forked from Bananymous/banan-os
Kernel: Big commit. Rewrite ELF loading code
We now load ELF files to VirtualRanges instead of using kmalloc. We have only a fixed 1 MiB kmalloc for big allocations and this allows loading files even when they don't fit in there. This caused me to rewrite the whole ELF loading process since the loaded ELF is not in memory mapped by every process. Virtual ranges allow you to zero out the memory and to copy into them from arbitary byte buffers.
This commit is contained in:
Bananymous
parent
96d6453ea8
commit
8af390e0f6
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@ -1,15 +1,54 @@
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#include <BAN/ScopeGuard.h>
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#include <kernel/Process.h>
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#include <LibELF/ELF.h>
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#include <LibELF/Values.h>
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#ifdef __is_kernel
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#include <kernel/FS/VirtualFileSystem.h>
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#include <kernel/Memory/PageTableScope.h>
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#include <kernel/Process.h>
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#endif
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#include <fcntl.h>
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#define ELF_PRINT_HEADERS 0
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#ifdef __is_kernel
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extern uint8_t g_kernel_end[];
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using namespace Kernel;
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#endif
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namespace LibELF
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{
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#ifdef __is_kernel
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BAN::ErrorOr<BAN::UniqPtr<ELF>> ELF::load_from_file(BAN::StringView file_path)
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{
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auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(file_path, true));
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PageTable::current().lock();
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size_t page_count = BAN::Math::div_round_up<size_t>(file.inode->size(), PAGE_SIZE);
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vaddr_t vaddr = PageTable::current().get_free_contiguous_pages(page_count, (vaddr_t)g_kernel_end);
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auto virtual_range = BAN::UniqPtr<VirtualRange>::adopt(
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VirtualRange::create(
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PageTable::current(),
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vaddr, page_count * PAGE_SIZE,
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PageTable::Flags::ReadWrite | PageTable::Flags::Present
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)
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);
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PageTable::current().unlock();
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TRY(file.inode->read(0, (void*)vaddr, file.inode->size()));
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ELF* elf_ptr = new ELF(BAN::move(virtual_range), file.inode->size());
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if (elf_ptr == nullptr)
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return BAN::Error::from_errno(ENOMEM);
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auto elf = BAN::UniqPtr<ELF>::adopt(elf_ptr);
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TRY(elf->load());
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return BAN::move(elf);
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}
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#else
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BAN::ErrorOr<ELF*> ELF::load_from_file(BAN::StringView file_path)
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{
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ELF* elf = nullptr;
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@ -39,6 +78,7 @@ namespace LibELF
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return elf;
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}
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#endif
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BAN::ErrorOr<void> ELF::load()
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{
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@ -1,6 +1,11 @@
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#pragma once
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#ifdef __is_kernel
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#include <kernel/Memory/VirtualRange.h>
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#endif
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#include <BAN/StringView.h>
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#include <BAN/UniqPtr.h>
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#include <BAN/Vector.h>
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#include <kernel/Arch.h>
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#include "Types.h"
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@ -11,7 +16,7 @@ namespace LibELF
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class ELF
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{
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public:
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static BAN::ErrorOr<ELF*> load_from_file(BAN::StringView);
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static BAN::ErrorOr<BAN::UniqPtr<ELF>> load_from_file(BAN::StringView);
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const Elf64FileHeader& file_header64() const;
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const Elf64ProgramHeader& program_header64(size_t) const;
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@ -47,9 +52,16 @@ namespace LibELF
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bool is_x86_64() const;
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private:
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#ifdef __is_kernel
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ELF(BAN::UniqPtr<Kernel::VirtualRange>&& storage, size_t size)
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: m_storage(BAN::move(storage))
