// layout.cc -- lay out output file sections for gold
-// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
-// Free Software Foundation, Inc.
+// Copyright (C) 2006-2016 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
program_name, Free_list::num_allocate_visits);
}
+// A Hash_task computes the MD5 checksum of an array of char.
+
+class Hash_task : public Task
+{
+ public:
+ Hash_task(Output_file* of,
+ size_t offset,
+ size_t size,
+ unsigned char* dst,
+ Task_token* final_blocker)
+ : of_(of), offset_(offset), size_(size), dst_(dst),
+ final_blocker_(final_blocker)
+ { }
+
+ void
+ run(Workqueue*)
+ {
+ const unsigned char* iv =
+ this->of_->get_input_view(this->offset_, this->size_);
+ md5_buffer(reinterpret_cast<const char*>(iv), this->size_, this->dst_);
+ this->of_->free_input_view(this->offset_, this->size_, iv);
+ }
+
+ Task_token*
+ is_runnable()
+ { return NULL; }
+
+ // Unblock FINAL_BLOCKER_ when done.
+ void
+ locks(Task_locker* tl)
+ { tl->add(this, this->final_blocker_); }
+
+ std::string
+ get_name() const
+ { return "Hash_task"; }
+
+ private:
+ Output_file* of_;
+ const size_t offset_;
+ const size_t size_;
+ unsigned char* const dst_;
+ Task_token* const final_blocker_;
+};
+
// Layout::Relaxation_debug_check methods.
// Check that sections and special data are in reset states.
void
Layout::Relaxation_debug_check::check_output_data_for_reset_values(
const Layout::Section_list& sections,
- const Layout::Data_list& special_outputs)
+ const Layout::Data_list& special_outputs,
+ const Layout::Data_list& relax_outputs)
{
for(Layout::Section_list::const_iterator p = sections.begin();
p != sections.end();
p != special_outputs.end();
++p)
gold_assert((*p)->address_and_file_offset_have_reset_values());
+
+ gold_assert(relax_outputs.empty());
}
// Save information of SECTIONS for checking later.
void
Layout_task_runner::run(Workqueue* workqueue, const Task* task)
{
+ // See if any of the input definitions violate the One Definition Rule.
+ // TODO: if this is too slow, do this as a task, rather than inline.
+ this->symtab_->detect_odr_violations(task, this->options_.output_file_name());
+
Layout* layout = this->layout_;
off_t file_size = layout->finalize(this->input_objects_,
this->symtab_,
section_list_(),
unattached_section_list_(),
special_output_list_(),
+ relax_output_list_(),
section_headers_(NULL),
tls_segment_(NULL),
relro_segment_(NULL),
resized_signatures_(false),
have_stabstr_section_(false),
section_ordering_specified_(false),
+ unique_segment_for_sections_specified_(false),
incremental_inputs_(NULL),
record_output_section_data_from_script_(false),
script_output_section_data_list_(),
segment_states_(NULL),
relaxation_debug_check_(NULL),
section_order_map_(),
+ section_segment_map_(),
input_section_position_(),
input_section_glob_(),
incremental_base_(NULL),
"addr", // Fission extension
// "aranges", // not used by gdb as of 7.4
"frame",
+ "gdb_scripts",
"info",
"types",
"line",
"macro",
// "pubnames", // not used by gdb as of 7.4
// "pubtypes", // not used by gdb as of 7.4
+ // "gnu_pubnames", // Fission extension
+ // "gnu_pubtypes", // Fission extension
"ranges",
"str",
+ "str_offsets",
};
// This is the minimum set of sections needed for line numbers.
// "addr", // Fission extension
// "aranges", // not used by gdb as of 7.4
// "frame",
+ // "gdb_scripts",
"info",
// "types",
"line",
// "macro",
// "pubnames", // not used by gdb as of 7.4
// "pubtypes", // not used by gdb as of 7.4
+ // "gnu_pubnames", // Fission extension
+ // "gnu_pubtypes", // Fission extension
// "ranges",
"str",
+ "str_offsets", // Fission extension
};
// These sections are the DWARF fast-lookup tables, and are not needed
{
"aranges",
"pubnames",
+ "gnu_pubnames",
"pubtypes",
+ "gnu_pubtypes",
};
// Returns whether the given debug section is in the list of
return (is_prefix_of(".zdebug", secname));
}
+std::string
+corresponding_uncompressed_section_name(std::string secname)
+{
+ gold_assert(secname[0] == '.' && secname[1] == 'z');
+ std::string ret(".");
+ ret.append(secname, 2, std::string::npos);
+ return ret;
+}
+
// Whether to include this section in the link.
template<int size, bool big_endian>
Layout::include_section(Sized_relobj_file<size, big_endian>*, const char* name,
const elfcpp::Shdr<size, big_endian>& shdr)
{
- if (shdr.get_sh_flags() & elfcpp::SHF_EXCLUDE)
+ if (!parameters->options().relocatable()
+ && (shdr.get_sh_flags() & elfcpp::SHF_EXCLUDE))
return false;
- switch (shdr.get_sh_type())
+ elfcpp::Elf_Word sh_type = shdr.get_sh_type();
+
+ if ((sh_type >= elfcpp::SHT_LOOS && sh_type <= elfcpp::SHT_HIOS)
+ || (sh_type >= elfcpp::SHT_LOPROC && sh_type <= elfcpp::SHT_HIPROC))
+ return parameters->target().should_include_section(sh_type);
+
+ switch (sh_type)
{
case elfcpp::SHT_NULL:
case elfcpp::SHT_SYMTAB:
case elfcpp::SHT_GROUP:
// If we are emitting relocations these should be handled
// elsewhere.
