// script-sections.cc -- linker script SECTIONS for gold
-// Copyright 2008 Free Software Foundation, Inc.
+// Copyright 2008, 2009 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
namespace gold
{
+// Manage orphan sections. This is intended to be largely compatible
+// with the GNU linker. The Linux kernel implicitly relies on
+// something similar to the GNU linker's orphan placement. We
+// originally used a simpler scheme here, but it caused the kernel
+// build to fail, and was also rather inefficient.
+
+class Orphan_section_placement
+{
+ private:
+ typedef Script_sections::Elements_iterator Elements_iterator;
+
+ public:
+ Orphan_section_placement();
+
+ // Handle an output section during initialization of this mapping.
+ void
+ output_section_init(const std::string& name, Output_section*,
+ Elements_iterator location);
+
+ // Initialize the last location.
+ void
+ last_init(Elements_iterator location);
+
+ // Set *PWHERE to the address of an iterator pointing to the
+ // location to use for an orphan section. Return true if the
+ // iterator has a value, false otherwise.
+ bool
+ find_place(Output_section*, Elements_iterator** pwhere);
+
+ // Return the iterator being used for sections at the very end of
+ // the linker script.
+ Elements_iterator
+ last_place() const;
+
+ private:
+ // The places that we specifically recognize. This list is copied
+ // from the GNU linker.
+ enum Place_index
+ {
+ PLACE_TEXT,
+ PLACE_RODATA,
+ PLACE_DATA,
+ PLACE_BSS,
+ PLACE_REL,
+ PLACE_INTERP,
+ PLACE_NONALLOC,
+ PLACE_LAST,
+ PLACE_MAX
+ };
+
+ // The information we keep for a specific place.
+ struct Place
+ {
+ // The name of sections for this place.
+ const char* name;
+ // Whether we have a location for this place.
+ bool have_location;
+ // The iterator for this place.
+ Elements_iterator location;
+ };
+
+ // Initialize one place element.
+ void
+ initialize_place(Place_index, const char*);
+
+ // The places.
+ Place places_[PLACE_MAX];
+ // True if this is the first call to output_section_init.
+ bool first_init_;
+};
+
+// Initialize Orphan_section_placement.
+
+Orphan_section_placement::Orphan_section_placement()
+ : first_init_(true)
+{
+ this->initialize_place(PLACE_TEXT, ".text");
+ this->initialize_place(PLACE_RODATA, ".rodata");
+ this->initialize_place(PLACE_DATA, ".data");
+ this->initialize_place(PLACE_BSS, ".bss");
+ this->initialize_place(PLACE_REL, NULL);
+ this->initialize_place(PLACE_INTERP, ".interp");
+ this->initialize_place(PLACE_NONALLOC, NULL);
+ this->initialize_place(PLACE_LAST, NULL);
+}
+
+// Initialize one place element.
+
+void
+Orphan_section_placement::initialize_place(Place_index index, const char* name)
+{
+ this->places_[index].name = name;
+ this->places_[index].have_location = false;
+}
+
+// While initializing the Orphan_section_placement information, this
+// is called once for each output section named in the linker script.
+// If we found an output section during the link, it will be passed in
+// OS.
+
+void
+Orphan_section_placement::output_section_init(const std::string& name,
+ Output_section* os,
+ Elements_iterator location)
+{
+ bool first_init = this->first_init_;
+ this->first_init_ = false;
+
+ for (int i = 0; i < PLACE_MAX; ++i)
+ {
+ if (this->places_[i].name != NULL && this->places_[i].name == name)
+ {
+ if (this->places_[i].have_location)
+ {
+ // We have already seen a section with this name.
+ return;
+ }
+
+ this->places_[i].location = location;
+ this->places_[i].have_location = true;
+
+ // If we just found the .bss section, restart the search for
+ // an unallocated section. This follows the GNU linker's
+ // behaviour.
+ if (i == PLACE_BSS)
+ this->places_[PLACE_NONALLOC].have_location = false;
+
+ return;
+ }
+ }
+
+ // Relocation sections.
+ if (!this->places_[PLACE_REL].have_location
+ && os != NULL
+ && (os->type() == elfcpp::SHT_REL || os->type() == elfcpp::SHT_RELA)
+ && (os->flags() & elfcpp::SHF_ALLOC) != 0)
+ {
+ this->places_[PLACE_REL].location = location;
+ this->places_[PLACE_REL].have_location = true;
+ }
+
+ // We find the location for unallocated sections by finding the
+ // first debugging or comment section after the BSS section (if
+ // there is one).
+ if (!this->places_[PLACE_NONALLOC].have_location
+ && (name == ".comment" || Layout::is_debug_info_section(name.c_str())))
+ {
+ // We add orphan sections after the location in PLACES_. We
+ // want to store unallocated sections before LOCATION. If this
+ // is the very first section, we can't use it.
+ if (!first_init)
+ {
+ --location;
+ this->places_[PLACE_NONALLOC].location = location;
+ this->places_[PLACE_NONALLOC].have_location = true;
+ }
+ }
+}
+
+// Initialize the last location.
