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authorIan Lance Taylor <iant@google.com>2006-11-14 19:21:05 +0000
committerIan Lance Taylor <iant@google.com>2006-11-14 19:21:05 +0000
commitdbe717effbdf31236088837f4686fd5ad5e71893 (patch)
treefd5ed267334d62fadcaf7ff7132c0a7287553ed8 /gold/dynobj.cc
parent6c73cbb1d9a26d1c4d9bd5464832846b7c049b9d (diff)
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More dynamic object support, initial scripting support.
Diffstat (limited to 'gold/dynobj.cc')
-rw-r--r--gold/dynobj.cc670
1 files changed, 670 insertions, 0 deletions
diff --git a/gold/dynobj.cc b/gold/dynobj.cc
new file mode 100644
index 0000000..ba1fb15
--- /dev/null
+++ b/gold/dynobj.cc
@@ -0,0 +1,670 @@
+// dynobj.cc -- dynamic object support for gold
+
+#include "gold.h"
+
+#include <vector>
+#include <cstring>
+
+#include "symtab.h"
+#include "dynobj.h"
+
+namespace gold
+{
+
+// Class Sized_dynobj.
+
+template<int size, bool big_endian>
+Sized_dynobj<size, big_endian>::Sized_dynobj(
+ const std::string& name,
+ Input_file* input_file,
+ off_t offset,
+ const elfcpp::Ehdr<size, big_endian>& ehdr)
+ : Dynobj(name, input_file, offset),
+ elf_file_(this, ehdr),
+ soname_()
+{
+}
+
+// Set up the object.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::setup(
+ const elfcpp::Ehdr<size, big_endian>& ehdr)
+{
+ this->set_target(ehdr.get_e_machine(), size, big_endian,
+ ehdr.get_e_ident()[elfcpp::EI_OSABI],
+ ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
+
+ const unsigned int shnum = this->elf_file_.shnum();
+ this->set_shnum(shnum);
+}
+
+// Find the SHT_DYNSYM section and the various version sections, and
+// the dynamic section, given the section headers.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::find_dynsym_sections(
+ const unsigned char* pshdrs,
+ unsigned int* pdynsym_shndx,
+ unsigned int* pversym_shndx,
+ unsigned int* pverdef_shndx,
+ unsigned int* pverneed_shndx,
+ unsigned int* pdynamic_shndx)
+{
+ *pdynsym_shndx = -1U;
+ *pversym_shndx = -1U;
+ *pverdef_shndx = -1U;
+ *pverneed_shndx = -1U;
+ *pdynamic_shndx = -1U;
+
+ const unsigned int shnum = this->shnum();
+ const unsigned char* p = pshdrs;
+ for (unsigned int i = 0; i < shnum; ++i, p += This::shdr_size)
+ {
+ typename This::Shdr shdr(p);
+
+ unsigned int* pi;
+ switch (shdr.get_sh_type())
+ {
+ case elfcpp::SHT_DYNSYM:
+ pi = pdynsym_shndx;
+ break;
+ case elfcpp::SHT_GNU_versym:
+ pi = pversym_shndx;
+ break;
+ case elfcpp::SHT_GNU_verdef:
+ pi = pverdef_shndx;
+ break;
+ case elfcpp::SHT_GNU_verneed:
+ pi = pverneed_shndx;
+ break;
+ case elfcpp::SHT_DYNAMIC:
+ pi = pdynamic_shndx;
+ break;
+ default:
+ pi = NULL;
+ break;
+ }
+
+ if (pi == NULL)
+ continue;
+
+ if (*pi != -1U)
+ {
+ fprintf(stderr,
+ _("%s: %s: unexpected duplicate type %u section: %u, %u\n"),
+ program_name, this->name().c_str(), shdr.get_sh_type(),
+ *pi, i);
+ gold_exit(false);
+ }
+
+ *pi = i;
+ }
+}
+
+// Read the contents of section SHNDX. PSHDRS points to the section
+// headers. TYPE is the expected section type. LINK is the expected
+// section link. Store the data in *VIEW and *VIEW_SIZE. The
+// section's sh_info field is stored in *VIEW_INFO.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::read_dynsym_section(
+ const unsigned char* pshdrs,
+ unsigned int shndx,
+ elfcpp::SHT type,
+ unsigned int link,
+ File_view** view,
+ off_t* view_size,
+ unsigned int* view_info)
+{
+ if (shndx == -1U)
+ {
+ *view = NULL;
+ *view_size = 0;
+ *view_info = 0;
+ return;
+ }
+
