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LibELF: Simplify R_386_32 relocations to ignore symbol bind value

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For dynamic loading, the symbol bind of a symbol actually doesn't
matter. We could do what old glibc did and try to find a strong
symbol for any weak definitions, but the ELF spec doesn't require
it and they changed that a few years ago anyway. So, moot point. :)
This commit is contained in:
Andrew Kaster 2020-01-02 00:21:38 -05:00 • committed by Andreas Kling
parent bc50a10cc9
commit 2c4f837428
1 changed files with 5 additions and 20 deletions
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25
Libraries/LibELF/ELFDynamicObject.cpp
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@ -264,11 +264,8 @@ bool ELFDynamicObject::load(unsigned flags)
void ELFDynamicObject::load_program_headers() void ELFDynamicObject::load_program_headers()
{ {
size_t total_required_allocation_size = 0; size_t total_required_allocation_size = 0; // NOTE: If we don't have any TEXTREL, we can keep RO data RO, which would be nice
// FIXME: Can we re-use ELFLoader? This and what follows looks a lot like what's in there...
// With the exception of using desired_load_address().offset(text_segment_begin)
// It seems kinda gross to expect the program headers to be in a specific order..
m_image->for_each_program_header([&](const ELFImage::ProgramHeader& program_header) { m_image->for_each_program_header([&](const ELFImage::ProgramHeader& program_header) {
ProgramHeaderRegion new_region(program_header.raw_header()); ProgramHeaderRegion new_region(program_header.raw_header());
if (new_region.is_load()) if (new_region.is_load())
@ -340,21 +337,9 @@ void ELFDynamicObject::do_relocations()
break; break;
case R_386_32: { case R_386_32: {
auto symbol = relocation.symbol(); auto symbol = relocation.symbol();
VERBOSE("Absolute relocation: name: '%s', value: %p\n", symbol.name(), symbol.value()); VERBOSE("Absolute relocation: name: '%s', value: %p\n", symbol.name(), symbol.value());
if (symbol.bind() == STB_LOCAL) { u32 symbol_address = symbol.value() + (u32)load_base_address;
u32 symbol_address = symbol.section().address() + symbol.value(); *patch_ptr += symbol_address;
*patch_ptr += symbol_address;
} else if (symbol.bind() == STB_GLOBAL) {
u32 symbol_address = symbol.value() + (u32)load_base_address;
*patch_ptr += symbol_address;
} else if (symbol.bind() == STB_WEAK) {
// FIXME: Handle weak symbols...
dbgprintf("ELFDynamicObject: Ignoring weak symbol %s\n", symbol.name());
} else {
VERBOSE("Found new fun symbol bind value %d\n", symbol.bind());
ASSERT_NOT_REACHED();
}
VERBOSE(" Symbol address: %p\n", *patch_ptr); VERBOSE(" Symbol address: %p\n", *patch_ptr);
break; break;
} }
@ -369,7 +354,7 @@ void ELFDynamicObject::do_relocations()
case R_386_GLOB_DAT: { case R_386_GLOB_DAT: {
auto symbol = relocation.symbol(); auto symbol = relocation.symbol();
VERBOSE("Global data relocation: '%s', value: %p\n", symbol.name(), symbol.value()); VERBOSE("Global data relocation: '%s', value: %p\n", symbol.name(), symbol.value());
u32 symbol_location = (u32)(m_data_region->base_address().as_ptr() + symbol.value()); u32 symbol_location = (u32)(load_base_address + symbol.value());
*patch_ptr = symbol_location; *patch_ptr = symbol_location;
VERBOSE(" Symbol address: %p\n", *patch_ptr); VERBOSE(" Symbol address: %p\n", *patch_ptr);
break; break;
@ -486,7 +471,7 @@ void ELFDynamicObject::call_object_init_functions()
InitFunc* init_begin = (InitFunc*)(load_addr + m_init_array_offset); InitFunc* init_begin = (InitFunc*)(load_addr + m_init_array_offset);
u32 init_end = (u32)((u8*)init_begin + m_init_array_size); u32 init_end = (u32)((u8*)init_begin + m_init_array_size);
while ((u32)init_begin < init_end) { while ((u32)init_begin < init_end) {
// Andriod sources claim that these can be -1, to be ignored. // Android sources claim that these can be -1, to be ignored.
// 0 definitely shows up. Apparently 0/-1 are valid? Confusing. // 0 definitely shows up. Apparently 0/-1 are valid? Confusing.
if (!*init_begin || ((i32)*init_begin == -1)) if (!*init_begin || ((i32)*init_begin == -1))
continue; continue;