Kernel/exec/elf/elf_rel.cpp
2024-01-19 06:47:42 +02:00

102 lines
3.0 KiB
C++

/*
This file is part of Fennix Kernel.
Fennix Kernel is free software: you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3 of
the License, or (at your option) any later version.
Fennix Kernel is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/
#include <exec.hpp>
#include <msexec.h>
#include "../../kernel.h"
namespace Execute
{
/* Originally from https://wiki.osdev.org/ELF_Tutorial */
void ELFLoadRel(void *BaseImage,
const char *Name,
Tasking::PCB *Process)
{
#if defined(a64)
UNUSED(Name);
debug("Relocatable");
/* TODO: I have to fully implement this, but for now I will leave it as it is now. */
warn("Relocatable ELF is not fully supported yet");
Elf64_Shdr *shdr = GetELFSheader(((Elf64_Ehdr *)BaseImage));
for (Elf64_Half i = 0; i < ((Elf64_Ehdr *)BaseImage)->e_shnum; i++)
{
Elf64_Shdr *Section = &shdr[i];
if (Section->sh_type == SHT_NOBITS)
{
if (!Section->sh_size)
continue;
if (Section->sh_flags & SHF_ALLOC)
{
void *Buffer = KernelAllocator.RequestPages(TO_PAGES(Section->sh_size + 1));
memset(Buffer, 0, Section->sh_size);
Memory::Virtual(Process->PageTable).Map((void *)Buffer, (void *)Buffer, Section->sh_size, Memory::PTFlag::RW | Memory::PTFlag::US);
Section->sh_offset = (uintptr_t)Buffer - (uintptr_t)BaseImage;
debug("Section %ld", Section->sh_size);
}
}
}
for (Elf64_Half i = 0; i < ((Elf64_Ehdr *)BaseImage)->e_shnum; i++)
{
Elf64_Shdr *Section = &shdr[i];
if (Section->sh_type == SHT_REL)
{
for (size_t Index = 0; Index < Section->sh_size / Section->sh_entsize; Index++)
{
Elf64_Rel *RelTable = &((Elf64_Rel *)((uintptr_t)BaseImage + Section->sh_offset))[Index];
Elf64_Shdr *Target = GetELFSection(((Elf64_Ehdr *)BaseImage), Section->sh_info);
uintptr_t *RelAddress = (uintptr_t *)(((uintptr_t)BaseImage + Target->sh_offset) + RelTable->r_offset);
uint64_t SymbolValue = 0;
if (ELF64_R_SYM(RelTable->r_info) != SHN_UNDEF)
{
SymbolValue = ELFGetSymbolValue(((Elf64_Ehdr *)BaseImage), Section->sh_link, ELF64_R_SYM(RelTable->r_info));
if (SymbolValue == 0xdead)
return;
}
switch (ELF64_R_TYPE(RelTable->r_info))
{
case R_386_NONE:
break;
case R_386_32:
*RelAddress = DO_64_64(SymbolValue, *RelAddress);
break;
case R_386_PC32:
*RelAddress = DO_64_PC32(SymbolValue, *RelAddress, (uintptr_t)RelAddress);
break;
default:
{
error("Unsupported relocation type: %d", ELF64_R_TYPE(RelTable->r_info));
return;
}
}
debug("Symbol value: %#lx", SymbolValue);
}
}
}
#elif defined(a32)
#endif
}
}