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, m_data((const uint8_t*)m_storage->vaddr(), size)
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{}
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#else
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ELF(BAN::Vector<uint8_t>&& data)
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: m_data(BAN::move(data))
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{}
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#endif
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BAN::ErrorOr<void> load();
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bool parse_elf64_file_header(const Elf64FileHeader&);
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@ -61,7 +73,12 @@ namespace LibELF
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bool parse_elf32_section_header(const Elf32SectionHeader&);
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private:
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#ifdef __is_kernel
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BAN::UniqPtr<Kernel::VirtualRange> m_storage;
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BAN::Span<const uint8_t> m_data;
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#else
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const BAN::Vector<uint8_t> m_data;
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#endif
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};
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}
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@ -23,11 +23,15 @@ namespace Kernel
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size_t size() const { return m_size; }
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uint8_t flags() const { return m_flags; }
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void set_zero();
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void copy_from(size_t offset, const uint8_t* buffer, size_t bytes);
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private:
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VirtualRange(PageTable&);
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private:
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PageTable& m_page_table;
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bool m_kmalloc { false };
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vaddr_t m_vaddr { 0 };
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size_t m_size { 0 };
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uint8_t m_flags { 0 };
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@ -49,8 +49,6 @@ namespace Kernel
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pid_t pid() const { return m_pid; }
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static BAN::ErrorOr<LibELF::ELF*> load_elf_for_exec(BAN::StringView file_path, const BAN::String& cwd, const BAN::Vector<BAN::StringView>& path_env);
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BAN::ErrorOr<Process*> fork(uintptr_t rsp, uintptr_t rip);
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BAN::ErrorOr<void> exec(BAN::StringView path, const char* const* argv, const char* const* envp);
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@ -96,7 +94,11 @@ namespace Kernel
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static Process* create_process();
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static void register_process(Process*);
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void load_elf(LibELF::ELF&);
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// Load an elf file to virtual address space of the current page table
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static BAN::ErrorOr<BAN::UniqPtr<LibELF::ELF>> load_elf_for_exec(BAN::StringView file_path, const BAN::String& cwd, const BAN::Vector<BAN::StringView>& path_env);
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// Copy an elf file from the current page table to the processes own
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void load_elf_to_memory(LibELF::ELF&);
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BAN::ErrorOr<BAN::String> absolute_path_of(BAN::StringView) const;
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@ -1,5 +1,4 @@
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#include <kernel/Memory/GeneralAllocator.h>
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#include <kernel/Memory/PageTableScope.h>
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namespace Kernel
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{
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@ -8,11 +8,11 @@ namespace Kernel
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{
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ASSERT(size % PAGE_SIZE == 0);
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ASSERT(vaddr % PAGE_SIZE == 0);
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ASSERT(&page_table != &PageTable::kernel());
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VirtualRange* result = new VirtualRange(page_table);
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ASSERT(result);
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result->m_kmalloc = false;
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result->m_size = size;
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result->m_flags = flags;
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MUST(result->m_physical_pages.reserve(size / PAGE_SIZE));
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@ -21,7 +21,7 @@ namespace Kernel
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if (vaddr == 0)
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{
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vaddr = page_table.get_free_contiguous_pages(size / PAGE_SIZE);
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vaddr = page_table.get_free_contiguous_pages(size / PAGE_SIZE, 0x400000);
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ASSERT(vaddr);
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}
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@ -43,8 +43,9 @@ namespace Kernel
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VirtualRange* VirtualRange::create_kmalloc(size_t size)
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{
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VirtualRange* result = new VirtualRange(PageTable::kernel());
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if (result == nullptr)
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return nullptr;