+
+void
+Orphan_section_placement::last_init(Elements_iterator location)
+{
+ this->places_[PLACE_LAST].location = location;
+ this->places_[PLACE_LAST].have_location = true;
+}
+
+// Set *PWHERE to the address of an iterator pointing to the location
+// to use for an orphan section. Return true if the iterator has a
+// value, false otherwise.
+
+bool
+Orphan_section_placement::find_place(Output_section* os,
+ Elements_iterator** pwhere)
+{
+ // Figure out where OS should go. This is based on the GNU linker
+ // code. FIXME: The GNU linker handles small data sections
+ // specially, but we don't.
+ elfcpp::Elf_Word type = os->type();
+ elfcpp::Elf_Xword flags = os->flags();
+ Place_index index;
+ if ((flags & elfcpp::SHF_ALLOC) == 0
+ && !Layout::is_debug_info_section(os->name()))
+ index = PLACE_NONALLOC;
+ else if ((flags & elfcpp::SHF_ALLOC) == 0)
+ index = PLACE_LAST;
+ else if (type == elfcpp::SHT_NOTE)
+ index = PLACE_INTERP;
+ else if (type == elfcpp::SHT_NOBITS)
+ index = PLACE_BSS;
+ else if ((flags & elfcpp::SHF_WRITE) != 0)
+ index = PLACE_DATA;
+ else if (type == elfcpp::SHT_REL || type == elfcpp::SHT_RELA)
+ index = PLACE_REL;
+ else if ((flags & elfcpp::SHF_EXECINSTR) == 0)
+ index = PLACE_RODATA;
+ else
+ index = PLACE_TEXT;
+
+ // If we don't have a location yet, try to find one based on a
+ // plausible ordering of sections.
+ if (!this->places_[index].have_location)
+ {
+ Place_index follow;
+ switch (index)
+ {
+ default:
+ follow = PLACE_MAX;
+ break;
+ case PLACE_RODATA:
+ follow = PLACE_TEXT;
+ break;
+ case PLACE_BSS:
+ follow = PLACE_DATA;
+ break;
+ case PLACE_REL:
+ follow = PLACE_TEXT;
+ break;
+ case PLACE_INTERP:
+ follow = PLACE_TEXT;
+ break;
+ }
+ if (follow != PLACE_MAX && this->places_[follow].have_location)
+ {
+ // Set the location of INDEX to the location of FOLLOW. The
+ // location of INDEX will then be incremented by the caller,
+ // so anything in INDEX will continue to be after anything
+ // in FOLLOW.
+ this->places_[index].location = this->places_[follow].location;
+ this->places_[index].have_location = true;
+ }
+ }
+
+ *pwhere = &this->places_[index].location;
+ bool ret = this->places_[index].have_location;
+
+ // The caller will set the location.
+ this->places_[index].have_location = true;
+
+ return ret;
+}
+
+// Return the iterator being used for sections at the very end of the
+// linker script.
+
+Orphan_section_placement::Elements_iterator
+Orphan_section_placement::last_place() const
+{
+ gold_assert(this->places_[PLACE_LAST].have_location);
+ return this->places_[PLACE_LAST].location;
+}
+
// An element in a SECTIONS clause.
class Sections_element
virtual ~Sections_element()
{ }
+ // Return whether an output section is relro.
+ virtual bool
+ is_relro() const
+ { return false; }
+
+ // Record that an output section is relro.
+ virtual void
+ set_is_relro()
+ { }
+
+ // Create any required output sections. The only real
+ // implementation is in Output_section_definition.
+ virtual void
+ create_sections(Layout*)
+ { }
+
// Add any symbol being defined to the symbol table.
virtual void
add_symbols_to_table(Symbol_table*)
output_section_name(const char*, const char*, Output_section***)
{ return NULL; }
- // Return whether to place an orphan output section after this
- // element.
- virtual bool
- place_orphan_here(const Output_section *, bool*) const
- { return false; }
+ // Initialize OSP with an output section.
+ virtual void
+ orphan_section_init(Orphan_section_placement*,
+ Script_sections::Elements_iterator)
+ { }
// Set section addresses. This includes applying assignments if the
// the expression is an absolute value.
virtual void
- set_section_addresses(Symbol_table*, Layout*, uint64_t*)
+ set_section_addresses(Symbol_table*, Layout*, uint64_t*, uint64_t*)
{ }
// Check a constraint (ONLY_IF_RO, etc.) on an output section. If
// Get the list of segments to use for an allocated section when
// using a PHDRS clause. If this is an allocated section, return
- // the Output_section, and set *PHDRS_LIST to the list of PHDRS to
- // which it should be attached. If the PHDRS were not specified,
- // don't change *PHDRS_LIST.
+ // the Output_section, and set *PHDRS_LIST (the first parameter) to
+ // the list of PHDRS to which it should be attached. If the PHDRS
+ // were not specified, don't change *PHDRS_LIST. When not returning
+ // NULL, set *ORPHAN (the second parameter) according to whether
+ // this is an orphan section--one that is not mentioned in the
+ // linker script.
virtual Output_section*
- allocate_to_segment(String_list**)
+ allocate_to_segment(String_list**, bool*)
+ { return NULL; }
+
+ // Look for an output section by name and return the address, the
+ // load address, the alignment, and the size. This is used when an
+ // expression refers to an output section which was not actually
+ // created. This returns true if the section was found, false
+ // otherwise. The only real definition is for
+ // Output_section_definition.
