1504 lines
43 KiB
C++
1504 lines
43 KiB
C++
// i386.cc -- i386 target support for gold.
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#include "gold.h"
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#include <cstring>
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#include "elfcpp.h"
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#include "reloc.h"
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#include "i386.h"
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#include "object.h"
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#include "symtab.h"
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#include "layout.h"
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#include "output.h"
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#include "target.h"
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#include "target-reloc.h"
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#include "target-select.h"
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namespace
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{
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using namespace gold;
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class Output_data_plt_i386;
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// The i386 target class.
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class Target_i386 : public Sized_target<32, false>
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{
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public:
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typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
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Target_i386()
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: Sized_target<32, false>(&i386_info),
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got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
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copy_relocs_(NULL), dynbss_(NULL)
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{ }
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// Scan the relocations to look for symbol adjustments.
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void
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scan_relocs(const General_options& options,
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Symbol_table* symtab,
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Layout* layout,
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Sized_relobj<32, false>* object,
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unsigned int data_shndx,
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unsigned int sh_type,
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const unsigned char* prelocs,
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size_t reloc_count,
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size_t local_symbol_count,
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const unsigned char* plocal_symbols,
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Symbol** global_symbols);
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// Finalize the sections.
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void
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do_finalize_sections(const General_options*, Layout*);
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// Relocate a section.
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void
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relocate_section(const Relocate_info<32, false>*,
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unsigned int sh_type,
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const unsigned char* prelocs,
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size_t reloc_count,
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unsigned char* view,
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elfcpp::Elf_types<32>::Elf_Addr view_address,
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off_t view_size);
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private:
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// The class which scans relocations.
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struct Scan
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{
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inline void
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local(const General_options& options, Symbol_table* symtab,
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Layout* layout, Target_i386* target,
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Sized_relobj<32, false>* object,
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unsigned int data_shndx,
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const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
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const elfcpp::Sym<32, false>& lsym);
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inline void
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global(const General_options& options, Symbol_table* symtab,
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Layout* layout, Target_i386* target,
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Sized_relobj<32, false>* object,
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unsigned int data_shndx,
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const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
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Symbol* gsym);
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};
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// The class which implements relocation.
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class Relocate
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{
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public:
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Relocate()
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: skip_call_tls_get_addr_(false)
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{ }
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~Relocate()
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{
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if (this->skip_call_tls_get_addr_)
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{
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// FIXME: This needs to specify the location somehow.
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fprintf(stderr, _("%s: missing expected TLS relocation\n"),
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program_name);
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gold_exit(false);
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}
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}
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// Do a relocation. Return false if the caller should not issue
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// any warnings about this relocation.
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inline bool
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relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum,
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const elfcpp::Rel<32, false>&,
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unsigned int r_type, const Sized_symbol<32>*,
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elfcpp::Elf_types<32>::Elf_Addr,
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unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
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off_t);
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private:
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// Do a TLS relocation.
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inline void
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relocate_tls(const Relocate_info<32, false>*, size_t relnum,
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const elfcpp::Rel<32, false>&,
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unsigned int r_type, const Sized_symbol<32>*,
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elfcpp::Elf_types<32>::Elf_Addr,
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unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t);
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// Do a TLS Initial-Exec to Local-Exec transition.
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static inline void
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tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
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Output_segment* tls_segment,
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const elfcpp::Rel<32, false>&, unsigned int r_type,
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elfcpp::Elf_types<32>::Elf_Addr value,
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unsigned char* view,
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off_t view_size);
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// Do a TLS Global-Dynamic to Local-Exec transition.
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inline void
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tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
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Output_segment* tls_segment,
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const elfcpp::Rel<32, false>&, unsigned int r_type,
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elfcpp::Elf_types<32>::Elf_Addr value,
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unsigned char* view,
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off_t view_size);
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// Check the range for a TLS relocation.
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static inline void
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check_range(const Relocate_info<32, false>*, size_t relnum,
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const elfcpp::Rel<32, false>&, off_t, off_t);
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// Check the validity of a TLS relocation. This is like assert.
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static inline void
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check_tls(const Relocate_info<32, false>*, size_t relnum,
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const elfcpp::Rel<32, false>&, bool);
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// This is set if we should skip the next reloc, which should be a
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// PLT32 reloc against ___tls_get_addr.
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bool skip_call_tls_get_addr_;
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};
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// Adjust TLS relocation type based on the options and whether this
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// is a local symbol.
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static unsigned int
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optimize_tls_reloc(const General_options*, bool is_final, int r_type);
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// Get the GOT section, creating it if necessary.
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Output_data_got<32, false>*
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got_section(const General_options*, Symbol_table*, Layout*);
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// Create a PLT entry for a global symbol.
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void
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make_plt_entry(const General_options* options, Symbol_table*,
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Layout*, Symbol*);
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// Get the PLT section.
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Output_data_plt_i386*
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plt_section() const
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{
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gold_assert(this->plt_ != NULL);
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return this->plt_;
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}
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// Get the dynamic reloc section, creating it if necessary.
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Reloc_section*
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rel_dyn_section(Layout*);
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// Copy a relocation against a global symbol.
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void
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copy_reloc(const General_options*, Symbol_table*, Layout*,
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Sized_relobj<32, false>*, unsigned int,
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Symbol*, const elfcpp::Rel<32, false>&);
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// Information about this specific target which we pass to the
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// general Target structure.
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static const Target::Target_info i386_info;
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// The GOT section.
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Output_data_got<32, false>* got_;
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// The PLT section.
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Output_data_plt_i386* plt_;
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// The GOT PLT section.
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Output_data_space* got_plt_;
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// The dynamic reloc section.
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Reloc_section* rel_dyn_;
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// Relocs saved to avoid a COPY reloc.
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Copy_relocs<32, false>* copy_relocs_;
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// Space for variables copied with a COPY reloc.
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Output_data_space* dynbss_;
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};
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const Target::Target_info Target_i386::i386_info =
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{
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32, // size
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false, // is_big_endian
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elfcpp::EM_386, // machine_code
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false, // has_make_symbol
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false, // has_resolve
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"/usr/lib/libc.so.1", // dynamic_linker
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0x08048000, // text_segment_address
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0x1000, // abi_pagesize
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0x1000 // common_pagesize
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};
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// Get the GOT section, creating it if necessary.
