mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2025-04-23 21:15:14 +00:00
LibELF: Perform weak relocations in much more straight-forward manner
There is no need to defer unresolved weak relocations until stage 3 -- it is not like we will magically find new symbols in the same objects.
This commit is contained in:
Dan Klishch
Andrew Kaster
parent
7b06417ccf
commit
49e09507d7
Notes:
sideshowbarker
2024-07-17 23:07:41 +09:00
Author: https://github.com/DanShaders Commit: https://github.com/SerenityOS/serenity/commit/49e09507d7 Pull-request: https://github.com/SerenityOS/serenity/pull/24086 Reviewed-by: https://github.com/ADKaster ✅
2 changed files with 10 additions and 42 deletions
|
|
@ -196,13 +196,10 @@ void DynamicLoader::do_main_relocations()
|
|||
|
||||
Optional<DynamicLoader::CachedLookupResult> cached_result;
|
||||
m_dynamic_object->relocation_section().for_each_relocation([&](DynamicObject::Relocation const& relocation) {
|
||||
switch (do_direct_relocation(relocation, cached_result, ShouldInitializeWeak::No, ShouldCallIfuncResolver::No)) {
|
||||
switch (do_direct_relocation(relocation, cached_result, ShouldCallIfuncResolver::No)) {
|
||||
case RelocationResult::Failed:
|
||||
dbgln("Loader.so: {} unresolved symbol '{}'", m_filepath, relocation.symbol().name());
|
||||
VERIFY_NOT_REACHED();
|
||||
case RelocationResult::ResolveLater:
|
||||
m_unresolved_relocations.append(relocation);
|
||||
break;
|
||||
case RelocationResult::CallIfuncResolver:
|
||||
m_direct_ifunc_relocations.append(relocation);
|
||||
break;
|
||||
|
|
@ -226,8 +223,8 @@ void DynamicLoader::do_main_relocations()
|
|||
if (static_cast<GenericDynamicRelocationType>(relocation.type()) == GenericDynamicRelocationType::TLSDESC) {
|
||||
// GNU ld for some reason puts TLSDESC relocations into .rela.plt
|
||||
// https://sourceware.org/bugzilla/show_bug.cgi?id=28387
|
||||
|
||||
VERIFY(do_direct_relocation(relocation, cached_result, ShouldInitializeWeak::No, ShouldCallIfuncResolver::No) == RelocationResult::Success);
|
||||
auto result = do_direct_relocation(relocation, cached_result, ShouldCallIfuncResolver::No);
|
||||
VERIFY(result == RelocationResult::Success);
|
||||
return;
|
||||
}
|
||||
|
||||
|
|
@ -237,8 +234,6 @@ void DynamicLoader::do_main_relocations()
|
|||
case RelocationResult::Failed:
|
||||
dbgln("Loader.so: {} unresolved symbol '{}'", m_filepath, relocation.symbol().name());
|
||||
VERIFY_NOT_REACHED();
|
||||
case RelocationResult::ResolveLater:
|
||||
VERIFY_NOT_REACHED();
|
||||
case RelocationResult::CallIfuncResolver:
|
||||
m_plt_ifunc_relocations.append(relocation);
|
||||
// Set up lazy binding, in case an IFUNC resolver calls another IFUNC that hasn't been resolved yet.
|
||||
|
|
@ -255,7 +250,6 @@ void DynamicLoader::do_main_relocations()
|
|||
|
||||
Result<NonnullRefPtr<DynamicObject>, DlErrorMessage> DynamicLoader::load_stage_3(unsigned flags)
|
||||
{
|
||||
do_lazy_relocations();
|
||||
if (flags & RTLD_LAZY) {
|
||||
if (m_dynamic_object->has_plt())
|
||||
setup_plt_trampoline();
|
||||
|
|
@ -270,7 +264,7 @@ Result<NonnullRefPtr<DynamicObject>, DlErrorMessage> DynamicLoader::load_stage_3
|
|||
|
||||
Optional<DynamicLoader::CachedLookupResult> cached_result;
|
||||
for (auto const& relocation : m_direct_ifunc_relocations) {
|
||||
auto result = do_direct_relocation(relocation, cached_result, ShouldInitializeWeak::No, ShouldCallIfuncResolver::Yes);
|
||||
auto result = do_direct_relocation(relocation, cached_result, ShouldCallIfuncResolver::Yes);
|
||||
VERIFY(result == RelocationResult::Success);
|
||||
}
|
||||
|
||||
|
|
@ -307,17 +301,6 @@ void DynamicLoader::load_stage_4()
|
|||
m_fully_initialized = true;
|
||||
}
|
||||
|
||||
void DynamicLoader::do_lazy_relocations()
|
||||
{
|
||||
Optional<DynamicLoader::CachedLookupResult> cached_result;