- gold_assert(!parameters->options().relocatable()
- && !parameters->options().emit_relocs());
+ gold_assert(!parameters->options().relocatable());
return false;
case elfcpp::SHT_PROGBITS:
return name != NULL && keep;
}
+// Clear the input section flags that should not be copied to the
+// output section.
+
+elfcpp::Elf_Xword
+Layout::get_output_section_flags(elfcpp::Elf_Xword input_section_flags)
+{
+ // Some flags in the input section should not be automatically
+ // copied to the output section.
+ input_section_flags &= ~ (elfcpp::SHF_INFO_LINK
+ | elfcpp::SHF_GROUP
+ | elfcpp::SHF_COMPRESSED
+ | elfcpp::SHF_MERGE
+ | elfcpp::SHF_STRINGS);
+
+ // We only clear the SHF_LINK_ORDER flag in for
+ // a non-relocatable link.
+ if (!parameters->options().relocatable())
+ input_section_flags &= ~elfcpp::SHF_LINK_ORDER;
+
+ return input_section_flags;
+}
+
// Pick the output section to use for section NAME, in input file
// RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
// linker created section. IS_INPUT_SECTION is true if we are
// sections to segments.
gold_assert(!is_input_section || !this->sections_are_attached_);
- // Some flags in the input section should not be automatically
- // copied to the output section.
- flags &= ~ (elfcpp::SHF_INFO_LINK
- | elfcpp::SHF_GROUP
- | elfcpp::SHF_MERGE
- | elfcpp::SHF_STRINGS);
-
- // We only clear the SHF_LINK_ORDER flag in for
- // a non-relocatable link.
- if (!parameters->options().relocatable())
- flags &= ~elfcpp::SHF_LINK_ORDER;
+ flags = this->get_output_section_flags(flags);
if (this->script_options_->saw_sections_clause())
{
// FIXME: Handle SHF_OS_NONCONFORMING somewhere.
size_t len = strlen(name);
- char* uncompressed_name = NULL;
+ std::string uncompressed_name;
// Compressed debug sections should be mapped to the corresponding
// uncompressed section.
if (is_compressed_debug_section(name))
{
- uncompressed_name = new char[len];
- uncompressed_name[0] = '.';
- gold_assert(name[0] == '.' && name[1] == 'z');
- strncpy(&uncompressed_name[1], &name[2], len - 2);
- uncompressed_name[len - 1] = '\0';
- len -= 1;
- name = uncompressed_name;
+ uncompressed_name =
+ corresponding_uncompressed_section_name(std::string(name, len));
+ name = uncompressed_name.c_str();
+ len = uncompressed_name.length();
}
// Turn NAME from the name of the input section into the name of the
Stringpool::Key name_key;
name = this->namepool_.add_with_length(name, len, true, &name_key);
- if (uncompressed_name != NULL)
- delete[] uncompressed_name;
-
// Find or make the output section. The output section is selected
// based on the section name, type, and flags.
return this->get_output_section(name, name_key, type, flags, order, is_relro);
return os;
}
+// Return the index by which an input section should be ordered. This
+// is used to sort some .text sections, for compatibility with GNU ld.
+
+int
+Layout::special_ordering_of_input_section(const char* name)
+{
+ // The GNU linker has some special handling for some sections that
+ // wind up in the .text section. Sections that start with these
+ // prefixes must appear first, and must appear in the order listed
+ // here.
+ static const char* const text_section_sort[] =
+ {
+ ".text.unlikely",
+ ".text.exit",
+ ".text.startup",
+ ".text.hot"
+ };
+
+ for (size_t i = 0;
+ i < sizeof(text_section_sort) / sizeof(text_section_sort[0]);
+ i++)
+ if (is_prefix_of(text_section_sort[i], name))
+ return i;
+
+ return -1;
+}
+
// Return the output section to use for input section SHNDX, with name
// NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
// index of a relocation section which applies to this section, or 0
if (parameters->options().relocatable()
&& (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0)
{
+ // Some flags in the input section should not be automatically
+ // copied to the output section.
+ elfcpp::Elf_Xword flags = (shdr.get_sh_flags()
+ & ~ elfcpp::SHF_COMPRESSED);
name = this->namepool_.add(name, true, NULL);
- os = this->make_output_section(name, sh_type, shdr.get_sh_flags(),
+ os = this->make_output_section(name, sh_type, flags,
ORDER_INVALID, false);
}
else
{
- os = this->choose_output_section(object, name, sh_type,
- shdr.get_sh_flags(), true,
- ORDER_INVALID, false);
+ // Plugins can choose to place one or more subsets of sections in
+ // unique segments and this is done by mapping these section subsets
+ // to unique output sections. Check if this section needs to be
+ // remapped to a unique output section.