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Output_data_got<32, false>*
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Target_i386::got_section(const General_options* options, Symbol_table* symtab,
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Layout* layout)
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{
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if (this->got_ == NULL)
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{
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gold_assert(options != NULL && symtab != NULL && layout != NULL);
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this->got_ = new Output_data_got<32, false>(options);
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layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
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elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
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this->got_);
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// The old GNU linker creates a .got.plt section. We just
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// create another set of data in the .got section. Note that we
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// always create a PLT if we create a GOT, although the PLT
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// might be empty.
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this->got_plt_ = new Output_data_space(4);
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layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
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elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
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this->got_plt_);
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// The first three entries are reserved.
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this->got_plt_->set_space_size(3 * 4);
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// Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
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symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL,
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this->got_plt_,
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0, 0, elfcpp::STT_OBJECT,
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elfcpp::STB_LOCAL,
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elfcpp::STV_HIDDEN, 0,
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false, false);
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}
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return this->got_;
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}
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// Get the dynamic reloc section, creating it if necessary.
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Target_i386::Reloc_section*
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Target_i386::rel_dyn_section(Layout* layout)
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{
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if (this->rel_dyn_ == NULL)
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{
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gold_assert(layout != NULL);
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this->rel_dyn_ = new Reloc_section();
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layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
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elfcpp::SHF_ALLOC, this->rel_dyn_);
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}
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return this->rel_dyn_;
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}
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// A class to handle the PLT data.
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class Output_data_plt_i386 : public Output_section_data
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{
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public:
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typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
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Output_data_plt_i386(Layout*, Output_data_space*, bool is_shared);
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// Add an entry to the PLT.
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void
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add_entry(Symbol* gsym);
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// Return the .rel.plt section data.
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const Reloc_section*
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rel_plt() const
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{ return this->rel_; }
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protected:
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void
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do_adjust_output_section(Output_section* os);
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private:
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// The size of an entry in the PLT.
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static const int plt_entry_size = 16;
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// The first entry in the PLT for an executable.
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static unsigned char exec_first_plt_entry[plt_entry_size];
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// The first entry in the PLT for a shared object.
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static unsigned char dyn_first_plt_entry[plt_entry_size];
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// Other entries in the PLT for an executable.
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static unsigned char exec_plt_entry[plt_entry_size];
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// Other entries in the PLT for a shared object.
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static unsigned char dyn_plt_entry[plt_entry_size];
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// Set the final size.
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void
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do_set_address(uint64_t, off_t)
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{ this->set_data_size((this->count_ + 1) * plt_entry_size); }
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// Write out the PLT data.
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void
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do_write(Output_file*);
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// The reloc section.
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Reloc_section* rel_;
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// The .got.plt section.
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Output_data_space* got_plt_;
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// The number of PLT entries.
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unsigned int count_;
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// Whether we are generated a shared object.
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bool is_shared_;
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};
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// Create the PLT section. The ordinary .got section is an argument,
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// since we need to refer to the start. We also create our own .got
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// section just for PLT entries.
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Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
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Output_data_space* got_plt,
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bool is_shared)
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: Output_section_data(4), got_plt_(got_plt), is_shared_(is_shared)
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{
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this->rel_ = new Reloc_section();
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layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
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elfcpp::SHF_ALLOC, this->rel_);
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}
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// For some reason
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void
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Output_data_plt_i386::do_adjust_output_section(Output_section* os)
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{
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// UnixWare sets the entsize of .plt to 4, and so does the old GNU
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// linker, and so do we.
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os->set_entsize(4);
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}
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// Add an entry to the PLT.
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void
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Output_data_plt_i386::add_entry(Symbol* gsym)
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{
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gold_assert(!gsym->has_plt_offset());
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// Note that when setting the PLT offset we skip the initial
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// reserved PLT entry.
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gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
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++this->count_;
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off_t got_offset = this->got_plt_->data_size();
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// Every PLT entry needs a GOT entry which points back to the PLT
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// entry (this will be changed by the dynamic linker, normally
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// lazily when the function is called).
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this->got_plt_->set_space_size(got_offset + 4);
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// Every PLT entry needs a reloc.
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gsym->set_needs_dynsym_entry();
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this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
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got_offset);
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// Note that we don't need to save the symbol. The contents of the
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// PLT are independent of which symbols are used. The symbols only
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// appear in the relocations.
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}
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// The first entry in the PLT for an executable.
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unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
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{
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0xff, 0x35, // pushl contents of memory address
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0, 0, 0, 0, // replaced with address of .got + 4
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0xff, 0x25, // jmp indirect
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0, 0, 0, 0, // replaced with address of .got + 8
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0, 0, 0, 0 // unused
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};
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// The first entry in the PLT for a shared object.
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unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
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{
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0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
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0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
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0, 0, 0, 0 // unused
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};
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// Subsequent entries in the PLT for an executable.
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unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
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{
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0xff, 0x25, // jmp indirect
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0, 0, 0, 0, // replaced with address of symbol in .got
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0x68, // pushl immediate
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0, 0, 0, 0, // replaced with offset into relocation table
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0xe9, // jmp relative
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0, 0, 0, 0 // replaced with offset to start of .plt
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};
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// Subsequent entries in the PLT for a shared object.
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unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
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{
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0xff, 0xa3, // jmp *offset(%ebx)
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0, 0, 0, 0, // replaced with offset of symbol in .got
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0x68, // pushl immediate
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0, 0, 0, 0, // replaced with offset into relocation table
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0xe9, // jmp relative
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0, 0, 0, 0 // replaced with offset to start of .plt
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};
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// Write out the PLT. This uses the hand-coded instructions above,
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// and adjusts them as needed. This is all specified by the i386 ELF
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// Processor Supplement.
