Kernel/core/symbols.cpp
2024-05-18 07:42:01 +03:00

331 lines
8.5 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 <symbols.hpp>
#include <memory.hpp>
#include <convert.h>
#include <debug.h>
#include <elf.h>
// #pragma GCC diagnostic ignored "-Wignored-qualifiers"
namespace SymbolResolver
{
const NIF char *Symbols::GetSymbol(uintptr_t Address)
{
SymbolTable Result{};
if (this->SymbolTableExists == false)
{
debug("Symbol table does not exist");
if (this->SymTable.size() > 0)
{
debug("SymbolTableExists is false but SymTable.size() is %d",
this->SymTable.size());
}
return Result.FunctionName;
}
for (auto it = this->SymTable.rbegin(); it != this->SymTable.rend(); ++it)
{
if (unlikely(it->Address <= Address && it->Address > Result.Address))
{
Result = *it;
break;
}
}
// debug("Symbol %#lx: %s", Result.Address, Result.FunctionName);
return Result.FunctionName;
}
uintptr_t Symbols::GetSymbol(const char *Name)
{
SymbolTable Result{};
if (this->SymbolTableExists == false)
{
debug("Symbol table does not exist");
if (this->SymTable.size() > 0)
{
debug("SymbolTableExists is false but SymTable.size() is %d",
this->SymTable.size());
}
return Result.Address;
}
for (auto it = this->SymTable.rbegin(); it != this->SymTable.rend(); ++it)
{
if (unlikely(strcmp(it->FunctionName, Name) == 0))
{
Result = *it;
break;
}
}
// debug("Symbol %#lx: %s", Result.Address, Result.FunctionName);
return Result.Address;
}
void Symbols::AddSymbol(uintptr_t Address, const char *Name)
{
SymbolTable tbl{};
tbl.Address = Address;
tbl.FunctionName = new char[strlen(Name) + 1];
strcpy(tbl.FunctionName, Name);
this->SymTable.push_back(tbl);
this->SymbolTableExists = true;
}
__no_sanitize("alignment") void Symbols::AddSymbolInfoFromGRUB(uint64_t Num,
uint64_t EntSize,
__unused uint64_t Shndx,
uintptr_t Sections)
{
char *sections = r_cst(char *, Sections);
Elf_Sym *Symbols = nullptr;
uint8_t *StringAddress = nullptr;
#if defined(a64) || defined(aa64)
Elf64_Xword SymbolSize = 0;
// Elf64_Xword StringSize = 0;
#elif defined(a32)
Elf32_Word SymbolSize = 0;
// Elf32_Word StringSize = 0;
#endif
size_t TotalEntries = 0;
for (size_t i = 0; i < Num; ++i)
{
Elf_Shdr *sym = (Elf_Shdr *)&sections[EntSize * i];
Elf_Shdr *str = (Elf_Shdr *)&sections[EntSize * sym->sh_link];
if (sym->sh_type == SHT_SYMTAB &&
str->sh_type == SHT_STRTAB)
{
Symbols = (Elf_Sym *)sym->sh_addr;
StringAddress = (uint8_t *)str->sh_addr;
SymbolSize = (int)sym->sh_size;
// StringSize = (int)str->sh_size;
// TotalEntries = Section.sh_size / sizeof(Elf64_Sym)
TotalEntries = sym->sh_size / sym->sh_entsize;
trace("Symbol table found, %d entries",
SymbolSize / sym->sh_entsize);
UNUSED(SymbolSize);
break;
}
}
if (Symbols != nullptr && StringAddress != nullptr)
{
size_t Index, MinimumIndex;
for (size_t i = 0; i < TotalEntries - 1; i++)
{
MinimumIndex = i;
for (Index = i + 1; Index < TotalEntries; Index++)
if (Symbols[Index].st_value < Symbols[MinimumIndex].st_value)
MinimumIndex = Index;
Elf_Sym tmp = Symbols[MinimumIndex];
Symbols[MinimumIndex] = Symbols[i];
Symbols[i] = tmp;
}
while (Symbols[0].st_value == 0)
{
if (TotalEntries <= 0)
break;
Symbols++;
TotalEntries--;
}
if (TotalEntries <= 0)
{
error("Symbol table is empty");
return;
}
trace("Symbol table loaded, %d entries (%ld KiB)",
TotalEntries, TO_KiB(TotalEntries * sizeof(SymbolTable)));
Elf_Sym *sym;
const char *name;
Memory::Virtual vmm;
for (size_t i = 0, g = TotalEntries; i < g; i++)
{
sym = &Symbols[i];
if (!vmm.Check(sym))
{
error("Symbol %d has invalid address %#lx!",
i, sym);
debug("Base: %#lx, Symbols[%d]: %#lx, Symbols[%d]: %#lx",
Symbols,
i - 1, &Symbols[i - 1],
