diff options
| -rw-r--r-- | gold/ChangeLog | 8 | ||||
| -rw-r--r-- | gold/gc.h | 7 | ||||
| -rw-r--r-- | gold/icf.cc | 84 |
3 files changed, 68 insertions, 31 deletions
diff --git a/gold/ChangeLog b/gold/ChangeLog index e38262e..26ccad1 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,5 +1,13 @@ 2018-04-24 Cary Coutant <ccoutant@gmail.com> + PR gold/20642 + PR gold/22820 + * gc.h (gc_process_relocs): Flag STT_SECTION symbols in symvec. + * icf.cc (get_section_contents): For merge sections, ignore the + addend for relocations against non-section symbols. + +2018-04-24 Cary Coutant <ccoutant@gmail.com> + PR gold/16504 * dynobj.cc (Versions::symbol_section_contents): Don't set VERSYM_HIDDEN flag for undefined symbols. @@ -247,7 +247,12 @@ gc_process_relocs( (*secvec).push_back(Section_id(src_obj, dst_indx)); else (*secvec).push_back(Section_id(NULL, 0)); - (*symvec).push_back(NULL); + // If the target of the relocation is an STT_SECTION symbol, + // make a note of that by storing -1 in the symbol vector. + if (lsym.get_st_type() == elfcpp::STT_SECTION) + (*symvec).push_back(reinterpret_cast<Symbol*>(-1)); + else + (*symvec).push_back(NULL); (*addendvec).push_back(std::make_pair( static_cast<long long>(symvalue), static_cast<long long>(addend))); diff --git a/gold/icf.cc b/gold/icf.cc index 62dade8..378a56b 100644 --- a/gold/icf.cc +++ b/gold/icf.cc @@ -327,6 +327,16 @@ get_section_contents(bool first_iteration, for (; it_v != v.end(); ++it_v, ++it_s, ++it_a, ++it_o, ++it_addend_size) { + Symbol* gsym = *it_s; + bool is_section_symbol = false; + + // A -1 value in the symbol vector indicates a local section symbol. + if (gsym == reinterpret_cast<Symbol*>(-1)) + { + is_section_symbol = true; + gsym = NULL; + } + if (first_iteration && it_v->first != NULL) { @@ -354,7 +364,7 @@ get_section_contents(bool first_iteration, // It would be nice if we could use format macros in inttypes.h // here but there are not in ISO/IEC C++ 1998. - snprintf(addend_str, sizeof(addend_str), "%llx %llx %llux", + snprintf(addend_str, sizeof(addend_str), "%llx %llx %llx", static_cast<long long>((*it_a).first), static_cast<long long>((*it_a).second), static_cast<unsigned long long>(*it_o)); @@ -367,8 +377,8 @@ get_section_contents(bool first_iteration, if (first_iteration) { // If the symbol name is available, use it. - if ((*it_s) != NULL) - buffer.append((*it_s)->name()); + if (gsym != NULL) + buffer.append(gsym->name()); // Append the addend. buffer.append(addend_str); buffer.append("@"); @@ -395,10 +405,10 @@ get_section_contents(bool first_iteration, symtab->icf()->section_to_int_map(); Icf::Uniq_secn_id_map::iterator section_id_map_it = section_id_map.find(reloc_secn); - bool is_sym_preemptible = (*it_s != NULL - && !(*it_s)->is_from_dynobj() - && !(*it_s)->is_undefined() - && (*it_s)->is_preemptible()); + bool is_sym_preemptible = (gsym != NULL + && !gsym->is_from_dynobj() + && !gsym->is_undefined() + && gsym->is_preemptible()); if (!is_sym_preemptible && section_id_map_it != section_id_map.end()) { @@ -436,27 +446,41 @@ get_section_contents(bool first_iteration, uint64_t entsize = (it_v->first)->section_entsize(it_v->second); long long offset = it_a->first; - // Handle SHT_RELA and SHT_REL addends, only one of these - // addends exists. - // Get the SHT_RELA addend. For RELA relocations, we have - // the addend from the relocation. - uint64_t reloc_addend_value = it_a->second; - - // Handle SHT_REL addends. - // For REL relocations, we need to fetch the addend from the - // section contents. - const unsigned char* reloc_addend_ptr = - contents + static_cast<unsigned long long>(*it_o); - - // Update the addend value with the SHT_REL addend if - // available. - get_rel_addend(reloc_addend_ptr, *it_addend_size, - &reloc_addend_value); - - // Ignore the addend when it is a negative value. See the - // comments in Merged_symbol_value::value in object.h. - if (reloc_addend_value < 0xffffff00) - offset = offset + reloc_addend_value; + + // Handle SHT_RELA and SHT_REL addends. Only one of these + // addends exists. When pointing to a merge section, the + // addend only matters if it's relative to a section + // symbol. In order to unambiguously identify the target + // of the relocation, the compiler (and assembler) must use + // a local non-section symbol unless Symbol+Addend does in + // fact point directly to the target. (In other words, + // a bias for a pc-relative reference or a non-zero based + // access forces the use of a local symbol, and the addend + // is used only to provide that bias.) + uint64_t reloc_addend_value = 0; + if (is_section_symbol) + { + // Get the SHT_RELA addend. For RELA relocations, + // we have the addend from the relocation. + reloc_addend_value = it_a->second; + + // Handle SHT_REL addends. + // For REL relocations, we need to fetch the addend + // from the section contents. + const unsigned char* reloc_addend_ptr = + contents + static_cast<unsigned long long>(*it_o); + + // Update the addend value with the SHT_REL addend if + // available. + get_rel_addend(reloc_addend_ptr, *it_addend_size, + &reloc_addend_value); + + // Ignore the addend when it is a negative value. + // See the comments in Merged_symbol_value::value + // in object.h. + if (reloc_addend_value < 0xffffff00) + offset = offset + reloc_addend_value; + } section_size_type secn_len; @@ -517,10 +541,10 @@ get_section_contents(bool first_iteration, } buffer.append("@"); } - else if ((*it_s) != NULL) + else if (gsym != NULL) { // If symbol name is available use that. - buffer.append((*it_s)->name()); + buffer.append(gsym->name()); // Append the addend. buffer.append(addend_str); buffer.append("@"); |