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Kernel: Big commit. Rewrite ELF loading code

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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
2023-06-09 00:37:43 +03:00
parent 59b10c4d25
commit 801025ad7b
9 changed files with 206 additions and 49 deletions
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42
LibELF/LibELF/ELF.cpp
View File

@@ -1,15 +1,54 @@
#include <BAN/ScopeGuard.h>
#include <kernel/Process.h>
#include <LibELF/ELF.h>
#include <LibELF/Values.h>
#ifdef __is_kernel
#include <kernel/FS/VirtualFileSystem.h>
#include <kernel/Memory/PageTableScope.h>
#include <kernel/Process.h>
#endif
#include <fcntl.h>
#define ELF_PRINT_HEADERS 0
#ifdef __is_kernel
extern uint8_t g_kernel_end[];
using namespace Kernel;
#endif
namespace LibELF
{
#ifdef __is_kernel
BAN::ErrorOr<BAN::UniqPtr<ELF>> ELF::load_from_file(BAN::StringView file_path)
{
auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(file_path, true));
PageTable::current().lock();
size_t page_count = BAN::Math::div_round_up<size_t>(file.inode->size(), PAGE_SIZE);
vaddr_t vaddr = PageTable::current().get_free_contiguous_pages(page_count, (vaddr_t)g_kernel_end);
auto virtual_range = BAN::UniqPtr<VirtualRange>::adopt(
VirtualRange::create(
PageTable::current(),
vaddr, page_count * PAGE_SIZE,
PageTable::Flags::ReadWrite | PageTable::Flags::Present
)
);
PageTable::current().unlock();
TRY(file.inode->read(0, (void*)vaddr, file.inode->size()));
ELF* elf_ptr = new ELF(BAN::move(virtual_range), file.inode->size());
if (elf_ptr == nullptr)
return BAN::Error::from_errno(ENOMEM);
auto elf = BAN::UniqPtr<ELF>::adopt(elf_ptr);
TRY(elf->load());
return BAN::move(elf);
}
#else
BAN::ErrorOr<ELF*> ELF::load_from_file(BAN::StringView file_path)
{
ELF* elf = nullptr;
@@ -39,6 +78,7 @@ namespace LibELF
return elf;
}
#endif
BAN::ErrorOr<void> ELF::load()
{

19
LibELF/include/LibELF/ELF.h
View File

@@ -1,6 +1,11 @@
#pragma once
#ifdef __is_kernel
#include <kernel/Memory/VirtualRange.h>
#endif
#include <BAN/StringView.h>
#include <BAN/UniqPtr.h>
#include <BAN/Vector.h>
#include <kernel/Arch.h>
#include "Types.h"
@@ -11,7 +16,7 @@ namespace LibELF
class ELF
{
public:
static BAN::ErrorOr<ELF*> load_from_file(BAN::StringView);
static BAN::ErrorOr<BAN::UniqPtr<ELF>> load_from_file(BAN::StringView);
const Elf64FileHeader& file_header64() const;
const Elf64ProgramHeader& program_header64(size_t) const;
@@ -47,9 +52,16 @@ namespace LibELF
bool is_x86_64() const;
private:
#ifdef __is_kernel
ELF(BAN::UniqPtr<Kernel::VirtualRange>&& storage, size_t size)
: m_storage(BAN::move(storage))
, m_data((const uint8_t*)m_storage->vaddr(), size)
{}
#else
ELF(BAN::Vector<uint8_t>&& data)
: m_data(BAN::move(data))
{}
#endif
BAN::ErrorOr<void> load();
bool parse_elf64_file_header(const Elf64FileHeader&);
@@ -61,7 +73,12 @@ namespace LibELF
bool parse_elf32_section_header(const Elf32SectionHeader&);
private:
#ifdef __is_kernel
BAN::UniqPtr<Kernel::VirtualRange> m_storage;
BAN::Span<const uint8_t> m_data;
#else
const BAN::Vector<uint8_t> m_data;
#endif
};
}