+ virtual bool
+ get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
+ uint64_t*) const
+ { return false; }
+
+ // Return the associated Output_section if there is one.
+ virtual Output_section*
+ get_output_section() const
{ return NULL; }
// Print the element for debugging purposes.
// absolute symbols when setting dot.
void
set_section_addresses(Symbol_table* symtab, Layout* layout,
- uint64_t* dot_value)
+ uint64_t* dot_value, uint64_t*)
{
this->assignment_.set_if_absolute(symtab, layout, true, *dot_value);
}
// output section definition the dot symbol is always considered
// to be absolute.
Output_section* dummy;
- *dot_value = this->val_->eval_with_dot(symtab, layout, *dot_value,
+ *dot_value = this->val_->eval_with_dot(symtab, layout, true, *dot_value,
NULL, &dummy);
}
// Update the dot symbol while setting section addresses.
void
set_section_addresses(Symbol_table* symtab, Layout* layout,
- uint64_t* dot_value)
+ uint64_t* dot_value, uint64_t* load_address)
{
Output_section* dummy;
- *dot_value = this->val_->eval_with_dot(symtab, layout, *dot_value,
+ *dot_value = this->val_->eval_with_dot(symtab, layout, false, *dot_value,
NULL, &dummy);
+ *load_address = *dot_value;
}
// Print for debugging.
virtual ~Output_section_element()
{ }
+ // Return whether this element requires an output section to exist.
+ virtual bool
+ needs_output_section() const
+ { return false; }
+
// Add any symbol being defined to the symbol table.
virtual void
add_symbols_to_table(Symbol_table*)
finalize_symbols(Symbol_table* symtab, const Layout* layout,
uint64_t* dot_value, Output_section** dot_section)
{
- *dot_value = this->val_->eval_with_dot(symtab, layout, *dot_value,
+ *dot_value = this->val_->eval_with_dot(symtab, layout, true, *dot_value,
*dot_section, dot_section);
}
std::string* fill,
Input_section_list*)
{
- uint64_t next_dot = this->val_->eval_with_dot(symtab, layout, *dot_value,
- *dot_section, dot_section);
+ uint64_t next_dot = this->val_->eval_with_dot(symtab, layout, false,
+ *dot_value, *dot_section,
+ dot_section);
if (next_dot < *dot_value)
gold_error(_("dot may not move backward"));
if (next_dot > *dot_value && output_section != NULL)
- *dot_value);
Output_section_data* posd;
if (fill->empty())
- posd = new Output_data_fixed_space(length, 0);
+ posd = new Output_data_zero_fill(length, 0);
else
{
std::string this_fill = this->get_fill_string(fill, length);
void
do_write_to_buffer(unsigned char*);
+ // Write to a map file.
+ void
+ do_print_to_mapfile(Mapfile* mapfile) const
+ { mapfile->print_output_data(this, _("** expression")); }
+
private:
template<bool big_endian>
void
{
Output_section* dummy;
uint64_t val = this->val_->eval_with_dot(this->symtab_, this->layout_,
- this->dot_value_,
+ true, this->dot_value_,
this->dot_section_, &dummy);
- if (parameters->is_big_endian())
+ if (parameters->target().is_big_endian())
this->endian_write_to_buffer<true>(val, buf);
else
this->endian_write_to_buffer<false>(val, buf);
elfcpp::Swap_unaligned<32, big_endian>::writeval(buf, val);
break;
case 8:
- if (parameters->get_size() == 32)
+ if (parameters->target().get_size() == 32)
{
val &= 0xffffffff;
if (this->is_signed_ && (val & 0x80000000) != 0)
: size_(size), is_signed_(is_signed), val_(val)
{ }
+ // If there is a data item, then we must create an output section.
+ bool
+ needs_output_section() const
+ { return true; }
+
// Finalize symbols--we just need to update dot.
void
finalize_symbols(Symbol_table*, const Layout*, uint64_t* dot_value,
std::string* fill, Input_section_list*)
{
Output_section* fill_section;
- uint64_t fill_val = this->val_->eval_with_dot(symtab, layout,
+ uint64_t fill_val = this->val_->eval_with_dot(symtab, layout, false,
*dot_value, *dot_section,
&fill_section);
if (fill_section != NULL)
void
add_input_section(const Input_section_spec* spec, bool keep);
+ // Return whether the output section is relro.
+ bool
+ is_relro() const
+ { return this->is_relro_; }
+
+ // Record that the output section is relro.
+ void
+ set_is_relro()
+ { this->is_relro_ = true; }
+
+ // Create any required output sections.
+ void
+ create_sections(Layout*);
+
// Add any symbols being defined to the symbol table.
void
add_symbols_to_table(Symbol_table* symtab);
output_section_name(const char* file_name, const char* section_name,
Output_section***);
- // Return whether to place an orphan section after this one.
- bool
- place_orphan_here(const Output_section *os, bool* exact) const;
+ // Initialize OSP with an output section.