+ typename This::Shdr shdr(pshdrs + shndx * This::shdr_size);
+
+ assert(shdr.get_sh_type() == type);
+
+ if (shdr.get_sh_link() != link)
+ {
+ fprintf(stderr,
+ _("%s: %s: unexpected link in section %u header: %u != %u\n"),
+ program_name, this->name().c_str(), shndx,
+ shdr.get_sh_link(), link);
+ gold_exit(false);
+ }
+
+ *view = this->get_lasting_view(shdr.get_sh_offset(), shdr.get_sh_size());
+ *view_size = shdr.get_sh_size();
+ *view_info = shdr.get_sh_info();
+}
+
+// Set soname_ if this shared object has a DT_SONAME tag. PSHDRS
+// points to the section headers. DYNAMIC_SHNDX is the section index
+// of the SHT_DYNAMIC section. STRTAB_SHNDX, STRTAB, and STRTAB_SIZE
+// are the section index and contents of a string table which may be
+// the one associated with the SHT_DYNAMIC section.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::set_soname(const unsigned char* pshdrs,
+ unsigned int dynamic_shndx,
+ unsigned int strtab_shndx,
+ const unsigned char* strtabu,
+ off_t strtab_size)
+{
+ typename This::Shdr dynamicshdr(pshdrs + dynamic_shndx * This::shdr_size);
+ assert(dynamicshdr.get_sh_type() == elfcpp::SHT_DYNAMIC);
+
+ const off_t dynamic_size = dynamicshdr.get_sh_size();
+ const unsigned char* pdynamic = this->get_view(dynamicshdr.get_sh_offset(),
+ dynamic_size);
+
+ const unsigned int link = dynamicshdr.get_sh_link();
+ if (link != strtab_shndx)
+ {
+ if (link >= this->shnum())
+ {
+ fprintf(stderr,
+ _("%s: %s: DYNAMIC section %u link out of range: %u\n"),
+ program_name, this->name().c_str(),
+ dynamic_shndx, link);
+ gold_exit(false);
+ }
+
+ typename This::Shdr strtabshdr(pshdrs + link * This::shdr_size);
+ if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
+ {
+ fprintf(stderr,
+ _("%s: %s: DYNAMIC section %u link %u is not a strtab\n"),
+ program_name, this->name().c_str(),
+ dynamic_shndx, link);
+ gold_exit(false);
+ }
+
+ strtab_size = strtabshdr.get_sh_size();
+ strtabu = this->get_view(strtabshdr.get_sh_offset(), strtab_size);
+ }
+
+ for (const unsigned char* p = pdynamic;
+ p < pdynamic + dynamic_size;
+ p += This::dyn_size)
+ {
+ typename This::Dyn dyn(p);
+
+ if (dyn.get_d_tag() == elfcpp::DT_SONAME)
+ {
+ off_t val = dyn.get_d_val();
+ if (val >= strtab_size)
+ {
+ fprintf(stderr,
+ _("%s: %s: DT_SONAME value out of range: "
+ "%lld >= %lld\n"),
+ program_name, this->name().c_str(),
+ static_cast<long long>(val),
+ static_cast<long long>(strtab_size));
+ gold_exit(false);
+ }
+
+ const char* strtab = reinterpret_cast<const char*>(strtabu);
+ this->soname_ = std::string(strtab + val);
+ return;
+ }
+
+ if (dyn.get_d_tag() == elfcpp::DT_NULL)
+ return;
+ }
+
+ fprintf(stderr, _("%s: %s: missing DT_NULL in dynamic segment\n"),
+ program_name, this->name().c_str());
+ gold_exit(false);
+}
+
+// Read the symbols and sections from a dynamic object. We read the
+// dynamic symbols, not the normal symbols.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
+{
+ this->read_section_data(&this->elf_file_, sd);
+
+ const unsigned char* const pshdrs = sd->section_headers->data();
+
+ unsigned int dynsym_shndx;
+ unsigned int versym_shndx;
+ unsigned int verdef_shndx;
+ unsigned int verneed_shndx;
+ unsigned int dynamic_shndx;
+ this->find_dynsym_sections(pshdrs, &dynsym_shndx, &versym_shndx,
+ &verdef_shndx, &verneed_shndx, &dynamic_shndx);
+
+ unsigned int strtab_shndx = -1U;
+
+ if (dynsym_shndx == -1U)
+ {
+ sd->symbols = NULL;
+ sd->symbols_size = 0;
+ sd->symbol_names = NULL;
+ sd->symbol_names_size = 0;
+ }
+ else
+ {
+ // Get the dynamic symbols.