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ASSERT(result);
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result->m_kmalloc = true;
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result->m_size = size;
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result->m_flags = PageTable::Flags::ReadWrite | PageTable::Flags::Present;
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result->m_vaddr = (vaddr_t)kmalloc(size);
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@ -53,6 +54,7 @@ namespace Kernel
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delete result;
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return nullptr;
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}
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return result;
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}
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@ -62,7 +64,7 @@ namespace Kernel
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VirtualRange::~VirtualRange()
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{
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if (&m_page_table == &PageTable::kernel())
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if (m_kmalloc)
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{
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kfree((void*)m_vaddr);
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return;
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@ -94,4 +96,82 @@ namespace Kernel
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return result;
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}
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void VirtualRange::set_zero()
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{
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PageTable& page_table = PageTable::current();
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if (&page_table == &m_page_table)
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{
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memset((void*)vaddr(), 0, size());
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return;
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}
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page_table.lock();
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ASSERT(page_table.is_page_free(0));
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for (size_t i = 0; i < m_physical_pages.size(); i++)
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{
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page_table.map_page_at(m_physical_pages[i], 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present);
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page_table.invalidate(0);
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memset((void*)0, 0, PAGE_SIZE);
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}
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page_table.unmap_page(0);
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page_table.invalidate(0);
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page_table.unlock();
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}
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void VirtualRange::copy_from(size_t offset, const uint8_t* buffer, size_t bytes)
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{
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if (bytes == 0)
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return;
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// NOTE: Handling overflow
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ASSERT(offset <= size());
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ASSERT(bytes <= size());
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ASSERT(offset + bytes <= size());
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PageTable& page_table = PageTable::current();
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if (&page_table == &m_page_table)
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{
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memcpy((void*)(vaddr() + offset), buffer, bytes);
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return;
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}
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page_table.lock();
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ASSERT(page_table.is_page_free(0));
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size_t off = offset % PAGE_SIZE;
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size_t i = offset / PAGE_SIZE;
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// NOTE: we map the first page separately since it needs extra calculations
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page_table.map_page_at(m_physical_pages[i], 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present);
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page_table.invalidate(0);
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memcpy((void*)off, buffer, PAGE_SIZE - off);
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buffer += PAGE_SIZE - off;
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bytes -= PAGE_SIZE - off;
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i++;
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while (bytes > 0)
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{
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size_t len = BAN::Math::min<size_t>(PAGE_SIZE, bytes);
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page_table.map_page_at(m_physical_pages[i], 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present);
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page_table.invalidate(0);
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memcpy((void*)0, buffer, len);
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buffer += len;
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bytes -= len;
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i++;
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}
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page_table.unmap_page(0);
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page_table.invalidate(0);
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page_table.unlock();
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}
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}
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#include <BAN/StringView.h>
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#include <kernel/CriticalScope.h>