+ void
+ orphan_section_init(Orphan_section_placement* osp,
+ Script_sections::Elements_iterator p)
+ { osp->output_section_init(this->name_, this->output_section_, p); }
// Set the section address.
void
set_section_addresses(Symbol_table* symtab, Layout* layout,
- uint64_t* dot_value);
+ uint64_t* dot_value, uint64_t* load_address);
// Check a constraint (ONLY_IF_RO, etc.) on an output section. If
// this section is constrained, and the input sections do not match,
alternate_constraint(Output_section_definition*, Section_constraint);
// Get the list of segments to use for an allocated section when
- // using a PHDRS clause. If this is an allocated section, return
- // the Output_section, and set *PHDRS_LIST to the list of PHDRS to
- // which it should be attached. If the PHDRS were not specified,
- // don't change *PHDRS_LIST.
+ // using a PHDRS clause.
+ Output_section*
+ allocate_to_segment(String_list** phdrs_list, bool* orphan);
+
+ // Look for an output section by name and return the address, the
+ // load address, the alignment, and the size. This is used when an
+ // expression refers to an output section which was not actually
+ // created. This returns true if the section was found, false
+ // otherwise.
+ bool
+ get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
+ uint64_t*) const;
+
+ // Return the associated Output_section if there is one.
Output_section*
- allocate_to_segment(String_list** phdrs_list);
+ get_output_section() const
+ { return this->output_section_; }
// Print the contents to the FILE. This is for debugging.
void
// The Output_section created for this definition. This will be
// NULL if none was created.
Output_section* output_section_;
+ // The address after it has been evaluated.
+ uint64_t evaluated_address_;
+ // The load address after it has been evaluated.
+ uint64_t evaluated_load_address_;
+ // The alignment after it has been evaluated.
+ uint64_t evaluated_addralign_;
+ // The output section is relro.
+ bool is_relro_;
};
// Constructor.
fill_(NULL),
phdrs_(NULL),
elements_(),
- output_section_(NULL)
+ output_section_(NULL),
+ evaluated_address_(0),
+ evaluated_load_address_(0),
+ evaluated_addralign_(0),
+ is_relro_(false)
{
}
this->elements_.push_back(p);
}
+// Create any required output sections. We need an output section if
+// there is a data statement here.
+
+void
+Output_section_definition::create_sections(Layout* layout)
+{
+ if (this->output_section_ != NULL)
+ return;
+ for (Output_section_elements::const_iterator p = this->elements_.begin();
+ p != this->elements_.end();
+ ++p)
+ {
+ if ((*p)->needs_output_section())
+ {
+ const char* name = this->name_.c_str();
+ this->output_section_ = layout->make_output_section_for_script(name);
+ return;
+ }
+ }
+}
+
// Add any symbols being defined to the symbol table.
void
if (this->address_ != NULL)
{
Output_section* dummy;
- address = this->address_->eval_with_dot(symtab, layout,
+ address = this->address_->eval_with_dot(symtab, layout, true,
*dot_value, NULL,
&dummy);
}
if (this->align_ != NULL)
{
Output_section* dummy;
- uint64_t align = this->align_->eval_with_dot(symtab, layout,
+ uint64_t align = this->align_->eval_with_dot(symtab, layout, true,
*dot_value,
NULL,
&dummy);
return NULL;
}
-// Return whether to place an orphan output section after this
-// section.
-
-bool
-Output_section_definition::place_orphan_here(const Output_section *os,
- bool* exact) const
-{
- // Check for the simple case first.
- if (this->output_section_ != NULL
- && this->output_section_->type() == os->type()
- && this->output_section_->flags() == os->flags())
- {
- *exact = true;
- return true;
- }
-
- // Otherwise use some heuristics.
-
- if ((os->flags() & elfcpp::SHF_ALLOC) == 0)
- return false;
-
- if (os->type() == elfcpp::SHT_NOBITS)
- {
- if (this->name_ == ".bss")
- {
- *exact = true;
- return true;
- }
- if (this->output_section_ != NULL
- && this->output_section_->type() == elfcpp::SHT_NOBITS)
- return true;
- }
- else if (os->type() == elfcpp::SHT_NOTE)
- {
- if (this->output_section_ != NULL
- && this->output_section_->type() == elfcpp::SHT_NOTE)
- {
- *exact = true;
- return true;
- }
- if (this->name_.compare(0, 5, ".note") == 0)
- {
- *exact = true;
- return true;
- }
- if (this->name_ == ".interp")
- return true;
- if (this->output_section_ != NULL
- && this->output_section_->type() == elfcpp::SHT_PROGBITS
- && (this->output_section_->flags() & elfcpp::SHF_WRITE) == 0)
- return true;
- }
- else if (os->type() == elfcpp::SHT_REL || os->type() == elfcpp::SHT_RELA)
- {
- if (this->name_.compare(0, 4, ".rel") == 0)
- {
- *exact = true;
- return true;
- }
- if (this->output_section_ != NULL
- && (this->output_section_->type() == elfcpp::SHT_REL
- || this->output_section_->type() == elfcpp::SHT_RELA))
- {
- *exact = true;
- return true;
- }
- if (this->output_section_ != NULL
- && this->output_section_->type() == elfcpp::SHT_PROGBITS
- && (this->output_section_->flags() & elfcpp::SHF_WRITE) == 0)
- return true;
- }
- else if (os->type() == elfcpp::SHT_PROGBITS
- && (os->flags() & elfcpp::SHF_WRITE) != 0)
- {
- if (this->name_ == ".data")
- {
- *exact = true;
- return true;
- }
- if (this->output_section_ != NULL
- && this->output_section_->type() == elfcpp::SHT_PROGBITS
- && (this->output_section_->flags() & elfcpp::SHF_WRITE) != 0)
- return true;
- }
- else if (os->type() == elfcpp::SHT_PROGBITS
- && (os->flags() & elfcpp::SHF_EXECINSTR) != 0)
- {
- if (this->name_ == ".text")
- {
- *exact = true;
- return true;
- }
- if (this->output_section_ != NULL
- && this->output_section_->type() == elfcpp::SHT_PROGBITS
- && (this->output_section_->flags() & elfcpp::SHF_EXECINSTR) != 0)
- return true;
- }
- else if (os->type() == elfcpp::SHT_PROGBITS
- || (os->type() != elfcpp::SHT_PROGBITS
- && (os->flags() & elfcpp::SHF_WRITE) == 0))
- {
- if (this->name_ == ".rodata")
- {
- *exact = true;
- return true;
- }
- if (this->output_section_ != NULL
- && this->output_section_->type() == elfcpp::SHT_PROGBITS
- && (this->output_section_->flags() & elfcpp::SHF_WRITE) == 0)
- return true;
- }
-
- return false;
-}
-
// Set the section address. Note that the OUTPUT_SECTION_ field will
// be NULL if no input sections were mapped to this output section.
