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Fix performance issue parsing relocations.

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Uses a map to track added relocations.
This commit is contained in:
Jacob Lewallen 2019-06-24 19:53:15 -07:00
parent 7ff0859879
commit 3be83b7b22
1 changed files with 36 additions and 13 deletions
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49
src/ELF/Parser.tcc
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@ -18,6 +18,7 @@
#include "LIEF/utils.hpp"
#include "LIEF/ELF/hash.hpp"
#include "LIEF/ELF/DynamicEntryFlags.hpp"
#include "Object.tcc"
@ -1339,6 +1340,29 @@ void Parser::parse_pltgot_relocations(uint64_t offset, uint64_t size) {
}
}
struct RelocationKey {
uint64_t address;
uint32_t type;
int64_t addend;
size_t symbol;
bool operator==(const RelocationKey &o) const {
return address == o.address && type == o.type && addend == o.addend && symbol == o.symbol;
}
bool operator<(const RelocationKey &o) const {
return address < o.address || (address == o.address && type < o.type) ||
((address == o.address && type == o.type) || addend < o .addend) ||
((address == o.address && type == o.type && addend == o.addend) && symbol < o.symbol);
}
bool operator>(const RelocationKey &o) const {
return address > o.address || (address == o.address && type > o.type) ||
((address == o.address && type == o.type) || addend > o.addend) ||
((address == o.address && type == o.type && addend == o.addend) && symbol > o.symbol);
}
};
template<typename ELF_T, typename REL_T>
void Parser::parse_section_relocations(Section const& section) {
using Elf_Rel = typename ELF_T::Elf_Rel;
@ -1370,6 +1394,8 @@ void Parser::parse_section_relocations(Section const& section) {
uint32_t nb_entries = static_cast<uint32_t>(section.size() / sizeof(REL_T));
nb_entries = std::min<uint32_t>(nb_entries, Parser::NB_MAX_RELOCATIONS);
std::map<RelocationKey, Relocation*> map;
this->stream_->setpos(offset_relocations);
for (uint32_t i = 0; i < nb_entries; ++i) {
if (not this->stream_->can_read<REL_T>()) {
@ -1392,19 +1418,16 @@ void Parser::parse_section_relocations(Section const& section) {
reloc->symbol_ = this->binary_->static_symbols_[idx];
}
// TODO: BAD CODE!!!!
if (std::find_if(
std::begin(this->binary_->relocations_),
std::end(this->binary_->relocations_),
[&reloc] (const Relocation* r) {
bool is_same = r->address() == reloc->address() and
r->type() == reloc->type() and
r->addend() == reloc->addend();
if(r->has_symbol())
is_same &= reloc->has_symbol() and reloc->symbol() == r->symbol();
return is_same;
}) == std::end(this->binary_->relocations_)) {
this->binary_->relocations_.push_back(reloc.release());
RelocationKey k = {
reloc->address(),
reloc->type(),
reloc->addend(),
reloc->has_symbol() ? LIEF::Hash::hash(reloc->symbol()) : 0
};
if (map[k] == nullptr) {
auto released = map[k] = reloc.release();
this->binary_->relocations_.push_back(released);
}
}
}