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#include <kernel/FS/VirtualFileSystem.h>
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#include <kernel/LockGuard.h>
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#include <kernel/Memory/Heap.h>
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@ -46,13 +47,18 @@ namespace Kernel
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BAN::ErrorOr<Process*> Process::create_userspace(BAN::StringView path)
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{
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auto* elf = TRY(load_elf_for_exec(path, "/"sv, {}));
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auto elf = TRY(load_elf_for_exec(path, "/"sv, {}));
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auto* process = create_process();
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MUST(process->m_working_directory.push_back('/'));
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process->m_page_table = BAN::UniqPtr<PageTable>::adopt(MUST(PageTable::create_userspace()));
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process->m_page_table = BAN::UniqPtr<PageTable>::adopt(MUST(PageTable::create_userspace()));;
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process->load_elf(*elf);
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process->load_elf_to_memory(*elf);
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process->m_userspace_info.entry = elf->file_header_native().e_entry;
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// NOTE: we clear the elf since we don't need the memory anymore
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elf.clear();
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char** argv = nullptr;
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char** envp = nullptr;
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@ -76,9 +82,6 @@ namespace Kernel
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process->m_userspace_info.argc = 1;
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process->m_userspace_info.argv = argv;
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process->m_userspace_info.envp = envp;
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process->m_userspace_info.entry = elf->file_header_native().e_entry;
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delete elf;
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auto* thread = MUST(Thread::create_userspace(process));
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process->add_thread(thread);
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@ -164,7 +167,7 @@ namespace Kernel
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return {};
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}
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BAN::ErrorOr<LibELF::ELF*> Process::load_elf_for_exec(BAN::StringView file_path, const BAN::String& cwd, const BAN::Vector<BAN::StringView>& path_env)
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BAN::ErrorOr<BAN::UniqPtr<LibELF::ELF>> Process::load_elf_for_exec(BAN::StringView file_path, const BAN::String& cwd, const BAN::Vector<BAN::StringView>& path_env)
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{
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if (file_path.empty())
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return BAN::Error::from_errno(ENOENT);
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@ -219,22 +222,20 @@ namespace Kernel
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return elf_or_error.error();
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}
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auto* elf = elf_or_error.release_value();
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auto elf = elf_or_error.release_value();
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if (!elf->is_native())
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{
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derrorln("ELF has invalid architecture");
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delete elf;
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return BAN::Error::from_errno(EINVAL);
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}
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if (elf->file_header_native().e_type != LibELF::ET_EXEC)
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{
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derrorln("Not an executable");
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delete elf;
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return BAN::Error::from_errno(ENOEXEC);
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}
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return elf;
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return BAN::move(elf);
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}
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BAN::ErrorOr<Process*> Process::fork(uintptr_t rsp, uintptr_t rip)
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@ -285,7 +286,7 @@ namespace Kernel
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path_env = TRY(BAN::StringView(envp[i]).substring(5).split(':'));
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}
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auto* elf = TRY(load_elf_for_exec(path, TRY(working_directory()), path_env));
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auto elf = TRY(load_elf_for_exec(path, TRY(working_directory()), path_env));
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LockGuard lock_guard(m_lock);
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@ -298,17 +299,18 @@ namespace Kernel
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m_open_files.clear();
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load_elf(*elf);
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load_elf_to_memory(*elf);
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m_userspace_info.entry = elf->file_header_native().e_entry;
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delete elf;
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// NOTE: we clear the elf since we don't need the memory anymore
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elf.clear();
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ASSERT(m_threads.size() == 1);
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ASSERT(&Process::current() == this);
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{
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PageTableScope _(page_table());
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LockGuard _(page_table());