i + 1, &Symbols[i + 1]);
continue;
}
name = (const char *)&StringAddress[Symbols[i].st_name];
if (!vmm.Check((void *)name))
{
error("String %d has invalid address %#lx!",
i, name);
debug("st_name: %d, st_info: %d, st_other: %d, st_shndx: %d, st_value: %d, st_size: %d",
sym->st_name, sym->st_info, sym->st_other,
sym->st_shndx, sym->st_value, sym->st_size);
continue;
}
if (strlen(name) == 0)
continue;
SymbolTable tbl{};
tbl.Address = sym->st_value;
tbl.FunctionName = new char[strlen(name) + 1];
strcpy(tbl.FunctionName, name);
this->SymTable.push_back(tbl);
this->SymbolTableExists = true;
// debug("Symbol %d: %#lx %s(%#lx)",
// i, tbl.Address,
// tbl.FunctionName,
// name);
}
}
}
void Symbols::AppendSymbols(uintptr_t ImageAddress, uintptr_t BaseAddress)
{
/* FIXME: Get only the required headers instead of the whole file */
if (ImageAddress == 0 ||
Memory::Virtual().Check((void *)ImageAddress) == false)
{
error("Invalid image address %#lx", ImageAddress);
return;
}
debug("Solving symbols for address: %#llx", ImageAddress);
#if defined(a64) || defined(aa64)
Elf64_Ehdr *Header = (Elf64_Ehdr *)ImageAddress;
#elif defined(a32)
Elf32_Ehdr *Header = (Elf32_Ehdr *)ImageAddress;
#endif
if (Header->e_ident[0] != 0x7F &&
Header->e_ident[1] != 'E' &&
Header->e_ident[2] != 'L' &&
Header->e_ident[3] != 'F')
{
error("Invalid ELF header");
return;
}
Elf_Shdr *ElfSections = (Elf_Shdr *)(ImageAddress + Header->e_shoff);
Elf_Sym *ElfSymbols = nullptr;
char *strtab = nullptr;
size_t TotalEntries = 0;
for (uint16_t i = 0; i < Header->e_shnum; i++)
{
switch (ElfSections[i].sh_type)
{
case SHT_SYMTAB:
ElfSymbols = (Elf_Sym *)(ImageAddress + ElfSections[i].sh_offset);
TotalEntries = ElfSections[i].sh_size / sizeof(Elf_Sym);
debug("Symbol table found, %d entries", TotalEntries);
break;
case SHT_STRTAB:
if (Header->e_shstrndx == i)
{
debug("String table found, %d entries", ElfSections[i].sh_size);
}
else
{
strtab = (char *)(ImageAddress + ElfSections[i].sh_offset);
debug("String table found, %d entries", ElfSections[i].sh_size);
}
break;
default:
break;
}
}
if (ElfSymbols != nullptr && strtab != nullptr)
{
size_t Index, MinimumIndex;
for (size_t i = 0; i < TotalEntries - 1; i++)
{
MinimumIndex = i;
for (Index = i + 1; Index < TotalEntries; Index++)
if (ElfSymbols[Index].st_value < ElfSymbols[MinimumIndex].st_value)
MinimumIndex = Index;
Elf_Sym tmp = ElfSymbols[MinimumIndex];
ElfSymbols[MinimumIndex] = ElfSymbols[i];
ElfSymbols[i] = tmp;
}
while (ElfSymbols[0].st_value == 0)
{
ElfSymbols++;
TotalEntries--;
}
trace("Symbol table loaded, %d entries (%ld KiB)",
TotalEntries, TO_KiB(TotalEntries * sizeof(SymbolTable)));
/* TODO: maybe a checker for duplicated addresses? */
Elf_Sym *sym = nullptr;
const char *name = nullptr;
for (size_t i = 0, g = TotalEntries; i < g; i++)
{
sym = &ElfSymbols[i];
name = &strtab[ElfSymbols[i].st_name];
SymbolTable tbl{};
tbl.Address = sym->st_value + BaseAddress;
tbl.FunctionName = new char[strlen(name) + 1];
strcpy(tbl.FunctionName, name);
this->SymTable.push_back(tbl);
this->SymbolTableExists = true;
// debug("Symbol %d: %#llx %s", i,
// this->SymTable[i].Address,
// this->SymTable[i].FunctionName);
}
}
if (this->SymbolTableExists)
{
debug("Symbol table exists, %d entries (%ld KiB)",
this->SymTable.size(), TO_KiB(this->SymTable.size() * sizeof(SymbolTable)));
}
}
Symbols::Symbols(uintptr_t ImageAddress)
{
debug("+ %#lx", this);
this->Image = (void *)ImageAddress;
this->AppendSymbols(ImageAddress);
}
Symbols::~Symbols()
{
debug("- %#lx", this);
debug("Freeing %d symbols",
this->SymTable.size());
foreach (auto tbl in this->SymTable)
delete[] tbl.FunctionName;
}
}