+ Section_segment_map::iterator it
+ = this->section_segment_map_.find(Const_section_id(object, shndx));
+ if (it == this->section_segment_map_.end())
+ {
+ os = this->choose_output_section(object, name, sh_type,
+ shdr.get_sh_flags(), true,
+ ORDER_INVALID, false);
+ }
+ else
+ {
+ // We know the name of the output section, directly call
+ // get_output_section here by-passing choose_output_section.
+ elfcpp::Elf_Xword flags
+ = this->get_output_section_flags(shdr.get_sh_flags());
+
+ const char* os_name = it->second->name;
+ Stringpool::Key name_key;
+ os_name = this->namepool_.add(os_name, true, &name_key);
+ os = this->get_output_section(os_name, name_key, sh_type, flags,
+ ORDER_INVALID, false);
+ if (!os->is_unique_segment())
+ {
+ os->set_is_unique_segment();
+ os->set_extra_segment_flags(it->second->flags);
+ os->set_segment_alignment(it->second->align);
+ }
+ }
if (os == NULL)
return NULL;
}
|| strcmp(name, ".dtors") == 0))))
os->set_must_sort_attached_input_sections();
+ // By default the GNU linker sorts some special text sections ahead
+ // of others. We are compatible.
+ if (parameters->options().text_reorder()
+ && !this->script_options_->saw_sections_clause()
+ && !this->is_section_ordering_specified()
+ && !parameters->options().relocatable()
+ && Layout::special_ordering_of_input_section(name) >= 0)
+ os->set_must_sort_attached_input_sections();
+
// If this is a .ctors or .ctors.* section being mapped to a
// .init_array section, or a .dtors or .dtors.* section being mapped
// to a .fini_array section, we will need to reverse the words if
return os;
}
+// Maps section SECN to SEGMENT s.
+void
+Layout::insert_section_segment_map(Const_section_id secn,
+ Unique_segment_info *s)
+{
+ gold_assert(this->unique_segment_for_sections_specified_);
+ this->section_segment_map_[secn] = s;
+}
+
// Handle a relocation section when doing a relocatable link.
template<int size, bool big_endian>
elfcpp::Elf_Xword orig_flags = os->flags();
- if (!parameters->incremental()
- && this->eh_frame_data_->add_ehframe_input_section(object,
- symbols,
- symbols_size,
- symbol_names,
- symbol_names_size,
- shndx,
- reloc_shndx,
- reloc_type))
+ Eh_frame::Eh_frame_section_disposition disp =
+ Eh_frame::EH_UNRECOGNIZED_SECTION;
+ if (!parameters->incremental())
+ {
+ disp = this->eh_frame_data_->add_ehframe_input_section(object,
+ symbols,
+ symbols_size,
+ symbol_names,
+ symbol_names_size,
+ shndx,
+ reloc_shndx,
+ reloc_type);
+ }
+
+ if (disp == Eh_frame::EH_OPTIMIZABLE_SECTION)
{
os->update_flags_for_input_section(shdr.get_sh_flags());
os->set_order(ORDER_RELRO);
}
- // We found a .eh_frame section we are going to optimize, so now
- // we can add the set of optimized sections to the output
- // section. We need to postpone adding this until we've found a
- // section we can optimize so that the .eh_frame section in
- // crtbegin.o winds up at the start of the output section.
- if (!this->added_eh_frame_data_)
- {
- os->add_output_section_data(this->eh_frame_data_);
- this->added_eh_frame_data_ = true;
- }
*off = -1;
+ return os;
}
- else
+
+ if (disp == Eh_frame::EH_END_MARKER_SECTION && !this->added_eh_frame_data_)
{
- // We couldn't handle this .eh_frame section for some reason.
- // Add it as a normal section.
- bool saw_sections_clause = this->script_options_->saw_sections_clause();
- *off = os->add_input_section(this, object, shndx, ".eh_frame", shdr,
- reloc_shndx, saw_sections_clause);
- this->have_added_input_section_ = true;
+ // We found the end marker section, so now we can add the set of
+ // optimized sections to the output section. We need to postpone
+ // adding this until we've found a section we can optimize so that
+ // the .eh_frame section in crtbeginT.o winds up at the start of
+ // the output section.
+ os->add_output_section_data(this->eh_frame_data_);
+ this->added_eh_frame_data_ = true;
+ }
- if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))
- != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)))
- os->set_order(this->default_section_order(os, false));
- }
+ // We couldn't handle this .eh_frame section for some reason.
+ // Add it as a normal section.
+ bool saw_sections_clause = this->script_options_->saw_sections_clause();
+ *off = os->add_input_section(this, object, shndx, ".eh_frame", shdr,
+ reloc_shndx, saw_sections_clause);
+ this->have_added_input_section_ = true;
+
+ if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))
+ != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)))
+ os->set_order(this->default_section_order(os, false));
return os;
}
+void
+Layout::finalize_eh_frame_section()
+{
+ // If we never found an end marker section, we need to add the
+ // optimized eh sections to the output section now.
