// layout.cc -- lay out output file sections for gold
-// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include <cstring>
#include <algorithm>
#include <iostream>
+#include <fstream>
#include <utility>
#include <fcntl.h>
+#include <fnmatch.h>
#include <unistd.h>
#include "libiberty.h"
#include "md5.h"
namespace gold
{
+// Class Free_list.
+
+// The total number of free lists used.
+unsigned int Free_list::num_lists = 0;
+// The total number of free list nodes used.
+unsigned int Free_list::num_nodes = 0;
+// The total number of calls to Free_list::remove.
+unsigned int Free_list::num_removes = 0;
+// The total number of nodes visited during calls to Free_list::remove.
+unsigned int Free_list::num_remove_visits = 0;
+// The total number of calls to Free_list::allocate.
+unsigned int Free_list::num_allocates = 0;
+// The total number of nodes visited during calls to Free_list::allocate.
+unsigned int Free_list::num_allocate_visits = 0;
+
+// Initialize the free list. Creates a single free list node that
+// describes the entire region of length LEN. If EXTEND is true,
+// allocate() is allowed to extend the region beyond its initial
+// length.
+
+void
+Free_list::init(off_t len, bool extend)
+{
+ this->list_.push_front(Free_list_node(0, len));
+ this->last_remove_ = this->list_.begin();
+ this->extend_ = extend;
+ this->length_ = len;
+ ++Free_list::num_lists;
+ ++Free_list::num_nodes;
+}
+
+// Remove a chunk from the free list. Because we start with a single
+// node that covers the entire section, and remove chunks from it one
+// at a time, we do not need to coalesce chunks or handle cases that
+// span more than one free node. We expect to remove chunks from the
+// free list in order, and we expect to have only a few chunks of free
+// space left (corresponding to files that have changed since the last
+// incremental link), so a simple linear list should provide sufficient
+// performance.
+
+void
+Free_list::remove(off_t start, off_t end)
+{
+ if (start == end)
+ return;
+ gold_assert(start < end);
+
+ ++Free_list::num_removes;
+
+ Iterator p = this->last_remove_;
+ if (p->start_ > start)
+ p = this->list_.begin();
+
+ for (; p != this->list_.end(); ++p)
+ {
+ ++Free_list::num_remove_visits;
+ // Find a node that wholly contains the indicated region.
+ if (p->start_ <= start && p->end_ >= end)
+ {
+ // Case 1: the indicated region spans the whole node.
+ // Add some fuzz to avoid creating tiny free chunks.
+ if (p->start_ + 3 >= start && p->end_ <= end + 3)
+ p = this->list_.erase(p);
+ // Case 2: remove a chunk from the start of the node.
+ else if (p->start_ + 3 >= start)
+ p->start_ = end;
+ // Case 3: remove a chunk from the end of the node.
+ else if (p->end_ <= end + 3)
+ p->end_ = start;
+ // Case 4: remove a chunk from the middle, and split
+ // the node into two.
+ else
+ {
+ Free_list_node newnode(p->start_, start);
+ p->start_ = end;
+ this->list_.insert(p, newnode);
+ ++Free_list::num_nodes;
+ }
+ this->last_remove_ = p;
+ return;
+ }
+ }
+
+ // Did not find a node containing the given chunk. This could happen
+ // because a small chunk was already removed due to the fuzz.
+ gold_debug(DEBUG_INCREMENTAL,
+ "Free_list::remove(%d,%d) not found",
+ static_cast<int>(start), static_cast<int>(end));
+}
+
+// Allocate a chunk of size LEN from the free list. Returns -1ULL
+// if a sufficiently large chunk of free space is not found.
+// We use a simple first-fit algorithm.
+
+off_t
+Free_list::allocate(off_t len, uint64_t align, off_t minoff)
+{
+ gold_debug(DEBUG_INCREMENTAL,
+ "Free_list::allocate(%08lx, %d, %08lx)",
+ static_cast<long>(len), static_cast<int>(align),
+ static_cast<long>(minoff));
+ if (len == 0)
+ return align_address(minoff, align);
+
+ ++Free_list::num_allocates;
+
+ for (Iterator p = this->list_.begin(); p != this->list_.end(); ++p)
+ {
+ ++Free_list::num_allocate_visits;
+ off_t start = p->start_ > minoff ? p->start_ : minoff;
+ start = align_address(start, align);
+ off_t end = start + len;
+ if (end <= p->end_)
+ {
+ if (p->start_ + 3 >= start && p->end_ <= end + 3)
+ this->list_.erase(p);
+ else if (p->start_ + 3 >= start)
+ p->start_ = end;
+ else if (p->end_ <= end + 3)
+ p->end_ = start;
+ else
+ {
+ Free_list_node newnode(p->start_, start);
+ p->start_ = end;
+ this->list_.insert(p, newnode);
+ ++Free_list::num_nodes;
+ }
+ return start;
+ }
+ }
+ return -1;
+}
+
+// Dump the free list (for debugging).
+void
+Free_list::dump()
+{
+ gold_info("Free list:\n start end length\n");
+ for (Iterator p = this->list_.begin(); p != this->list_.end(); ++p)
+ gold_info(" %08lx %08lx %08lx", static_cast<long>(p->start_),
+ static_cast<long>(p->end_),
+ static_cast<long>(p->end_ - p->start_));
+}
+
+// Print the statistics for the free lists.
+void
+Free_list::print_stats()
+{
+ fprintf(stderr, _("%s: total free lists: %u\n"),
+ program_name, Free_list::num_lists);
+ fprintf(stderr, _("%s: total free list nodes: %u\n"),
+ program_name, Free_list::num_nodes);
+ fprintf(stderr, _("%s: calls to Free_list::remove: %u\n"),
+ program_name, Free_list::num_removes);
+ fprintf(stderr, _("%s: nodes visited: %u\n"),
+ program_name, Free_list::num_remove_visits);
+ fprintf(stderr, _("%s: calls to Free_list::allocate: %u\n"),
+ program_name, Free_list::num_allocates);
+ fprintf(stderr, _("%s: nodes visited: %u\n"),
+ program_name, Free_list::num_allocate_visits);
+}
+
// Layout::Relaxation_debug_check methods.
// Check that sections and special data are in reset states.
this->layout_->print_to_mapfile(this->mapfile_);
}
- Output_file* of = new Output_file(parameters->options().output_file_name());
- if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
- of->set_is_temporary();
- of->open(file_size);
+ Output_file* of;
+ if (this->layout_->incremental_base() == NULL)
+ {
+ of = new Output_file(parameters->options().output_file_name());
+ if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
+ of->set_is_temporary();
+ of->open(file_size);
+ }
+ else
+ {
+ of = this->layout_->incremental_base()->output_file();
+ of->resize(file_size);
+ }
// Queue up the final set of tasks.
gold::queue_final_tasks(this->options_, this->input_objects_,
section_headers_(NULL),
tls_segment_(NULL),
relro_segment_(NULL),
+ increase_relro_(0),
symtab_section_(NULL),
symtab_xindex_(NULL),
dynsym_section_(NULL),
dynsym_xindex_(NULL),
dynamic_section_(NULL),
+ dynamic_symbol_(NULL),
dynamic_data_(NULL),
eh_frame_section_(NULL),
eh_frame_data_(NULL),
debug_info_(NULL),
group_signatures_(),
output_file_size_(-1),
+ have_added_input_section_(false),
sections_are_attached_(false),
input_requires_executable_stack_(false),
input_with_gnu_stack_note_(false),
record_output_section_data_from_script_(false),
script_output_section_data_list_(),
segment_states_(NULL),
- relaxation_debug_check_(NULL)
+ relaxation_debug_check_(NULL),
+ incremental_base_(NULL),
+ free_list_()
{
// Make space for more than enough segments for a typical file.
// This is just for efficiency--it's OK if we wind up needing more.
this->special_output_list_.reserve(2);
// Initialize structure needed for an incremental build.
- if (parameters->options().incremental())
+ if (parameters->incremental())
this->incremental_inputs_ = new Incremental_inputs;
// The section name pool is worth optimizing in all cases, because
this->namepool_.set_optimize();
}
+// For incremental links, record the base file to be modified.