// We still have to adjust dot and process symbol assignments.
void
Output_section_definition::set_section_addresses(Symbol_table* symtab,
Layout* layout,
- uint64_t* dot_value)
+ uint64_t* dot_value,
+ uint64_t* load_address)
{
uint64_t address;
if (this->address_ == NULL)
else
{
Output_section* dummy;
- address = this->address_->eval_with_dot(symtab, layout, *dot_value,
- NULL, &dummy);
+ address = this->address_->eval_with_dot(symtab, layout, true,
+ *dot_value, NULL, &dummy);
}
uint64_t align;
else
{
Output_section* align_section;
- align = this->align_->eval_with_dot(symtab, layout, *dot_value,
+ align = this->align_->eval_with_dot(symtab, layout, true, *dot_value,
NULL, &align_section);
if (align_section != NULL)
gold_warning(_("alignment of section %s is not absolute"),
address = align_address(address, align);
+ uint64_t start_address = address;
+
*dot_value = address;
// The address of non-SHF_ALLOC sections is forced to zero,
&& (this->output_section_->flags() & elfcpp::SHF_ALLOC) != 0)
this->output_section_->set_address(address);
- if (this->load_address_ != NULL && this->output_section_ != NULL)
+ this->evaluated_address_ = address;
+ this->evaluated_addralign_ = align;
+
+ if (this->load_address_ == NULL)
+ this->evaluated_load_address_ = address;
+ else
{
Output_section* dummy;
uint64_t load_address =
- this->load_address_->eval_with_dot(symtab, layout, *dot_value,
+ this->load_address_->eval_with_dot(symtab, layout, true, *dot_value,
this->output_section_, &dummy);
- this->output_section_->set_load_address(load_address);
+ if (this->output_section_ != NULL)
+ this->output_section_->set_load_address(load_address);
+ this->evaluated_load_address_ = load_address;
}
uint64_t subalign;
else
{
Output_section* subalign_section;
- subalign = this->subalign_->eval_with_dot(symtab, layout, *dot_value,
- NULL, &subalign_section);
+ subalign = this->subalign_->eval_with_dot(symtab, layout, true,
+ *dot_value, NULL,
+ &subalign_section);
if (subalign_section != NULL)
gold_warning(_("subalign of section %s is not absolute"),
this->name_.c_str());
// FIXME: The GNU linker supports fill values of arbitrary
// length.
Output_section* fill_section;
- uint64_t fill_val = this->fill_->eval_with_dot(symtab, layout,
+ uint64_t fill_val = this->fill_->eval_with_dot(symtab, layout, true,
*dot_value,
NULL,
&fill_section);
&input_sections);
gold_assert(input_sections.empty());
+
+ if (this->load_address_ == NULL || this->output_section_ == NULL)
+ *load_address = *dot_value;
+ else
+ *load_address = (this->output_section_->load_address()
+ + (*dot_value - start_address));
+
+ if (this->output_section_ != NULL)
+ {
+ if (this->is_relro_)
+ this->output_section_->set_is_relro();
+ else
+ this->output_section_->clear_is_relro();
+ }
}
// Check a constraint (ONLY_IF_RO, etc.) on an output section. If
this->output_section_ = posd->output_section_;
posd->output_section_ = NULL;
+ if (this->is_relro_)
+ this->output_section_->set_is_relro();
+ else
+ this->output_section_->clear_is_relro();
+
return true;
}
// Get the list of segments to use for an allocated section when using
-// a PHDRS clause. If this is an allocated section, return the
-// Output_section, and set *PHDRS_LIST to the list of PHDRS to which
-// it should be attached. If the PHDRS were not specified, don't
-// change *PHDRS_LIST.
+// a PHDRS clause.
