diff options
Diffstat (limited to 'REORG.TODO/sysdeps/x86_64/dl-machine.h')
| -rw-r--r-- | REORG.TODO/sysdeps/x86_64/dl-machine.h | 601 |
1 files changed, 601 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/x86_64/dl-machine.h b/REORG.TODO/sysdeps/x86_64/dl-machine.h new file mode 100644 index 0000000000..0015db4d6a --- /dev/null +++ b/REORG.TODO/sysdeps/x86_64/dl-machine.h @@ -0,0 +1,601 @@ +/* Machine-dependent ELF dynamic relocation inline functions. x86-64 version. + Copyright (C) 2001-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Andreas Jaeger <aj@suse.de>. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#ifndef dl_machine_h +#define dl_machine_h + +#define ELF_MACHINE_NAME "x86_64" + +#include <sys/param.h> +#include <sysdep.h> +#include <tls.h> +#include <dl-tlsdesc.h> +#include <cpu-features.c> + +/* Return nonzero iff ELF header is compatible with the running host. */ +static inline int __attribute__ ((unused)) +elf_machine_matches_host (const ElfW(Ehdr) *ehdr) +{ + return ehdr->e_machine == EM_X86_64; +} + + +/* Return the link-time address of _DYNAMIC. Conveniently, this is the + first element of the GOT. This must be inlined in a function which + uses global data. */ +static inline ElfW(Addr) __attribute__ ((unused)) +elf_machine_dynamic (void) +{ + /* This produces an IP-relative reloc which is resolved at link time. */ + extern const ElfW(Addr) _GLOBAL_OFFSET_TABLE_[] attribute_hidden; + return _GLOBAL_OFFSET_TABLE_[0]; +} + + +/* Return the run-time load address of the shared object. */ +static inline ElfW(Addr) __attribute__ ((unused)) +elf_machine_load_address (void) +{ + /* Compute the difference between the runtime address of _DYNAMIC as seen + by an IP-relative reference, and the link-time address found in the + special unrelocated first GOT entry. */ + extern ElfW(Dyn) _DYNAMIC[] attribute_hidden; + return (ElfW(Addr)) &_DYNAMIC - elf_machine_dynamic (); +} + +/* Set up the loaded object described by L so its unrelocated PLT + entries will jump to the on-demand fixup code in dl-runtime.c. */ + +static inline int __attribute__ ((unused, always_inline)) +elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) +{ + Elf64_Addr *got; + extern void _dl_runtime_resolve_sse (ElfW(Word)) attribute_hidden; + extern void _dl_runtime_resolve_avx (ElfW(Word)) attribute_hidden; + extern void _dl_runtime_resolve_avx_slow (ElfW(Word)) attribute_hidden; + extern void _dl_runtime_resolve_avx_opt (ElfW(Word)) attribute_hidden; + extern void _dl_runtime_resolve_avx512 (ElfW(Word)) attribute_hidden; + extern void _dl_runtime_resolve_avx512_opt (ElfW(Word)) attribute_hidden; + extern void _dl_runtime_profile_sse (ElfW(Word)) attribute_hidden; + extern void _dl_runtime_profile_avx (ElfW(Word)) attribute_hidden; + extern void _dl_runtime_profile_avx512 (ElfW(Word)) attribute_hidden; + + if (l->l_info[DT_JMPREL] && lazy) + { + /* The GOT entries for functions in the PLT have not yet been filled + in. Their initial contents will arrange when called to push an + offset into the .rel.plt section, push _GLOBAL_OFFSET_TABLE_[1], + and then jump to _GLOBAL_OFFSET_TABLE_[2]. */ + got = (Elf64_Addr *) D_PTR (l, l_info[DT_PLTGOT]); + /* If a library is prelinked but we have to relocate anyway, + we have to be able to undo the prelinking of .got.plt. + The prelinker saved us here address of .plt + 0x16. */ + if (got[1]) + { + l->l_mach.plt = got[1] + l->l_addr; + l->l_mach.gotplt = (ElfW(Addr)) &got[3]; + } + /* Identify this shared object. */ + *(ElfW(Addr) *) (got + 1) = (ElfW(Addr)) l; + + /* The got[2] entry contains the address of a function which gets + called to get the address of a so far unresolved function and + jump to it. The profiling extension of the dynamic linker allows + to intercept the calls to collect information. In this case we + don't store the address in the GOT so