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DynamicLoader: Cleanup lazy PLT relocations

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Bananymous
2026-05-20 05:02:48 +03:00
parent a19e6938eb
commit aa8be130f9
1 changed files with 9 additions and 43 deletions
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44
userspace/programs/DynamicLoader/main.cpp
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@@ -700,53 +700,19 @@ static void relocate_elf(LoadedElf& elf, bool lazy_load)
}
else
{
const size_t pltrelent = (elf.pltrel == DT_REL)
? sizeof(ElfNativeRelocation)
: sizeof(ElfNativeRelocationA);
for (size_t i = 0; i < elf.pltrelsz / pltrelent; i++)
{
const auto info = (elf.pltrel == DT_REL)
? reinterpret_cast<ElfNativeRelocation*>(elf.jmprel)[i].r_info
: reinterpret_cast<ElfNativeRelocationA*>(elf.jmprel)[i].r_info;
const auto offset = (elf.pltrel == DT_REL)
? reinterpret_cast<ElfNativeRelocation*>(elf.jmprel)[i].r_offset
: reinterpret_cast<ElfNativeRelocationA*>(elf.jmprel)[i].r_offset;
#if defined(__x86_64__)
if (ELF64_R_TYPE(info) != R_X86_64_JUMP_SLOT)
print_error_and_exit("jmprel relocation not R_X86_64_JUMP_SLOT", 0);
#elif defined(__i686__)
if (ELF32_R_TYPE(info) != R_386_JMP_SLOT)
print_error_and_exit("jmprel relocation not R_386_JMP_SLOT", 0);
#else
#error "unsupported architecture"
#endif
bool do_relocation = false;
if (const uint32_t symbol_index = ELF_R_SYM(info))
{
const auto& symbol = *reinterpret_cast<ElfNativeSymbol*>(elf.symtab + symbol_index * elf.syment);
const char* symbol_name = reinterpret_cast<const char*>(elf.strtab + symbol.st_name);
if (strcmp(symbol_name, "__tls_get_addr") == 0 || strcmp(symbol_name, "___tls_get_addr") == 0)
do_relocation = true;
}
if (!do_relocation)
*reinterpret_cast<uintptr_t*>(elf.base + offset) += elf.base;
else switch (elf.pltrel)
switch (elf.pltrel)
{
case DT_REL:
handle_relocation(elf, reinterpret_cast<ElfNativeRelocation*>(elf.jmprel)[i], true);
for (size_t i = 0; i < elf.pltrelsz / sizeof(ElfNativeRelocation); i++)
*reinterpret_cast<uintptr_t*>(elf.base + reinterpret_cast<ElfNativeRelocation*>(elf.jmprel)[i].r_offset) += elf.base;
break;
case DT_RELA:
handle_relocation(elf, reinterpret_cast<ElfNativeRelocationA*>(elf.jmprel)[i], true);
for (size_t i = 0; i < elf.pltrelsz / sizeof(ElfNativeRelocationA); i++)
*reinterpret_cast<uintptr_t*>(elf.base + reinterpret_cast<ElfNativeRelocationA*>(elf.jmprel)[i].r_offset) += elf.base;
break;
}
}
}
}
}
extern "C"