libluna/StaticString: Rename OSize to OtherSize

Since the alignment must be known at compile-time, the compiler will optimize for powers of two and leave an inefficient implementation for other values.

kernel/src/arch/x86_64/CPU.cpp

@@ -23,6 +23,18 @@ extern void pic_eoi(unsigned char irq);
 extern void pic_eoi(Registers* regs);
 extern void setup_idt();
 
+void FPData::save()
+{
+    asm volatile("fxsave (%0)" : : "r"(m_data));
+    m_already_saved = true;
+}
+
+void FPData::restore()
+{
+    if (!m_already_saved) return;
+    asm volatile("fxrstor (%0)" : : "r"(m_data));
+}
+
 // Interrupt handling
 
 #define FIXME_UNHANDLED_INTERRUPT(name)                                                                                \
@@ -52,6 +64,13 @@ void decode_page_fault_error_code(u64 code)
 
     decode_page_fault_error_code(regs->error);
 
+    if (!is_in_kernel(regs))
+    {
+        // FIXME: Kill this process with SIGSEGV once we have signals and all that.
+        kerrorln("Current task %zu was terminated because of a page fault", Scheduler::current()->id);
+        kernel_exit();
+    }
+
     CPU::print_stack_trace_at(regs);
 
     CPU::efficient_halt();

kernel/src/arch/x86_64/CPU.h

@@ -9,6 +9,16 @@ struct Registers // Saved CPU registers for x86-64
     u64 rip, cs, rflags, rsp, ss;
 };
 
+struct FPData
+{
+    void save();
+    void restore();
+
+  private:
+    char m_data[512] alignas(16);
+    bool m_already_saved;
+};
+
 struct [[gnu::packed]] TSS
 {
     u32 reserved0;

kernel/src/fs/tmpfs/FileSystem.cpp

@@ -7,7 +7,7 @@ namespace TmpFS
 {
     Result<SharedPtr<VFS::FileSystem>> FileSystem::create()
     {
-        SharedPtr<FileSystem> fs = TRY(adopt_shared(new (std::nothrow) FileSystem()));
+        SharedPtr<FileSystem> fs = TRY(adopt_shared_if_nonnull(new (std::nothrow) FileSystem()));
         SharedPtr<VFS::Inode> root = TRY(fs->create_dir_inode({}));
         fs->set_root(root);
         return (SharedPtr<VFS::FileSystem>)fs;

kernel/src/thread/Scheduler.cpp

@@ -219,10 +219,12 @@ namespace Scheduler
         if (old_thread != new_thread)
         {
             switch_context(old_thread, new_thread, regs);
+            if (!old_thread->is_kernel) old_thread->fp_data.save();
             if (!new_thread->is_kernel)
             {
                 MMU::switch_page_directory(new_thread->directory);
                 CPU::switch_kernel_stack(new_thread->kernel_stack.top());
+                new_thread->fp_data.restore();
             }
         }
 

kernel/src/thread/Thread.h

@@ -21,8 +21,6 @@ enum class ThreadState
     Dying
 };
 
-// FIXME: Save floating point state. (SSE registers on x86_64 using FXSAVE and FXRSTOR)
-
 struct Thread : public LinkedListNode<Thread>
 {
     Registers regs;
@@ -41,6 +39,8 @@ struct Thread : public LinkedListNode<Thread>
 
     OwnedPtr<UserVM> vm_allocator;
 
+    FPData fp_data;
+
     ThreadState state = ThreadState::Runnable;
 
     bool is_kernel { true };

libluna/include/luna/Alignment.h

@@ -2,10 +2,8 @@
 #include <luna/TypeTraits.h>
 #include <luna/Types.h>
 
-// Must ALWAYS be called with a power of two as alignment.
+template <usize alignment, typename T> constexpr inline T is_aligned(T value)
-template <usize alignment, typename T> constexpr T is_aligned(T value)
 {
-    static_assert(IsPowerOfTwo<usize, alignment>);
     return (value % alignment == 0);
 }
 
