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LibELF: Move DynamicObject::lookup_symbol() to DynamicLoader

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Also simplify it by removing an unreachable code path.
This commit is contained in:
Andreas Kling 2021-02-21 00:29:08 +01:00
parent a43910acc3
commit f23b29f605
4 changed files with 14 additions and 22 deletions
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11
Userland/Libraries/LibELF/DynamicLoader.cpp
View file

@ -1,6 +1,7 @@
/* /*
* Copyright (c) 2019-2020, Andrew Kaster <andrewdkaster@gmail.com> * Copyright (c) 2019-2020, Andrew Kaster <andrewdkaster@gmail.com>
* Copyright (c) 2020, Itamar S. <itamar8910@gmail.com> * Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
* All rights reserved. * All rights reserved.
* *
* Redistribution and use in source and binary forms, with or without * Redistribution and use in source and binary forms, with or without
@ -28,6 +29,7 @@
#include <AK/Debug.h> #include <AK/Debug.h>
#include <AK/Optional.h> #include <AK/Optional.h>
#include <AK/StringBuilder.h> #include <AK/StringBuilder.h>
#include <LibELF/DynamicLinker.h>
#include <LibELF/DynamicLoader.h> #include <LibELF/DynamicLoader.h>
#include <LibELF/Validation.h> #include <LibELF/Validation.h>
#include <assert.h> #include <assert.h>
@ -570,9 +572,14 @@ void DynamicLoader::call_object_init_functions()
} }
} }
Optional<DynamicObject::SymbolLookupResult> DynamicLoader::lookup_symbol(const ELF::DynamicObject::Symbol& symbol) const Optional<DynamicObject::SymbolLookupResult> DynamicLoader::lookup_symbol(const ELF::DynamicObject::Symbol& symbol)
{ {
return m_dynamic_object->lookup_symbol(symbol); dbgln_if(DYNAMIC_LOAD_DEBUG, "looking up symbol: {}", symbol.name());
if (symbol.is_undefined() || symbol.bind() == STB_WEAK)
return DynamicLinker::lookup_global_symbol(symbol.name());
dbgln_if(DYNAMIC_LOAD_DEBUG, "symbol is defined in its object");
return DynamicObject::SymbolLookupResult { symbol.value(), symbol.address(), symbol.bind(), &symbol.object() };
} }
} // end namespace ELF } // end namespace ELF

4
Userland/Libraries/LibELF/DynamicLoader.h
View file

@ -71,6 +71,8 @@ public:
VirtualAddress text_segment_load_address() const { return m_text_segment_load_address; } VirtualAddress text_segment_load_address() const { return m_text_segment_load_address; }
bool is_dynamic() const { return m_elf_image.is_dynamic(); } bool is_dynamic() const { return m_elf_image.is_dynamic(); }
static Optional<DynamicObject::SymbolLookupResult> lookup_symbol(const ELF::DynamicObject::Symbol&);
private: private:
DynamicLoader(int fd, String filename, void* file_data, size_t file_size); DynamicLoader(int fd, String filename, void* file_data, size_t file_size);
@ -121,8 +123,6 @@ private:
RelocationResult do_relocation(size_t total_tls_size, const DynamicObject::Relocation&); RelocationResult do_relocation(size_t total_tls_size, const DynamicObject::Relocation&);
size_t calculate_tls_size() const; size_t calculate_tls_size() const;
Optional<DynamicObject::SymbolLookupResult> lookup_symbol(const ELF::DynamicObject::Symbol&) const;
String m_filename; String m_filename;
String m_program_interpreter; String m_program_interpreter;
size_t m_file_size { 0 }; size_t m_file_size { 0 };

19
Userland/Libraries/LibELF/DynamicObject.cpp
View file

@ -28,7 +28,7 @@
#include <AK/Debug.h> #include <AK/Debug.h>
#include <AK/String.h> #include <AK/String.h>
#include <AK/StringBuilder.h> #include <AK/StringBuilder.h>
#include <LibELF/DynamicLinker.h> #include <LibELF/DynamicLoader.h>
#include <LibELF/DynamicObject.h> #include <LibELF/DynamicObject.h>
#include <LibELF/exec_elf.h> #include <LibELF/exec_elf.h>
#include <string.h> #include <string.h>
@ -458,7 +458,7 @@ static const char* name_for_dtag(Elf32_Sword d_tag)
} }
} }
Optional<DynamicObject::SymbolLookupResult> DynamicObject::lookup_symbol(const StringView& name) const auto DynamicObject::lookup_symbol(const StringView& name) const -> Optional<SymbolLookupResult>
{ {
auto result = hash_section().lookup_symbol(name); auto result = hash_section().lookup_symbol(name);
if (!result.has_value()) if (!result.has_value())
@ -482,7 +482,7 @@ VirtualAddress DynamicObject::patch_plt_entry(u32 relocation_offset)
auto symbol = relocation.symbol(); auto symbol = relocation.symbol();
u8* relocation_address = relocation.address().as_ptr(); u8* relocation_address = relocation.address().as_ptr();
auto result = lookup_symbol(symbol); auto result = DynamicLoader::lookup_symbol(symbol);
if (!result.has_value()) { if (!result.has_value()) {
dbgln("did not find symbol: {}", symbol.name()); dbgln("did not find symbol: {}", symbol.name());
ASSERT_NOT_REACHED(); ASSERT_NOT_REACHED();
@ -496,17 +496,4 @@ VirtualAddress DynamicObject::patch_plt_entry(u32 relocation_offset)
return symbol_location; return symbol_location;
} }
Optional<DynamicObject::SymbolLookupResult> DynamicObject::lookup_symbol(const ELF::DynamicObject::Symbol& symbol) const
{
dbgln_if(DYNAMIC_LOAD_DEBUG, "looking up symbol: {}", symbol.name());
if (symbol.is_undefined() || symbol.bind() == STB_WEAK)
return DynamicLinker::lookup_global_symbol(symbol.name());
if (!symbol.is_undefined()) {
dbgln_if(DYNAMIC_LOAD_DEBUG, "symbol is defined in its object");
return SymbolLookupResult { symbol.value(), symbol.address(), symbol.bind(), &symbol.object() };
}
return DynamicLinker::lookup_global_symbol(symbol.name());
}
} // end namespace ELF } // end namespace ELF

2
Userland/Libraries/LibELF/DynamicObject.h
View file

@ -264,8 +264,6 @@ public:
// Will be called from _fixup_plt_entry, as part of the PLT trampoline // Will be called from _fixup_plt_entry, as part of the PLT trampoline
VirtualAddress patch_plt_entry(u32 relocation_offset); VirtualAddress patch_plt_entry(u32 relocation_offset);
Optional<SymbolLookupResult> lookup_symbol(const ELF::DynamicObject::Symbol&) const;
bool elf_is_dynamic() const { return m_is_elf_dynamic; } bool elf_is_dynamic() const { return m_is_elf_dynamic; }
private: private: