#include "parameters.h"
#include "options.h"
+#include "mapfile.h"
#include "script.h"
#include "script-sections.h"
#include "output.h"
#include "dynobj.h"
#include "ehframe.h"
#include "compressed_output.h"
+#include "reduced_debug_output.h"
#include "reloc.h"
+#include "descriptors.h"
#include "layout.h"
+#include "plugin.h"
namespace gold
{
// Now we know the final size of the output file and we know where
// each piece of information goes.
+
+ if (this->mapfile_ != NULL)
+ {
+ this->mapfile_->print_discarded_sections(this->input_objects_);
+ 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();
special_output_list_(),
section_headers_(NULL),
tls_segment_(NULL),
+ relro_segment_(NULL),
symtab_section_(NULL),
symtab_xindex_(NULL),
dynsym_section_(NULL),
added_eh_frame_data_(false),
eh_frame_hdr_section_(NULL),
build_id_note_(NULL),
+ debug_abbrev_(NULL),
+ debug_info_(NULL),
group_signatures_(),
output_file_size_(-1),
input_requires_executable_stack_(false),
".debug_str",
};
+static const char* lines_only_debug_sections[] =
+{ ".debug_abbrev",
+ // ".debug_aranges", // not used by gdb as of 6.7.1
+ // ".debug_frame",
+ ".debug_info",
+ ".debug_line",
+ // ".debug_loc",
+ // ".debug_macinfo",
+ // ".debug_pubnames", // not used by gdb as of 6.7.1
+ // ".debug_ranges",
+ ".debug_str",
+};
+
static inline bool
is_gdb_debug_section(const char* str)
{
return false;
}
+static inline bool
+is_lines_only_debug_section(const char* str)
+{
+ // We can do this faster: binary search or a hashtable. But why bother?
+ for (size_t i = 0;
+ i < sizeof(lines_only_debug_sections)/sizeof(*lines_only_debug_sections);
+ ++i)
+ if (strcmp(str, lines_only_debug_sections[i]) == 0)
+ return true;
+ return false;
+}
+
// Whether to include this section in the link.
template<int size, bool big_endian>
Layout::include_section(Sized_relobj<size, big_endian>*, const char* name,
const elfcpp::Shdr<size, big_endian>& shdr)
{
+ if (shdr.get_sh_flags() & elfcpp::SHF_EXCLUDE)
+ return false;
+
switch (shdr.get_sh_type())
{
case elfcpp::SHT_NULL:
case elfcpp::SHT_SYMTAB:
case elfcpp::SHT_DYNSYM:
- case elfcpp::SHT_STRTAB:
case elfcpp::SHT_HASH:
case elfcpp::SHT_DYNAMIC:
case elfcpp::SHT_SYMTAB_SHNDX:
return false;
+ case elfcpp::SHT_STRTAB:
+ // Discard the sections which have special meanings in the ELF
+ // ABI. Keep others (e.g., .stabstr). We could also do this by
+ // checking the sh_link fields of the appropriate sections.
+ return (strcmp(name, ".dynstr") != 0
+ && strcmp(name, ".strtab") != 0
+ && strcmp(name, ".shstrtab") != 0);
+
case elfcpp::SHT_RELA:
case elfcpp::SHT_REL:
case elfcpp::SHT_GROUP:
case elfcpp::SHT_PROGBITS:
if (parameters->options().strip_debug()
&& (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+ {
+ if (is_debug_info_section(name))
+ return false;
+ }
+ if (parameters->options().strip_debug_non_line()
+ && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
{
// Debugging sections can only be recognized by name.
if (is_prefix_of(".debug", name)
- || is_prefix_of(".gnu.linkonce.wi.", name)
- || is_prefix_of(".line", name)
- || is_prefix_of(".stab", name))
+ && !is_lines_only_debug_section(name))
return false;
}
if (parameters->options().strip_debug_gdb()
&& !is_gdb_debug_section(name))
return false;
}
+ if (parameters->options().strip_lto_sections()
+ && !parameters->options().relocatable()
+ && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+ {
+ // Ignore LTO sections containing intermediate code.