+
+void
+Layout::set_incremental_base(Incremental_binary* base)
+{
+ this->incremental_base_ = base;
+ this->free_list_.init(base->output_file()->filesize(), true);
+}
+
// Hash a key we use to look up an output section mapping.
size_t
// ".debug_aranges", // not used by gdb as of 6.7.1
".debug_frame",
".debug_info",
+ ".debug_types",
".debug_line",
".debug_loc",
".debug_macinfo",
// ".debug_aranges", // not used by gdb as of 6.7.1
// ".debug_frame",
".debug_info",
+ // ".debug_types",
".debug_line",
// ".debug_loc",
// ".debug_macinfo",
return false;
}
+// Sometimes we compress sections. This is typically done for
+// sections that are not part of normal program execution (such as
+// .debug_* sections), and where the readers of these sections know
+// how to deal with compressed sections. This routine doesn't say for
+// certain whether we'll compress -- it depends on commandline options
+// as well -- just whether this section is a candidate for compression.
+// (The Output_compressed_section class decides whether to compress
+// a given section, and picks the name of the compressed section.)
+
+static bool
+is_compressible_debug_section(const char* secname)
+{
+ return (is_prefix_of(".debug", secname));
+}
+
+// We may see compressed debug sections in input files. Return TRUE
+// if this is the name of a compressed debug section.
+
+bool
+is_compressed_debug_section(const char* secname)
+{
+ return (is_prefix_of(".zdebug", secname));
+}
+
// Whether to include this section in the link.
template<int size, bool big_endian>
if (is_prefix_of(".gnu.lto_", name))
return false;
}
+ // The GNU linker strips .gnu_debuglink sections, so we do too.
+ // This is a feature used to keep debugging information in
+ // separate files.
+ if (strcmp(name, ".gnu_debuglink") == 0)
+ return false;
return true;
default:
// and section flags FLAGS. NAME must be canonicalized in the string
// pool, and NAME_KEY is the key. IS_INTERP is true if this is the
// .interp section. IS_DYNAMIC_LINKER_SECTION is true if this section
-// is used by the dynamic linker.
+// is used by the dynamic linker. IS_RELRO is true for a relro
+// section. IS_LAST_RELRO is true for the last relro section.
+// IS_FIRST_NON_RELRO is true for the first non-relro section.
Output_section*
Layout::get_output_section(const char* name, Stringpool::Key name_key,
elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
- bool is_interp, bool is_dynamic_linker_section)
+ Output_section_order order, bool is_relro)
{
elfcpp::Elf_Xword lookup_flags = flags;
}
if (os == NULL)
- os = this->make_output_section(name, type, flags, is_interp,
- is_dynamic_linker_section);
+ os = this->make_output_section(name, type, flags, order, is_relro);
+
ins.first->second = os;
return os;
}
// choosing an output section for an input section found in a input
// file. IS_INTERP is true if this is the .interp section.
// IS_DYNAMIC_LINKER_SECTION is true if this section is used by the
-// dynamic linker. This will return NULL if the input section should
-// be discarded.
+// dynamic linker. IS_RELRO is true for a relro section.
+// IS_LAST_RELRO is true for the last relro section.
+// IS_FIRST_NON_RELRO is true for the first non-relro section. This
+// will return NULL if the input section should be discarded.
Output_section*
Layout::choose_output_section(const Relobj* relobj, const char* name,
elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
- bool is_input_section, bool is_interp,
- bool is_dynamic_linker_section)
+ bool is_input_section, Output_section_order order,
+ bool is_relro)
{
// We should not see any input sections after we have attached
// sections to segments.
// Some flags in the input section should not be automatically
// copied to the output section.
flags &= ~ (elfcpp::SHF_INFO_LINK
- | elfcpp::SHF_LINK_ORDER
| 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;
+
if (this->script_options_->saw_sections_clause())
{
// We are using a SECTIONS clause, so the output section is
Script_sections* ss = this->script_options_->script_sections();
const char* file_name = relobj == NULL ? NULL : relobj->name().c_str();
Output_section** output_section_slot;
- name = ss->output_section_name(file_name, name, &output_section_slot);
+ Script_sections::Section_type script_section_type;
+ const char* orig_name = name;
+ name = ss->output_section_name(file_name, name, &output_section_slot,
+ &script_section_type);
if (name == NULL)
{
+ gold_debug(DEBUG_SCRIPT, _("Unable to create output section '%s' "
+ "because it is not allowed by the "
+ "SECTIONS clause of the linker script"),
+ orig_name);
// The SECTIONS clause says to discard this input section.
return NULL;
}
+ // We can only handle script section types ST_NONE and ST_NOLOAD.
+ switch (script_section_type)
+ {
+ case Script_sections::ST_NONE:
+ break;
+ case Script_sections::ST_NOLOAD:
+ flags &= elfcpp::SHF_ALLOC;
+ break;
+ default:
+ gold_unreachable();
+ }
+
// If this is an orphan section--one not mentioned in the linker
// script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
// default processing below.
name = this->namepool_.add(name, false, NULL);
- Output_section* os =
- this->make_output_section(name, type, flags, is_interp,
- is_dynamic_linker_section);
+ Output_section* os = this->make_output_section(name, type, flags,
+ order, is_relro);
+
os->set_found_in_sections_clause();
+
+ // Special handling for NOLOAD sections.
+ if (script_section_type == Script_sections::ST_NOLOAD)
+ {
+ os->set_is_noload();
+
+ // The constructor of Output_section sets addresses of non-ALLOC
+ // sections to 0 by default. We don't want that for NOLOAD
+ // sections even if they have no SHF_ALLOC flag.
+ if ((os->flags() & elfcpp::SHF_ALLOC) == 0
+ && os->is_address_valid())
+ {
+ gold_assert(os->address() == 0
+ && !os->is_offset_valid()
+ && !os->is_data_size_valid());
+ os->reset_address_and_file_offset();
+ }
+ }
+
*output_section_slot = os;
return os;
}
// FIXME: Handle SHF_OS_NONCONFORMING somewhere.
+ size_t len = strlen(name);
+ char* uncompressed_name = NULL;
+
+ // 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;
+ }
+
// Turn NAME from the name of the input section into the name of the
// output section.
-
- size_t len = strlen(name);
if (is_input_section
&& !this->script_options_->saw_sections_clause()
&& !parameters->options().relocatable())
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, is_interp,
- is_dynamic_linker_section);
+ return this->get_output_section(name, name_key, type, flags, order, is_relro);
+}
+
+// For incremental links, record the initial fixed layout of a section
+// from the base file, and return a pointer to the Output_section.
+
+template<int size, bool big_endian>
+Output_section*
+Layout::init_fixed_output_section(const char* name,
+ elfcpp::Shdr<size, big_endian>& shdr)
+{
+ unsigned int sh_type = shdr.get_sh_type();
+
+ // We preserve the layout of PROGBITS, NOBITS, and NOTE sections.
+ // All others will be created from scratch and reallocated.
+ if (sh_type != elfcpp::SHT_PROGBITS
+ && sh_type != elfcpp::SHT_NOBITS
+ && sh_type != elfcpp::SHT_NOTE)
+ return NULL;
+
+ typename elfcpp::Elf_types<size>::Elf_Addr sh_addr = shdr.get_sh_addr();
+ typename elfcpp::Elf_types<size>::Elf_Off sh_offset = shdr.get_sh_offset();
+ typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
+ typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
+ typename elfcpp::Elf_types<size>::Elf_WXword sh_addralign =
+ shdr.get_sh_addralign();
+
+ // Make the output section.
+ Stringpool::Key name_key;
+ name = this->namepool_.add(name, true, &name_key);
+ Output_section* os = this->get_output_section(name, name_key, sh_type,
+ sh_flags, ORDER_INVALID, false);
+ os->set_fixed_layout(sh_addr, sh_offset, sh_size, sh_addralign);
+ if (sh_type != elfcpp::SHT_NOBITS)
+ this->free_list_.remove(sh_offset, sh_offset + sh_size);
+ return os;
}
// Return the output section to use for input section SHNDX, with name
Output_section* os;
+ // Sometimes .init_array*, .preinit_array* and .fini_array* do not have
+ // correct section types. Force them here.
