* layout.cc (Layout::Layout): Initialize relro_segment_.
(Layout::add_output_section_data): Return the output section.
(Layout::make_output_section): Rcognize relro sections and mark
them appropriately.
(Layout::attach_allocated_section_to_segment): Put relro sections
in a PT_GNU_RELRO segment.
(Layout::create_initial_dynamic_sections): Mark the .dynamic
section as relro.
(Layout::segment_precedes): Sort PT_GNU_RELRO segments after
PT_TLS segments.
(Layout::linkonce_mapping): Map d.rel.ro.local to
.data.rel.ro.local.
(Layout::output_section_name): Us .data.rel.ro.local for any
section which begins with that.
* layout.h (class Layout): Update add_output_section_data
declaration. Add relro_segment_ field.
* output.cc (Output_section::Output_section): Initialize is_relro_
and is_relro_local_ fields.
(Output_segment::add_output_section): Group relro sections.
(Output_segment::is_first_section_relro): New function.
(Output_segment::maximum_alignment): If there is a relro section,
align the segment to the common page size.
(Output_segment::set_section_addresses): Track whether we are
looking at relro sections. If the last section is a relro
section, align to the common page size.
(Output_segment::set_section_list_addresses): Add in_relro
parameter. Change all callers. Align to the page size when
moving from relro to non-relro section.
(Output_segment::set_offset): Align memsz of a PT_GNU_RELRO
segment.
* output.h (class Output_section): Add is_relro_ and
is_relro_local_ fields.
(Output_section::is_relro): New function.
(Output_section::set_is_relro): New function.
(Output_section::is_relro_local): New function.
(Output_section::set_is_relro_local): New function.
(class Output_segment): Update declarations.
* i386.cc (Target_i386::got_section): Mark .got section as relro.
* sparc.cc (Target_sparc::got_section): Likewise.
* x86_64.cc (Target_x86_64::got_section): Likewise.
* testsuite/relro_test_main.cc: New file.
* testsuite/relro_test.cc: New file.
* testsuite/Makefile.am (check_PROGRAMS): Add relro_test.
(relro_test_SOURCES, relro_test_DEPENDENCIES): New variables.
(relro_test_LDFLAGS, relro_test_LDADD): New variables.
(relro_test.so, relro_test_pic.o): New targets.
* testsuite/Makefile.in: Rebuild.
+2008-05-19 Ian Lance Taylor <iant@google.com>
+
+ * options.h (class General_options): Add -z relro.
+ * layout.cc (Layout::Layout): Initialize relro_segment_.
+ (Layout::add_output_section_data): Return the output section.
+ (Layout::make_output_section): Rcognize relro sections and mark
+ them appropriately.
+ (Layout::attach_allocated_section_to_segment): Put relro sections
+ in a PT_GNU_RELRO segment.
+ (Layout::create_initial_dynamic_sections): Mark the .dynamic
+ section as relro.
+ (Layout::segment_precedes): Sort PT_GNU_RELRO segments after
+ PT_TLS segments.
+ (Layout::linkonce_mapping): Map d.rel.ro.local to
+ .data.rel.ro.local.
+ (Layout::output_section_name): Us .data.rel.ro.local for any
+ section which begins with that.
+ * layout.h (class Layout): Update add_output_section_data
+ declaration. Add relro_segment_ field.
+ * output.cc (Output_section::Output_section): Initialize is_relro_
+ and is_relro_local_ fields.
+ (Output_segment::add_output_section): Group relro sections.
+ (Output_segment::is_first_section_relro): New function.
+ (Output_segment::maximum_alignment): If there is a relro section,
+ align the segment to the common page size.
+ (Output_segment::set_section_addresses): Track whether we are
+ looking at relro sections. If the last section is a relro
+ section, align to the common page size.
+ (Output_segment::set_section_list_addresses): Add in_relro
+ parameter. Change all callers. Align to the page size when
+ moving from relro to non-relro section.
+ (Output_segment::set_offset): Align memsz of a PT_GNU_RELRO
+ segment.
+ * output.h (class Output_section): Add is_relro_ and
+ is_relro_local_ fields.
+ (Output_section::is_relro): New function.
+ (Output_section::set_is_relro): New function.
