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#include "ELFLoader.h"
#include <AK/kstdio.h>
#include <AK/QuickSort.h>
//#define ELFLOADER_DEBUG
ELFLoader::ELFLoader(const byte* buffer)
: m_image(buffer)
{
}
ELFLoader::~ELFLoader()
{
}
bool ELFLoader::load()
{
#ifdef ELFLOADER_DEBUG
m_image.dump();
#endif
if (!m_image.is_valid())
return false;
if (!layout())
return false;
return true;
}
bool ELFLoader::layout()
{
bool failed = false;
m_image.for_each_program_header([&] (const ELFImage::ProgramHeader& program_header) {
if (program_header.type() != PT_LOAD)
return;
#ifdef ELFLOADER_DEBUG
kprintf("PH: L%x %u r:%u w:%u\n", program_header.laddr().get(), program_header.size_in_memory(), program_header.is_readable(), program_header.is_writable());
#endif
if (program_header.is_writable()) {
alloc_section_hook(
program_header.laddr(),
program_header.size_in_memory(),
program_header.alignment(),
program_header.is_readable(),
program_header.is_writable(),
String::format("elf-alloc-%s%s", program_header.is_readable() ? "r" : "", program_header.is_writable() ? "w" : "")
);
memcpy(program_header.laddr().as_ptr(), program_header.raw_data(), program_header.size_in_image());
} else {
map_section_hook(
program_header.laddr(),
program_header.size_in_memory(),
program_header.alignment(),
program_header.offset(),
program_header.is_readable(),
program_header.is_writable(),
String::format("elf-map-%s%s", program_header.is_readable() ? "r" : "", program_header.is_writable() ? "w" : "")
);
}
});
return !failed;
}
char* ELFLoader::symbol_ptr(const char* name)
{
char* found_ptr = nullptr;
m_image.for_each_symbol([&] (const ELFImage::Symbol symbol) {
if (symbol.type() != STT_FUNC)
return IterationDecision::Continue;
if (strcmp(symbol.name(), name))
return IterationDecision::Continue;
if (m_image.is_executable())
found_ptr = (char*)symbol.value();
else
ASSERT_NOT_REACHED();
return IterationDecision::Abort;
});
return found_ptr;
}
String ELFLoader::symbolicate(dword address) const
{
if (m_sorted_symbols.is_empty()) {
m_sorted_symbols.ensure_capacity(m_image.symbol_count());
m_image.for_each_symbol([this] (auto& symbol) {
m_sorted_symbols.append({ symbol.value(), symbol.name() });
return IterationDecision::Continue;
});
quick_sort(m_sorted_symbols.begin(), m_sorted_symbols.end(), [] (auto& a, auto& b) {
return a.address < b.address;
});
}
for (int i = 0; i < m_sorted_symbols.size(); ++i) {
if (m_sorted_symbols[i].address > address) {
if (i == 0)
return "!!";
auto& symbol = m_sorted_symbols[i - 1];
return String::format("%s +%u", symbol.name, address - symbol.address);
}
}
return "??";
}
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