+ elfcpp::Elf_Word sh_type = shdr.get_sh_type();
+ if (sh_type == elfcpp::SHT_PROGBITS)
+ {
+ static const char init_array_prefix[] = ".init_array";
+ static const char preinit_array_prefix[] = ".preinit_array";
+ static const char fini_array_prefix[] = ".fini_array";
+ static size_t init_array_prefix_size = sizeof(init_array_prefix) - 1;
+ static size_t preinit_array_prefix_size =
+ sizeof(preinit_array_prefix) - 1;
+ static size_t fini_array_prefix_size = sizeof(fini_array_prefix) - 1;
+
+ if (strncmp(name, init_array_prefix, init_array_prefix_size) == 0)
+ sh_type = elfcpp::SHT_INIT_ARRAY;
+ else if (strncmp(name, preinit_array_prefix, preinit_array_prefix_size)
+ == 0)
+ sh_type = elfcpp::SHT_PREINIT_ARRAY;
+ else if (strncmp(name, fini_array_prefix, fini_array_prefix_size) == 0)
+ sh_type = elfcpp::SHT_FINI_ARRAY;
+ }
+
// In a relocatable link a grouped section must not be combined with
// any other sections.
if (parameters->options().relocatable()
&& (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0)
{
name = this->namepool_.add(name, true, NULL);
- os = this->make_output_section(name, shdr.get_sh_type(),
- shdr.get_sh_flags(), false, false);
+ os = this->make_output_section(name, sh_type, shdr.get_sh_flags(),
+ ORDER_INVALID, false);
}
else
{
- os = this->choose_output_section(object, name, shdr.get_sh_type(),
- shdr.get_sh_flags(), true, false,
- false);
+ os = this->choose_output_section(object, name, sh_type,
+ shdr.get_sh_flags(), true,
+ ORDER_INVALID, false);
if (os == NULL)
return NULL;
}
// FIXME: Handle SHF_LINK_ORDER somewhere.
- *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx,
+ *off = os->add_input_section(this, object, shndx, name, shdr, reloc_shndx,
this->script_options_->saw_sections_clause());
+ this->have_added_input_section_ = true;
return os;
}
gold_unreachable();
name += data_section->name();
- Output_section* os = this->choose_output_section(object, name.c_str(),
- sh_type,
- shdr.get_sh_flags(),
- false, false, false);
+ // In a relocatable link relocs for a grouped section must not be
+ // combined with other reloc sections.
+ Output_section* os;
+ if (!parameters->options().relocatable()
+ || (data_section->flags() & elfcpp::SHF_GROUP) == 0)
+ os = this->choose_output_section(object, name.c_str(), sh_type,
+ shdr.get_sh_flags(), false,
+ ORDER_INVALID, false);
+ else
+ {
+ const char* n = this->namepool_.add(name.c_str(), true, NULL);
+ os = this->make_output_section(n, sh_type, shdr.get_sh_flags(),
+ ORDER_INVALID, false);
+ }
os->set_should_link_to_symtab();
os->set_info_section(data_section);
Output_section* os = this->make_output_section(group_section_name,
elfcpp::SHT_GROUP,
shdr.get_sh_flags(),
- false, false);
+ ORDER_INVALID, false);
// We need to find a symbol with the signature in the symbol table.
// If we don't find one now, we need to look again later.
gold_assert((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
const char* const name = ".eh_frame";
- Output_section* os = this->choose_output_section(object,
- name,
+ Output_section* os = this->choose_output_section(object, name,
elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC,
- false, false, false);
+ elfcpp::SHF_ALLOC, false,
+ ORDER_EHFRAME, false);
if (os == NULL)
return NULL;
this->eh_frame_section_ = os;
this->eh_frame_data_ = new Eh_frame();
- if (parameters->options().eh_frame_hdr())
+ // For incremental linking, we do not optimize .eh_frame sections
+ // or create a .eh_frame_hdr section.
+ if (parameters->options().eh_frame_hdr() && !parameters->incremental())
{
Output_section* hdr_os =
- this->choose_output_section(NULL,
- ".eh_frame_hdr",
+ this->choose_output_section(NULL, ".eh_frame_hdr",
elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC,
- false, false, false);
+ elfcpp::SHF_ALLOC, false,
+ ORDER_EHFRAME, false);
if (hdr_os != NULL)
{
Output_segment* hdr_oseg;
hdr_oseg = this->make_output_segment(elfcpp::PT_GNU_EH_FRAME,
elfcpp::PF_R);
- hdr_oseg->add_output_section(hdr_os, elfcpp::PF_R, false);
+ hdr_oseg->add_output_section_to_nonload(hdr_os,
+ elfcpp::PF_R);
}
this->eh_frame_data_->set_eh_frame_hdr(hdr_posd);
gold_assert(this->eh_frame_section_ == os);
- if (this->eh_frame_data_->add_ehframe_input_section(object,
- symbols,
- symbols_size,
- symbol_names,
- symbol_names_size,
- shndx,
- reloc_shndx,
- reloc_type))
+ 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))
{
os->update_flags_for_input_section(shdr.get_sh_flags());
+ // A writable .eh_frame section is a RELRO section.
+ if ((shdr.get_sh_flags() & elfcpp::SHF_WRITE) != 0)
+ os->set_is_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
// 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(object, shndx, name, shdr, reloc_shndx,
+ *off = os->add_input_section(this, object, shndx, name, shdr, reloc_shndx,
saw_sections_clause);
+ this->have_added_input_section_ = true;
}
return os;
Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
elfcpp::Elf_Xword flags,
Output_section_data* posd,
- bool is_dynamic_linker_section)
+ Output_section_order order, bool is_relro)
{
Output_section* os = this->choose_output_section(NULL, name, type, flags,
- false, false,
- is_dynamic_linker_section);
+ false, order, is_relro);
if (os != NULL)
os->add_output_section_data(posd);
return os;
return ret;
}
-// Sometimes we compress sections. This is typically done for
-// sections that are not part of normal program execution (such as
-// .debug_* sections), and where the readers of these sections know
-// how to deal with compressed sections. This routine doesn't say for
-// certain whether we'll compress -- it depends on commandline options
-// as well -- just whether this section is a candidate for compression.
-// (The Output_compressed_section class decides whether to compress
-// a given section, and picks the name of the compressed section.)
-
-static bool
-is_compressible_debug_section(const char* secname)
-{
- return (strncmp(secname, ".debug", sizeof(".debug") - 1) == 0);
-}
-
// Make a new Output_section, and attach it to segments as
-// appropriate. IS_INTERP is true if this is the .interp section.
-// IS_DYNAMIC_LINKER_SECTION is true if this section is used by the
-// dynamic linker.
+// appropriate. ORDER is the order in which this section should
+// appear in the output segment. IS_RELRO is true if this is a relro
+// (read-only after relocations) section.
Output_section*
Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
- elfcpp::Elf_Xword flags, bool is_interp,
- bool is_dynamic_linker_section)
+ elfcpp::Elf_Xword flags,
+ Output_section_order order, bool is_relro)
{
Output_section* os;
if ((flags & elfcpp::SHF_ALLOC) == 0
if (this->debug_abbrev_)
this->debug_info_->set_abbreviations(this->debug_abbrev_);
}
- else
+ else
{
// FIXME: const_cast is ugly.
Target* target = const_cast<Target*>(¶meters->target());
os = target->make_output_section(name, type, flags);
}
- if (is_interp)
- os->set_is_interp();
- if (is_dynamic_linker_section)
- os->set_is_dynamic_linker_section();
+ // With -z relro, we have to recognize the special sections by name.
+ // There is no other way.
+ bool is_relro_local = false;
+ if (!this->script_options_->saw_sections_clause()
+ && parameters->options().relro()
+ && type == elfcpp::SHT_PROGBITS
+ && (flags & elfcpp::SHF_ALLOC) != 0
+ && (flags & elfcpp::SHF_WRITE) != 0)
+ {
+ if (strcmp(name, ".data.rel.ro") == 0)
+ is_relro = true;
+ else if (strcmp(name, ".data.rel.ro.local") == 0)
+ {
+ is_relro = true;
+ is_relro_local = true;
+ }
+ else if (type == elfcpp::SHT_INIT_ARRAY
+ || type == elfcpp::SHT_FINI_ARRAY
+ || type == elfcpp::SHT_PREINIT_ARRAY)
+ is_relro = true;
+ else if (strcmp(name, ".ctors") == 0
+ || strcmp(name, ".dtors") == 0
+ || strcmp(name, ".jcr") == 0)
+ is_relro = true;
+ }
+
+ if (is_relro)
+ os->set_is_relro();
+
+ if (order == ORDER_INVALID && (flags & elfcpp::SHF_ALLOC) != 0)
+ order = this->default_section_order(os, is_relro_local);
+
+ os->set_order(order);
parameters->target().new_output_section(os);
|| strcmp(name, ".fini_array") == 0))
os->set_may_sort_attached_input_sections();
- // With -z relro, we have to recognize the special sections by name.
- // There is no other way.