+ (Output_section::is_relro_local): New function.
+ (Output_section::set_is_relro_local): New function.
+ (class Output_segment): Update declarations.
+ * i386.cc (Target_i386::got_section): Mark .got section as relro.
+ * sparc.cc (Target_sparc::got_section): Likewise.
+ * x86_64.cc (Target_x86_64::got_section): Likewise.
+ * testsuite/relro_test_main.cc: New file.
+ * testsuite/relro_test.cc: New file.
+ * testsuite/Makefile.am (check_PROGRAMS): Add relro_test.
+ (relro_test_SOURCES, relro_test_DEPENDENCIES): New variables.
+ (relro_test_LDFLAGS, relro_test_LDADD): New variables.
+ (relro_test.so, relro_test_pic.o): New targets.
+ * testsuite/Makefile.in: Rebuild.
+
2008-05-16 Ian Lance Taylor <iant@google.com>
* output.cc (Output_segment::add_output_section): Remove front
this->got_ = new Output_data_got<32, false>();
- layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
- this->got_);
+ Output_section* os;
+ os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_);
+ os->set_is_relro();
// The old GNU linker creates a .got.plt section. We just
// create another set of data in the .got section. Note that we
// always create a PLT if we create a GOT, although the PLT
// might be empty.
this->got_plt_ = new Output_data_space(4);
- layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
- this->got_plt_);
+ os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_plt_);
+ os->set_is_relro();
// The first three entries are reserved.
this->got_plt_->set_current_data_size(3 * 4);
special_output_list_(),
section_headers_(NULL),
tls_segment_(NULL),
+ relro_segment_(NULL),
symtab_section_(NULL),
symtab_xindex_(NULL),
dynsym_section_(NULL),
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(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.
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->relro_segment_ = 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 (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();
#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)
{
// Add an Output_section_data to the layout. This is used for
// special sections like the GOT section.
- void
+ Output_section*
add_output_section_data(const char* name, elfcpp::Elf_Word type,
elfcpp::Elf_Xword flags,
Output_section_data*);
Output_section_headers* section_headers_;
// A pointer to the PT_TLS segment if there is one.
Output_segment* tls_segment_;
+ // A pointer to the PT_GNU_RELRO segment if there is one.
+ Output_segment* relro_segment_;
// The SHT_SYMTAB output section.
Output_section* symtab_section_;
// The SHT_SYMTAB_SHNDX for the regular symbol table if there is one.
DEFINE_bool(nodump, options::DASH_Z, '\0', false,
N_("Mark DSO not available to dldump"),
NULL);
+ DEFINE_bool(relro, options::DASH_Z, '\0', false,
+ N_("Where possible mark variables read-only after relocation"),
+ N_("Don't mark variables read-only after relocation"));
public:
typedef options::Dir_list Dir_list;
may_sort_attached_input_sections_(false),
must_sort_attached_input_sections_(false),
attached_input_sections_are_sorted_(false),
+ is_relro_(false),
+ is_relro_local_(false),
tls_offset_(0)
{
// An unallocated section has no address. Forcing this means that
{
sawtls = true;
// Put a NOBITS section after the first TLS section.
- // But a PROGBITS section after the first TLS/PROGBITS
+ // Put a PROGBITS section after the first TLS/PROGBITS
// section.
insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
}
// location in the section list.
}
+ // For the PT_GNU_RELRO segment, we need to group relro sections,
+ // and we need to put them before any non-relro sections. Also,
+ // relro local sections go before relro non-local sections.
+ if (parameters->options().relro() && os->is_relro())
+ {
+ gold_assert(pdl == &this->output_data_);
+ Output_segment::Output_data_list::iterator p;
+ for (p = pdl->begin(); p != pdl->end(); ++p)
+ {
+ if (!(*p)->is_section())
+ break;
+
+ Output_section* pos = (*p)->output_section();
+ if (!pos->is_relro()
+ || (os->is_relro_local() && !pos->is_relro_local()))
+ break;
+ }
+
+ pdl->insert(p, os);
+ return;
+ }
+
pdl->push_back(os);
}
this->output_data_.push_front(od);
}
+// Return whether the first data section is a relro section.