|
||||
for (auto const& relocation : m_unresolved_relocations) {
|
||||
if (auto res = do_direct_relocation(relocation, cached_result, ShouldInitializeWeak::Yes, ShouldCallIfuncResolver::Yes); res != RelocationResult::Success) {
|
||||
dbgln("Loader.so: {} unresolved symbol '{}'", m_filepath, relocation.symbol().name());
|
||||
VERIFY_NOT_REACHED();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
void DynamicLoader::load_program_headers()
|
||||
{
|
||||
FlatPtr ph_load_start = SIZE_MAX;
|
||||
|
|
@ -520,7 +503,6 @@ void DynamicLoader::load_program_headers()
|
|||
|
||||
DynamicLoader::RelocationResult DynamicLoader::do_direct_relocation(DynamicObject::Relocation const& relocation,
|
||||
Optional<DynamicLoader::CachedLookupResult>& cached_result,
|
||||
ShouldInitializeWeak should_initialize_weak,
|
||||
ShouldCallIfuncResolver should_call_ifunc_resolver)
|
||||
{
|
||||
FlatPtr* patch_ptr = nullptr;
|
||||
|
|
@ -571,10 +553,7 @@ DynamicLoader::RelocationResult DynamicLoader::do_direct_relocation(DynamicObjec
|
|||
auto res = lookup_symbol(symbol);
|
||||
VirtualAddress symbol_address;
|
||||
if (!res.has_value()) {
|
||||
if (symbol.bind() == STB_WEAK) {
|
||||
if (should_initialize_weak == ShouldInitializeWeak::No)
|
||||
return RelocationResult::ResolveLater;
|
||||
} else {
|
||||
if (symbol.bind() != STB_WEAK) {
|
||||
dbgln("ERROR: symbol not found: {}.", symbol.name());
|
||||
return RelocationResult::Failed;
|
||||
}
|
||||
|
|
@ -598,10 +577,7 @@ DynamicLoader::RelocationResult DynamicLoader::do_direct_relocation(DynamicObjec
|
|||
auto res = lookup_symbol(symbol);
|
||||
VirtualAddress symbol_location;
|
||||
if (!res.has_value()) {
|
||||
if (symbol.bind() == STB_WEAK) {
|
||||
if (should_initialize_weak == ShouldInitializeWeak::No)
|
||||
return RelocationResult::ResolveLater;
|
||||
} else {
|
||||
if (symbol.bind() != STB_WEAK) {
|
||||
// Symbol not found
|
||||
return RelocationResult::Failed;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -35,11 +35,6 @@ private:
|
|||
size_t m_size;
|
||||
};
|
||||
|
||||
enum class ShouldInitializeWeak {
|
||||
Yes,
|
||||
No
|
||||
};
|
||||
|
||||
enum class ShouldCallIfuncResolver {
|
||||
Yes,
|
||||
No
|
||||
|
|
@ -127,7 +122,6 @@ private:
|
|||
void do_main_relocations();
|
||||
|
||||
// Stage 3
|
||||
void do_lazy_relocations();
|
||||
void setup_plt_trampoline();
|
||||
|
||||
// Stage 4
|
||||
|
|
@ -138,16 +132,15 @@ private:
|
|||
friend FlatPtr _fixup_plt_entry(DynamicObject*, u32);
|
||||
|
||||
enum class RelocationResult : uint8_t {
|
||||
Failed = 0,
|
||||
Success = 1,
|
||||
ResolveLater = 2,
|
||||
CallIfuncResolver = 3,
|
||||
Failed,
|
||||
Success,
|
||||
CallIfuncResolver,
|
||||
};
|
||||
struct CachedLookupResult {
|
||||
DynamicObject::Symbol symbol;
|
||||
Optional<DynamicObject::SymbolLookupResult> result;
|
||||
};
|
||||
RelocationResult do_direct_relocation(DynamicObject::Relocation const&, Optional<CachedLookupResult>&, ShouldInitializeWeak, ShouldCallIfuncResolver);
|
||||
RelocationResult do_direct_relocation(DynamicObject::Relocation const&, Optional<CachedLookupResult>&, ShouldCallIfuncResolver);
|
||||
// Will be called from _fixup_plt_entry, as part of the PLT trampoline
|
||||
static RelocationResult do_plt_relocation(DynamicObject::Relocation const&, ShouldCallIfuncResolver);
|
||||
void do_relr_relocations();
|
||||
|
|
@ -174,7 +167,6 @@ private:
|
|||
size_t m_tls_size_of_current_object { 0 };
|
||||
size_t m_tls_alignment_of_current_object { 0 };
|
||||
|
||||
Vector<DynamicObject::Relocation> m_unresolved_relocations;
|
||||
Vector<DynamicObject::Relocation> m_direct_ifunc_relocations;
|
||||
Vector<DynamicObject::Relocation> m_plt_ifunc_relocations;
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue