mirror of
https://github.com/RGBCube/serenity
synced 2025-07-25 09:37:44 +00:00
c087abc48d
I caught myself wondering what "pdb" stood for, so let's rename this to something more obvious.
67 lines
2 KiB
C++
67 lines
2 KiB
C++
#include <Kernel/Process.h>
|
|
#include <Kernel/Thread.h>
|
|
#include <Kernel/VM/MemoryManager.h>
|
|
#include <Kernel/VM/PageDirectory.h>
|
|
|
|
static const u32 userspace_range_base = 0x01000000;
|
|
static const u32 kernelspace_range_base = 0xc0000000;
|
|
|
|
static HashMap<u32, PageDirectory*>& cr3_map()
|
|
{
|
|
ASSERT_INTERRUPTS_DISABLED();
|
|
static HashMap<u32, PageDirectory*>* map;
|
|
if (!map)
|
|
map = new HashMap<u32, PageDirectory*>;
|
|
return *map;
|
|
}
|
|
|
|
RefPtr<PageDirectory> PageDirectory::find_by_cr3(u32 cr3)
|
|
{
|
|
InterruptDisabler disabler;
|
|
return cr3_map().get(cr3).value_or({});
|
|
}
|
|
|
|
PageDirectory::PageDirectory(PhysicalAddress paddr)
|
|
: m_range_allocator(VirtualAddress(0xc0000000), 0x3f000000)
|
|
{
|
|
m_directory_page = PhysicalPage::create(paddr, true, false);
|
|
InterruptDisabler disabler;
|
|
cr3_map().set(cr3(), this);
|
|
}
|
|
|
|
PageDirectory::PageDirectory(Process& process, const RangeAllocator* parent_range_allocator)
|
|
: m_process(&process)
|
|
, m_range_allocator(parent_range_allocator ? RangeAllocator(*parent_range_allocator) : RangeAllocator(VirtualAddress(userspace_range_base), kernelspace_range_base - userspace_range_base))
|
|
{
|
|
MM.populate_page_directory(*this);
|
|
InterruptDisabler disabler;
|
|
cr3_map().set(cr3(), this);
|
|
}
|
|
|
|
PageDirectory::~PageDirectory()
|
|
{
|
|
#ifdef MM_DEBUG
|
|
dbgprintf("MM: ~PageDirectory K%x\n", this);
|
|
#endif
|
|
InterruptDisabler disabler;
|
|
cr3_map().remove(cr3());
|
|
}
|
|
|
|
void PageDirectory::flush(VirtualAddress vaddr)
|
|
{
|
|
#ifdef MM_DEBUG
|
|
dbgprintf("MM: Flush page V%p\n", vaddr.get());
|
|
#endif
|
|
if (!current)
|
|
return;
|
|
if (this == &MM.kernel_page_directory() || ¤t->process().page_directory() == this)
|
|
MM.flush_tlb(vaddr);
|
|
}
|
|
|
|
void PageDirectory::update_kernel_mappings()
|
|
{
|
|
// This ensures that the kernel virtual address space is up-to-date in this page directory.
|
|
// This may be necessary to avoid triple faulting when entering a process's paging scope
|
|
// whose mappings are out-of-date.
|
|
memcpy(entries() + 768, MM.kernel_page_directory().entries() + 768, sizeof(PageDirectoryEntry) * 256);
|
|
}
|