Output_section*
-Output_section_definition::allocate_to_segment(String_list** phdrs_list)
+Output_section_definition::allocate_to_segment(String_list** phdrs_list,
+ bool* orphan)
{
if (this->output_section_ == NULL)
return NULL;
if ((this->output_section_->flags() & elfcpp::SHF_ALLOC) == 0)
return NULL;
+ *orphan = false;
if (this->phdrs_ != NULL)
*phdrs_list = this->phdrs_;
return this->output_section_;
}
+// Look for an output section by name and return the address, the load
+// address, the alignment, and the size. This is used when an
+// expression refers to an output section which was not actually
+// created. This returns true if the section was found, false
+// otherwise.
+
+bool
+Output_section_definition::get_output_section_info(const char* name,
+ uint64_t* address,
+ uint64_t* load_address,
+ uint64_t* addralign,
+ uint64_t* size) const
+{
+ if (this->name_ != name)
+ return false;
+
+ if (this->output_section_ != NULL)
+ {
+ *address = this->output_section_->address();
+ if (this->output_section_->has_load_address())
+ *load_address = this->output_section_->load_address();
+ else
+ *load_address = *address;
+ *addralign = this->output_section_->addralign();
+ *size = this->output_section_->current_data_size();
+ }
+ else
+ {
+ *address = this->evaluated_address_;
+ *load_address = this->evaluated_load_address_;
+ *addralign = this->evaluated_addralign_;
+ *size = 0;
+ }
+
+ return true;
+}
+
// Print for debugging.
void
: os_(os)
{ }
- // Return whether to place an orphan section after this one.
+ // Return whether the orphan output section is relro. We can just
+ // check the output section because we always set the flag, if
+ // needed, just after we create the Orphan_output_section.
bool
- place_orphan_here(const Output_section *os, bool* exact) const;
+ is_relro() const
+ { return this->os_->is_relro(); }
+
+ // Initialize OSP with an output section. This should have been
+ // done already.
+ void
+ orphan_section_init(Orphan_section_placement*,
+ Script_sections::Elements_iterator)
+ { gold_unreachable(); }
// Set section addresses.
void
- set_section_addresses(Symbol_table*, Layout*, uint64_t*);
+ set_section_addresses(Symbol_table*, Layout*, uint64_t*, uint64_t*);
// Get the list of segments to use for an allocated section when
- // using a PHDRS clause. If this is an allocated section, return
- // the Output_section.
+ // using a PHDRS clause.
Output_section*
- allocate_to_segment(String_list**);
+ allocate_to_segment(String_list**, bool*);
+
+ // Return the associated Output_section.
+ Output_section*
+ get_output_section() const
+ { return this->os_; }
// Print for debugging.
void
Output_section* os_;
};
-// Whether to place another orphan section after this one.
-
-bool
-Orphan_output_section::place_orphan_here(const Output_section* os,
- bool* exact) const
-{
- if (this->os_->type() == os->type()
- && this->os_->flags() == os->flags())
- {
- *exact = true;
- return true;
- }
- return false;
-}
-
// Set section addresses.
void
Orphan_output_section::set_section_addresses(Symbol_table*, Layout*,
- uint64_t* dot_value)
+ uint64_t* dot_value,
+ uint64_t* load_address)
{
typedef std::list<std::pair<Relobj*, unsigned int> > Input_section_list;
+ bool have_load_address = *load_address != *dot_value;
+
uint64_t address = *dot_value;
address = align_address(address, this->os_->addralign());
if ((this->os_->flags() & elfcpp::SHF_ALLOC) != 0)
- this->os_->set_address(address);
+ {
+ this->os_->set_address(address);
+ if (have_load_address)
+ this->os_->set_load_address(align_address(*load_address,
+ this->os_->addralign()));
+ }
Input_section_list input_sections;
address += this->os_->get_input_sections(address, "", &input_sections);
}
address = align_address(address, addralign);
- this->os_->add_input_section_for_script(p->first, p->second, size, 0);
+ this->os_->add_input_section_for_script(p->first, p->second, size,
+ addralign);
address += size;
}
+ if (!have_load_address)
+ *load_address = address;
+ else
+ *load_address += address - *dot_value;
+
*dot_value = address;
}
// Output_section. We don't change the list of segments.
Output_section*
-Orphan_output_section::allocate_to_segment(String_list**)
+Orphan_output_section::allocate_to_segment(String_list**, bool* orphan)
{
if ((this->os_->flags() & elfcpp::SHF_ALLOC) == 0)
return NULL;
+ *orphan = true;
return this->os_;
}
eval_load_address(Symbol_table* symtab, Layout* layout)
{
if (this->load_address_ != NULL)
- this->load_address_value_ = this->load_address_->eval(symtab, layout);
+ this->load_address_value_ = this->load_address_->eval(symtab, layout,
+ true);
}
// Return the load address.
in_sections_clause_(false),
sections_elements_(NULL),
output_section_(NULL),
- phdrs_elements_(NULL)
+ phdrs_elements_(NULL),
+ orphan_section_placement_(NULL),
+ data_segment_align_start_(),
+ saw_data_segment_align_(false),
+ saw_relro_end_(false)
{
}
this->output_section_->add_input_section(spec, keep);
}
+// This is called when we see DATA_SEGMENT_ALIGN. It means that any
+// subsequent output sections may be relro.