+ if (is_prefix_of(".gnu.lto_", name))
+ return false;
+ }
return true;
default:
const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
unsigned int reloc_shndx, unsigned int, off_t* off)
{
+ *off = 0;
+
if (!this->include_section(object, name, shdr))
return NULL;
const char* group_section_name,
const char* signature,
const elfcpp::Shdr<size, big_endian>& shdr,
- const elfcpp::Elf_Word* contents)
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes)
{
gold_assert(parameters->options().relocatable());
gold_assert(shdr.get_sh_type() == elfcpp::SHT_GROUP);
section_size_type entry_count =
convert_to_section_size_type(shdr.get_sh_size() / 4);
Output_section_data* posd =
- new Output_data_group<size, big_endian>(object, entry_count, contents);
+ new Output_data_group<size, big_endian>(object, entry_count, flags,
+ shndxes);
os->add_output_section_data(posd);
}
return os;
}
-// Add POSD to an output section using NAME, TYPE, and FLAGS.
+// Add POSD to an output section using NAME, TYPE, and FLAGS. Return
+// the output section.
-void
+Output_section*
Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
elfcpp::Elf_Xword flags,
Output_section_data* posd)
false);
if (os != NULL)
os->add_output_section_data(posd);
+ return os;
}
// Map section flags to segment flags.
&& strcmp(this->options_.compress_debug_sections(), "none") != 0
&& is_compressible_debug_section(name))
os = new Output_compressed_section(&this->options_, name, type, flags);
- else
+
+ else if ((flags & elfcpp::SHF_ALLOC) == 0
+ && this->options_.strip_debug_non_line()
+ && strcmp(".debug_abbrev", name) == 0)
+ {
+ os = this->debug_abbrev_ = new Output_reduced_debug_abbrev_section(
+ name, type, flags);
+ if (this->debug_info_)
+ this->debug_info_->set_abbreviations(this->debug_abbrev_);
+ }
+ else if ((flags & elfcpp::SHF_ALLOC) == 0
+ && this->options_.strip_debug_non_line()
+ && strcmp(".debug_info", name) == 0)
+ {
+ os = this->debug_info_ = new Output_reduced_debug_info_section(
+ name, type, flags);
+ if (this->debug_abbrev_)
+ this->debug_info_->set_abbreviations(this->debug_abbrev_);
+ }
+ else
os = new Output_section(name, type, flags);
this->section_list_.push_back(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();
+ }
+ }
+
// If we have already attached the sections to segments, then we
// need to attach this one now. This happens for sections created
// directly by the linker.
++p)
{
if ((*p)->type() == elfcpp::PT_LOAD
- && ((*p)->flags() & elfcpp::PF_W) == (seg_flags & elfcpp::PF_W))
+ && (parameters->options().omagic()
+ || ((*p)->flags() & elfcpp::PF_W) == (seg_flags & elfcpp::PF_W)))
{
// If -Tbss was specified, we need to separate the data
// and BSS segments.
if ((flags & elfcpp::SHF_TLS) != 0)
{
if (this->tls_segment_ == NULL)
- this->tls_segment_ = this->make_output_segment(elfcpp::PT_TLS,
- seg_flags);
+ this->make_output_segment(elfcpp::PT_TLS, seg_flags);
this->tls_segment_->add_output_section(os, seg_flags);
}
+
+ // If -z relro is in effect, and we see a relro section, we create a
+ // PT_GNU_RELRO segment. There can only be one such segment.
+ if (os->is_relro() && parameters->options().relro())
+ {
+ 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);
+ }
}
// Make an output section for a script.
(elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE),
false);
+ this->dynamic_section_->set_is_relro();
symtab->define_in_output_data("_DYNAMIC", NULL, this->dynamic_section_, 0, 0,
elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
{
if ((*p)->type() == elfcpp::PT_LOAD
&& ((*p)->flags() & elfcpp::PF_R) != 0
- && ((*p)->flags() & elfcpp::PF_W) == 0)
+ && (parameters->options().omagic()
+ || ((*p)->flags() & elfcpp::PF_W) == 0))
return *p;
}
elfcpp::SHT_NOTE,
flags);
Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz,
- size / 8);
+ size / 8,
+ "** note header");
os->add_output_section_data(posd);
*trailing_padding = aligned_descsz - descsz;
if (trailing_padding > 0)
{
- posd = new Output_data_fixed_space(trailing_padding, 0);
+ posd = new Output_data_zero_fill(trailing_padding, 0);
os->add_output_section_data(posd);
}
}
char buffer[uuidsz];
memset(buffer, 0, uuidsz);
- int descriptor = ::open("/dev/urandom", O_RDONLY);
+ int descriptor = open_descriptor(-1, "/dev/urandom", O_RDONLY);
if (descriptor < 0)
gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
strerror(errno));
else
{
ssize_t got = ::read(descriptor, buffer, uuidsz);
- ::close(descriptor);
+ release_descriptor(descriptor, true);
if (got < 0)
gold_error(_("/dev/urandom: read failed: %s"), strerror(errno));
else if (static_cast<size_t>(got) != uuidsz)
if (trailing_padding != 0)
{
- posd = new Output_data_fixed_space(trailing_padding, 0);
+ posd = new Output_data_zero_fill(trailing_padding, 0);
os->add_output_section_data(posd);
}
}
// We need to compute a checksum after we have completed the
// link.
gold_assert(trailing_padding == 0);
- this->build_id_note_ = new Output_data_fixed_space(descsz, 4);
+ this->build_id_note_ = new Output_data_zero_fill(descsz, 4);
os->add_output_section_data(this->build_id_note_);
os->set_after_input_sections();
}
if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD)
return false;
- // We put the PT_TLS segment last, because that is where the dynamic
- // linker expects to find it (this is just for efficiency; other
- // positions would also work correctly).
- if (type1 == elfcpp::PT_TLS && type2 != elfcpp::PT_TLS)
+ // We put the PT_TLS segment last except for the PT_GNU_RELRO
+ // segment, because that is where the dynamic linker expects to find
+ // it (this is just for efficiency; other positions would also work
+ // correctly).
+ if (type1 == elfcpp::PT_TLS
+ && type2 != elfcpp::PT_TLS
+ && type2 != elfcpp::PT_GNU_RELRO)
+ return false;
+ if (type2 == elfcpp::PT_TLS
+ && type1 != elfcpp::PT_TLS
+ && type1 != elfcpp::PT_GNU_RELRO)
+ return true;
+
+ // We put the PT_GNU_RELRO segment last, because that is where the
+ // dynamic linker expects to find it (as with PT_TLS, this is just
+ // for efficiency).
+ if (type1 == elfcpp::PT_GNU_RELRO && type2 != elfcpp::PT_GNU_RELRO)
return false;
- if (type2 == elfcpp::PT_TLS && type1 != elfcpp::PT_TLS)
+ if (type2 == elfcpp::PT_GNU_RELRO && type1 != elfcpp::PT_GNU_RELRO)
return true;
const elfcpp::Elf_Word flags1 = seg1->flags();
}
}
+ 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();
uint64_t aligned_addr = 0;
uint64_t abi_pagesize = target->abi_pagesize();
+ uint64_t common_pagesize = target->common_pagesize();
- // FIXME: This should depend on the -n and -N options.
- (*p)->set_minimum_p_align(target->common_pagesize());
+ if (!parameters->options().nmagic()
+ && !parameters->options().omagic())
+ (*p)->set_minimum_p_align(common_pagesize);
if (are_addresses_set)
{
- // Adjust the file offset to the same address modulo the
- // page size.
- uint64_t unsigned_off = off;
- uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1))
- | (addr & (abi_pagesize - 1)));
- if (aligned_off < unsigned_off)
- aligned_off += abi_pagesize;
- off = aligned_off;
+ if (!parameters->options().nmagic()
+ && !parameters->options().omagic())
+ {
+ // Adjust the file offset to the same address modulo
+ // the page size.