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void
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Output_data_plt_i386::do_write(Output_file* of)
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{
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const off_t offset = this->offset();
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const off_t oview_size = this->data_size();
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unsigned char* const oview = of->get_output_view(offset, oview_size);
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const off_t got_file_offset = this->got_plt_->offset();
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const off_t got_size = this->got_plt_->data_size();
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unsigned char* const got_view = of->get_output_view(got_file_offset,
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got_size);
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unsigned char* pov = oview;
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elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
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elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
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if (this->is_shared_)
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memcpy(pov, dyn_first_plt_entry, plt_entry_size);
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else
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{
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memcpy(pov, exec_first_plt_entry, plt_entry_size);
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elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
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elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
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}
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pov += plt_entry_size;
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unsigned char* got_pov = got_view;
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memset(got_pov, 0, 12);
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got_pov += 12;
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const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
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unsigned int plt_offset = plt_entry_size;
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unsigned int plt_rel_offset = 0;
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unsigned int got_offset = 12;
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const unsigned int count = this->count_;
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for (unsigned int i = 0;
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i < count;
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++i,
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pov += plt_entry_size,
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got_pov += 4,
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plt_offset += plt_entry_size,
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plt_rel_offset += rel_size,
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got_offset += 4)
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{
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// Set and adjust the PLT entry itself.
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if (this->is_shared_)
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{
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memcpy(pov, dyn_plt_entry, plt_entry_size);
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elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
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}
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else
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{
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memcpy(pov, exec_plt_entry, plt_entry_size);
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elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
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(got_address
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+ got_offset));
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}
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elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
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elfcpp::Swap<32, false>::writeval(pov + 12,
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- (plt_offset + plt_entry_size));
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// Set the entry in the GOT.
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elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
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}
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gold_assert(pov - oview == oview_size);
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gold_assert(got_pov - got_view == got_size);
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of->write_output_view(offset, oview_size, oview);
|
|
of->write_output_view(got_file_offset, got_size, got_view);
|
|
}
|
|
|
|
// Create a PLT entry for a global symbol.
|
|
|
|
void
|
|
Target_i386::make_plt_entry(const General_options* options,
|
|
Symbol_table* symtab, Layout* layout, Symbol* gsym)
|
|
{
|
|
if (gsym->has_plt_offset())
|
|
return;
|
|
|
|
if (this->plt_ == NULL)
|
|
{
|
|
// Create the GOT sections first.
|
|
this->got_section(options, symtab, layout);
|
|
|
|
this->plt_ = new Output_data_plt_i386(layout, this->got_plt_,
|
|
options->is_shared());
|
|
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
|
|
(elfcpp::SHF_ALLOC
|
|
| elfcpp::SHF_EXECINSTR),
|
|
this->plt_);
|
|
}
|
|
|
|
this->plt_->add_entry(gsym);
|
|
}
|
|
|
|
// Handle a relocation against a non-function symbol defined in a
|
|
// dynamic object. The traditional way to handle this is to generate
|
|
// a COPY relocation to copy the variable at runtime from the shared
|
|
// object into the executable's data segment. However, this is
|
|
// undesirable in general, as if the size of the object changes in the
|
|
// dynamic object, the executable will no longer work correctly. If
|
|
// this relocation is in a writable section, then we can create a
|
|
// dynamic reloc and the dynamic linker will resolve it to the correct
|
|
// address at runtime. However, we do not want do that if the
|
|
// relocation is in a read-only section, as it would prevent the
|
|
// readonly segment from being shared. And if we have to eventually
|
|
// generate a COPY reloc, then any dynamic relocations will be
|
|
// useless. So this means that if this is a writable section, we need
|
|
// to save the relocation until we see whether we have to create a
|
|
// COPY relocation for this symbol for any other relocation.
|
|
|
|
void
|
|
Target_i386::copy_reloc(const General_options* options,
|
|
Symbol_table* symtab,
|
|
Layout* layout,
|
|
Sized_relobj<32, false>* object,
|
|
unsigned int data_shndx, Symbol* gsym,
|
|
const elfcpp::Rel<32, false>& rel)
|
|
{
|
|
Sized_symbol<32>* ssym;
|
|
ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym
|
|
SELECT_SIZE(32));
|
|
|
|
if (!Copy_relocs<32, false>::need_copy_reloc(options, object,
|
|
data_shndx, ssym))
|
|
{
|
|
// So far we do not need a COPY reloc. Save this relocation.
|
|
// If it turns out that we never need a COPY reloc for this
|
|
// symbol, then we will emit the relocation.
|
|
if (this->copy_relocs_ == NULL)
|
|
this->copy_relocs_ = new Copy_relocs<32, false>();
|
|
this->copy_relocs_->save(ssym, object, data_shndx, rel);
|
|
}
|
|
else
|
|
{
|
|
// Allocate space for this symbol in the .bss section.
|
|
|
|
elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize();
|
|
|
|
// There is no defined way to determine the required alignment
|
|
// of the symbol. We pick the alignment based on the size. We
|
|
// set an arbitrary maximum of 256.
|
|
unsigned int align;
|
|
for (align = 1; align < 512; align <<= 1)
|
|
if ((symsize & align) != 0)
|
|
break;
|
|
|
|
if (this->dynbss_ == NULL)
|
|
{
|
|
this->dynbss_ = new Output_data_space(align);
|
|
layout->add_output_section_data(".bss",
|
|
elfcpp::SHT_NOBITS,
|
|
(elfcpp::SHF_ALLOC
|
|
| elfcpp::SHF_WRITE),
|
|
this->dynbss_);
|
|
}
|
|
|
|
Output_data_space* dynbss = this->dynbss_;
|
|
|
|
if (align > dynbss->addralign())
|
|
dynbss->set_space_alignment(align);
|
|
|
|
off_t dynbss_size = dynbss->data_size();
|
|
dynbss_size = align_address(dynbss_size, align);
|
|
off_t offset = dynbss_size;
|
|
dynbss->set_space_size(dynbss_size + symsize);
|
|
|
|
// Define the symbol in the .dynbss section.
|
|
symtab->define_in_output_data(this, ssym->name(), ssym->version(),
|
|
dynbss, offset, symsize, ssym->type(),
|
|
ssym->binding(), ssym->visibility(),
|
|
ssym->nonvis(), false, false);
|
|
|
|
// Add the COPY reloc.
|
|
ssym->set_needs_dynsym_entry();
|
|
Reloc_section* rel_dyn = this->rel_dyn_section(layout);
|
|
rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset);
|
|
}
|
|
}
|
|
|
|
// Optimize the TLS relocation type based on what we know about the
|
|
// symbol. IS_FINAL is true if the final address of this symbol is
|
|
// known at link time.
|
|
|
|
unsigned int
|
|
Target_i386::optimize_tls_reloc(const General_options* options,
|
|
bool is_final,
|
|
int r_type)
|
|
{
|
|
// If we are generating a shared library, then we can't do anything
|
|
// in the linker.
|
|
if (options->is_shared())
|
|
return r_type;
|
|
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_TLS_GD:
|
|
case elfcpp::R_386_TLS_GOTDESC:
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
// These are Global-Dynamic which permits fully general TLS
|
|
// access. Since we know that we are generating an executable,
|
|
// we can convert this to Initial-Exec. If we also know that
|
|
// this is a local symbol, we can further switch to Local-Exec.
|
|
if (is_final)
|
|
return elfcpp::R_386_TLS_LE_32;
|
|
return elfcpp::R_386_TLS_IE_32;
|
|
|
|
case elfcpp::R_386_TLS_LDM:
|
|
// This is Local-Dynamic, which refers to a local symbol in the
|
|
// dynamic TLS block. Since we know that we generating an
|
|
// executable, we can switch to Local-Exec.
|
|
return elfcpp::R_386_TLS_LE_32;
|
|
|
|
case elfcpp::R_386_TLS_LDO_32:
|
|
// Another type of Local-Dynamic relocation.
|
|
return elfcpp::R_386_TLS_LE;
|
|
|
|
case elfcpp::R_386_TLS_IE:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
// These are Initial-Exec relocs which get the thread offset
|
|
// from the GOT. If we know that we are linking against the
|
|
// local symbol, we can switch to Local-Exec, which links the
|
|
// thread offset into the instruction.
|
|
if (is_final)
|
|
return elfcpp::R_386_TLS_LE_32;
|
|
return r_type;
|
|
|
|
case elfcpp::R_386_TLS_LE:
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
// When we already have Local-Exec, there is nothing further we
|
|
// can do.
|
|
return r_type;
|
|
|
|
default:
|
|
gold_unreachable();
|
|
}
|
|
}
|
|
|
|
// Scan a relocation for a local symbol.
|
|
|
|
inline void
|
|
Target_i386::Scan::local(const General_options& options,
|
|
Symbol_table* symtab,
|
|
Layout* layout,
|
|
Target_i386* target,
|
|
Sized_relobj<32, false>* object,
|
|
unsigned int,
|
|
const elfcpp::Rel<32, false>&,
|
|
unsigned int r_type,
|
|
const elfcpp::Sym<32, false>&)
|
|
{
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_NONE:
|
|
case elfcpp::R_386_GNU_VTINHERIT:
|
|
case elfcpp::R_386_GNU_VTENTRY:
|
|
break;
|
|
|
|
case elfcpp::R_386_32:
|
|
case elfcpp::R_386_16:
|
|
case elfcpp::R_386_8:
|
|
// FIXME: If we are generating a shared object we need to copy
|
|
// this relocation into the object.
|
|
gold_assert(!options.is_shared());
|
|
break;
|
|
|
|
case elfcpp::R_386_PC32:
|
|
case elfcpp::R_386_PC16:
|
|
case elfcpp::R_386_PC8:
|
|
break;
|
|
|
|
case elfcpp::R_386_GOTOFF:
|
|
case elfcpp::R_386_GOTPC:
|
|
// We need a GOT section.
|
|
target->got_section(&options, symtab, layout);
|
|
break;
|
|
|
|
case elfcpp::R_386_COPY:
|
|
case elfcpp::R_386_GLOB_DAT:
|
|
case elfcpp::R_386_JUMP_SLOT:
|
|
case elfcpp::R_386_RELATIVE:
|
|
case elfcpp::R_386_TLS_TPOFF:
|
|
case elfcpp::R_386_TLS_DTPMOD32:
|
|
case elfcpp::R_386_TLS_DTPOFF32:
|
|
case elfcpp::R_386_TLS_TPOFF32:
|
|
case elfcpp::R_386_TLS_DESC:
|
|
fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
|
|
program_name, object->name().c_str(), r_type);
|
|
gold_exit(false);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_IE:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_LE:
|
|
case elfcpp::R_386_TLS_GD:
|
|
case elfcpp::R_386_TLS_LDM:
|
|
case elfcpp::R_386_TLS_LDO_32:
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
case elfcpp::R_386_TLS_GOTDESC:
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
r_type = Target_i386::optimize_tls_reloc(&options,
|
|
!options.is_shared(),
|
|
r_type);
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_TLS_LE:
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
// FIXME: If generating a shared object, we need to copy
|
|
// this relocation into the object.
|
|
gold_assert(!options.is_shared());
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_IE:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_GD:
|
|
case elfcpp::R_386_TLS_LDM:
|
|
case elfcpp::R_386_TLS_LDO_32:
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
case elfcpp::R_386_TLS_GOTDESC:
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
fprintf(stderr,
|
|
_("%s: %s: unsupported reloc %u against local symbol\n"),
|
|
program_name, object->name().c_str(), r_type);
|
|
break;
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_GOT32:
|
|
case elfcpp::R_386_PLT32:
|
|
case elfcpp::R_386_32PLT:
|
|
case elfcpp::R_386_TLS_GD_32:
|
|
case elfcpp::R_386_TLS_GD_PUSH:
|
|
case elfcpp::R_386_TLS_GD_CALL:
|
|
case elfcpp::R_386_TLS_GD_POP:
|
|
case elfcpp::R_386_TLS_LDM_32:
|
|
case elfcpp::R_386_TLS_LDM_PUSH:
|
|
case elfcpp::R_386_TLS_LDM_CALL:
|
|
case elfcpp::R_386_TLS_LDM_POP:
|
|
case elfcpp::R_386_USED_BY_INTEL_200:
|
|
default:
|
|
fprintf(stderr, _("%s: %s: unsupported reloc %u against local symbol\n"),
|
|
program_name, object->name().c_str(), r_type);
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Scan a relocation for a global symbol.
|
|
|
|
inline void
|
|
Target_i386::Scan::global(const General_options& options,
|
|
Symbol_table* symtab,
|
|
Layout* layout,
|
|
Target_i386* target,
|
|
Sized_relobj<32, false>* object,
|
|
unsigned int data_shndx,
|
|
const elfcpp::Rel<32, false>& reloc,
|
|
unsigned int r_type,
|
|
Symbol* gsym)
|
|
{
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_NONE:
|
|
case elfcpp::R_386_GNU_VTINHERIT:
|
|
case elfcpp::R_386_GNU_VTENTRY:
|
|
break;
|
|
|
|
case elfcpp::R_386_32:
|
|
case elfcpp::R_386_PC32:
|
|
case elfcpp::R_386_16:
|
|
case elfcpp::R_386_PC16:
|
|
case elfcpp::R_386_8:
|
|
case elfcpp::R_386_PC8:
|
|
// FIXME: If we are generating a shared object we may need to
|
|
// copy this relocation into the object. If this symbol is
|
|
// defined in a shared object, we may need to copy this
|
|
// relocation in order to avoid a COPY relocation.
|
|
gold_assert(!options.is_shared());
|
|
|
|
if (gsym->is_from_dynobj())
|
|
{
|
|
// This symbol is defined in a dynamic object. If it is a
|
|
// function, we make a PLT entry. Otherwise we need to
|
|
// either generate a COPY reloc or copy this reloc.
|
|
if (gsym->type() == elfcpp::STT_FUNC)
|
|
target->make_plt_entry(&options, symtab, layout, gsym);
|
|
else
|
|
target->copy_reloc(&options, symtab, layout, object, data_shndx,
|
|
gsym, reloc);
|
|
}
|
|
|
|
break;
|
|
|
|
case elfcpp::R_386_GOT32:
|
|
// The symbol requires a GOT entry.
|
|
if (target->got_section(&options, symtab, layout)->add_global(gsym))
|
|
{
|
|
// If this symbol is not fully resolved, we need to add a
|
|
// dynamic relocation for it.
|
|
if (!gsym->final_value_is_known(&options))
|
|
gold_unreachable();
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_PLT32:
|
|
// If the symbol is fully resolved, this is just a PC32 reloc.
|
|
// Otherwise we need a PLT entry.
|
|
if (gsym->final_value_is_known(&options))
|
|
break;
|
|
target->make_plt_entry(&options, symtab, layout, gsym);
|
|
break;
|
|
|
|
case elfcpp::R_386_GOTOFF:
|
|
case elfcpp::R_386_GOTPC:
|
|
// We need a GOT section.
|
|
target->got_section(&options, symtab, layout);
|
|
break;
|
|
|
|
case elfcpp::R_386_COPY:
|
|
case elfcpp::R_386_GLOB_DAT:
|
|
case elfcpp::R_386_JUMP_SLOT:
|
|
case elfcpp::R_386_RELATIVE:
|
|
case elfcpp::R_386_TLS_TPOFF:
|
|
case elfcpp::R_386_TLS_DTPMOD32:
|
|
case elfcpp::R_386_TLS_DTPOFF32:
|
|
case elfcpp::R_386_TLS_TPOFF32:
|
|
case elfcpp::R_386_TLS_DESC:
|
|
fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
|
|
program_name, object->name().c_str(), r_type);
|
|
gold_exit(false);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_IE:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_LE:
|
|
case elfcpp::R_386_TLS_GD:
|
|
case elfcpp::R_386_TLS_LDM:
|
|
case elfcpp::R_386_TLS_LDO_32:
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
case elfcpp::R_386_TLS_GOTDESC:
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
{
|
|
const bool is_final = gsym->final_value_is_known(&options);
|
|
r_type = Target_i386::optimize_tls_reloc(&options, is_final, r_type);
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_TLS_LE:
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
// FIXME: If generating a shared object, we need to copy
|
|
// this relocation into the object.
|
|
gold_assert(!options.is_shared());
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_IE:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_GD:
|
|
case elfcpp::R_386_TLS_LDM:
|
|
case elfcpp::R_386_TLS_LDO_32:
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
case elfcpp::R_386_TLS_GOTDESC:
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
fprintf(stderr,
|
|
_("%s: %s: unsupported reloc %u "
|
|
"against global symbol %s\n"),
|
|
program_name, object->name().c_str(), r_type,
|
|
gsym->name());
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_32PLT:
|
|
case elfcpp::R_386_TLS_GD_32:
|
|
case elfcpp::R_386_TLS_GD_PUSH:
|
|
case elfcpp::R_386_TLS_GD_CALL:
|
|
case elfcpp::R_386_TLS_GD_POP:
|
|
case elfcpp::R_386_TLS_LDM_32:
|
|
case elfcpp::R_386_TLS_LDM_PUSH:
|
|
case elfcpp::R_386_TLS_LDM_CALL:
|
|
case elfcpp::R_386_TLS_LDM_POP:
|
|
case elfcpp::R_386_USED_BY_INTEL_200:
|
|
default:
|
|
fprintf(stderr,
|
|
_("%s: %s: unsupported reloc %u against global symbol %s\n"),
|
|
program_name, object->name().c_str(), r_type, gsym->name());
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Scan relocations for a section.
|
|
|
|
void
|
|
Target_i386::scan_relocs(const General_options& options,
|
|
Symbol_table* symtab,
|
|
Layout* layout,
|
|
Sized_relobj<32, false>* object,
|
|
unsigned int data_shndx,
|
|
unsigned int sh_type,
|
|
const unsigned char* prelocs,
|
|
size_t reloc_count,
|
|
size_t local_symbol_count,
|
|
const unsigned char* plocal_symbols,
|
|
Symbol** global_symbols)
|
|
{
|
|
if (sh_type == elfcpp::SHT_RELA)
|
|
{
|
|
fprintf(stderr, _("%s: %s: unsupported RELA reloc section\n"),
|
|
program_name, object->name().c_str());
|
|
gold_exit(false);
|
|
}
|
|
|
|
gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
|
|
Target_i386::Scan>(
|
|
options,
|
|
symtab,
|
|
layout,
|
|
this,
|
|
object,
|
|
data_shndx,
|
|
prelocs,
|
|
reloc_count,
|
|
local_symbol_count,
|
|
plocal_symbols,
|
|
global_symbols);
|
|
}
|
|
|
|
// Finalize the sections.