+
+bool
+Output_segment::is_first_section_relro() const
+{
+ return (!this->output_data_.empty()
+ && this->output_data_.front()->is_section()
+ && this->output_data_.front()->output_section()->is_relro());
+}
+
// Return the maximum alignment of the Output_data in Output_segment.
uint64_t
if (addralign > this->max_align_)
this->max_align_ = addralign;
+ // If -z relro is in effect, and the first section in this
+ // segment is a relro section, then the segment must be aligned
+ // to at least the common page size. This ensures that the
+ // PT_GNU_RELRO segment will start at a page boundary.
+ if (parameters->options().relro() && this->is_first_section_relro())
+ {
+ addralign = parameters->target().common_pagesize();
+ if (addralign > this->max_align_)
+ this->max_align_ = addralign;
+ }
+
this->is_max_align_known_ = true;
}
bool in_tls = false;
+ bool in_relro = (parameters->options().relro()
+ && this->is_first_section_relro());
+
off_t orig_off = *poff;
this->offset_ = orig_off;
addr = this->set_section_list_addresses(layout, reset, &this->output_data_,
- addr, poff, pshndx, &in_tls);
+ addr, poff, pshndx, &in_tls,
+ &in_relro);
this->filesz_ = *poff - orig_off;
off_t off = *poff;
uint64_t ret = this->set_section_list_addresses(layout, reset,
&this->output_bss_,
addr, poff, pshndx,
- &in_tls);
+ &in_tls, &in_relro);
// If the last section was a TLS section, align upward to the
// alignment of the TLS segment, so that the overall size of the TLS
*poff = align_address(*poff, segment_align);
}
+ // If all the sections were relro sections, align upward to the
+ // common page size.
+ if (in_relro)
+ {
+ uint64_t page_align = parameters->target().common_pagesize();
+ *poff = align_address(*poff, page_align);
+ }
+
this->memsz_ = *poff - orig_off;
// Ignore the file offset adjustments made by the BSS Output_data
Output_data_list* pdl,
uint64_t addr, off_t* poff,
unsigned int* pshndx,
- bool* in_tls)
+ bool* in_tls, bool* in_relro)
{
off_t startoff = *poff;
}
}
+ // If this is a non-relro section after a relro section,
+ // align it to a common page boundary so that the dynamic
+ // linker has a page to mark as read-only.
+ if (*in_relro
+ && (!(*p)->is_section()
+ || !(*p)->output_section()->is_relro()))
+ {
+ uint64_t page_align = parameters->target().common_pagesize();
+ if (page_align > align)
+ align = page_align;
+ *in_relro = false;
+ }
+
off = align_address(off, align);
(*p)->set_address_and_file_offset(addr + (off - startoff), off);
}
gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
this->memsz_ = align_address(this->memsz_, segment_align);
}
+
+ // If this is a RELRO segment, align the memory size. The code in
+ // set_section_list ensures that the section after the RELRO segment
+ // is aligned to give us room.
+ if (this->type_ == elfcpp::PT_GNU_RELRO)
+ {
+ uint64_t page_align = parameters->target().common_pagesize();
+ gold_assert(this->vaddr_ == align_address(this->vaddr_, page_align));
+ this->memsz_ = align_address(this->memsz_, page_align);
+ }
}
// Set the TLS offsets of the sections in the PT_TLS segment.
set_must_sort_attached_input_sections()
{ this->must_sort_attached_input_sections_ = true; }
+ // Return whether this section holds relro data--data which has
+ // dynamic relocations but which may be marked read-only after the
+ // dynamic relocations have been completed.
+ bool
+ is_relro() const
+ { return this->is_relro_; }
+
+ // Record that this section holds relro data.
+ void
+ set_is_relro()
+ { this->is_relro_ = true; }
+
+ // True if this section holds relro local data--relro data for which
+ // the dynamic relocations are all RELATIVE relocations.
+ bool
+ is_relro_local() const
+ { return this->is_relro_local_; }
+
+ // Record that this section holds relro local data.
+ void
+ set_is_relro_local()
+ { this->is_relro_local_ = true; }
+
// Return whether this section should be written after all the input
// sections are complete.
bool
// True if the input sections attached to this output section have
// already been sorted.
bool attached_input_sections_are_sorted_ : 1;
+ // True if this section holds relro data.