+ uint64_t unsigned_off = off;
+ uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1))
+ | (addr & (abi_pagesize - 1)));
+ if (aligned_off < unsigned_off)
+ aligned_off += abi_pagesize;
+ off = aligned_off;
+ }
}
else
{
if (!are_addresses_set && aligned_addr != addr)
{
- uint64_t common_pagesize = target->common_pagesize();
uint64_t first_off = (common_pagesize
- (aligned_addr
& (common_pagesize - 1)));
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)
+ {
+ gold_assert(last_load_segment->paddr() <= (*p)->paddr());
+ if (last_load_segment->paddr() + last_load_segment->memsz()
+ > (*p)->paddr())
+ {
+ unsigned long long lb1 = last_load_segment->paddr();
+ unsigned long long le1 = lb1 + last_load_segment->memsz();
+ unsigned long long lb2 = (*p)->paddr();
+ unsigned long long le2 = lb2 + (*p)->memsz();
+ gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
+ "[0x%llx -> 0x%llx]"),
+ lb1, le1, lb2, le2);
+ }
+ }
+ last_load_segment = *p;
}
}
this->symtab_section_ = osymtab;
Output_section_data* pos = new Output_data_fixed_space(off - startoff,
- align);
+ align,
+ "** symtab");
osymtab->add_output_section_data(pos);
// We generate a .symtab_shndx section if we have more than
false);
Output_section_data* odata = new Output_data_fixed_space(index * symsize,
- align);
+ align,
+ "** dynsym");
dynsym->add_output_section_data(odata);
dynsym->set_info(local_symcount);
Output_section_data* hashdata = new Output_data_const_buffer(phash,
hashlen,
- align);
+ align,
+ "** hash");
hashsec->add_output_section_data(hashdata);
hashsec->set_link_section(dynsym);
Output_section_data* hashdata = new Output_data_const_buffer(phash,
hashlen,
- align);
+ align,
+ "** hash");
hashsec->add_output_section_data(hashdata);
hashsec->set_link_section(dynsym);
dynamic_symbols,
&vbuf, &vsize);
- Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2);
+ Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2,
+ "** versions");
vsec->add_output_section_data(vdata);
vsec->set_entsize(2);
versions->def_section_contents<size, big_endian>(&this->dynpool_, &vdbuf,
&vdsize, &vdentries);
- Output_section_data* vddata = new Output_data_const_buffer(vdbuf,
- vdsize,
- 4);
+ Output_section_data* vddata =
+ new Output_data_const_buffer(vdbuf, vdsize, 4, "** version defs");
vdsec->add_output_section_data(vddata);
vdsec->set_link_section(dynstr);
&vnbuf, &vnsize,
&vnentries);
- Output_section_data* vndata = new Output_data_const_buffer(vnbuf,
- vnsize,
- 4);
+ Output_section_data* vndata =
+ new Output_data_const_buffer(vnbuf, vnsize, 4, "** version refs");
vnsec->add_output_section_data(vndata);
vnsec->set_link_section(dynstr);
{
Output_segment* oseg = this->make_output_segment(elfcpp::PT_INTERP,
elfcpp::PF_R);
- oseg->add_initial_output_section(osec, elfcpp::PF_R);
+ oseg->add_output_section(osec, elfcpp::PF_R);
}
}
Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC,
(elfcpp::PF_R
| elfcpp::PF_W));
- oseg->add_initial_output_section(this->dynamic_section_,
- elfcpp::PF_R | elfcpp::PF_W);
+ oseg->add_output_section(this->dynamic_section_,
+ elfcpp::PF_R | elfcpp::PF_W);
}
Output_data_dynamic* const odyn = this->dynamic_data_;
}
if (parameters->options().shared() && this->has_static_tls())
flags |= elfcpp::DF_STATIC_TLS;
+ if (parameters->options().origin())
+ flags |= elfcpp::DF_ORIGIN;
odyn->add_constant(elfcpp::DT_FLAGS, flags);
flags = 0;
flags &= ~(elfcpp::DF_1_INITFIRST
| elfcpp::DF_1_NODELETE
| elfcpp::DF_1_NOOPEN);
+ if (parameters->options().origin())
+ flags |= elfcpp::DF_1_ORIGIN;
if (flags)
odyn->add_constant(elfcpp::DT_FLAGS_1, flags);
}
#define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
const Layout::Linkonce_mapping Layout::linkonce_mapping[] =
{
- MAPPING_INIT("d.rel.ro", ".data.rel.ro"), // Must be before "d".
+ MAPPING_INIT("d.rel.ro.local", ".data.rel.ro.local"), // Before "d.rel.ro".