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m_userspace_info.argv = (char**)MUST(allocate(sizeof(char**) * (str_argv.size() + 1)));
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for (size_t i = 0; i < str_argv.size(); i++)
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@ -396,7 +398,7 @@ namespace Kernel
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return {};
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}
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void Process::load_elf(LibELF::ELF& elf)
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void Process::load_elf_to_memory(LibELF::ELF& elf)
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{
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ASSERT(elf.is_native());
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@ -411,6 +413,16 @@ namespace Kernel
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break;
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case LibELF::PT_LOAD:
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{
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uint8_t flags = PageTable::Flags::UserSupervisor | PageTable::Flags::Present;
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if (elf_program_header.p_flags & LibELF::PF_W)
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flags |= PageTable::Flags::ReadWrite;
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size_t page_start = elf_program_header.p_vaddr / PAGE_SIZE;
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size_t page_end = BAN::Math::div_round_up<size_t>(elf_program_header.p_vaddr + elf_program_header.p_memsz, PAGE_SIZE);
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size_t page_count = page_end - page_start + 1;
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page_table().lock();
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if (!page_table().is_range_free(elf_program_header.p_vaddr, elf_program_header.p_memsz))
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{
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page_table().debug_dump();
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@ -419,20 +431,16 @@ namespace Kernel
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elf_program_header.p_vaddr + elf_program_header.p_memsz
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);
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}
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uint8_t flags = PageTable::Flags::UserSupervisor | PageTable::Flags::Present;
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if (elf_program_header.p_flags & LibELF::PF_W)
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flags |= PageTable::Flags::ReadWrite;
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size_t page_start = elf_program_header.p_vaddr / PAGE_SIZE;
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size_t page_end = BAN::Math::div_round_up<size_t>(elf_program_header.p_vaddr + elf_program_header.p_memsz, PAGE_SIZE);
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size_t page_count = page_end - page_start + 1;
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MUST(m_mapped_ranges.push_back(VirtualRange::create(page_table(), page_start * PAGE_SIZE, page_count * PAGE_SIZE, flags)));
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{
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PageTableScope _(page_table());
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memcpy((void*)elf_program_header.p_vaddr, elf.data() + elf_program_header.p_offset, elf_program_header.p_filesz);
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memset((void*)(elf_program_header.p_vaddr + elf_program_header.p_filesz), 0, elf_program_header.p_memsz - elf_program_header.p_filesz);
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LockGuard _(m_lock);
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MUST(m_mapped_ranges.push_back(VirtualRange::create(page_table(), page_start * PAGE_SIZE, page_count * PAGE_SIZE, flags)));
|
||||
m_mapped_ranges.back()->set_zero();
|
||||
m_mapped_ranges.back()->copy_from(elf_program_header.p_vaddr % PAGE_SIZE, elf.data() + elf_program_header.p_offset, elf_program_header.p_filesz);
|
||||
}
|
||||
|
||||
page_table().unlock();
|
||||
|
||||
break;
|
||||
}
|
||||
default:
|
||||
|
|
|
|||
|
|
@ -1,6 +1,6 @@
|
|||
#include <kernel/LockGuard.h>
|
||||
#include <kernel/Memory/Heap.h>
|
||||
#include <kernel/Memory/PageTableScope.h>
|
||||
#include <kernel/Memory/PageTable.h>
|
||||
#include <kernel/Storage/DiskCache.h>
|
||||
#include <kernel/Storage/StorageDevice.h>
|
||||
|
||||
|
|
@ -225,24 +225,30 @@ namespace Kernel
|
|||
{
|
||||
ASSERT(index < sectors.size());
|
||||
|
||||
PageTableScope _(PageTable::current());
|
||||
ASSERT(PageTable::current().is_page_free(0));
|
||||
PageTable::current().map_page_at(paddr, 0, PageTable::Flags::Present);
|
||||
PageTable& page_table = PageTable::current();
|
||||
|
||||
page_table.lock();
|
||||
ASSERT(page_table.is_page_free(0));
|
||||
page_table.map_page_at(paddr, 0, PageTable::Flags::Present);
|
||||
memcpy(buffer, (void*)(index * device.sector_size()), device.sector_size());
|
||||
PageTable::current().unmap_page(0);
|
||||
PageTable::current().invalidate(0);
|
||||
page_table.unmap_page(0);
|
||||
page_table.invalidate(0);
|
||||
page_table.unlock();
|
||||
}
|
||||
|
||||
void DiskCache::CacheBlock::write_sector(StorageDevice& device, size_t index, const uint8_t* buffer)
|
||||
{
|
||||
ASSERT(index < sectors.size());
|
||||
|
||||
PageTableScope _(PageTable::current());
|
||||
ASSERT(PageTable::current().is_page_free(0));
|
||||
PageTable::current().map_page_at(paddr, 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present);
|
||||
PageTable& page_table = PageTable::current();
|
||||
|
||||
page_table.lock();
|
||||
ASSERT(page_table.is_page_free(0));
|
||||
page_table.map_page_at(paddr, 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present);
|
||||
memcpy((void*)(index * device.sector_size()), buffer, device.sector_size());
|
||||
PageTable::current().unmap_page(0);
|
||||
PageTable::current().invalidate(0);
|
||||
page_table.unmap_page(0);
|
||||
page_table.invalidate(0);
|
||||
page_table.unlock();
|
||||
}
|
||||
|
||||
}
|
||||
|
|
@ -140,6 +140,7 @@ namespace Kernel
|
|||
|
||||
// Setup stack for returning
|
||||
{
|
||||
// FIXME: don't use PageTableScope
|
||||
PageTableScope _(m_process->page_table());
|
||||
write_to_stack<sizeof(void*)>(m_rsp, this);
|
||||
write_to_stack<sizeof(void*)>(m_rsp, &Thread::on_exit);
|
||||
|
|
|
|||
Loading…
Reference in New Issue