Kernel/Execute/Elf/Exec.cpp
2023-05-13 07:40:07 +03:00

230 lines
9.0 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 <memory.hpp>
#include <lock.hpp>
#include <msexec.h>
#include <cwalk.h>
#include <elf.h>
#include <abi.h>
#include "../../kernel.h"
#include "../../Fex.hpp"
using namespace Tasking;
namespace Execute
{
ELFBaseLoad ELFLoadExec(void *ElfFile,
VirtualFileSystem::File &ExFile,
Tasking::PCB *Process)
{
#if defined(a64)
debug("Executable");
ELFBaseLoad ELFBase = {};
/* This should be deleted inside BaseLoad.cpp */
ELFBase.TmpMem = new Memory::MemMgr(Process->PageTable);
Elf64_Ehdr *ELFHeader = (Elf64_Ehdr *)ElfFile;
Memory::Virtual pV(Process->PageTable);
uintptr_t BaseAddress = UINTPTR_MAX;
uint64_t ElfAppSize = 0;
uintptr_t EntryPoint = ELFHeader->e_entry;
debug("%s's entry point is %#lx", ExFile.Name, EntryPoint);
Elf64_Phdr ItrPhdr;
/* Get base address */
for (Elf64_Half i = 0; i < ELFHeader->e_phnum; i++)
{
memcpy(&ItrPhdr,
(uint8_t *)ElfFile + ELFHeader->e_phoff + ELFHeader->e_phentsize * i,
sizeof(Elf64_Phdr));
BaseAddress = MIN(BaseAddress, ItrPhdr.p_vaddr);
}
/* Get size */
for (Elf64_Half i = 0; i < ELFHeader->e_phnum; i++)
{
memcpy(&ItrPhdr,
(uint8_t *)ElfFile + ELFHeader->e_phoff + ELFHeader->e_phentsize * i,
sizeof(Elf64_Phdr));
uintptr_t SegmentEnd;
SegmentEnd = ItrPhdr.p_vaddr - BaseAddress + ItrPhdr.p_memsz;
ElfAppSize = MAX(ElfAppSize, SegmentEnd);
}
debug("BaseAddress: %#lx | ElfAppSize: %#lx (%ld, %ld KB)", BaseAddress, ElfAppSize, ElfAppSize, TO_KB(ElfAppSize));
/* If required, MemoryImage will be at virtual address. (unless has PIE)
*
* tl;dr this is where the code is stored. */
MmImage MemoryImage = ELFCreateMemoryImage(ELFBase.TmpMem, pV, ElfFile, ElfAppSize);
debug("Solving symbols for address: %#llx", (uintptr_t)ElfFile);
Elf64_Shdr *ElfSections = (Elf64_Shdr *)((uintptr_t)ElfFile + ELFHeader->e_shoff);
Elf64_Shdr *DynamicString = nullptr;
Elf64_Shdr *StringTable = nullptr;
for (Elf64_Half i = 0; i < ELFHeader->e_shnum; i++)
{
char *DynamicStringTable = (char *)((uintptr_t)ElfFile + ElfSections[ELFHeader->e_shstrndx].sh_offset + ElfSections[i].sh_name);
if (strcmp(DynamicStringTable, ".dynstr") == 0)
{
DynamicString = &ElfSections[i];
debug("Found .dynstr");
}
else if (strcmp(DynamicStringTable, ".strtab") == 0)
{
StringTable = &ElfSections[i];
debug("Found .strtab");
}
}
if (!DynamicString)
DynamicString = StringTable;
/* Calculate entry point */
memcpy(&ItrPhdr, (uint8_t *)ElfFile + ELFHeader->e_phoff, sizeof(Elf64_Phdr));
if (ItrPhdr.p_vaddr == 0)
EntryPoint += (uintptr_t)MemoryImage.Virtual;
char InterpreterPath[256] = {'\0'};
for (Elf64_Half i = 0; i < ELFHeader->e_phnum; i++)
{
memcpy(&ItrPhdr,
(uint8_t *)ElfFile + ELFHeader->e_phoff + ELFHeader->e_phentsize * i,
sizeof(Elf64_Phdr));
switch (ItrPhdr.p_type)
{
case PT_NULL:
fixme("PT_NULL");
break;
case PT_LOAD:
{
debug("PT_LOAD - Offset: %#lx, VirtAddr: %#lx, FileSiz: %ld, MemSiz: %ld, Align: %#lx",
ItrPhdr.p_offset, ItrPhdr.p_vaddr,
ItrPhdr.p_filesz, ItrPhdr.p_memsz, ItrPhdr.p_align);
uintptr_t MAddr = (ItrPhdr.p_vaddr - BaseAddress) + (uintptr_t)MemoryImage.Physical;
fixme("Address: %#lx %s%s%s", MAddr,
(ItrPhdr.p_flags & PF_R) ? "R" : "",