+ if (!parameters->incremental()
+ && this->eh_frame_section_ != NULL
+ && !this->added_eh_frame_data_)
+ {
+ this->eh_frame_section_->add_output_section_data(this->eh_frame_data_);
+ this->added_eh_frame_data_ = true;
+ }
+}
+
// Create and return the magic .eh_frame section. Create
// .eh_frame_hdr also if appropriate. OBJECT is the object with the
// input .eh_frame section; it may be NULL.
|| strcmp(name, ".dtors") == 0))))
os->set_may_sort_attached_input_sections();
+ // The GNU linker by default sorts .text.{unlikely,exit,startup,hot}
+ // sections before other .text sections. We are compatible. We
+ // need to know that this might happen before we attach any input
+ // sections.
+ if (parameters->options().text_reorder()
+ && !this->script_options_->saw_sections_clause()
+ && !this->is_section_ordering_specified()
+ && !parameters->options().relocatable()
+ && strcmp(name, ".text") == 0)
+ os->set_may_sort_attached_input_sections();
+
+ // GNU linker sorts section by name with --sort-section=name.
+ if (strcmp(parameters->options().sort_section(), "name") == 0)
+ os->set_must_sort_attached_input_sections();
+
// Check for .stab*str sections, as .stab* sections need to link to
// them.
if (type == elfcpp::SHT_STRTAB
elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
+ // If this output section's segment has extra flags that need to be set,
+ // coming from a linker plugin, do that.
+ seg_flags |= os->extra_segment_flags();
+
// Check for --section-start.
uint64_t addr;
bool is_address_set = parameters->options().section_start(os->name(), &addr);
// have to use a linker script.
Segment_list::const_iterator p;
- for (p = this->segment_list_.begin();
- p != this->segment_list_.end();
- ++p)
+ if (!os->is_unique_segment())
{
- if ((*p)->type() != elfcpp::PT_LOAD)
- continue;
- if (!parameters->options().omagic()
- && ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W))
- continue;
- if ((target->isolate_execinstr() || parameters->options().rosegment())
- && ((*p)->flags() & elfcpp::PF_X) != (seg_flags & elfcpp::PF_X))
- continue;
- // If -Tbss was specified, we need to separate the data and BSS
- // segments.
- if (parameters->options().user_set_Tbss())
+ for (p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
{
- if ((os->type() == elfcpp::SHT_NOBITS)
- == (*p)->has_any_data_sections())
+ if ((*p)->type() != elfcpp::PT_LOAD)
continue;
- }
- if (os->is_large_data_section() && !(*p)->is_large_data_segment())
- continue;
-
- if (is_address_set)
- {
- if ((*p)->are_addresses_set())
+ if ((*p)->is_unique_segment())
+ continue;
+ if (!parameters->options().omagic()
+ && ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W))
+ continue;
+ if ((target->isolate_execinstr() || parameters->options().rosegment())
+ && ((*p)->flags() & elfcpp::PF_X) != (seg_flags & elfcpp::PF_X))
+ continue;
+ // If -Tbss was specified, we need to separate the data and BSS
+ // segments.
+ if (parameters->options().user_set_Tbss())
+ {
+ if ((os->type() == elfcpp::SHT_NOBITS)
+ == (*p)->has_any_data_sections())
+ continue;
+ }
+ if (os->is_large_data_section() && !(*p)->is_large_data_segment())
continue;
- (*p)->add_initial_output_data(os);
- (*p)->update_flags_for_output_section(seg_flags);
- (*p)->set_addresses(addr, addr);
+ if (is_address_set)
+ {
+ if ((*p)->are_addresses_set())
+ continue;
+
+ (*p)->add_initial_output_data(os);
+ (*p)->update_flags_for_output_section(seg_flags);
+ (*p)->set_addresses(addr, addr);
+ break;
+ }
+
+ (*p)->add_output_section_to_load(this, os, seg_flags);
break;
}
-
- (*p)->add_output_section_to_load(this, os, seg_flags);
- break;
}
- if (p == this->segment_list_.end())
+ if (p == this->segment_list_.end()
+ || os->is_unique_segment())
{
Output_segment* oseg = this->make_output_segment(elfcpp::PT_LOAD,
seg_flags);
oseg->add_output_section_to_load(this, os, seg_flags);
if (is_address_set)
oseg->set_addresses(addr, addr);
+ // Check if segment should be marked unique. For segments marked
+ // unique by linker plugins, set the new alignment if specified.
+ if (os->is_unique_segment())
+ {
+ oseg->set_is_unique_segment();
+ if (os->segment_alignment() != 0)
+ oseg->set_minimum_p_align(os->segment_alignment());
+ }
}
// If we see a loadable SHT_NOTE section, we create a PT_NOTE
if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
{
this->input_requires_executable_stack_ = true;
- if (parameters->options().warn_execstack()
- || parameters->options().is_stack_executable())
+ if (parameters->options().warn_execstack())
gold_warning(_("%s: requires executable stack"),
obj->name().c_str());
}
++p)
delete *p;
this->script_output_section_data_list_.clear();
+
+ // Special-case fill output objects are recreated each time through
+ // the relaxation loop.