+ MAPPING_INIT("d.rel.ro", ".data.rel.ro"), // Before "d".
MAPPING_INIT("t", ".text"),
MAPPING_INIT("r", ".rodata"),
MAPPING_INIT("d", ".data"),
// initial '.', we use the name unchanged (i.e., "mysection" and
// ".text" are unchanged).
+ // If the name starts with ".data.rel.ro.local" we use
+ // ".data.rel.ro.local".
+
// If the name starts with ".data.rel.ro" we use ".data.rel.ro".
// Otherwise, we drop the second '.' and everything that comes after
if (sdot == NULL)
return name;
+ const char* const data_rel_ro_local = ".data.rel.ro.local";
+ if (strncmp(name, data_rel_ro_local, strlen(data_rel_ro_local)) == 0)
+ {
+ *plen = strlen(data_rel_ro_local);
+ return data_rel_ro_local;
+ }
+
const char* const data_rel_ro = ".data.rel.ro";
if (strncmp(name, data_rel_ro, strlen(data_rel_ro)) == 0)
{
// want a linkonce signature to block another linkonce signature.
bool
-Layout::add_comdat(const char* signature, bool group)
+Layout::add_comdat(Relobj* object, unsigned int shndx,
+ const std::string& signature, bool group)
{
- std::string sig(signature);
+ Kept_section kept(object, shndx, group);
std::pair<Signatures::iterator, bool> ins(
- this->signatures_.insert(std::make_pair(sig, group)));
+ this->signatures_.insert(std::make_pair(signature, kept)));
if (ins.second)
{
return true;
}
- if (ins.first->second)
+ if (ins.first->second.group_)
{
// We've already seen a real section group with this signature.
+ // If the kept group is from a plugin object, and we're in
+ // the replacement phase, accept the new one as a replacement.
+ if (ins.first->second.object_ == NULL
+ && parameters->options().plugins()->in_replacement_phase())
+ {
+ ins.first->second = kept;
+ return true;
+ }
return false;
}
else if (group)
// This is a real section group, and we've already seen a
// linkonce section with this signature. Record that we've seen
// a section group, and don't include this section group.
- ins.first->second = true;
+ ins.first->second.group_ = true;
return false;
}
else
}
}
+// Find the given comdat signature, and return the object and section
+// index of the kept group.
+Relobj*
+Layout::find_kept_object(const std::string& signature,
+ unsigned int* pshndx) const
+{
+ Signatures::const_iterator p = this->signatures_.find(signature);
+ if (p == this->signatures_.end())
+ return NULL;
+ if (pshndx != NULL)
+ *pshndx = p->second.shndx_;
+ return p->second.object_;
+}
+
// Store the allocated sections into the section list.
void
gold_assert(!parameters->options().relocatable());
Output_segment* oseg = new Output_segment(type, flags);
this->segment_list_.push_back(oseg);
+
+ if (type == elfcpp::PT_TLS)
+ this->tls_segment_ = oseg;
+ else if (type == elfcpp::PT_GNU_RELRO)
+ this->relro_segment_ = oseg;
+
return oseg;
}
out.close();
}
+// Print the output sections to the map file.
+
+void
+Layout::print_to_mapfile(Mapfile* mapfile) const
+{
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ (*p)->print_sections_to_mapfile(mapfile);
+}
+
// Print statistical information to stderr. This is used for --stats.
void
const char* group_section_name,
const char* signature,
const elfcpp::Shdr<32, false>& shdr,
- const elfcpp::Elf_Word* contents);
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
#endif
#ifdef HAVE_TARGET_32_BIG
const char* group_section_name,
const char* signature,
const elfcpp::Shdr<32, true>& shdr,
- const elfcpp::Elf_Word* contents);
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
#endif
#ifdef HAVE_TARGET_64_LITTLE
const char* group_section_name,
const char* signature,
const elfcpp::Shdr<64, false>& shdr,
- const elfcpp::Elf_Word* contents);
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
#endif
#ifdef HAVE_TARGET_64_BIG
const char* group_section_name,
const char* signature,
const elfcpp::Shdr<64, true>& shdr,
- const elfcpp::Elf_Word* contents);
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
#endif
#ifdef HAVE_TARGET_32_LITTLE