|
|
|
|
void
|
|
Target_i386::do_finalize_sections(const General_options* options,
|
|
Layout* layout)
|
|
{
|
|
// Fill in some more dynamic tags.
|
|
Output_data_dynamic* const odyn = layout->dynamic_data();
|
|
if (odyn != NULL)
|
|
{
|
|
if (this->got_plt_ != NULL)
|
|
odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
|
|
|
|
if (this->plt_ != NULL)
|
|
{
|
|
const Output_data* od = this->plt_->rel_plt();
|
|
odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
|
|
odyn->add_section_address(elfcpp::DT_JMPREL, od);
|
|
odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
|
|
}
|
|
|
|
if (this->rel_dyn_ != NULL)
|
|
{
|
|
const Output_data* od = this->rel_dyn_;
|
|
odyn->add_section_address(elfcpp::DT_REL, od);
|
|
odyn->add_section_size(elfcpp::DT_RELSZ, od);
|
|
odyn->add_constant(elfcpp::DT_RELENT,
|
|
elfcpp::Elf_sizes<32>::rel_size);
|
|
}
|
|
|
|
if (!options->is_shared())
|
|
{
|
|
// The value of the DT_DEBUG tag is filled in by the dynamic
|
|
// linker at run time, and used by the debugger.
|
|
odyn->add_constant(elfcpp::DT_DEBUG, 0);
|
|
}
|
|
}
|
|
|
|
// Emit any relocs we saved in an attempt to avoid generating COPY
|
|
// relocs.
|
|
if (this->copy_relocs_ == NULL)
|
|
return;
|
|
if (this->copy_relocs_->any_to_emit())
|
|
{
|
|
Reloc_section* rel_dyn = this->rel_dyn_section(layout);
|
|
this->copy_relocs_->emit(rel_dyn);
|
|
}
|
|
delete this->copy_relocs_;
|
|
this->copy_relocs_ = NULL;
|
|
}
|
|
|
|
// Perform a relocation.
|
|
|
|
inline bool
|
|
Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
|
|
Target_i386* target,
|
|
size_t relnum,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
unsigned int r_type,
|
|
const Sized_symbol<32>* gsym,
|
|
elfcpp::Elf_types<32>::Elf_Addr value,
|
|
unsigned char* view,
|
|
elfcpp::Elf_types<32>::Elf_Addr address,
|
|
off_t view_size)
|
|
{
|
|
if (this->skip_call_tls_get_addr_)
|
|
{
|
|
if (r_type != elfcpp::R_386_PLT32
|
|
|| gsym == NULL
|
|
|| strcmp(gsym->name(), "___tls_get_addr") != 0)
|
|
{
|
|
fprintf(stderr, _("%s: %s: missing expected TLS relocation\n"),
|
|
program_name,
|
|
relinfo->location(relnum, rel.get_r_offset()).c_str());
|
|
gold_exit(false);
|
|
}
|
|
|
|
this->skip_call_tls_get_addr_ = false;
|
|
|
|
return false;
|
|
}
|
|
|
|
// Pick the value to use for symbols defined in shared objects.
|
|
if (gsym != NULL && gsym->is_from_dynobj())
|
|
{
|
|
if (gsym->has_plt_offset())
|
|
value = target->plt_section()->address() + gsym->plt_offset();
|
|
else
|
|
gold_unreachable();
|
|
}
|
|
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_NONE:
|
|
case elfcpp::R_386_GNU_VTINHERIT:
|
|
case elfcpp::R_386_GNU_VTENTRY:
|
|
break;
|
|
|
|
case elfcpp::R_386_32:
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
break;
|
|
|
|
case elfcpp::R_386_PC32:
|
|
Relocate_functions<32, false>::pcrel32(view, value, address);
|
|
break;
|
|
|
|
case elfcpp::R_386_16:
|
|
Relocate_functions<32, false>::rel16(view, value);
|
|
break;
|
|
|
|
case elfcpp::R_386_PC16:
|
|
Relocate_functions<32, false>::pcrel16(view, value, address);
|
|
break;
|
|
|
|
case elfcpp::R_386_8:
|
|
Relocate_functions<32, false>::rel8(view, value);
|
|
break;
|
|
|
|
case elfcpp::R_386_PC8:
|
|
Relocate_functions<32, false>::pcrel8(view, value, address);
|
|
break;
|
|
|
|
case elfcpp::R_386_PLT32:
|
|
gold_assert(gsym->has_plt_offset()
|
|
|| gsym->final_value_is_known(relinfo->options));
|
|
Relocate_functions<32, false>::pcrel32(view, value, address);
|
|
break;
|
|
|
|
case elfcpp::R_386_GOT32:
|
|
// Local GOT offsets not yet supported.