+ typename This::Shdr dynsymshdr(pshdrs + dynsym_shndx * This::shdr_size);
+ assert(dynsymshdr.get_sh_type() == elfcpp::SHT_DYNSYM);
+
+ sd->symbols = this->get_lasting_view(dynsymshdr.get_sh_offset(),
+ dynsymshdr.get_sh_size());
+ sd->symbols_size = dynsymshdr.get_sh_size();
+
+ // Get the symbol names.
+ strtab_shndx = dynsymshdr.get_sh_link();
+ if (strtab_shndx >= this->shnum())
+ {
+ fprintf(stderr,
+ _("%s: %s: invalid dynamic symbol table name index: %u\n"),
+ program_name, this->name().c_str(), strtab_shndx);
+ gold_exit(false);
+ }
+ typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
+ if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
+ {
+ fprintf(stderr,
+ _("%s: %s: dynamic symbol table name section "
+ "has wrong type: %u\n"),
+ program_name, this->name().c_str(),
+ static_cast<unsigned int>(strtabshdr.get_sh_type()));
+ gold_exit(false);
+ }
+
+ sd->symbol_names = this->get_lasting_view(strtabshdr.get_sh_offset(),
+ strtabshdr.get_sh_size());
+ sd->symbol_names_size = strtabshdr.get_sh_size();
+
+ // Get the version information.
+
+ unsigned int dummy;
+ this->read_dynsym_section(pshdrs, versym_shndx, elfcpp::SHT_GNU_versym,
+ dynsym_shndx, &sd->versym, &sd->versym_size,
+ &dummy);
+
+ // We require that the version definition and need section link
+ // to the same string table as the dynamic symbol table. This
+ // is not a technical requirement, but it always happens in
+ // practice. We could change this if necessary.
+
+ this->read_dynsym_section(pshdrs, verdef_shndx, elfcpp::SHT_GNU_verdef,
+ strtab_shndx, &sd->verdef, &sd->verdef_size,
+ &sd->verdef_info);
+
+ this->read_dynsym_section(pshdrs, verneed_shndx, elfcpp::SHT_GNU_verneed,
+ strtab_shndx, &sd->verneed, &sd->verneed_size,
+ &sd->verneed_info);
+ }
+
+ // Read the SHT_DYNAMIC section to find whether this shared object
+ // has a DT_SONAME tag. This doesn't really have anything to do
+ // with reading the symbols, but this is a convenient place to do
+ // it.
+ if (dynamic_shndx != -1U)
+ this->set_soname(pshdrs, dynamic_shndx, strtab_shndx,
+ (sd->symbol_names == NULL
+ ? NULL
+ : sd->symbol_names->data()),
+ sd->symbol_names_size);
+}
+
+// Lay out the input sections for a dynamic object. We don't want to
+// include sections from a dynamic object, so all that we actually do
+// here is check for .gnu.warning sections.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::do_layout(const General_options&,
+ Symbol_table* symtab,
+ Layout*,
+ Read_symbols_data* sd)
+{
+ const unsigned int shnum = this->shnum();
+ if (shnum == 0)
+ return;
+
+ // Get the section headers.
+ const unsigned char* pshdrs = sd->section_headers->data();
+
+ // Get the section names.
+ const unsigned char* pnamesu = sd->section_names->data();
+ const char* pnames = reinterpret_cast<const char*>(pnamesu);
+
+ // Skip the first, dummy, section.
+ pshdrs += This::shdr_size;
+ for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
+ {
+ typename This::Shdr shdr(pshdrs);
+
+ if (shdr.get_sh_name() >= sd->section_names_size)
+ {
+ fprintf(stderr,
+ _("%s: %s: bad section name offset for section %u: %lu\n"),
+ program_name, this->name().c_str(), i,
+ static_cast<unsigned long>(shdr.get_sh_name()));
+ gold_exit(false);
+ }
+
+ const char* name = pnames + shdr.get_sh_name();
+
+ this->handle_gnu_warning_section(name, i, symtab);
+ }
+
+ delete sd->section_headers;
+ sd->section_headers = NULL;
+ delete sd->section_names;
+ sd->section_names = NULL;
+}
+
+// Add an entry to the vector mapping version numbers to version
+// strings.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::set_version_map(
+ Version_map* version_map,
+ unsigned int ndx,
+ const char* name) const
+{
+ assert(ndx < version_map->size());
+ if ((*version_map)[ndx] != NULL)
+ {
+ fprintf(stderr, _("%s: %s: duplicate definition for version %u\n"),
+ program_name, this->name().c_str(), ndx);
+ gold_exit(false);
+ }
+ (*version_map)[ndx] = name;
+}
+
+// Create a vector mapping version numbers to version strings.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::make_version_map(
+ Read_symbols_data* sd,
+ Version_map* version_map) const
+{
+ if (sd->verdef == NULL && sd->verneed == NULL)
+ return;
+
+ // First find the largest version index.