(ItrPhdr.p_flags & PF_W) ? "W" : "",
(ItrPhdr.p_flags & PF_X) ? "X" : "");
memcpy((void *)MAddr, (uint8_t *)ElfFile + ItrPhdr.p_offset, ItrPhdr.p_filesz);
debug("memcpy: %#lx => %#lx (%ld bytes)", (uint8_t *)ElfFile + ItrPhdr.p_offset, MAddr, ItrPhdr.p_filesz);
break;
}
case PT_DYNAMIC:
{
debug("PT_DYNAMIC - Offset: %#lx VirtAddr: %#lx FileSiz: %ld MemSiz: %ld Align: %#lx",
ItrPhdr.p_offset, ItrPhdr.p_vaddr,
ItrPhdr.p_filesz, ItrPhdr.p_memsz, ItrPhdr.p_align);
Elf64_Dyn *Dynamic = (Elf64_Dyn *)((uint8_t *)ElfFile + ItrPhdr.p_offset);
for (size_t i = 0; i < ItrPhdr.p_filesz / sizeof(Elf64_Dyn); i++)
{
if (Dynamic[i].d_tag == DT_NEEDED)
{
if (!DynamicString)
{
error("DynamicString is null");
break;
}
const char *ReqLib = (const char *)((uintptr_t)ElfFile + DynamicString->sh_offset + Dynamic[i].d_un.d_val);
debug("DT_NEEDED - Name[%ld]: %s", i, ReqLib);
ELFBase.NeededLibraries.push_back(ReqLib);
}
else if (Dynamic[i].d_tag == DT_NULL)
break;
}
break;
}
case PT_INTERP:
{
debug("PT_INTERP - Offset: %#lx VirtAddr: %#lx FileSiz: %ld MemSiz: %ld Align: %#lx",
ItrPhdr.p_offset, ItrPhdr.p_vaddr,
ItrPhdr.p_filesz, ItrPhdr.p_memsz, ItrPhdr.p_align);
memcpy((void *)InterpreterPath, (uint8_t *)ElfFile + ItrPhdr.p_offset, 256);
debug("Interpreter: %s", InterpreterPath);
VirtualFileSystem::File InterpreterFile = vfs->Open(InterpreterPath);
if (!InterpreterFile.IsOK())
warn("Failed to open interpreter file: %s", InterpreterPath);
vfs->Close(InterpreterFile);
break;
}
/* ... */
case PT_PHDR:
{
fixme("PT_PHDR - Offset: %#lx VirtAddr: %#lx FileSiz: %ld MemSiz: %ld Align: %#lx",
ItrPhdr.p_offset, ItrPhdr.p_vaddr,
ItrPhdr.p_filesz, ItrPhdr.p_memsz, ItrPhdr.p_align);
break;
}
default:
{
warn("Unknown or unsupported program header type: %d", ItrPhdr.p_type);
break;
}
}
}
if (strlen(InterpreterPath) > 1)
{
EntryPoint = LoadELFInterpreter(ELFBase.TmpMem, pV, InterpreterPath);
ELFBase.Interpreter = true;
}
debug("Entry Point: %#lx", EntryPoint);
char *aux_platform = (char *)ELFBase.TmpMem->RequestPages(1, true);
strcpy(aux_platform, "x86_64");
ELFBase.auxv.push_back({.archaux = {.a_type = AT_NULL, .a_un = {.a_val = 0}}});
ELFBase.auxv.push_back({.archaux = {.a_type = AT_EXECFN, .a_un = {.a_val = (uint64_t)vfs->GetPathFromNode(ExFile.node).get()}}});
ELFBase.auxv.push_back({.archaux = {.a_type = AT_PLATFORM, .a_un = {.a_val = (uint64_t)aux_platform}}});
ELFBase.auxv.push_back({.archaux = {.a_type = AT_ENTRY, .a_un = {.a_val = (uint64_t)EntryPoint}}});
ELFBase.auxv.push_back({.archaux = {.a_type = AT_BASE, .a_un = {.a_val = (uint64_t)MemoryImage.Virtual}}});
ELFBase.auxv.push_back({.archaux = {.a_type = AT_PAGESZ, .a_un = {.a_val = (uint64_t)PAGE_SIZE}}});
ELFBase.auxv.push_back({.archaux = {.a_type = AT_PHNUM, .a_un = {.a_val = (uint64_t)ELFHeader->e_phnum}}});
ELFBase.auxv.push_back({.archaux = {.a_type = AT_PHENT, .a_un = {.a_val = (uint64_t)ELFHeader->e_phentsize}}});
ELFBase.auxv.push_back({.archaux = {.a_type = AT_PHDR, .a_un = {.a_val = (uint64_t)ELFHeader->e_phoff}}});
ELFBase.InstructionPointer = EntryPoint;
ELFBase.MemoryImage = MemoryImage.Physical;
ELFBase.VirtualMemoryImage = MemoryImage.Virtual;
ELFBase.Success = true;
return ELFBase;
#elif defined(a32)
return {};
#endif
}
}