticFileSystem::makeDirectory(InodeIdentifier parentInode, const String& name, Unix::mode_t)
 {
+    (void) parentInode;
+    (void) name;
     kprintf("FIXME: Implement SyntheticFileSystem::makeDirectory().\n");
     return { };
 }
+
+auto SyntheticFileSystem::generateInodeIndex() -> InodeIndex
+{
+    return m_nextInodeIndex++;
+}

VirtualFileSystem/SyntheticFileSystem.h

@@ -21,21 +21,31 @@ public:
     virtual InodeIdentifier makeDirectory(InodeIdentifier parentInode, const String& name, Unix::mode_t) override;
 
 protected:
+    typedef unsigned InodeIndex;
+
+    InodeIndex generateInodeIndex();
+    static constexpr InodeIndex RootInodeIndex = 1;
+
     SyntheticFileSystem();
 
     struct File {
         String name;
         InodeMetadata metadata;
+        InodeIdentifier parent;
         ByteBuffer data;
         Function<ByteBuffer()> generator;
+        Vector<File*> children;
     };
 
+    OwnPtr<File> createDirectory(String&& name);
     OwnPtr<File> createTextFile(String&& name, String&& text);
     OwnPtr<File> createGeneratedFile(String&& name, Function<ByteBuffer()>&&);
 
-    void addFile(OwnPtr<File>&&);
+    InodeIdentifier addFile(OwnPtr<File>&&, InodeIndex parent = RootInodeIndex);
+    bool removeFile(InodeIndex);
 
 private:
-    Vector<OwnPtr<File>> m_files;
+    InodeIndex m_nextInodeIndex { 2 };
+    HashMap<InodeIndex, OwnPtr<File>> m_inodes;
 };
 

VirtualFileSystem/VirtualFileSystem.cpp

@@ -52,6 +52,7 @@ VirtualFileSystem::VirtualFileSystem()
 VirtualFileSystem::~VirtualFileSystem()
 {
     kprintf("[VFS] ~VirtualFileSystem with %u nodes allocated\n", allocatedNodeCount());
+    // FIXME: m_nodes is never freed. Does it matter though?
 }
 
 auto VirtualFileSystem::makeNode(InodeIdentifier inode) -> RetainPtr<Node>