|
|
gold_assert(gsym);
|
|
gold_assert(gsym->has_got_offset());
|
|
value = gsym->got_offset();
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
break;
|
|
|
|
case elfcpp::R_386_GOTOFF:
|
|
value -= target->got_section(NULL, NULL, NULL)->address();
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
break;
|
|
|
|
case elfcpp::R_386_GOTPC:
|
|
value = target->got_section(NULL, NULL, NULL)->address();
|
|
Relocate_functions<32, false>::pcrel32(view, value, address);
|
|
break;
|
|
|
|
case elfcpp::R_386_COPY:
|
|
case elfcpp::R_386_GLOB_DAT:
|
|
case elfcpp::R_386_JUMP_SLOT:
|
|
case elfcpp::R_386_RELATIVE:
|
|
case elfcpp::R_386_TLS_TPOFF:
|
|
case elfcpp::R_386_TLS_DTPMOD32:
|
|
case elfcpp::R_386_TLS_DTPOFF32:
|
|
case elfcpp::R_386_TLS_TPOFF32:
|
|
case elfcpp::R_386_TLS_DESC:
|
|
fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
|
|
program_name,
|
|
relinfo->location(relnum, rel.get_r_offset()).c_str(),
|
|
r_type);
|
|
gold_exit(false);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_IE:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_LE:
|
|
case elfcpp::R_386_TLS_GD:
|
|
case elfcpp::R_386_TLS_LDM:
|
|
case elfcpp::R_386_TLS_LDO_32:
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
case elfcpp::R_386_TLS_GOTDESC:
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
this->relocate_tls(relinfo, relnum, rel, r_type, gsym, value, view,
|
|
address, view_size);
|
|
break;
|
|
|
|
case elfcpp::R_386_32PLT:
|
|
case elfcpp::R_386_TLS_GD_32:
|
|
case elfcpp::R_386_TLS_GD_PUSH:
|
|
case elfcpp::R_386_TLS_GD_CALL:
|
|
case elfcpp::R_386_TLS_GD_POP:
|
|
case elfcpp::R_386_TLS_LDM_32:
|
|
case elfcpp::R_386_TLS_LDM_PUSH:
|
|
case elfcpp::R_386_TLS_LDM_CALL:
|
|
case elfcpp::R_386_TLS_LDM_POP:
|
|
case elfcpp::R_386_USED_BY_INTEL_200:
|
|
default:
|
|
fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
|
|
program_name,
|
|
relinfo->location(relnum, rel.get_r_offset()).c_str(),
|
|
r_type);
|
|
// gold_exit(false);
|
|
break;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// Perform a TLS relocation.
|
|
|
|
inline void
|
|
Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
|
|
size_t relnum,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
unsigned int r_type,
|
|
const Sized_symbol<32>* gsym,
|
|
elfcpp::Elf_types<32>::Elf_Addr value,
|
|
unsigned char* view,
|
|
elfcpp::Elf_types<32>::Elf_Addr,
|
|
off_t view_size)
|
|
{
|
|
Output_segment* tls_segment = relinfo->layout->tls_segment();
|
|
if (tls_segment == NULL)
|
|
{
|
|
fprintf(stderr, _("%s: %s: TLS reloc but no TLS segment\n"),
|
|
program_name,
|
|
relinfo->location(relnum, rel.get_r_offset()).c_str());
|
|
gold_exit(false);
|
|
}
|
|
|
|
const bool is_final = (gsym == NULL
|
|
? !relinfo->options->is_shared()
|
|
: gsym->final_value_is_known(relinfo->options));
|
|
const unsigned int opt_r_type =
|
|
Target_i386::optimize_tls_reloc(relinfo->options, is_final, r_type);
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
value = tls_segment->vaddr() + tls_segment->memsz() - value;
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_LE:
|
|
value = value - (tls_segment->vaddr() + tls_segment->memsz());
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_IE:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
if (opt_r_type == elfcpp::R_386_TLS_LE_32)
|
|
{
|
|
Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
|
|
rel, r_type, value, view,
|
|
view_size);
|
|
break;
|
|
}
|
|
fprintf(stderr, _("%s: %s: unsupported reloc type %u\n"),
|
|
program_name,
|
|
relinfo->location(relnum, rel.get_r_offset()).c_str(),
|
|
r_type);
|
|
// gold_exit(false);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_GD:
|
|
if (opt_r_type == elfcpp::R_386_TLS_LE_32)
|
|
{
|
|
this->tls_gd_to_le(relinfo, relnum, tls_segment,
|
|
rel, r_type, value, view,
|
|
view_size);
|
|
break;
|
|
}
|
|
fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
|
|
program_name,
|
|
relinfo->location(relnum, rel.get_r_offset()).c_str(),
|
|
r_type);
|
|
// gold_exit(false);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_LDM:
|
|
case elfcpp::R_386_TLS_LDO_32:
|
|
case elfcpp::R_386_TLS_GOTDESC:
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
|
|
program_name,
|
|
relinfo->location(relnum, rel.get_r_offset()).c_str(),
|
|
r_type);
|
|
// gold_exit(false);
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Do a relocation in which we convert a TLS Initial-Exec to a
|
|
// Local-Exec.
|
|
|
|
inline void
|
|
Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
|
|
size_t relnum,
|
|
Output_segment* tls_segment,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
unsigned int r_type,
|
|
elfcpp::Elf_types<32>::Elf_Addr value,
|
|
unsigned char* view,
|
|
off_t view_size)
|
|
{
|
|
// We have to actually change the instructions, which means that we
|
|
// need to examine the opcodes to figure out which instruction we
|
|
// are looking at.
|
|
if (r_type == elfcpp::R_386_TLS_IE)
|
|
{
|
|
// movl %gs:XX,%eax ==> movl $YY,%eax
|
|
// movl %gs:XX,%reg ==> movl $YY,%reg
|
|
// addl %gs:XX,%reg ==> addl $YY,%reg
|
|
Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -1);
|
|
Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4);
|
|
|
|
unsigned char op1 = view[-1];
|
|
if (op1 == 0xa1)
|
|
{
|
|
// movl XX,%eax ==> movl $YY,%eax
|
|
view[-1] = 0xb8;
|
|
}
|
|
else
|
|
{
|
|
Target_i386::Relocate::check_range(relinfo, relnum, rel,
|
|
view_size, -2);
|
|
|
|
unsigned char op2 = view[-2];
|
|
if (op2 == 0x8b)
|
|
{
|
|
// movl XX,%reg ==> movl $YY,%reg
|
|
Target_i386::Relocate::check_tls(relinfo, relnum, rel,
|
|
(op1 & 0xc7) == 0x05);
|
|
view[-2] = 0xc7;
|
|
view[-1] = 0xc0 | ((op1 >> 3) & 7);
|
|
}
|
|
else if (op2 == 0x03)
|
|
{
|
|
// addl XX,%reg ==> addl $YY,%reg
|
|
Target_i386::Relocate::check_tls(relinfo, relnum, rel,
|
|
(op1 & 0xc7) == 0x05);
|
|
view[-2] = 0x81;
|
|
view[-1] = 0xc0 | ((op1 >> 3) & 7);
|
|
}
|
|
else
|
|
Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
// subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
|
|
// movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
|
|
// addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
|
|
Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2);
|
|
Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4);
|
|
|
|
unsigned char op1 = view[-1];
|
|
unsigned char op2 = view[-2];
|
|
Target_i386::Relocate::check_tls(relinfo, relnum, rel,
|
|
(op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
|
|
if (op2 == 0x8b)
|
|
{
|
|
// movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
|
|
view[-2] = 0xc7;
|
|
view[-1] = 0xc0 | ((op1 >> 3) & 7);
|
|
}
|
|
else if (op2 == 0x2b)
|
|
{
|
|
// subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
|
|
view[-2] = 0x81;
|
|
view[-1] = 0xe8 | ((op1 >> 3) & 7);
|
|
}
|
|
else if (op2 == 0x03)
|
|
{
|
|
// addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
|
|
view[-2] = 0x81;
|
|
view[-1] = 0xc0 | ((op1 >> 3) & 7);
|
|
}
|
|
else
|
|
Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0);
|
|
}
|
|
|
|
value = tls_segment->vaddr() + tls_segment->memsz() - value;
|
|
if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
|
|
value = - value;
|
|
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
}
|
|
|
|
// Do a relocation in which we convert a TLS Global-Dynamic to a
|
|
// Local-Exec.