+
+void
+Script_sections::data_segment_align()
+{
+ if (this->saw_data_segment_align_)
+ gold_error(_("DATA_SEGMENT_ALIGN may only appear once in a linker script"));
+ gold_assert(!this->sections_elements_->empty());
+ Sections_elements::iterator p = this->sections_elements_->end();
+ --p;
+ this->data_segment_align_start_ = p;
+ this->saw_data_segment_align_ = true;
+}
+
+// This is called when we see DATA_SEGMENT_RELRO_END. It means that
+// any output sections seen since DATA_SEGMENT_ALIGN are relro.
+
+void
+Script_sections::data_segment_relro_end()
+{
+ if (this->saw_relro_end_)
+ gold_error(_("DATA_SEGMENT_RELRO_END may only appear once "
+ "in a linker script"));
+ this->saw_relro_end_ = true;
+
+ if (!this->saw_data_segment_align_)
+ gold_error(_("DATA_SEGMENT_RELRO_END must follow DATA_SEGMENT_ALIGN"));
+ else
+ {
+ Sections_elements::iterator p = this->data_segment_align_start_;
+ for (++p; p != this->sections_elements_->end(); ++p)
+ (*p)->set_is_relro();
+ }
+}
+
+// Create any required sections.
+
+void
+Script_sections::create_sections(Layout* layout)
+{
+ if (!this->saw_sections_clause_)
+ return;
+ for (Sections_elements::iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ (*p)->create_sections(layout);
+}
+
// Add any symbols we are defining to the symbol table.
void
void
Script_sections::place_orphan(Output_section* os)
{
- // Look for an output section definition which matches the output
- // section. Put a marker after that section.
- Sections_elements::iterator place = this->sections_elements_->end();
- for (Sections_elements::iterator p = this->sections_elements_->begin();
- p != this->sections_elements_->end();
- ++p)
+ Orphan_section_placement* osp = this->orphan_section_placement_;
+ if (osp == NULL)
{
- bool exact;
- if ((*p)->place_orphan_here(os, &exact))
- {
- place = p;
- if (exact)
- break;
- }
+ // Initialize the Orphan_section_placement structure.
+ osp = new Orphan_section_placement();
+ for (Sections_elements::iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ (*p)->orphan_section_init(osp, p);
+ gold_assert(!this->sections_elements_->empty());
+ Sections_elements::iterator last = this->sections_elements_->end();
+ --last;
+ osp->last_init(last);
+ this->orphan_section_placement_ = osp;
}
- // The insert function puts the new element before the iterator.
- if (place != this->sections_elements_->end())
- ++place;
+ Orphan_output_section* orphan = new Orphan_output_section(os);
- this->sections_elements_->insert(place, new Orphan_output_section(os));
+ // Look for where to put ORPHAN.
+ Sections_elements::iterator* where;
+ if (osp->find_place(os, &where))
+ {
+ if ((**where)->is_relro())
+ os->set_is_relro();
+ else
+ os->clear_is_relro();
+
+ // We want to insert ORPHAN after *WHERE, and then update *WHERE
+ // so that the next one goes after this one.
+ Sections_elements::iterator p = *where;
+ gold_assert(p != this->sections_elements_->end());
+ ++p;
+ *where = this->sections_elements_->insert(p, orphan);
+ }
+ else
+ {
+ os->clear_is_relro();
+ // We don't have a place to put this orphan section. Put it,
+ // and all other sections like it, at the end, but before the
+ // sections which always come at the end.
+ Sections_elements::iterator last = osp->last_place();
+ *where = this->sections_elements_->insert(last, orphan);
+ }
}
// Set the addresses of all the output sections. Walk through all the
}
}
+ // Force the alignment of the first TLS section to be the maximum
+ // alignment of all TLS sections.
+ Output_section* first_tls = NULL;
+ uint64_t tls_align = 0;
+ for (Sections_elements::const_iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ {
+ Output_section *os = (*p)->get_output_section();
+ if (os != NULL && (os->flags() & elfcpp::SHF_TLS) != 0)
+ {
+ if (first_tls == NULL)
+ first_tls = os;
+ if (os->addralign() > tls_align)
+ tls_align = os->addralign();
+ }
+ }
+ if (first_tls != NULL)
+ first_tls->set_addralign(tls_align);
+
// For a relocatable link, we implicitly set dot to zero.
uint64_t dot_value = 0;
+ uint64_t load_address = 0;
for (Sections_elements::iterator p = this->sections_elements_->begin();
p != this->sections_elements_->end();
++p)
- (*p)->set_section_addresses(symtab, layout, &dot_value);
+ (*p)->set_section_addresses(symtab, layout, &dot_value, &load_address);
if (this->phdrs_elements_ != NULL)
{
size_t segment_count = layout->segment_count();
size_t file_header_size;
size_t segment_headers_size;
- if (parameters->get_size() == 32)
+ if (parameters->target().get_size() == 32)
{
file_header_size = elfcpp::Elf_sizes<32>::ehdr_size;
segment_headers_size = segment_count * elfcpp::Elf_sizes<32>::phdr_size;
}
- else if (parameters->get_size() == 64)
+ else if (parameters->target().get_size() == 64)
{
file_header_size = elfcpp::Elf_sizes<64>::ehdr_size;
segment_headers_size = segment_count * elfcpp::Elf_sizes<64>::phdr_size;
Script_sections::header_size_adjustment(uint64_t lma,
size_t sizeof_headers) const
{
- const uint64_t abi_pagesize = parameters->target()->abi_pagesize();
+ const uint64_t abi_pagesize = parameters->target().abi_pagesize();
uint64_t hdr_lma = lma - sizeof_headers;
hdr_lma &= ~(abi_pagesize - 1);
return lma - hdr_lma;
{
gold_assert(this->saw_sections_clause_);
- if (parameters->output_is_object())
+ if (parameters->options().relocatable())
return NULL;
if (this->saw_phdrs_clause())
this->create_note_and_tls_segments(layout, §ions);
// Walk through the sections adding them to PT_LOAD segments.