+ this->reset_relax_output();
+}
+
+void
+Layout::reset_relax_output()
+{
+ for (Data_list::const_iterator p = this->relax_output_list_.begin();
+ p != this->relax_output_list_.end();
+ ++p)
+ delete *p;
+ this->relax_output_list_.clear();
}
// Prepare for relaxation.
if (is_debugging_enabled(DEBUG_RELAXATION))
this->relaxation_debug_check_->check_output_data_for_reset_values(
- this->section_list_, this->special_output_list_);
+ this->section_list_, this->special_output_list_,
+ this->relax_output_list_);
// Also enable recording of output section data from scripts.
this->record_output_section_data_from_script_ = true;
}
+// If the user set the address of the text segment, that may not be
+// compatible with putting the segment headers and file headers into
+// that segment. For isolate_execinstr() targets, it's the rodata
+// segment rather than text where we might put the headers.
+static inline bool
+load_seg_unusable_for_headers(const Target* target)
+{
+ const General_options& options = parameters->options();
+ if (target->isolate_execinstr())
+ return (options.user_set_Trodata_segment()
+ && options.Trodata_segment() % target->abi_pagesize() != 0);
+ else
+ return (options.user_set_Ttext()
+ && options.Ttext() % target->abi_pagesize() != 0);
+}
+
// Relaxation loop body: If target has no relaxation, this runs only once
// Otherwise, the target relaxation hook is called at the end of
// each iteration. If the hook returns true, it means re-layout of
!= General_options::OBJECT_FORMAT_ELF)
load_seg = NULL;
- // If the user set the address of the text segment, that may not be
- // compatible with putting the segment headers and file headers into
- // that segment.
- if (parameters->options().user_set_Ttext()
- && parameters->options().Ttext() % target->common_pagesize() != 0)
+ if (load_seg_unusable_for_headers(target))
{
load_seg = NULL;
phdr_seg = NULL;
// If there is a load segment that contains the file and program headers,
// provide a symbol __ehdr_start pointing there.
// A program can use this to examine itself robustly.
- if (load_seg != NULL)
- symtab->define_in_output_segment("__ehdr_start", NULL,
- Symbol_table::PREDEFINED, load_seg, 0, 0,
- elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
- elfcpp::STV_DEFAULT, 0,
- Symbol::SEGMENT_START, true);
+ Symbol *ehdr_start = symtab->lookup("__ehdr_start");
+ if (ehdr_start != NULL && ehdr_start->is_predefined())
+ {
+ if (load_seg != NULL)
+ ehdr_start->set_output_segment(load_seg, Symbol::SEGMENT_START);
+ else
+ ehdr_start->set_undefined();
+ }
// Set the file offsets of all the non-data sections we've seen so
// far which don't have to wait for the input sections. We need
{
bool is_stack_executable;
if (parameters->options().is_execstack_set())
- is_stack_executable = parameters->options().is_stack_executable();
+ {
+ is_stack_executable = parameters->options().is_stack_executable();
+ if (!is_stack_executable
+ && this->input_requires_executable_stack_
+ && parameters->options().warn_execstack())
+ gold_warning(_("one or more inputs require executable stack, "
+ "but -z noexecstack was given"));
+ }
else if (!this->input_with_gnu_stack_note_)
return;
else
std::string desc;
if (strcmp(style, "md5") == 0)
descsz = 128 / 8;
- else if (strcmp(style, "sha1") == 0)
+ else if ((strcmp(style, "sha1") == 0) || (strcmp(style, "tree") == 0))
descsz = 160 / 8;
else if (strcmp(style, "uuid") == 0)
{
// The order of non-PT_LOAD segments is unimportant. We simply sort
// by the numeric segment type and flags values. There should not
- // be more than one segment with the same type and flags.
+ // be more than one segment with the same type and flags, except
+ // when a linker script specifies such.
if (type1 != elfcpp::PT_LOAD)
{
if (type1 != type2)
return type1 < type2;
- gold_assert(flags1 != flags2);
+ gold_assert(flags1 != flags2
+ || this->script_options_->saw_phdrs_clause());
return flags1 < flags2;
}
// We shouldn't get here--we shouldn't create segments which we
// can't distinguish. Unless of course we are using a weird linker
- // script or overlapping --section-start options.
+ // script or overlapping --section-start options. We could also get
+ // here if plugins want unique segments for subsets of sections.
gold_assert(this->script_options_->saw_phdrs_clause()
- || parameters->options().any_section_start());
+ || parameters->options().any_section_start()
+ || this->is_unique_segment_for_sections_specified());
return false;
}
return aligned_off;
}
+// On targets where the text segment contains only executable code,
+// a non-executable segment is never the text segment.