- if (!this->script_options_->saw_sections_clause()
- && parameters->options().relro()
- && type == elfcpp::SHT_PROGBITS
- && (flags & elfcpp::SHF_ALLOC) != 0
- && (flags & elfcpp::SHF_WRITE) != 0)
- {
- if (strcmp(name, ".data.rel.ro") == 0)
- os->set_is_relro();
- else if (strcmp(name, ".data.rel.ro.local") == 0)
- {
- os->set_is_relro();
- os->set_is_relro_local();
- }
- }
-
// Check for .stab*str sections, as .stab* sections need to link to
// them.
if (type == elfcpp::SHT_STRTAB
return os;
}
+// Return the default order in which a section should be placed in an
+// output segment. This function captures a lot of the ideas in
+// ld/scripttempl/elf.sc in the GNU linker. Note that the order of a
+// linker created section is normally set when the section is created;
+// this function is used for input sections.
+
+Output_section_order
+Layout::default_section_order(Output_section* os, bool is_relro_local)
+{
+ gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
+ bool is_write = (os->flags() & elfcpp::SHF_WRITE) != 0;
+ bool is_execinstr = (os->flags() & elfcpp::SHF_EXECINSTR) != 0;
+ bool is_bss = false;
+
+ switch (os->type())
+ {
+ default:
+ case elfcpp::SHT_PROGBITS:
+ break;
+ case elfcpp::SHT_NOBITS:
+ is_bss = true;
+ break;
+ case elfcpp::SHT_RELA:
+ case elfcpp::SHT_REL:
+ if (!is_write)
+ return ORDER_DYNAMIC_RELOCS;
+ break;
+ case elfcpp::SHT_HASH:
+ case elfcpp::SHT_DYNAMIC:
+ case elfcpp::SHT_SHLIB:
+ case elfcpp::SHT_DYNSYM:
+ case elfcpp::SHT_GNU_HASH:
+ case elfcpp::SHT_GNU_verdef:
+ case elfcpp::SHT_GNU_verneed:
+ case elfcpp::SHT_GNU_versym:
+ if (!is_write)
+ return ORDER_DYNAMIC_LINKER;
+ break;
+ case elfcpp::SHT_NOTE:
+ return is_write ? ORDER_RW_NOTE : ORDER_RO_NOTE;
+ }
+
+ if ((os->flags() & elfcpp::SHF_TLS) != 0)
+ return is_bss ? ORDER_TLS_BSS : ORDER_TLS_DATA;
+
+ if (!is_bss && !is_write)
+ {
+ if (is_execinstr)
+ {
+ if (strcmp(os->name(), ".init") == 0)
+ return ORDER_INIT;
+ else if (strcmp(os->name(), ".fini") == 0)
+ return ORDER_FINI;
+ }
+ return is_execinstr ? ORDER_TEXT : ORDER_READONLY;
+ }
+
+ if (os->is_relro())
+ return is_relro_local ? ORDER_RELRO_LOCAL : ORDER_RELRO;
+
+ if (os->is_small_section())
+ return is_bss ? ORDER_SMALL_BSS : ORDER_SMALL_DATA;
+ if (os->is_large_section())
+ return is_bss ? ORDER_LARGE_BSS : ORDER_LARGE_DATA;
+
+ return is_bss ? ORDER_BSS : ORDER_DATA;
+}
+
// Attach output sections to segments. This is called after we have
// seen all the input sections.
elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
- bool sort_sections = !this->script_options_->saw_sections_clause();
+ // Check for --section-start.
+ uint64_t addr;
+ bool is_address_set = parameters->options().section_start(os->name(), &addr);
// In general the only thing we really care about for PT_LOAD
- // segments is whether or not they are writable, so that is how we
- // search for them. Large data sections also go into their own
- // PT_LOAD segment. People who need segments sorted on some other
- // basis will have to use a linker script.
+ // segments is whether or not they are writable or executable,
+ // so that is how we search for them.
+ // Large data sections also go into their own PT_LOAD segment.
+ // People who need segments sorted on some other basis will
+ // have to use a linker script.
Segment_list::const_iterator p;
for (p = this->segment_list_.begin();
if (!parameters->options().omagic()
&& ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W))
continue;
+ if (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->is_large_data_section() && !(*p)->is_large_data_segment())
continue;
- (*p)->add_output_section(os, seg_flags, sort_sections);
+ 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;
}
seg_flags);
if (os->is_large_data_section())
oseg->set_is_large_data_segment();
- oseg->add_output_section(os, seg_flags, sort_sections);
+ oseg->add_output_section_to_load(this, os, seg_flags);
+ if (is_address_set)
+ oseg->set_addresses(addr, addr);
}
// If we see a loadable SHT_NOTE section, we create a PT_NOTE
&& (((*p)->flags() & elfcpp::PF_W)
== (seg_flags & elfcpp::PF_W)))
{
- (*p)->add_output_section(os, seg_flags, false);
+ (*p)->add_output_section_to_nonload(os, seg_flags);
break;
}
}
{
Output_segment* oseg = this->make_output_segment(elfcpp::PT_NOTE,
seg_flags);
- oseg->add_output_section(os, seg_flags, false);
+ oseg->add_output_section_to_nonload(os, seg_flags);
}
}
{
if (this->tls_segment_ == NULL)
this->make_output_segment(elfcpp::PT_TLS, seg_flags);
- this->tls_segment_->add_output_section(os, seg_flags, false);
+ this->tls_segment_->add_output_section_to_nonload(os, seg_flags);
}
// If -z relro is in effect, and we see a relro section, we create a
gold_assert(seg_flags == (elfcpp::PF_R | elfcpp::PF_W));
if (this->relro_segment_ == NULL)
this->make_output_segment(elfcpp::PT_GNU_RELRO, seg_flags);
- this->relro_segment_->add_output_section(os, seg_flags, false);
+ this->relro_segment_->add_output_section_to_nonload(os, seg_flags);
}
}
// Make an output section for a script.
Output_section*
-Layout::make_output_section_for_script(const char* name)
+Layout::make_output_section_for_script(
+ const char* name,
+ Script_sections::Section_type section_type)
{
name = this->namepool_.add(name, false, NULL);
+ elfcpp::Elf_Xword sh_flags = elfcpp::SHF_ALLOC;
+ if (section_type == Script_sections::ST_NOLOAD)
+ sh_flags = 0;
Output_section* os = this->make_output_section(name, elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC, false,
+ sh_flags, ORDER_INVALID,
false);
os->set_found_in_sections_clause();
+ if (section_type == Script_sections::ST_NOLOAD)
+ os->set_is_noload();
return os;
}
// object. On some targets that will force an executable stack.
void
-Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags)
+Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags,
+ const Object* obj)
{
if (!seen_gnu_stack)
- this->input_without_gnu_stack_note_ = true;
+ {
+ this->input_without_gnu_stack_note_ = true;
+ if (parameters->options().warn_execstack()
+ && parameters->target().is_default_stack_executable())
+ gold_warning(_("%s: missing .note.GNU-stack section"
+ " implies executable stack"),
+ obj->name().c_str());
+ }
else
{
this->input_with_gnu_stack_note_ = true;
if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
- this->input_requires_executable_stack_ = true;
+ {
+ this->input_requires_executable_stack_ = true;
+ if (parameters->options().warn_execstack()
+ || parameters->options().is_stack_executable())
+ gold_warning(_("%s: requires executable stack"),
+ obj->name().c_str());
+ }
}
}
elfcpp::SHT_DYNAMIC,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE),
- false, false, true);
- this->dynamic_section_->set_is_relro();
+ false, ORDER_RELRO,
+ true);
- symtab->define_in_output_data("_DYNAMIC", NULL, this->dynamic_section_, 0, 0,
- elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
- elfcpp::STV_HIDDEN, 0, false, false);
+ this->dynamic_symbol_ =
+ symtab->define_in_output_data("_DYNAMIC", NULL, Symbol_table::PREDEFINED,
+ this->dynamic_section_, 0, 0,
+ elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
+ elfcpp::STV_HIDDEN, 0, false, false);
this->dynamic_data_ = new Output_data_dynamic(&this->dynpool_);
++p)
{
const char* const name = (*p)->name();
- if (name[strspn(name,
- ("0123456789"
- "ABCDEFGHIJKLMNOPWRSTUVWXYZ"
- "abcdefghijklmnopqrstuvwxyz"
- "_"))]
- == '\0')
+ if (is_cident(name))
{
const std::string name_string(name);
- const std::string start_name("__start_" + name_string);
- const std::string stop_name("__stop_" + name_string);
+ const std::string start_name(cident_section_start_prefix
+ + name_string);
+ const std::string stop_name(cident_section_stop_prefix
+ + name_string);
symtab->define_in_output_data(start_name.c_str(),
NULL, // version
+ Symbol_table::PREDEFINED,
*p,
0, // value
0, // symsize
symtab->define_in_output_data(stop_name.c_str(),
NULL, // version
+ Symbol_table::PREDEFINED,
*p,
0, // value
0, // symsize
Output_segment*
Layout::find_first_load_seg()
{
+ Output_segment* best = NULL;
for (Segment_list::const_iterator p = this->segment_list_.begin();
p != this->segment_list_.end();
++p)
&& ((*p)->flags() & elfcpp::PF_R) != 0
&& (parameters->options().omagic()
|| ((*p)->flags() & elfcpp::PF_W) == 0))
- return *p;
+ {
+ if (best == NULL || this->segment_precedes(*p, best))
+ best = *p;
+ }
}
+ if (best != NULL)
+ return best;
gold_assert(!this->script_options_->saw_phdrs_clause());
p != this->section_list_.end();
++p)
{
- (*p)->reset_address_and_file_offset();
(*p)->restore_states();
+
+ // If an input section changes size because of relaxation,
+ // we need to adjust the section offsets of all input sections.