+ bool is_relro_ : 1;
+ // True if this section holds relro local data.
+ bool is_relro_local_ : 1;
// For SHT_TLS sections, the offset of this section relative to the base
// of the TLS segment.
uint64_t tls_offset_;
static uint64_t
maximum_alignment_list(const Output_data_list*);
+ // Return whether the first data section is a relro section.
+ bool
+ is_first_section_relro() const;
+
// Set the section addresses in an Output_data_list.
uint64_t
set_section_list_addresses(const Layout*, bool reset, Output_data_list*,
uint64_t addr, off_t* poff, unsigned int* pshndx,
- bool* in_tls);
+ bool* in_tls, bool* in_relro);
// Return the number of Output_sections in an Output_data_list.
unsigned int
this->got_ = new Output_data_got<size, big_endian>();
- layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
- this->got_);
+ Output_section* os;
+ os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_);
+ os->set_is_relro();
// Define _GLOBAL_OFFSET_TABLE_ at the start of the .got section.
symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
protected_2_LDFLAGS = -Bgcctestdir/ -Wl,-R,.
protected_2_LDADD = protected_1.so
+check_PROGRAMS += relro_test
+relro_test_SOURCES = relro_test_main.cc
+relro_test_DEPENDENCIES = gcctestdir/ld relro_test.so
+relro_test_LDFLAGS = -Bgcctestdir/ -Wl,-R,.
+relro_test_LDADD = relro_test.so
+relro_test.so: gcctestdir/ld relro_test_pic.o
+ $(CXXLINK) -Bgcctestdir/ -shared -Wl,-z,relro relro_test_pic.o
+relro_test_pic.o: relro_test.cc
+ $(CXXCOMPILE) -c -fpic -o $@ $<
+
check_PROGRAMS += script_test_1
script_test_1_SOURCES = script_test_1.cc
script_test_1_DEPENDENCIES = gcctestdir/ld script_test_1.t
@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_19 = ver_test ver_test_2 \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ ver_test_6 ver_test_8 \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ protected_1 protected_2 \
-@GCC_TRUE@@NATIVE_LINKER_TRUE@ script_test_1 script_test_2 \
-@GCC_TRUE@@NATIVE_LINKER_TRUE@ justsyms binary_test \
-@GCC_TRUE@@NATIVE_LINKER_TRUE@ script_test_3
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ relro_test script_test_1 \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ script_test_2 justsyms \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ binary_test script_test_3
@GCC_FALSE@script_test_1_DEPENDENCIES = libgoldtest.a ../libgold.a \
@GCC_FALSE@ ../../libiberty/libiberty.a $(am__DEPENDENCIES_1) \
@GCC_FALSE@ $(am__DEPENDENCIES_1)
@GCC_TRUE@@NATIVE_LINKER_TRUE@ ver_test_8$(EXEEXT) \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ protected_1$(EXEEXT) \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ protected_2$(EXEEXT) \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ relro_test$(EXEEXT) \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ script_test_1$(EXEEXT) \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ script_test_2$(EXEEXT) \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ justsyms$(EXEEXT) \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ protected_main_1.$(OBJEXT) \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ protected_3.$(OBJEXT)
protected_2_OBJECTS = $(am_protected_2_OBJECTS)
+am__relro_test_SOURCES_DIST = relro_test_main.cc
+@GCC_TRUE@@NATIVE_LINKER_TRUE@am_relro_test_OBJECTS = \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ relro_test_main.$(OBJEXT)
+relro_test_OBJECTS = $(am_relro_test_OBJECTS)
am__script_test_1_SOURCES_DIST = script_test_1.cc
@GCC_TRUE@@NATIVE_LINKER_TRUE@am_script_test_1_OBJECTS = \
@GCC_TRUE@@NATIVE_LINKER_TRUE@ script_test_1.$(OBJEXT)
$(initpri1_SOURCES) $(justsyms_SOURCES) many_sections_r_test.c \
$(many_sections_test_SOURCES) $(object_unittest_SOURCES) \
$(protected_1_SOURCES) $(protected_2_SOURCES) \
- $(script_test_1_SOURCES) $(script_test_2_SOURCES) \