+
+static inline bool
+is_text_segment(const Target* target, const Output_segment* seg)
+{
+ elfcpp::Elf_Xword flags = seg->flags();
+ if ((flags & elfcpp::PF_W) != 0)
+ return false;
+ if ((flags & elfcpp::PF_X) == 0)
+ return !target->isolate_execinstr();
+ return true;
+}
+
// Set the file offsets of all the segments, and all the sections they
// contain. They have all been created. LOAD_SEG must be be laid out
// first. Return the offset of the data to follow.
addr = (*p)->paddr();
}
else if (parameters->options().user_set_Ttext()
- && ((*p)->flags() & elfcpp::PF_W) == 0)
+ && (parameters->options().omagic()
+ || is_text_segment(target, *p)))
{
are_addresses_set = true;
}
+ else if (parameters->options().user_set_Trodata_segment()
+ && ((*p)->flags() & (elfcpp::PF_W | elfcpp::PF_X)) == 0)
+ {
+ addr = parameters->options().Trodata_segment();
+ are_addresses_set = true;
+ }
else if (parameters->options().user_set_Tdata()
&& ((*p)->flags() & elfcpp::PF_W) != 0
&& (!parameters->options().user_set_Tbss()
if (!parameters->options().nmagic()
&& !parameters->options().omagic())
- (*p)->set_minimum_p_align(common_pagesize);
+ (*p)->set_minimum_p_align(abi_pagesize);
if (!are_addresses_set)
{
// put them on different pages in memory. We will revisit this
// decision once we know the size of the segment.
- addr = align_address(addr, (*p)->maximum_alignment());
+ uint64_t max_align = (*p)->maximum_alignment();
+ if (max_align > abi_pagesize)
+ addr = align_address(addr, max_align);
aligned_addr = addr;
if (load_seg == *p)
// If the target wants a fixed minimum distance from the
// text segment to the read-only segment, move up now.
- uint64_t min_addr = start_addr + target->rosegment_gap();
+ uint64_t min_addr =
+ start_addr + (parameters->options().user_set_rosegment_gap()
+ ? parameters->options().rosegment_gap()
+ : target->rosegment_gap());
if (addr < min_addr)
addr = min_addr;
if (!parameters->options().nmagic()
&& !parameters->options().omagic())
- off = align_file_offset(off, addr, abi_pagesize);
+ {
+ // Here we are also taking care of the case when
+ // the maximum segment alignment is larger than the page size.
+ off = align_file_offset(off, addr,
+ std::max(abi_pagesize,
+ (*p)->maximum_alignment()));
+ }
else
{
// This is -N or -n with a section script which prevents
unsigned int shndx_hold = *pshndx;
bool has_relro = false;
- uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
+ uint64_t new_addr = (*p)->set_section_addresses(target, this,
+ false, addr,
&increase_relro,
&has_relro,
&off, pshndx);
*pshndx = shndx_hold;
addr = align_address(aligned_addr, common_pagesize);
addr = align_address(addr, (*p)->maximum_alignment());
+ if ((addr & (abi_pagesize - 1)) != 0)
+ addr = addr + abi_pagesize;
off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
off = align_file_offset(off, addr, abi_pagesize);
increase_relro = 0;
has_relro = false;
- new_addr = (*p)->set_section_addresses(this, true, addr,
+ new_addr = (*p)->set_section_addresses(target, this,
+ true, addr,
&increase_relro,
&has_relro,
&off, pshndx);
// so they land after the segments starting at LOAD_SEG.
off = align_file_offset(off, 0, target->abi_pagesize());
+ this->reset_relax_output();
+
for (Segment_list::iterator p = this->segment_list_.begin();
*p != load_seg;
++p)
bool has_relro = false;
const uint64_t old_addr = (*p)->vaddr();
const uint64_t old_end = old_addr + (*p)->memsz();
- uint64_t new_addr = (*p)->set_section_addresses(this, true,
- old_addr,
+ uint64_t new_addr = (*p)->set_section_addresses(target, this,
+ true, old_addr,
&increase_relro,
&has_relro,
&off,
(*p)->set_address(0);
(*p)->set_file_offset(off);
(*p)->finalize_data_size();
- off += (*p)->data_size();
+ if ((*p)->type() != elfcpp::SHT_NOBITS)
+ off += (*p)->data_size();
(*p)->set_out_shndx(*pshndx);
++*pshndx;
false,
ORDER_DYNAMIC_LINKER,
false);
-
+ *pdynstr = dynstr;
if (dynstr != NULL)
{
Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
odyn->add_section_address(elfcpp::DT_STRTAB, dynstr);
odyn->add_section_size(elfcpp::DT_STRSZ, dynstr);
}
-
- *pdynstr = dynstr;
}
- // Create the hash tables.
+ // Create the hash tables. The Gnu-style hash table must be
+ // built first, because it changes the order of the symbols
+ // in the dynamic symbol table.
- if (strcmp(parameters->options().hash_style(), "sysv") == 0
+ if (strcmp(parameters->options().hash_style(), "gnu") == 0
|| strcmp(parameters->options().hash_style(), "both") == 0)
{
unsigned char* phash;
unsigned int hashlen;
- Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
+ Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount,
&phash, &hashlen);
Output_section* hashsec =
- this->choose_output_section(NULL, ".hash", elfcpp::SHT_HASH,
+ this->choose_output_section(NULL, ".gnu.hash", elfcpp::SHT_GNU_HASH,
elfcpp::SHF_ALLOC, false,
ORDER_DYNAMIC_LINKER, false);
{
if (dynsym != NULL)
hashsec->set_link_section(dynsym);
- hashsec->set_entsize(4);
- }
- if (odyn != NULL)
- odyn->add_section_address(elfcpp::DT_HASH, hashsec);
+ // For a 64-bit target, the entries in .gnu.hash do not have
+ // a uniform size, so we only set the entry size for a
+ // 32-bit target.