+ // after such a section.
+ if ((*p)->section_offsets_need_adjustment())
+ (*p)->adjust_section_offsets();
+
+ (*p)->reset_address_and_file_offset();
}
// Reset special output object address and file offsets.
!= 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())
+ load_seg = NULL;
+
gold_assert(phdr_seg == NULL
|| load_seg != NULL
|| this->script_options_->saw_sections_clause());
+ // If the address of the load segment we found has been set by
+ // --section-start rather than by a script, then adjust the VMA and
+ // LMA downward if possible to include the file and section headers.
+ uint64_t header_gap = 0;
+ if (load_seg != NULL
+ && load_seg->are_addresses_set()
+ && !this->script_options_->saw_sections_clause()
+ && !parameters->options().relocatable())
+ {
+ file_header->finalize_data_size();
+ segment_headers->finalize_data_size();
+ size_t sizeof_headers = (file_header->data_size()
+ + segment_headers->data_size());
+ const uint64_t abi_pagesize = target->abi_pagesize();
+ uint64_t hdr_paddr = load_seg->paddr() - sizeof_headers;
+ hdr_paddr &= ~(abi_pagesize - 1);
+ uint64_t subtract = load_seg->paddr() - hdr_paddr;
+ if (load_seg->paddr() < subtract || load_seg->vaddr() < subtract)
+ load_seg = NULL;
+ else
+ {
+ load_seg->set_addresses(load_seg->vaddr() - subtract,
+ load_seg->paddr() - subtract);
+ header_gap = subtract - sizeof_headers;
+ }
+ }
+
// Lay out the segment headers.
if (!parameters->options().relocatable())
{
gold_assert(segment_headers != NULL);
+ if (header_gap != 0 && load_seg != NULL)
+ {
+ Output_data_zero_fill* z = new Output_data_zero_fill(header_gap, 1);
+ load_seg->add_initial_output_data(z);
+ }
if (load_seg != NULL)
load_seg->add_initial_output_data(segment_headers);
if (phdr_seg != NULL)
return off;
}
+// Search the list of patterns and find the postion of the given section
+// name in the output section. If the section name matches a glob
+// pattern and a non-glob name, then the non-glob position takes
+// precedence. Return 0 if no match is found.
+
+unsigned int
+Layout::find_section_order_index(const std::string& section_name)
+{
+ Unordered_map<std::string, unsigned int>::iterator map_it;
+ map_it = this->input_section_position_.find(section_name);
+ if (map_it != this->input_section_position_.end())
+ return map_it->second;
+
+ // Absolute match failed. Linear search the glob patterns.
+ std::vector<std::string>::iterator it;
+ for (it = this->input_section_glob_.begin();
+ it != this->input_section_glob_.end();
+ ++it)
+ {
+ if (fnmatch((*it).c_str(), section_name.c_str(), FNM_NOESCAPE) == 0)
+ {
+ map_it = this->input_section_position_.find(*it);
+ gold_assert(map_it != this->input_section_position_.end());
+ return map_it->second;
+ }
+ }
+ return 0;
+}
+
+// Read the sequence of input sections from the file specified with
+// --section-ordering-file.
+
+void
+Layout::read_layout_from_file()
+{
+ const char* filename = parameters->options().section_ordering_file();
+ std::ifstream in;
+ std::string line;
+
+ in.open(filename);
+ if (!in)
+ gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
+ filename, strerror(errno));
+
+ std::getline(in, line); // this chops off the trailing \n, if any
+ unsigned int position = 1;
+
+ while (in)
+ {
+ if (!line.empty() && line[line.length() - 1] == '\r') // Windows
+ line.resize(line.length() - 1);
+ // Ignore comments, beginning with '#'
+ if (line[0] == '#')
+ {
+ std::getline(in, line);
+ continue;
+ }
+ this->input_section_position_[line] = position;
+ // Store all glob patterns in a vector.
+ if (is_wildcard_string(line.c_str()))
+ this->input_section_glob_.push_back(line);
+ position++;
+ std::getline(in, line);
+ }
+}
+
// Finalize the layout. When this is called, we have created all the
// output sections and all the output segments which are based on
// input sections. We have several things to do, and we have to do
// dynamic string table is complete.
this->create_version_sections(&versions, symtab, local_dynamic_count,
dynamic_symbols, dynstr);
+
+ // Set the size of the _DYNAMIC symbol. We can't do this until
+ // after we call create_version_sections.
+ this->set_dynamic_symbol_size(symtab);
}
- if (this->incremental_inputs_)
- {
- this->incremental_inputs_->finalize();
- this->create_incremental_info_sections();
- }
-
// Create segment headers.
Output_segment_headers* segment_headers =
(parameters->options().relocatable()
pass++;
}
while (target->may_relax()
- && target->relax(pass, input_objects, symtab, this));
+ && target->relax(pass, input_objects, symtab, this, task));
// 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
// be called after the symbol table has been finalized.
this->script_options_->finalize_symbols(symtab, this);
+ // Create the incremental inputs sections.
+ if (this->incremental_inputs_)
+ {
+ this->incremental_inputs_->finalize();
+ this->create_incremental_info_sections(symtab);
+ }
+
// Create the .shstrtab section.
Output_section* shstrtab_section = this->create_shstrtab();
// If there are no sections which require postprocessing, we can
// handle the section names now, and avoid a resize later.
if (!this->any_postprocessing_sections_)
- off = this->set_section_offsets(off,
+ {
+ off = this->set_section_offsets(off,
+ POSTPROCESSING_SECTIONS_PASS);
+ off =
+ this->set_section_offsets(off,
STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
+ }
file_header->set_section_info(this->section_headers_, shstrtab_section);
memcpy(buffer + 3 * (size / 8), name, namesz);
elfcpp::Elf_Xword flags = 0;
+ Output_section_order order = ORDER_INVALID;
if (allocate)
- flags = elfcpp::SHF_ALLOC;
+ {
+ flags = elfcpp::SHF_ALLOC;
+ order = ORDER_RO_NOTE;
+ }
Output_section* os = this->choose_output_section(NULL, section_name,
elfcpp::SHT_NOTE,
- flags, false, false,
- false);
+ flags, false, order, false);
if (os == NULL)
return NULL;
void
Layout::create_gold_note()
{
- if (parameters->options().relocatable())
+ if (parameters->options().relocatable()
+ || parameters->incremental_update())
return;
std::string desc = std::string("gold ") + gold::get_version_string();
size_t trailing_padding;
- Output_section *os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
+ Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
".note.gnu.gold-version", desc.size(),
false, &trailing_padding);
if (os == NULL)
elfcpp::Elf_Xword flags = 0;
if (is_stack_executable)
flags |= elfcpp::SHF_EXECINSTR;
- this->make_output_section(name, elfcpp::SHT_PROGBITS, flags, false,
- false);
+ this->make_output_section(name, elfcpp::SHT_PROGBITS, flags,
+ ORDER_INVALID, false);
}
else
{
}
}
-// Create .gnu_incremental_inputs and .gnu_incremental_strtab sections needed
+// Create .gnu_incremental_inputs and related sections needed
// for the next run of incremental linking to check what has changed.
void
-Layout::create_incremental_info_sections()
+Layout::create_incremental_info_sections(Symbol_table* symtab)
{
- gold_assert(this->incremental_inputs_ != NULL);
+ Incremental_inputs* incr = this->incremental_inputs_;
+
+ gold_assert(incr != NULL);
+
+ // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
+ incr->create_data_sections(symtab);
// Add the .gnu_incremental_inputs section.