@@ -13,10 +11,8 @@ static_assert(is_aligned<512>(1024u));
 static_assert(!is_aligned<32>(235u));
 static_assert(is_aligned<4096>(40960u));
 
-// Must ALWAYS be called with a power of two as alignment.
+template <usize alignment, typename T> constexpr inline T align_down(T value)
-template <usize alignment, typename T> constexpr T align_down(T value)
 {
-    static_assert(IsPowerOfTwo<usize, alignment>);
     return value - value % alignment;
 }
 
@@ -24,8 +20,7 @@ static_assert(align_down<512>(598ul) == 512ul);
 static_assert(align_down<64>(194ul) == 192ul);
 static_assert(align_down<32>(64ul) == 64ul);
 
-// Must ALWAYS be called with a power of two as alignment.
+template <usize alignment, typename T> constexpr inline T align_up(T value)
-template <usize alignment, typename T> constexpr T align_up(T value)
 {
     if (is_aligned<alignment>(value)) return value;
     return align_down<alignment>(value) + alignment;
@@ -47,7 +42,7 @@ static_assert(get_blocks_from_size(0, 256) == 0);
 
 // Offset a pointer by exactly <offset> bytes, no matter the type. Useful to avoid the quirks that come from C pointer
 // arithmetic.
-template <typename T, typename Offset> constexpr T* offset_ptr(T* ptr, Offset offset)
+template <typename T, typename Offset> constexpr inline T* offset_ptr(T* ptr, Offset offset)
 {
     return (T*)((u8*)ptr + offset);
 }

libluna/include/luna/StaticString.h

@@ -11,6 +11,11 @@ template <usize Size> class StaticString
         adopt(string);
     }
 
+    template<usize OtherSize> StaticString(const StaticString<OtherSize>& other)
+    {
+        adopt(other.chars());
+    }
+
     void adopt(const char* string)
     {
         usize length = strlcpy(m_buffer, string, sizeof(m_buffer));
@@ -25,9 +30,9 @@ template <usize Size> class StaticString
         return *this;
     }
 
-    template <usize OSize> StaticString<Size>& operator=(const StaticString<OSize>& string)
+    template <usize OtherSize> StaticString<Size>& operator=(const StaticString<OtherSize>& string)
     {
-        if constexpr (OSize == Size)
+        if constexpr (OtherSize == Size)
         {
             if (this == &string) return *this;
         }

libluna/src/Heap.cpp

@@ -105,7 +105,9 @@ static Option<HeapBlock*> split(HeapBlock* block, usize size)
     const usize offset = get_fair_offset_to_split_at(block, size + sizeof(HeapBlock));
     block->full_size = offset; // shrink the old block to fit this offset
 
-    HeapBlock* new_block = offset_ptr(block, offset + sizeof(HeapBlock));
+    HeapBlock* const new_block = offset_ptr(block, offset + sizeof(HeapBlock));
+
+    memset(new_block, 0, sizeof(*new_block));
 
     new_block->magic = BLOCK_MAGIC;
     new_block->status = (block->status & BLOCK_END_MEM) ? BLOCK_END_MEM : 0;
@@ -212,6 +214,8 @@ Result<void*> malloc_impl(usize size, bool should_scrub)
         usize pages = get_pages_for_allocation(size + sizeof(HeapBlock));
         HeapBlock* const current = (HeapBlock*)TRY(allocate_pages_impl(pages));
 
+        memset(current, 0, sizeof(*current));
+
         current->full_size = (pages * PAGE_SIZE) - sizeof(HeapBlock);
         current->magic = BLOCK_MAGIC;
         current->status = BLOCK_START_MEM | BLOCK_END_MEM;

tools/run-clang-format.sh

@@ -6,8 +6,8 @@ source $(dirname $0)/env.sh
 cd $LUNA_ROOT
 
 SOURCES=($(find kernel/src -type f | grep -v "\.asm"))
-SOURCES+=($(find luna/src -type f))
+SOURCES+=($(find libluna/src -type f))
-SOURCES+=($(find luna/include/luna -type f))
+SOURCES+=($(find libluna/include/luna -type f))
 
 for f in ${SOURCES[@]}
 do