+ if (parameters->target().get_size() == 32)
+ hashsec->set_entsize(4);
+
+ if (odyn != NULL)
+ odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec);
+ }
}
- if (strcmp(parameters->options().hash_style(), "gnu") == 0
+ if (strcmp(parameters->options().hash_style(), "sysv") == 0
|| strcmp(parameters->options().hash_style(), "both") == 0)
{
unsigned char* phash;
unsigned int hashlen;
- Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount,
+ Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
&phash, &hashlen);
Output_section* hashsec =
- this->choose_output_section(NULL, ".gnu.hash", elfcpp::SHT_GNU_HASH,
+ this->choose_output_section(NULL, ".hash", elfcpp::SHT_HASH,
elfcpp::SHF_ALLOC, false,
ORDER_DYNAMIC_LINKER, false);
{
if (dynsym != NULL)
hashsec->set_link_section(dynsym);
-
- // For a 64-bit target, the entries in .gnu.hash do not have
- // a uniform size, so we only set the entry size for a
- // 32-bit target.
- if (parameters->target().get_size() == 32)
- hashsec->set_entsize(4);
-
- if (odyn != NULL)
- odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec);
+ hashsec->set_entsize(parameters->target().hash_entry_size() / 8);
}
+
+ if (odyn != NULL)
+ odyn->add_section_address(elfcpp::DT_HASH, hashsec);
}
}
}
}
+void
+Layout::add_target_specific_dynamic_tag(elfcpp::DT tag, unsigned int val)
+{
+ Output_data_dynamic* odyn = this->dynamic_data_;
+ if (odyn == NULL)
+ return;
+ odyn->add_constant(tag, val);
+}
+
// Finish the .dynamic section and PT_DYNAMIC segment.
void
}
}
- odyn->add_string(elfcpp::DT_RPATH, rpath_val);
- if (parameters->options().enable_new_dtags())
+ if (!parameters->options().enable_new_dtags())
+ odyn->add_string(elfcpp::DT_RPATH, rpath_val);
+ else
odyn->add_string(elfcpp::DT_RUNPATH, rpath_val);
}
flags |= elfcpp::DF_STATIC_TLS;
if (parameters->options().origin())
flags |= elfcpp::DF_ORIGIN;
- if (parameters->options().Bsymbolic())
+ if (parameters->options().Bsymbolic()
+ && !parameters->options().have_dynamic_list())
{
flags |= elfcpp::DF_SYMBOLIC;
// Add DT_SYMBOLIC for compatibility with older loaders.
odyn->add_constant(elfcpp::DT_FLAGS, flags);
flags = 0;
+ if (parameters->options().global())
+ flags |= elfcpp::DF_1_GLOBAL;
if (parameters->options().initfirst())
flags |= elfcpp::DF_1_INITFIRST;
if (parameters->options().interpose())
section_list->push_back(*p);
}
+// Store the executable sections into the section list.
+
+void
+Layout::get_executable_sections(Section_list* section_list) const
+{
+ for (Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ if (((*p)->flags() & (elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR))
+ == (elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR))
+ section_list->push_back(*p);
+}
+
// Create an output segment.
Output_segment*
p != this->special_output_list_.end();
++p)
(*p)->write(of);
+
+ // Write out the Output_data which are not in an Output_section
+ // and are regenerated in each iteration of relaxation.
+ for (Data_list::const_iterator p = this->relax_output_list_.begin();
+ p != this->relax_output_list_.end();
+ ++p)
+ (*p)->write(of);
}
// Write out the Output_sections which can only be written after the
this->section_headers_->write(of);
}
-// If the build ID requires computing a checksum, do so here, and
-// write it out. We compute a checksum over the entire file because
-// that is simplest.
+// If a tree-style build ID was requested, the parallel part of that computation
+// is already done, and the final hash-of-hashes is computed here. For other
+// types of build IDs, all the work is done here.
void
-Layout::write_build_id(Output_file* of) const
+Layout::write_build_id(Output_file* of, unsigned char* array_of_hashes,
+ size_t size_of_hashes) const
{
if (this->build_id_note_ == NULL)
return;
- const unsigned char* iv = of->get_input_view(0, this->output_file_size_);
-
unsigned char* ov = of->get_output_view(this->build_id_note_->offset(),
this->build_id_note_->data_size());
- const char* style = parameters->options().build_id();
- if (strcmp(style, "sha1") == 0)
+ if (array_of_hashes == NULL)
{
- sha1_ctx ctx;
- sha1_init_ctx(&ctx);
- sha1_process_bytes(iv, this->output_file_size_, &ctx);
- sha1_finish_ctx(&ctx, ov);
+ const size_t output_file_size = this->output_file_size();
+ const unsigned char* iv = of->get_input_view(0, output_file_size);
+ const char* style = parameters->options().build_id();
+
+ // If we get here with style == "tree" then the output must be
+ // too small for chunking, and we use SHA-1 in that case.