- const char *incremental_inputs_name =
+ const char* incremental_inputs_name =
this->namepool_.add(".gnu_incremental_inputs", false, NULL);
- Output_section* inputs_os =
+ Output_section* incremental_inputs_os =
this->make_output_section(incremental_inputs_name,
elfcpp::SHT_GNU_INCREMENTAL_INPUTS, 0,
- false, false);
- Output_section_data* posd =
- this->incremental_inputs_->create_incremental_inputs_section_data();
- inputs_os->add_output_section_data(posd);
-
+ ORDER_INVALID, false);
+ incremental_inputs_os->add_output_section_data(incr->inputs_section());
+
+ // Add the .gnu_incremental_symtab section.
+ const char* incremental_symtab_name =
+ this->namepool_.add(".gnu_incremental_symtab", false, NULL);
+ Output_section* incremental_symtab_os =
+ this->make_output_section(incremental_symtab_name,
+ elfcpp::SHT_GNU_INCREMENTAL_SYMTAB, 0,
+ ORDER_INVALID, false);
+ incremental_symtab_os->add_output_section_data(incr->symtab_section());
+ incremental_symtab_os->set_entsize(4);
+
+ // Add the .gnu_incremental_relocs section.
+ const char* incremental_relocs_name =
+ this->namepool_.add(".gnu_incremental_relocs", false, NULL);
+ Output_section* incremental_relocs_os =
+ this->make_output_section(incremental_relocs_name,
+ elfcpp::SHT_GNU_INCREMENTAL_RELOCS, 0,
+ ORDER_INVALID, false);
+ incremental_relocs_os->add_output_section_data(incr->relocs_section());
+ incremental_relocs_os->set_entsize(incr->relocs_entsize());
+
+ // Add the .gnu_incremental_got_plt section.
+ const char* incremental_got_plt_name =
+ this->namepool_.add(".gnu_incremental_got_plt", false, NULL);
+ Output_section* incremental_got_plt_os =
+ this->make_output_section(incremental_got_plt_name,
+ elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT, 0,
+ ORDER_INVALID, false);
+ incremental_got_plt_os->add_output_section_data(incr->got_plt_section());
+
// Add the .gnu_incremental_strtab section.
- const char *incremental_strtab_name =
+ const char* incremental_strtab_name =
this->namepool_.add(".gnu_incremental_strtab", false, NULL);
- Output_section* strtab_os = this->make_output_section(incremental_strtab_name,
- elfcpp::SHT_STRTAB,
- 0, false, false);
+ Output_section* incremental_strtab_os = this->make_output_section(incremental_strtab_name,
+ elfcpp::SHT_STRTAB, 0,
+ ORDER_INVALID, false);
Output_data_strtab* strtab_data =
- new Output_data_strtab(this->incremental_inputs_->get_stringpool());
- strtab_os->add_output_section_data(strtab_data);
-
- inputs_os->set_link_section(strtab_data);
+ new Output_data_strtab(incr->get_stringpool());
+ incremental_strtab_os->add_output_section_data(strtab_data);
+
+ incremental_inputs_os->set_after_input_sections();
+ incremental_symtab_os->set_after_input_sections();
+ incremental_relocs_os->set_after_input_sections();
+ incremental_got_plt_os->set_after_input_sections();
+
+ incremental_inputs_os->set_link_section(incremental_strtab_os);
+ incremental_symtab_os->set_link_section(incremental_inputs_os);
+ incremental_relocs_os->set_link_section(incremental_inputs_os);
+ incremental_got_plt_os->set_link_section(incremental_inputs_os);
}
// Return whether SEG1 should be before SEG2 in the output file. This
if (section_count1 > 0 && section_count2 == 0)
return false;
- uint64_t paddr1 = seg1->first_section_load_address();
- uint64_t paddr2 = seg2->first_section_load_address();
+ uint64_t paddr1 = (seg1->are_addresses_set()
+ ? seg1->paddr()
+ : seg1->first_section_load_address());
+ uint64_t paddr2 = (seg2->are_addresses_set()
+ ? seg2->paddr()
+ : seg2->first_section_load_address());
+
if (paddr1 != paddr2)
return paddr1 < paddr2;
}
off_t
Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
- unsigned int *pshndx)
+ unsigned int* pshndx)
{
// Sort them into the final order.
std::sort(this->segment_list_.begin(), this->segment_list_.end(),
}
}
+ unsigned int increase_relro = this->increase_relro_;
+ if (this->script_options_->saw_sections_clause())
+ increase_relro = 0;
+
const bool check_sections = parameters->options().check_sections();
Output_segment* last_load_segment = NULL;
- bool was_readonly = false;
for (Segment_list::iterator p = this->segment_list_.begin();
p != this->segment_list_.end();
++p)
if (!are_addresses_set)
{
- // If the last segment was readonly, and this one is
- // not, then skip the address forward one page,
- // maintaining the same position within the page. This
- // lets us store both segments overlapping on a single
- // page in the file, but the loader will put them on
- // different pages in memory.
+ // Skip the address forward one page, maintaining the same
+ // position within the page. This lets us store both segments
+ // overlapping on a single page in the file, but the loader will
+ // 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());
aligned_addr = addr;
- if (was_readonly && ((*p)->flags() & elfcpp::PF_W) != 0)
- {
- if ((addr & (abi_pagesize - 1)) != 0)
- addr = addr + abi_pagesize;
- }
+ if ((addr & (abi_pagesize - 1)) != 0)
+ addr = addr + abi_pagesize;
off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
}
}
unsigned int shndx_hold = *pshndx;
+ bool has_relro = false;
uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
+ &increase_relro,
+ &has_relro,
&off, pshndx);
// Now that we know the size of this segment, we may be able
// to save a page in memory, at the cost of wasting some
// file space, by instead aligning to the start of a new
// page. Here we use the real machine page size rather than
- // the ABI mandated page size.
-
- if (!are_addresses_set && aligned_addr != addr)
+ // the ABI mandated page size. If the segment has been
+ // aligned so that the relro data ends at a page boundary,
+ // we do not try to realign it.
+
+ if (!are_addresses_set
+ && !has_relro
+ && aligned_addr != addr
+ && !parameters->incremental_update())
{
uint64_t first_off = (common_pagesize
- (aligned_addr
addr = align_address(addr, (*p)->maximum_alignment());
off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
off = align_file_offset(off, addr, abi_pagesize);
+
+ increase_relro = this->increase_relro_;
+ if (this->script_options_->saw_sections_clause())
+ increase_relro = 0;
+ has_relro = false;
+
new_addr = (*p)->set_section_addresses(this, true, addr,
+ &increase_relro,
+ &has_relro,
&off, pshndx);
}
}
addr = new_addr;
- if (((*p)->flags() & elfcpp::PF_W) == 0)
- was_readonly = true;
-
// Implement --check-sections. We know that the segments
// are sorted by LMA.
if (check_sections && last_load_segment != NULL)
++p)
{
if ((*p)->type() != elfcpp::PT_LOAD)
- (*p)->set_offset();
+ (*p)->set_offset((*p)->type() == elfcpp::PT_GNU_RELRO
+ ? increase_relro
+ : 0);
}
// Set the TLS offsets for each section in the PT_TLS segment.
off_t
Layout::set_relocatable_section_offsets(Output_data* file_header,
- unsigned int *pshndx)
+ unsigned int* pshndx)
{
off_t off = 0;
off_t
Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
{
+ off_t startoff = off;
+ off_t maxoff = off;
+
for (Section_list::iterator p = this->unattached_section_list_.begin();
p != this->unattached_section_list_.end();
++p)
|| (*p)->type() != elfcpp::SHT_STRTAB))
continue;
- off = align_address(off, (*p)->addralign());
- (*p)->set_file_offset(off);
- (*p)->finalize_data_size();
+ if (!parameters->incremental_update())
+ {
+ off = align_address(off, (*p)->addralign());
+ (*p)->set_file_offset(off);
+ (*p)->finalize_data_size();
+ }
+ else
+ {
+ // Incremental update: allocate file space from free list.