- script_test_3.c $(tls_pic_test_SOURCES) \
- $(tls_shared_gd_to_ie_test_SOURCES) \
+ $(relro_test_SOURCES) $(script_test_1_SOURCES) \
+ $(script_test_2_SOURCES) script_test_3.c \
+ $(tls_pic_test_SOURCES) $(tls_shared_gd_to_ie_test_SOURCES) \
$(tls_shared_gnu2_gd_to_ie_test_SOURCES) \
$(tls_shared_gnu2_test_SOURCES) $(tls_shared_ie_test_SOURCES) \
$(tls_shared_nonpic_test_SOURCES) $(tls_shared_test_SOURCES) \
$(am__initpri1_SOURCES_DIST) $(am__justsyms_SOURCES_DIST) \
many_sections_r_test.c $(am__many_sections_test_SOURCES_DIST) \
$(object_unittest_SOURCES) $(am__protected_1_SOURCES_DIST) \
- $(am__protected_2_SOURCES_DIST) \
+ $(am__protected_2_SOURCES_DIST) $(am__relro_test_SOURCES_DIST) \
$(am__script_test_1_SOURCES_DIST) \
$(am__script_test_2_SOURCES_DIST) script_test_3.c \
$(am__tls_pic_test_SOURCES_DIST) \
@GCC_TRUE@@NATIVE_LINKER_TRUE@protected_2_DEPENDENCIES = gcctestdir/ld protected_1.so
@GCC_TRUE@@NATIVE_LINKER_TRUE@protected_2_LDFLAGS = -Bgcctestdir/ -Wl,-R,.
@GCC_TRUE@@NATIVE_LINKER_TRUE@protected_2_LDADD = protected_1.so
+@GCC_TRUE@@NATIVE_LINKER_TRUE@relro_test_SOURCES = relro_test_main.cc
+@GCC_TRUE@@NATIVE_LINKER_TRUE@relro_test_DEPENDENCIES = gcctestdir/ld relro_test.so
+@GCC_TRUE@@NATIVE_LINKER_TRUE@relro_test_LDFLAGS = -Bgcctestdir/ -Wl,-R,.
+@GCC_TRUE@@NATIVE_LINKER_TRUE@relro_test_LDADD = relro_test.so
@GCC_TRUE@@NATIVE_LINKER_TRUE@script_test_1_SOURCES = script_test_1.cc
@GCC_TRUE@@NATIVE_LINKER_TRUE@script_test_1_DEPENDENCIES = gcctestdir/ld script_test_1.t
@GCC_TRUE@@NATIVE_LINKER_TRUE@script_test_1_LDFLAGS = -Bgcctestdir/ -Wl,-R,. -T $(srcdir)/script_test_1.t
protected_2$(EXEEXT): $(protected_2_OBJECTS) $(protected_2_DEPENDENCIES)
@rm -f protected_2$(EXEEXT)
$(CXXLINK) $(protected_2_LDFLAGS) $(protected_2_OBJECTS) $(protected_2_LDADD) $(LIBS)
+relro_test$(EXEEXT): $(relro_test_OBJECTS) $(relro_test_DEPENDENCIES)
+ @rm -f relro_test$(EXEEXT)
+ $(CXXLINK) $(relro_test_LDFLAGS) $(relro_test_OBJECTS) $(relro_test_LDADD) $(LIBS)
script_test_1$(EXEEXT): $(script_test_1_OBJECTS) $(script_test_1_DEPENDENCIES)
@rm -f script_test_1$(EXEEXT)
$(CXXLINK) $(script_test_1_LDFLAGS) $(script_test_1_OBJECTS) $(script_test_1_LDADD) $(LIBS)
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/protected_main_1.Po@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/protected_main_2.Po@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/protected_main_3.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/relro_test_main.Po@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/script_test_1.Po@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/script_test_2.Po@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/script_test_2a.Po@am__quote@
@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXCOMPILE) -c -fpic -o $@ $<
@GCC_TRUE@@NATIVE_LINKER_TRUE@protected_3_pic.o: protected_3.cc
@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXCOMPILE) -c -fpic -o $@ $<
+@GCC_TRUE@@NATIVE_LINKER_TRUE@relro_test.so: gcctestdir/ld relro_test_pic.o
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXLINK) -Bgcctestdir/ -shared -Wl,-z,relro relro_test_pic.o
+@GCC_TRUE@@NATIVE_LINKER_TRUE@relro_test_pic.o: relro_test.cc
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXCOMPILE) -c -fpic -o $@ $<
@GCC_TRUE@@NATIVE_LINKER_TRUE@justsyms_2.o: justsyms_2.cc
@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXCOMPILE) -c -o $@ $<
@GCC_TRUE@@NATIVE_LINKER_TRUE@justsyms_2r.o: justsyms_2.o gcctestdir/ld $(srcdir)/justsyms.t
--- /dev/null
+// relro_test.cc -- test -z relro for gold
+
+// Copyright 2008 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#include <cassert>
+#include <csignal>
+#include <stdint.h>
+#include <unistd.h>
+
+// This code is put into a shared library linked with -z relro.