+ unsigned int maxver = 0;
+
+ if (sd->verdef != NULL)
+ {
+ const unsigned char* pverdef = sd->verdef->data();
+ off_t verdef_size = sd->verdef_size;
+ const unsigned int count = sd->verdef_info;
+
+ const unsigned char* p = pverdef;
+ for (unsigned int i = 0; i < count; ++i)
+ {
+ elfcpp::Verdef<size, big_endian> verdef(p);
+
+ const unsigned int vd_ndx = verdef.get_vd_ndx();
+
+ // The GNU linker clears the VERSYM_HIDDEN bit. I'm not
+ // sure why.
+
+ if (vd_ndx > maxver)
+ maxver = vd_ndx;
+
+ const unsigned int vd_next = verdef.get_vd_next();
+ if ((p - pverdef) + vd_next >= verdef_size)
+ {
+ fprintf(stderr,
+ _("%s: %s: verdef vd_next field out of range: %u\n"),
+ program_name, this->name().c_str(), vd_next);
+ gold_exit(false);
+ }
+
+ p += vd_next;
+ }
+ }
+
+ if (sd->verneed != NULL)
+ {
+ const unsigned char* pverneed = sd->verneed->data();
+ off_t verneed_size = sd->verneed_size;
+ const unsigned int count = sd->verneed_info;
+
+ const unsigned char* p = pverneed;
+ for (unsigned int i = 0; i < count; ++i)
+ {
+ elfcpp::Verneed<size, big_endian> verneed(p);
+
+ const unsigned int vn_aux = verneed.get_vn_aux();
+ if ((p - pverneed) + vn_aux >= verneed_size)
+ {
+ fprintf(stderr,
+ _("%s: %s: verneed vn_aux field out of range: %u\n"),
+ program_name, this->name().c_str(), vn_aux);
+ gold_exit(false);
+ }
+
+ const unsigned int vn_cnt = verneed.get_vn_cnt();
+ const unsigned char* pvna = p + vn_aux;
+ for (unsigned int j = 0; j < vn_cnt; ++j)
+ {
+ elfcpp::Vernaux<size, big_endian> vernaux(pvna);
+
+ const unsigned int vna_other = vernaux.get_vna_other();
+ if (vna_other > maxver)
+ maxver = vna_other;
+
+ const unsigned int vna_next = vernaux.get_vna_next();
+ if ((pvna - pverneed) + vna_next >= verneed_size)
+ {
+ fprintf(stderr,
+ _("%s: %s: verneed vna_next field "
+ "out of range: %u\n"),
+ program_name, this->name().c_str(), vna_next);
+ gold_exit(false);
+ }
+
+ pvna += vna_next;
+ }
+
+ const unsigned int vn_next = verneed.get_vn_next();
+ if ((p - pverneed) + vn_next >= verneed_size)
+ {
+ fprintf(stderr,
+ _("%s: %s: verneed vn_next field out of range: %u\n"),
+ program_name, this->name().c_str(), vn_next);
+ gold_exit(false);
+ }
+
+ p += vn_next;
+ }
+ }
+
+ // Now MAXVER is the largest version index we have seen.