- const uint64_t abi_pagesize = parameters->target()->abi_pagesize();
+ const uint64_t abi_pagesize = parameters->target().abi_pagesize();
Output_segment* first_seg = NULL;
Output_segment* current_seg = NULL;
bool is_current_seg_readonly = true;
need_new_segment = true;
}
else if (is_current_seg_readonly
- && ((*p)->flags() & elfcpp::SHF_WRITE) != 0)
+ && ((*p)->flags() & elfcpp::SHF_WRITE) != 0
+ && !parameters->options().omagic())
{
// Don't put a writable section in the same segment as a
// non-writable section.
// efficient in any case. We try to use the first PT_LOAD segment
// if we can, otherwise we make a new one.
+ if (first_seg == NULL)
+ return NULL;
+
size_t sizeof_headers = this->total_header_size(layout);
- if (first_seg != NULL
- && (first_seg->paddr() & (abi_pagesize - 1)) >= sizeof_headers)
+ uint64_t vma = first_seg->vaddr();
+ uint64_t lma = first_seg->paddr();
+
+ uint64_t subtract = this->header_size_adjustment(lma, sizeof_headers);
+
+ if ((lma & (abi_pagesize - 1)) >= sizeof_headers)
{
- first_seg->set_addresses(first_seg->vaddr() - sizeof_headers,
- first_seg->paddr() - sizeof_headers);
+ first_seg->set_addresses(vma - subtract, lma - subtract);
return first_seg;
}
+ // If there is no room to squeeze in the headers, then punt. The
+ // resulting executable probably won't run on GNU/Linux, but we
+ // trust that the user knows what they are doing.
+ if (lma < subtract || vma < subtract)
+ return NULL;
+
Output_segment* load_seg = layout->make_output_segment(elfcpp::PT_LOAD,
elfcpp::PF_R);
- if (first_seg == NULL)
- load_seg->set_addresses(0, 0);
- else
- {
- uint64_t vma = first_seg->vaddr();
- uint64_t lma = first_seg->paddr();
-
- uint64_t subtract = this->header_size_adjustment(lma, sizeof_headers);
- if (lma >= subtract && vma >= subtract)
- load_seg->set_addresses(vma - subtract, lma - subtract);
- else
- {
- // We could handle this case by create the file header
- // outside of any PT_LOAD segment, and creating a new
- // PT_LOAD segment after the others to hold the segment
- // headers.
- gold_error(_("sections loaded on first page without room for "
- "file and program headers are not supported"));
- }
- }
+ load_seg->set_addresses(vma - subtract, lma - subtract);
return load_seg;
}
p != this->sections_elements_->end();
++p)
{
- Output_section* os = (*p)->allocate_to_segment(&phdr_names);
+ bool orphan;
+ Output_section* os = (*p)->allocate_to_segment(&phdr_names, &orphan);
if (os == NULL)
continue;
continue;
}
+ // If this is an orphan section--one that was not explicitly
+ // mentioned in the linker script--then it should not inherit
+ // any segment type other than PT_LOAD. Otherwise, e.g., the
+ // PT_INTERP segment will pick up following orphan sections,
+ // which does not make sense. If this is not an orphan section,
+ // we trust the linker script.
+ if (orphan)
+ {
+ String_list::iterator q = phdr_names->begin();
+ while (q != phdr_names->end())
+ {
+ Name_to_segment::const_iterator r = name_to_segment.find(*q);
+ // We give errors about unknown segments below.
+ if (r == name_to_segment.end()
+ || r->second->type() == elfcpp::PT_LOAD)
+ ++q;
+ else
+ q = phdr_names->erase(q);
+ }
+ }
+
bool in_load_segment = false;
for (String_list::const_iterator q = phdr_names->begin();
q != phdr_names->end();
}
}
+// Look for an output section by name and return the address, the load
+// address, the alignment, and the size. This is used when an
+// expression refers to an output section which was not actually
+// created. This returns true if the section was found, false
+// otherwise.
+
+bool
+Script_sections::get_output_section_info(const char* name, uint64_t* address,
+ uint64_t* load_address,
+ uint64_t* addralign,
+ uint64_t* size) const
+{
+ if (!this->saw_sections_clause_)
+ return false;
+ for (Sections_elements::const_iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ if ((*p)->get_output_section_info(name, address, load_address, addralign,
+ size))
+ return true;
+ return false;
+}
+
// Print the SECTIONS clause to F for debugging.
void