+ (*p)->pre_finalize_data_size();
+ off_t current_size = (*p)->current_data_size();
+ off = this->allocate(current_size, (*p)->addralign(), startoff);
+ if (off == -1)
+ {
+ if (is_debugging_enabled(DEBUG_INCREMENTAL))
+ this->free_list_.dump();
+ gold_assert((*p)->output_section() != NULL);
+ gold_fatal(_("out of patch space for section %s; "
+ "relink with --incremental-full"),
+ (*p)->output_section()->name());
+ }
+ (*p)->set_file_offset(off);
+ (*p)->finalize_data_size();
+ if ((*p)->data_size() > current_size)
+ {
+ gold_assert((*p)->output_section() != NULL);
+ gold_fatal(_("%s: section changed size; "
+ "relink with --incremental-full"),
+ (*p)->output_section()->name());
+ }
+ gold_debug(DEBUG_INCREMENTAL,
+ "set_section_offsets: %08lx %08lx %s",
+ static_cast<long>(off),
+ static_cast<long>((*p)->data_size()),
+ ((*p)->output_section() != NULL
+ ? (*p)->output_section()->name() : "(special)"));
+ }
+
off += (*p)->data_size();
+ if (off > maxoff)
+ maxoff = off;
// At this point the name must be set.
if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
this->namepool_.add((*p)->name(), false, NULL);
}
- return off;
+ return maxoff;
}
// Set the section indexes of all the sections not associated with a
else
gold_unreachable();
- off_t off = *poff;
- off = align_address(off, align);
- off_t startoff = off;
+ // Compute file offsets relative to the start of the symtab section.
+ off_t off = 0;
// Save space for the dummy symbol at the start of the section. We
// never bother to write this out--it will just be left as zero.
}
unsigned int local_symcount = local_symbol_index;
- gold_assert(static_cast<off_t>(local_symcount * symsize) == off - startoff);
+ gold_assert(static_cast<off_t>(local_symcount * symsize) == off);
off_t dynoff;
size_t dyn_global_index;
== this->dynsym_section_->data_size() - locsize);
}
+ off_t global_off = off;
off = symtab->finalize(off, dynoff, dyn_global_index, dyncount,
&this->sympool_, &local_symcount);
const char* symtab_name = this->namepool_.add(".symtab", false, NULL);
Output_section* osymtab = this->make_output_section(symtab_name,
elfcpp::SHT_SYMTAB,
- 0, false, false);
+ 0, ORDER_INVALID,
+ false);
this->symtab_section_ = osymtab;
- Output_section_data* pos = new Output_data_fixed_space(off - startoff,
- align,
+ Output_section_data* pos = new Output_data_fixed_space(off, align,
"** symtab");
osymtab->add_output_section_data(pos);
false, NULL);
Output_section* osymtab_xindex =
this->make_output_section(symtab_xindex_name,
- elfcpp::SHT_SYMTAB_SHNDX, 0, false,
- false);
+ elfcpp::SHT_SYMTAB_SHNDX, 0,
+ ORDER_INVALID, false);
- size_t symcount = (off - startoff) / symsize;
+ size_t symcount = off / symsize;
this->symtab_xindex_ = new Output_symtab_xindex(symcount);
osymtab_xindex->add_output_section_data(this->symtab_xindex_);
const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
Output_section* ostrtab = this->make_output_section(strtab_name,
elfcpp::SHT_STRTAB,
- 0, false, false);
+ 0, ORDER_INVALID,
+ false);
Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
ostrtab->add_output_section_data(pstr);
- osymtab->set_file_offset(startoff);
+ off_t symtab_off;
+ if (!parameters->incremental_update())
+ symtab_off = align_address(*poff, align);
+ else
+ {
+ symtab_off = this->allocate(off, align, *poff);
+ if (off == -1)
+ gold_fatal(_("out of patch space for symbol table; "
+ "relink with --incremental-full"));
+ gold_debug(DEBUG_INCREMENTAL,
+ "create_symtab_sections: %08lx %08lx .symtab",
+ static_cast<long>(symtab_off),
+ static_cast<long>(off));
+ }
+
+ symtab->set_file_offset(symtab_off + global_off);
+ osymtab->set_file_offset(symtab_off);
osymtab->finalize_data_size();
osymtab->set_link_section(ostrtab);
osymtab->set_info(local_symcount);
osymtab->set_entsize(symsize);
- *poff = off;
+ if (symtab_off + off > *poff)
+ *poff = symtab_off + off;
}
}
const char* name = this->namepool_.add(".shstrtab", false, NULL);
Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0,
- false, false);
+ ORDER_INVALID, false);
if (strcmp(parameters->options().compress_debug_sections(), "none") != 0)
{
&this->unattached_section_list_,
&this->namepool_,
shstrtab_section);
- off_t off = align_address(*poff, oshdrs->addralign());
+ off_t off;
+ if (!parameters->incremental_update())
+ off = align_address(*poff, oshdrs->addralign());
+ else
+ {
+ oshdrs->pre_finalize_data_size();
+ off = this->allocate(oshdrs->data_size(), oshdrs->addralign(), *poff);
+ if (off == -1)
+ gold_fatal(_("out of patch space for section header table; "
+ "relink with --incremental-full"));
+ gold_debug(DEBUG_INCREMENTAL,
+ "create_shdrs: %08lx %08lx (section header table)",
+ static_cast<long>(off),
+ static_cast<long>(off + oshdrs->data_size()));
+ }
oshdrs->set_address_and_file_offset(0, off);
off += oshdrs->data_size();
- *poff = off;
+ if (off > *poff)
+ *poff = off;
this->section_headers_ = oshdrs;
}
void
Layout::create_dynamic_symtab(const Input_objects* input_objects,
Symbol_table* symtab,
- Output_section **pdynstr,
+ Output_section** pdynstr,
unsigned int* plocal_dynamic_count,
std::vector<Symbol*>* pdynamic_symbols,
Versions* pversions)
Output_section* dynsym = this->choose_output_section(NULL, ".dynsym",
elfcpp::SHT_DYNSYM,
elfcpp::SHF_ALLOC,
- false, false, true);
+ false,
+ ORDER_DYNAMIC_LINKER,
+ false);
Output_section_data* odata = new Output_data_fixed_space(index * symsize,
align,
this->choose_output_section(NULL, ".dynsym_shndx",
elfcpp::SHT_SYMTAB_SHNDX,
elfcpp::SHF_ALLOC,
- false, false, true);
+ false, ORDER_DYNAMIC_LINKER, false);
this->dynsym_xindex_ = new Output_symtab_xindex(index);
Output_section* dynstr = this->choose_output_section(NULL, ".dynstr",
elfcpp::SHT_STRTAB,
elfcpp::SHF_ALLOC,
- false, false, true);
+ false,
+ ORDER_DYNAMIC_LINKER,
+ false);
Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
dynstr->add_output_section_data(strdata);
Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
&phash, &hashlen);
- Output_section* hashsec = this->choose_output_section(NULL, ".hash",
- elfcpp::SHT_HASH,
- elfcpp::SHF_ALLOC,
- false, false, true);
+ Output_section* hashsec =
+ this->choose_output_section(NULL, ".hash", elfcpp::SHT_HASH,
+ elfcpp::SHF_ALLOC, false,
+ ORDER_DYNAMIC_LINKER, false);
Output_section_data* hashdata = new Output_data_const_buffer(phash,
hashlen,
Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount,
&phash, &hashlen);
- Output_section* hashsec = this->choose_output_section(NULL, ".gnu.hash",
- elfcpp::SHT_GNU_HASH,
- elfcpp::SHF_ALLOC,
- false, false, true);
+ Output_section* hashsec =
+ this->choose_output_section(NULL, ".gnu.hash", elfcpp::SHT_GNU_HASH,
+ elfcpp::SHF_ALLOC, false,
+ ORDER_DYNAMIC_LINKER, false);
Output_section_data* hashdata = new Output_data_const_buffer(phash,
hashlen,
hashsec->add_output_section_data(hashdata);
hashsec->set_link_section(dynsym);
- hashsec->set_entsize(4);
+
+ // 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);
odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec);
}
Output_section* vsec = this->choose_output_section(NULL, ".gnu.version",
elfcpp::SHT_GNU_versym,
elfcpp::SHF_ALLOC,
- false, false, true);
+ false,
+ ORDER_DYNAMIC_LINKER,
+ false);
unsigned char* vbuf;
unsigned int vsize;
vdsec= this->choose_output_section(NULL, ".gnu.version_d",
elfcpp::SHT_GNU_verdef,
elfcpp::SHF_ALLOC,
- false, false, true);
+ false, ORDER_DYNAMIC_LINKER, false);
unsigned char* vdbuf;
unsigned int vdsize;
vnsec = this->choose_output_section(NULL, ".gnu.version_r",
elfcpp::SHT_GNU_verneed,
elfcpp::SHF_ALLOC,
- false, false, true);
+ false, ORDER_DYNAMIC_LINKER, false);
unsigned char* vnbuf;
unsigned int vnsize;
Output_section* osec = this->choose_output_section(NULL, ".interp",
elfcpp::SHT_PROGBITS,
elfcpp::SHF_ALLOC,
- false, true, true);
+ false, ORDER_INTERP,
+ false);
osec->add_output_section_data(odata);
if (!this->script_options_->saw_phdrs_clause())
{
Output_segment* oseg = this->make_output_segment(elfcpp::PT_INTERP,
elfcpp::PF_R);
- oseg->add_output_section(osec, elfcpp::PF_R, false);
+ oseg->add_output_section_to_nonload(osec, elfcpp::PF_R);
+ }
+}
+
+// Add dynamic tags for the PLT and the dynamic relocs. This is
+// called by the target-specific code. This does nothing if not doing
+// a dynamic link.