+ if ((strcmp(style, "sha1") == 0) || (strcmp(style, "tree") == 0))
+ sha1_buffer(reinterpret_cast<const char*>(iv), output_file_size, ov);
+ else if (strcmp(style, "md5") == 0)
+ md5_buffer(reinterpret_cast<const char*>(iv), output_file_size, ov);
+ else
+ gold_unreachable();
+
+ of->free_input_view(0, output_file_size, iv);
}
- else if (strcmp(style, "md5") == 0)
+ else
{
- md5_ctx ctx;
- md5_init_ctx(&ctx);
- md5_process_bytes(iv, this->output_file_size_, &ctx);
- md5_finish_ctx(&ctx, ov);
+ // Non-overlapping substrings of the output file have been hashed.
+ // Compute SHA-1 hash of the hashes.
+ sha1_buffer(reinterpret_cast<const char*>(array_of_hashes),
+ size_of_hashes, ov);
+ delete[] array_of_hashes;
}
- else
- gold_unreachable();
of->write_output_view(this->build_id_note_->offset(),
this->build_id_note_->data_size(),
ov);
-
- of->free_input_view(0, this->output_file_size_, iv);
}
// Write out a binary file. This is called after the link is
p != this->segment_list_.end();
++p)
(*p)->print_sections_to_mapfile(mapfile);
+ for (Section_list::const_iterator p = this->unattached_section_list_.begin();
+ p != this->unattached_section_list_.end();
+ ++p)
+ (*p)->print_to_mapfile(mapfile);
}
// Print statistical information to stderr. This is used for --stats.
Write_sections_task::locks(Task_locker* tl)
{
tl->add(this, this->output_sections_blocker_);
+ if (this->input_sections_blocker_ != NULL)
+ tl->add(this, this->input_sections_blocker_);
tl->add(this, this->final_blocker_);
}
this->layout_->write_sections_after_input_sections(this->of_);
}
+// Build IDs can be computed as a "flat" sha1 or md5 of a string of bytes,
+// or as a "tree" where each chunk of the string is hashed and then those
+// hashes are put into a (much smaller) string which is hashed with sha1.
+// We compute a checksum over the entire file because that is simplest.
+
+void
+Build_id_task_runner::run(Workqueue* workqueue, const Task*)
+{
+ Task_token* post_hash_tasks_blocker = new Task_token(true);
+ const Layout* layout = this->layout_;
+ Output_file* of = this->of_;
+ const size_t filesize = (layout->output_file_size() <= 0 ? 0
+ : static_cast<size_t>(layout->output_file_size()));
+ unsigned char* array_of_hashes = NULL;
+ size_t size_of_hashes = 0;
+
+ if (strcmp(this->options_->build_id(), "tree") == 0
+ && this->options_->build_id_chunk_size_for_treehash() > 0
+ && filesize > 0
+ && (filesize >= this->options_->build_id_min_file_size_for_treehash()))
+ {
+ static const size_t MD5_OUTPUT_SIZE_IN_BYTES = 16;
+ const size_t chunk_size =
+ this->options_->build_id_chunk_size_for_treehash();
+ const size_t num_hashes = ((filesize - 1) / chunk_size) + 1;
+ post_hash_tasks_blocker->add_blockers(num_hashes);
+ size_of_hashes = num_hashes * MD5_OUTPUT_SIZE_IN_BYTES;
+ array_of_hashes = new unsigned char[size_of_hashes];
+ unsigned char *dst = array_of_hashes;
+ for (size_t i = 0, src_offset = 0; i < num_hashes;
+ i++, dst += MD5_OUTPUT_SIZE_IN_BYTES, src_offset += chunk_size)
+ {
+ size_t size = std::min(chunk_size, filesize - src_offset);
+ workqueue->queue(new Hash_task(of,
+ src_offset,
+ size,
+ dst,
+ post_hash_tasks_blocker));
+ }
+ }
+
+ // Queue the final task to write the build id and close the output file.
+ workqueue->queue(new Task_function(new Close_task_runner(this->options_,
+ layout,
+ of,
+ array_of_hashes,
+ size_of_hashes),
+ post_hash_tasks_blocker,
+ "Task_function Close_task_runner"));
+}
+
// Close_task_runner methods.
-// Run the task--close the file.
+// Finish up the build ID computation, if necessary, and write a binary file,
+// if necessary. Then close the output file.
void
Close_task_runner::run(Workqueue*, const Task*)
{
- // If we need to compute a checksum for the BUILD if, we do so here.
- this->layout_->write_build_id(this->of_);
+ // At this point the multi-threaded part of the build ID computation,
+ // if any, is done. See Build_id_task_runner.
+ this->layout_->write_build_id(this->of_, this->array_of_hashes_,
+ this->size_of_hashes_);
// If we've been asked to create a binary file, we do so here.
if (this->options_->oformat_enum() != General_options::OBJECT_FORMAT_ELF)