+
+ version_map->resize(maxver + 1);
+
+ const char* names = reinterpret_cast<const char*>(sd->symbol_names->data());
+ off_t names_size = sd->symbol_names_size;
+
+ if (sd->verdef != NULL)
+ {
+ const unsigned char* pverdef = sd->verdef->data();
+ off_t verdef_size = sd->verdef_size;
+ const unsigned int count = sd->verdef_info;
+
+ const unsigned char* p = pverdef;
+ for (unsigned int i = 0; i < count; ++i)
+ {
+ elfcpp::Verdef<size, big_endian> verdef(p);
+
+ const unsigned int vd_cnt = verdef.get_vd_cnt();
+ if (vd_cnt < 1)
+ {
+ fprintf(stderr, _("%s: %s: verdef vd_cnt field too small: %u\n"),
+ program_name, this->name().c_str(), vd_cnt);
+ gold_exit(false);
+ }
+
+ const unsigned int vd_aux = verdef.get_vd_aux();
+ if ((p - pverdef) + vd_aux >= verdef_size)
+ {
+ fprintf(stderr,
+ _("%s: %s: verdef vd_aux field out of range: %u\n"),
+ program_name, this->name().c_str(), vd_aux);
+ gold_exit(false);
+ }
+
+ const unsigned char* pvda = p + vd_aux;
+ elfcpp::Verdaux<size, big_endian> verdaux(pvda);
+
+ const unsigned int vda_name = verdaux.get_vda_name();
+ if (vda_name >= names_size)
+ {
+ fprintf(stderr,
+ _("%s: %s: verdaux vda_name field out of range: %u\n"),
+ program_name, this->name().c_str(), vda_name);
+ gold_exit(false);
+ }
+
+ this->set_version_map(version_map, verdef.get_vd_ndx(),
+ names + vda_name);
+
+ const unsigned int vd_next = verdef.get_vd_next();
+ if ((p - pverdef) + vd_next >= verdef_size)
+ {
+ fprintf(stderr,
+ _("%s: %s: verdef vd_next field out of range: %u\n"),
+ program_name, this->name().c_str(), vd_next);
+ gold_exit(false);
+ }
+
+ p += vd_next;
+ }
+ }
+
+ if (sd->verneed != NULL)
+ {
+ const unsigned char* pverneed = sd->verneed->data();
+ const unsigned int count = sd->verneed_info;
+
+ const unsigned char* p = pverneed;
+ for (unsigned int i = 0; i < count; ++i)
+ {
+ elfcpp::Verneed<size, big_endian> verneed(p);
+
+ const unsigned int vn_aux = verneed.get_vn_aux();
+ const unsigned int vn_cnt = verneed.get_vn_cnt();
+ const unsigned char* pvna = p + vn_aux;
+ for (unsigned int j = 0; j < vn_cnt; ++j)
+ {
+ elfcpp::Vernaux<size, big_endian> vernaux(pvna);
+
+ const unsigned int vna_name = vernaux.get_vna_name();
+ if (vna_name >= names_size)
+ {
+ fprintf(stderr,
+ _("%s: %s: vernaux vna_name field "
+ "out of range: %u\n"),
+ program_name, this->name().c_str(), vna_name);
+ gold_exit(false);
+ }
+
+ this->set_version_map(version_map, vernaux.get_vna_other(),
+ names + vna_name);
+
+ pvna += vernaux.get_vna_next();
+ }
+
+ p += verneed.get_vn_next();
+ }
+ }
+}
+
+// Add the dynamic symbols to the symbol table.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
+ Read_symbols_data* sd)
+{
+ if (sd->symbols == NULL)
+ {
+ assert(sd->symbol_names == NULL);
+ assert(sd->versym == NULL && sd->verdef == NULL && sd->verneed == NULL);
+ return;
+ }
+
+ const int sym_size = This::sym_size;
+ const size_t symcount = sd->symbols_size / sym_size;
+ if (symcount * sym_size != sd->symbols_size)
+ {
+ fprintf(stderr,
+ _("%s: %s: size of dynamic symbols is not "
+ "multiple of symbol size\n"),
+ program_name, this->name().c_str());
+ gold_exit(false);
+ }
+
+ Version_map version_map;
+ this->make_version_map(sd, &version_map);
+
+ const char* sym_names =
+ reinterpret_cast<const char*>(sd->symbol_names->data());
+ symtab->add_from_dynobj(this, sd->symbols->data(), symcount,
+ sym_names, sd->symbol_names_size,
+ (sd->versym == NULL
+ ? NULL
+ : sd->versym->data()),
+ sd->versym_size,
+ &version_map);
+
+ delete sd->symbols;
+ sd->symbols = NULL;
+ delete sd->symbol_names;
+ sd->symbol_names = NULL;
+ if (sd->versym != NULL)
+ {
+ delete sd->versym;
+ sd->versym = NULL;
+ }
+ if (sd->verdef != NULL)
+ {
+ delete sd->verdef;
+ sd->verdef = NULL;
+ }
+ if (sd->verneed != NULL)
+ {
+ delete sd->verneed;
+ sd->verneed = NULL;
+ }
+}
+
+// Instantiate the templates we need. We could use the configure
+// script to restrict this to only the ones for implemented targets.
+
+template
+class Sized_dynobj<32, false>;
+
+template
+class Sized_dynobj<32, true>;
+
+template
+class Sized_dynobj<64, false>;
+
+template
+class Sized_dynobj<64, true>;
+
+} // End namespace gold.