+
+// USE_REL is true for REL relocs rather than RELA relocs.
+
+// If PLT_GOT is not NULL, then DT_PLTGOT points to it.
+
+// If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
+// and we also set DT_PLTREL. We use PLT_REL's output section, since
+// some targets have multiple reloc sections in PLT_REL.
+
+// If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
+// DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT.
+
+// If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
+// executable.
+
+void
+Layout::add_target_dynamic_tags(bool use_rel, const Output_data* plt_got,
+ const Output_data* plt_rel,
+ const Output_data_reloc_generic* dyn_rel,
+ bool add_debug, bool dynrel_includes_plt)
+{
+ Output_data_dynamic* odyn = this->dynamic_data_;
+ if (odyn == NULL)
+ return;
+
+ if (plt_got != NULL && plt_got->output_section() != NULL)
+ odyn->add_section_address(elfcpp::DT_PLTGOT, plt_got);
+
+ if (plt_rel != NULL && plt_rel->output_section() != NULL)
+ {
+ odyn->add_section_size(elfcpp::DT_PLTRELSZ, plt_rel->output_section());
+ odyn->add_section_address(elfcpp::DT_JMPREL, plt_rel->output_section());
+ odyn->add_constant(elfcpp::DT_PLTREL,
+ use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA);
+ }
+
+ if (dyn_rel != NULL && dyn_rel->output_section() != NULL)
+ {
+ odyn->add_section_address(use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA,
+ dyn_rel);
+ if (plt_rel != NULL && dynrel_includes_plt)
+ odyn->add_section_size(use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ,
+ dyn_rel, plt_rel);
+ else
+ odyn->add_section_size(use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ,
+ dyn_rel);
+ const int size = parameters->target().get_size();
+ elfcpp::DT rel_tag;
+ int rel_size;
+ if (use_rel)
+ {
+ rel_tag = elfcpp::DT_RELENT;
+ if (size == 32)
+ rel_size = Reloc_types<elfcpp::SHT_REL, 32, false>::reloc_size;
+ else if (size == 64)
+ rel_size = Reloc_types<elfcpp::SHT_REL, 64, false>::reloc_size;
+ else
+ gold_unreachable();
+ }
+ else
+ {
+ rel_tag = elfcpp::DT_RELAENT;
+ if (size == 32)
+ rel_size = Reloc_types<elfcpp::SHT_RELA, 32, false>::reloc_size;
+ else if (size == 64)
+ rel_size = Reloc_types<elfcpp::SHT_RELA, 64, false>::reloc_size;
+ else
+ gold_unreachable();
+ }
+ odyn->add_constant(rel_tag, rel_size);
+
+ if (parameters->options().combreloc())
+ {
+ size_t c = dyn_rel->relative_reloc_count();
+ if (c > 0)
+ odyn->add_constant((use_rel
+ ? elfcpp::DT_RELCOUNT
+ : elfcpp::DT_RELACOUNT),
+ c);
+ }
+ }
+
+ if (add_debug && !parameters->options().shared())
+ {
+ // The value of the DT_DEBUG tag is filled in by the dynamic
+ // linker at run time, and used by the debugger.
+ odyn->add_constant(elfcpp::DT_DEBUG, 0);
}
}
Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC,
(elfcpp::PF_R
| elfcpp::PF_W));
- oseg->add_output_section(this->dynamic_section_,
- elfcpp::PF_R | elfcpp::PF_W,
- false);
+ oseg->add_output_section_to_nonload(this->dynamic_section_,
+ elfcpp::PF_R | elfcpp::PF_W);
}
Output_data_dynamic* const odyn = this->dynamic_data_;
++p)
{
if (!(*p)->is_needed()
+ && !(*p)->is_incremental()
&& (*p)->input_file()->options().as_needed())
{
// This dynamic object was linked with --as-needed, but it
++p)
{
if (((*p)->flags() & elfcpp::PF_W) == 0
- && (*p)->dynamic_reloc_count() > 0)
+ && (*p)->has_dynamic_reloc())
{
have_textrel = true;
break;
{
if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0
&& ((*p)->flags() & elfcpp::SHF_WRITE) == 0
- && ((*p)->dynamic_reloc_count() > 0))
+ && ((*p)->has_dynamic_reloc()))
{
have_textrel = true;
break;
// Add a DT_TEXTREL for compatibility with older loaders.
odyn->add_constant(elfcpp::DT_TEXTREL, 0);
flags |= elfcpp::DF_TEXTREL;
+
+ if (parameters->options().text())
+ gold_error(_("read-only segment has dynamic relocations"));
+ else if (parameters->options().warn_shared_textrel()
+ && parameters->options().shared())
+ gold_warning(_("shared library text segment is not shareable"));
}
if (parameters->options().shared() && this->has_static_tls())
flags |= elfcpp::DF_STATIC_TLS;
odyn->add_constant(elfcpp::DT_FLAGS_1, flags);
}
+// Set the size of the _DYNAMIC symbol table to be the size of the
+// dynamic data.
+
+void
+Layout::set_dynamic_symbol_size(const Symbol_table* symtab)
+{
+ Output_data_dynamic* const odyn = this->dynamic_data_;
+ odyn->finalize_data_size();
+ off_t data_size = odyn->data_size();
+ const int size = parameters->target().get_size();
+ if (size == 32)
+ symtab->get_sized_symbol<32>(this->dynamic_symbol_)->set_symsize(data_size);
+ else if (size == 64)
+ symtab->get_sized_symbol<64>(this->dynamic_symbol_)->set_symsize(data_size);
+ else
+ gold_unreachable();
+}
+
// The mapping of input section name prefixes to output section names.
// In some cases one prefix is itself a prefix of another prefix; in
// such a case the longer prefix must come first. These prefixes are
MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
- MAPPING_INIT(".ARM.extab.", ".ARM.extab"),
+ MAPPING_INIT(".ARM.extab", ".ARM.extab"),
MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
- MAPPING_INIT(".ARM.exidx.", ".ARM.exidx"),
+ MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
};
#undef MAPPING_INIT
return oseg;
}
+// Return the file offset of the normal symbol table.
+
+off_t
+Layout::symtab_section_offset() const
+{
+ if (this->symtab_section_ != NULL)
+ return this->symtab_section_->offset();
+ return 0;
+}
+
// Write out the Output_sections. Most won't have anything to write,
// since most of the data will come from input sections which are
// handled elsewhere. But some Output_sections do have Output_data.
// Instantiate the templates we need. We could use the configure
// script to restrict this to only the ones for implemented targets.
+#ifdef HAVE_TARGET_32_LITTLE
+template
+Output_section*
+Layout::init_fixed_output_section<32, false>(
+ const char* name,
+ elfcpp::Shdr<32, false>& shdr);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+Output_section*
+Layout::init_fixed_output_section<32, true>(
+ const char* name,
+ elfcpp::Shdr<32, true>& shdr);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+Output_section*
+Layout::init_fixed_output_section<64, false>(
+ const char* name,
+ elfcpp::Shdr<64, false>& shdr);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+Output_section*
+Layout::init_fixed_output_section<64, true>(
+ const char* name,
+ elfcpp::Shdr<64, true>& shdr);
+#endif
+
#ifdef HAVE_TARGET_32_LITTLE
template
Output_section*