that all future calls also + end in this function. */ + if (__glibc_unlikely (profile)) + { + if (HAS_ARCH_FEATURE (AVX512F_Usable)) + *(ElfW(Addr) *) (got + 2) = (ElfW(Addr)) &_dl_runtime_profile_avx512; + else if (HAS_ARCH_FEATURE (AVX_Usable)) + *(ElfW(Addr) *) (got + 2) = (ElfW(Addr)) &_dl_runtime_profile_avx; + else + *(ElfW(Addr) *) (got + 2) = (ElfW(Addr)) &_dl_runtime_profile_sse; + + if (GLRO(dl_profile) != NULL + && _dl_name_match_p (GLRO(dl_profile), l)) + /* This is the object we are looking for. Say that we really + want profiling and the timers are started. */ + GL(dl_profile_map) = l; + } + else + { + /* This function will get called to fix up the GOT entry + indicated by the offset on the stack, and then jump to + the resolved address. */ + if (HAS_ARCH_FEATURE (AVX512F_Usable)) + { + if (HAS_ARCH_FEATURE (Use_dl_runtime_resolve_opt)) + *(ElfW(Addr) *) (got + 2) + = (ElfW(Addr)) &_dl_runtime_resolve_avx512_opt; + else + *(ElfW(Addr) *) (got + 2) + = (ElfW(Addr)) &_dl_runtime_resolve_avx512; + } + else if (HAS_ARCH_FEATURE (AVX_Usable)) + { + if (HAS_ARCH_FEATURE (Use_dl_runtime_resolve_opt)) + *(ElfW(Addr) *) (got + 2) + = (ElfW(Addr)) &_dl_runtime_resolve_avx_opt; + else if (HAS_ARCH_FEATURE (Use_dl_runtime_resolve_slow)) + *(ElfW(Addr) *) (got + 2) + = (ElfW(Addr)) &_dl_runtime_resolve_avx_slow; + else + *(ElfW(Addr) *) (got + 2) + = (ElfW(Addr)) &_dl_runtime_resolve_avx; + } + else + *(ElfW(Addr) *) (got + 2) = (ElfW(Addr)) &_dl_runtime_resolve_sse; + } + } + + if (l->l_info[ADDRIDX (DT_TLSDESC_GOT)] && lazy) + *(ElfW(Addr)*)(D_PTR (l, l_info[ADDRIDX (DT_TLSDESC_GOT)]) + l->l_addr) + = (ElfW(Addr)) &_dl_tlsdesc_resolve_rela; + + return lazy; +} + +/* Initial entry point code for the dynamic linker. + The C function `_dl_start' is the real entry point; + its return value is the user program's entry point. */ +#define RTLD_START asm ("\n\ +.text\n\ + .align 16\n\ +.globl _start\n\ +.globl _dl_start_user\n\ +_start:\n\ + movq %rsp, %rdi\n\ + call _dl_start\n\ +_dl_start_user:\n\ + # Save the user entry point address in %r12.\n\ + movq %rax, %r12\n\ + # See if we were run as a command with the executable file\n\ + # name as an extra leading argument.\n\ + movl _dl_skip_args(%rip), %eax\n\ + # Pop the original argument count.\n\ + popq %rdx\n\ + # Adjust the stack pointer to skip _dl_skip_args words.\n\ + leaq (%rsp,%rax,8), %rsp\n\ + # Subtract _dl_skip_args from argc.\n\ + subl %eax, %edx\n\ + # Push argc back on the stack.\n\ + pushq %rdx\n\ + # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)\n\ + # argc -> rsi\n\ + movq %rdx, %rsi\n\ + # Save %rsp value in %r13.\n\ + movq %rsp, %r13\n\ + # And align stack for the _dl_init call. \n\ + andq $-16, %rsp\n\ + # _dl_loaded -> rdi\n\ + movq _rtld_local(%rip), %rdi\n\ + # env -> rcx\n\ + leaq 16(%r13,%rdx,8), %rcx\n\ + # argv -> rdx\n\ + leaq 8(%r13), %rdx\n\ + # Clear %rbp to mark outermost frame obviously even for constructors.\n\ + xorl %ebp, %ebp\n\ + # Call the function to run the initializers.\n\ + call _dl_init\n\ + # Pass our finalizer function to the user in %rdx, as per ELF ABI.\n\ + leaq _dl_fini(%rip), %rdx\n\ + # And make sure %rsp points to argc stored on the stack.\n\ + movq %r13, %rsp\n\ + # Jump to the user's entry point.\n\ + jmp *%r12\n\ +.previous\n\ +"); + +/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or + TLS variable, so undefined references should not be allowed to + define the value. + ELF_RTYPE_CLASS_COPY iff TYPE should not be allowed to resolve to one + of the main executable's symbols, as for a COPY reloc. + ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA iff TYPE describes relocation may + against protected data whose address be external due to copy relocation. + */ +#define elf_machine_type_class(type) \ + ((((type) == R_X86_64_JUMP_SLOT \ + || (type) == R_X86_64_DTPMOD64 \ + || (type) == R_X86_64_DTPOFF64 \ + || (type) == R_X86_64_TPOFF64 \ + || (type) == R_X86_64_TLSDESC) \ + * ELF_RTYPE_CLASS_PLT) \ + | (((type) == R_X86_64_COPY) * ELF_RTYPE_CLASS_COPY) \ + | (((type) == R_X86_64_GLOB_DAT) * ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA)) + +/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */ +#define ELF_MACHINE_JMP_SLOT R_X86_64_JUMP_SLOT + +/* The relative ifunc relocation. */ +// XXX This is a work-around for a broken linker. Remove! +#define ELF_MACHINE_IRELATIVE R_X86_64_IRELATIVE + +/* The x86-64 never uses Elf64_Rel/Elf32_Rel relocations. */ +#define ELF_MACHINE_NO_REL 1 +#define ELF_MACHINE_NO_RELA 0 + +/* We define an initialization function. This is called very early in + _dl_sysdep_start. */ +#define DL_PLATFORM_INIT dl_platform_init () + +static inline void __attribute__ ((unused)) +dl_platform_init (void) +{ +#if IS_IN (rtld) + /* init_cpu_features has been called early from __libc_start_main in + static executable. */ + init_cpu_features (&GLRO(dl_x86_cpu_features)); +#else + if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0') + /* Avoid an empty string which would disturb us. */ + GLRO(dl_platform) = NULL; +#endif +} + +static inline ElfW(Addr) +elf_machine_fixup_plt (struct link_map *map, lookup_t t, + const ElfW(Rela) *reloc, + ElfW(Addr) *reloc_addr, ElfW(Addr) value) +{ + return *reloc_addr = value; +} + +/* Return the final value of a PLT relocation. On x86-64 the + JUMP_SLOT relocation ignores the addend. */ +static inline ElfW(Addr) +elf_machine_plt_value (struct link_map *map, const ElfW(Rela) *reloc, + ElfW(Addr) value) +{ + return value; +} + + +/* Names of the architecture-specific auditing callback functions. */ +#define ARCH_LA_PLTENTER x86_64_gnu_pltenter +#define ARCH_LA_PLTEXIT x86_64_gnu_pltexit + +#endif /* !dl_machine_h */ + +#ifdef RESOLVE_MAP + +/* Perform the relocation specified by RELOC and SYM (which is fully resolved). + MAP is the object containing the reloc. */ + +auto inline void +__attribute__ ((always_inline)) +elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc, + const ElfW(Sym) *sym, const struct r_found_version *version, + void *const reloc_addr_arg, int skip_ifunc) +{ + ElfW(Addr) *const reloc_addr = reloc_addr_arg; + const unsigned long int r_type = ELFW(R_TYPE) (reloc->r_info); + +# if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC + if (__glibc_unlikely (r_type == R_X86_64_RELATIVE)) + { +# if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC + /* This is defined in rtld.c, but nowhere in the static libc.a; + make the reference weak so static programs can still link. + This declaration cannot be done when compiling rtld.c + (i.e. #ifdef RTLD_BOOTSTRAP) because rtld.c contains the + common defn for _dl_rtld_map, which is incompatible with a + weak decl in the same file. */ +# ifndef SHARED + weak_extern (GL(dl_rtld_map)); +# endif + if (map != &GL(dl_rtld_map)) /* Already done in rtld itself. */ +# endif + *reloc_addr = map->l_addr + reloc->r_addend; + } + else +# endif +# if !defined RTLD_BOOTSTRAP + /* l_addr + r_addend may be > 0xffffffff and R_X86_64_RELATIVE64 + relocation updates the whole 64-bit entry. */ + if (__glibc_unlikely (r_type == R_X86_64_RELATIVE64)) + *(Elf64_Addr *) reloc_addr = (Elf64_Addr) map->l_addr + reloc->r_addend; + else +# endif + if (__glibc_unlikely (r_type == R_X86_64_NONE)) + return; + else + { +# ifndef RTLD_BOOTSTRAP + const ElfW(Sym) *const refsym = sym; +# endif + struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type); + ElfW(Addr) value = (sym == NULL ? 