|
|
|
|
inline void
|
|
Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
|
|
size_t relnum,
|
|
Output_segment* tls_segment,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
unsigned int,
|
|
elfcpp::Elf_types<32>::Elf_Addr value,
|
|
unsigned char* view,
|
|
off_t view_size)
|
|
{
|
|
// leal foo(,%reg,1),%eax; call ___tls_get_addr
|
|
// ==> movl %gs,0,%eax; subl $foo@tpoff,%eax
|
|
// leal foo(%reg),%eax; call ___tls_get_addr
|
|
// ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
|
|
|
|
Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2);
|
|
Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 9);
|
|
|
|
unsigned char op1 = view[-1];
|
|
unsigned char op2 = view[-2];
|
|
|
|
Target_i386::Relocate::check_tls(relinfo, relnum, rel,
|
|
op2 == 0x8d || op2 == 0x04);
|
|
Target_i386::Relocate::check_tls(relinfo, relnum, rel,
|
|
view[4] == 0xe8);
|
|
|
|
int roff = 5;
|
|
|
|
if (op2 == 0x04)
|
|
{
|
|
Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -3);
|
|
Target_i386::Relocate::check_tls(relinfo, relnum, rel,
|
|
view[-3] == 0x8d);
|
|
Target_i386::Relocate::check_tls(relinfo, relnum, rel,
|
|
((op1 & 0xc7) == 0x05
|
|
&& op1 != (4 << 3)));
|
|
memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
|
|
}
|
|
else
|
|
{
|
|
Target_i386::Relocate::check_tls(relinfo, relnum, rel,
|
|
(op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
|
|
if (rel.get_r_offset() + 9 < view_size && view[9] == 0x90)
|
|
{
|
|
// There is a trailing nop. Use the size byte subl.
|
|
memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
|
|
roff = 6;
|
|
}
|
|
else
|
|
{
|
|
// Use the five byte subl.
|
|
memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
|
|
}
|
|
}
|
|
|
|
value = tls_segment->vaddr() + tls_segment->memsz() - value;
|
|
Relocate_functions<32, false>::rel32(view + roff, value);
|
|
|
|
// The next reloc should be a PLT32 reloc against __tls_get_addr.
|
|
// We can skip it.
|
|
this->skip_call_tls_get_addr_ = true;
|
|
}
|
|
|
|
// Check the range for a TLS relocation.
|
|
|
|
inline void
|
|
Target_i386::Relocate::check_range(const Relocate_info<32, false>* relinfo,
|
|
size_t relnum,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
off_t view_size, off_t off)
|
|
{
|
|
off_t offset = rel.get_r_offset() + off;
|
|
if (offset < 0 || offset > view_size)
|
|
{
|
|
fprintf(stderr, _("%s: %s: TLS relocation out of range\n"),
|
|
program_name,
|
|
relinfo->location(relnum, rel.get_r_offset()).c_str());
|
|
gold_exit(false);
|
|
}
|
|
}
|
|
|
|
// Check the validity of a TLS relocation. This is like assert.
|
|
|
|
inline void
|
|
Target_i386::Relocate::check_tls(const Relocate_info<32, false>* relinfo,
|
|
size_t relnum,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
bool valid)
|
|
{
|
|
if (!valid)
|
|
{
|
|
fprintf(stderr,
|
|
_("%s: %s: TLS relocation against invalid instruction\n"),
|
|
program_name,
|
|
relinfo->location(relnum, rel.get_r_offset()).c_str());
|
|
gold_exit(false);
|
|
}
|
|
}
|
|
|
|
// Relocate section data.
|
|
|
|
void
|
|
Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
|
|
unsigned int sh_type,
|
|
const unsigned char* prelocs,
|
|
size_t reloc_count,
|
|
unsigned char* view,
|
|
elfcpp::Elf_types<32>::Elf_Addr address,
|
|
off_t view_size)
|
|
{
|
|
gold_assert(sh_type == elfcpp::SHT_REL);
|
|
|
|
gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
|
|
Target_i386::Relocate>(
|
|
relinfo,
|
|
this,
|
|
prelocs,
|
|
reloc_count,
|
|
view,
|
|
address,
|
|
view_size);
|
|
}
|
|
|
|
// The selector for i386 object files.
|
|
|
|
class Target_selector_i386 : public Target_selector
|
|
{
|
|
public:
|
|
Target_selector_i386()
|
|
: Target_selector(elfcpp::EM_386, 32, false)
|
|
{ }
|
|
|
|
Target*
|
|
recognize(int machine, int osabi, int abiversion);
|
|
|
|
private:
|
|
Target_i386* target_;
|
|
};
|
|
|
|
// Recognize an i386 object file when we already know that the machine
|
|
// number is EM_386.
|
|
|
|
Target*
|
|
Target_selector_i386::recognize(int, int, int)
|
|
{
|
|
if (this->target_ == NULL)
|
|
this->target_ = new Target_i386();
|
|
return this->target_;
|
|
}
|
|
|
|
Target_selector_i386 target_selector_i386;
|
|
|
|
} // End anonymous namespace.
|