+
+// i1 and i2 are not relro variables.
+int i1 = 1;
+static int i2 = 2;
+
+// P1 is a global relro variable.
+int* const p1 = &i1;
+
+// P2 is a local relro variable.
+int* const p2 = &i2;
+
+// Test symbol addresses.
+
+bool
+t1()
+{
+ void* i1addr = static_cast<void*>(&i1);
+ void* i2addr = static_cast<void*>(&i2);
+ const void* p1addr = static_cast<const void*>(&p1);
+ const void* p2addr = static_cast<const void*>(&p2);
+
+ // The relro variables should precede the non-relro variables in the
+ // memory image.
+ assert(i1addr > p1addr);
+ assert(i1addr > p2addr);
+ assert(i2addr > p1addr);
+ assert(i2addr > p2addr);
+
+ // The relro variables should not be on the same page as the
+ // non-relro variables.
+ const size_t page_size = getpagesize();
+ uintptr_t i1page = reinterpret_cast<uintptr_t>(i1addr) & ~ (page_size - 1);
+ uintptr_t i2page = reinterpret_cast<uintptr_t>(i2addr) & ~ (page_size - 1);
+ uintptr_t p1page = reinterpret_cast<uintptr_t>(p1addr) & ~ (page_size - 1);
+ uintptr_t p2page = reinterpret_cast<uintptr_t>(p2addr) & ~ (page_size - 1);
+ assert(i1page != p1page);
+ assert(i1page != p2page);
+ assert(i2page != p1page);
+ assert(i2page != p2page);
+
+ return true;
+}
+
+// A signal handler for SIGSEGV.
+
+extern "C"
+void
+sigsegv_handler(int)
+{
+ throw 0;
+}
+
+// Use a separate function to throw the exception, so that we don't
+// need to use -fnon-call-exceptions.
+
+void f2() __attribute__ ((noinline));
+void
+f2()
+{
+ int** pp1 = const_cast<int**>(&p1);
+ *pp1 = &i2;
+
+ // We shouldn't get here--the assignment to *pp1 should write to
+ // memory which the dynamic linker marked as read-only, giving us a
+ // SIGSEGV, causing sigsegv_handler to be invoked, to throw past us.
+ assert(0);
+}
+
+// Changing a relro variable should give us a SIGSEGV.
+
+bool
+t2()
+{
+ signal(SIGSEGV, sigsegv_handler);
+
+ try
+ {
+ f2();
+ return false;
+ }
+ catch (int i)
+ {
+ assert(i == 0);
+ return true;
+ }
+}
--- /dev/null
+// relro_test_main.cc -- test -z relro for gold, main function
+
+// Copyright 2008 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#include <cassert>
+
+extern bool t1();
+extern bool t2();
+
+int
+main()
+{
+ assert(t1());
+ assert(t2());
+}
this->got_ = new Output_data_got<64, false>();
- layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
- this->got_);
+ Output_section* os;
+ os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_);
+ os->set_is_relro();
// The old GNU linker creates a .got.plt section. We just
// create another set of data in the .got section. Note that we
// always create a PLT if we create a GOT, although the PLT
// might be empty.
this->got_plt_ = new Output_data_space(8);
- layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
- this->got_plt_);
+ os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_plt_);
+ os->set_is_relro();
// The first three entries are reserved.
this->got_plt_->set_current_data_size(3 * 8);
projects / binutils-gdb.git / commitdiff