0 + : (ElfW(Addr)) sym_map->l_addr + sym->st_value); + + if (sym != NULL + && __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC, + 0) + && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1) + && __builtin_expect (!skip_ifunc, 1)) + { +# ifndef RTLD_BOOTSTRAP + if (sym_map != map + && sym_map->l_type != lt_executable + && !sym_map->l_relocated) + { + const char *strtab + = (const char *) D_PTR (map, l_info[DT_STRTAB]); + _dl_error_printf ("\ +%s: Relink `%s' with `%s' for IFUNC symbol `%s'\n", + RTLD_PROGNAME, map->l_name, + sym_map->l_name, + strtab + refsym->st_name); + } +# endif + value = ((ElfW(Addr) (*) (void)) value) (); + } + + switch (r_type) + { +# ifndef RTLD_BOOTSTRAP +# ifdef __ILP32__ + case R_X86_64_SIZE64: + /* Set to symbol size plus addend. */ + *(Elf64_Addr *) (uintptr_t) reloc_addr + = (Elf64_Addr) sym->st_size + reloc->r_addend; + break; + + case R_X86_64_SIZE32: +# else + case R_X86_64_SIZE64: +# endif + /* Set to symbol size plus addend. */ + value = sym->st_size; +# endif + case R_X86_64_GLOB_DAT: + case R_X86_64_JUMP_SLOT: + *reloc_addr = value + reloc->r_addend; + break; + +# ifndef RESOLVE_CONFLICT_FIND_MAP + case R_X86_64_DTPMOD64: +# ifdef RTLD_BOOTSTRAP + /* During startup the dynamic linker is always the module + with index 1. + XXX If this relocation is necessary move before RESOLVE + call. */ + *reloc_addr = 1; +# else + /* Get the information from the link map returned by the + resolve function. */ + if (sym_map != NULL) + *reloc_addr = sym_map->l_tls_modid; +# endif + break; + case R_X86_64_DTPOFF64: +# ifndef RTLD_BOOTSTRAP + /* During relocation all TLS symbols are defined and used. + Therefore the offset is already correct. */ + if (sym != NULL) + { + value = sym->st_value + reloc->r_addend; +# ifdef __ILP32__ + /* This relocation type computes a signed offset that is + usually negative. The symbol and addend values are 32 + bits but the GOT entry is 64 bits wide and the whole + 64-bit entry is used as a signed quantity, so we need + to sign-extend the computed value to 64 bits. */ + *(Elf64_Sxword *) reloc_addr = (Elf64_Sxword) (Elf32_Sword) value; +# else + *reloc_addr = value; +# endif + } +# endif + break; + case R_X86_64_TLSDESC: + { + struct tlsdesc volatile *td = + (struct tlsdesc volatile *)reloc_addr; + +# ifndef RTLD_BOOTSTRAP + if (! sym) + { + td->arg = (void*)reloc->r_addend; + td->entry = _dl_tlsdesc_undefweak; + } + else +# endif + { +# ifndef RTLD_BOOTSTRAP +# ifndef SHARED + CHECK_STATIC_TLS (map, sym_map); +# else + if (!TRY_STATIC_TLS (map, sym_map)) + { + td->arg = _dl_make_tlsdesc_dynamic + (sym_map, sym->st_value + reloc->r_addend); + td->entry = _dl_tlsdesc_dynamic; + } + else +# endif +# endif + { + td->arg = (void*)(sym->st_value - sym_map->l_tls_offset + + reloc->r_addend); + td->entry = _dl_tlsdesc_return; + } + } + break; + } + case R_X86_64_TPOFF64: + /* The offset is negative, forward from the thread pointer. */ +# ifndef RTLD_BOOTSTRAP + if (sym != NULL) +# endif + { +# ifndef RTLD_BOOTSTRAP + CHECK_STATIC_TLS (map, sym_map); +# endif + /* We know the offset of the object the symbol is contained in. + It is a negative value which will be added to the + thread pointer. */ + value = (sym->st_value + reloc->r_addend + - sym_map->l_tls_offset); +# ifdef __ILP32__ + /* The symbol and addend values are 32 bits but the GOT + entry is 64 bits wide and the whole 64-bit entry is used + as a signed quantity, so we need to sign-extend the + computed value to 64 bits. */ + *(Elf64_Sxword *) reloc_addr = (Elf64_Sxword) (Elf32_Sword) value; +# else + *reloc_addr = value; +# endif + } + break; +# endif + +# ifndef RTLD_BOOTSTRAP + case R_X86_64_64: + /* value + r_addend may be > 0xffffffff and R_X86_64_64 + relocation updates the whole 64-bit entry. */ + *(Elf64_Addr *) reloc_addr = (Elf64_Addr) value + reloc->r_addend; + break; +# ifndef __ILP32__ + case R_X86_64_SIZE32: + /* Set to symbol size plus addend. */ + value = sym->st_size; +# endif + case R_X86_64_32: + value += reloc->r_addend; + *(unsigned int *) reloc_addr = value; + + const char *fmt; + if (__glibc_unlikely (value > UINT_MAX)) + { + const char *strtab; + + fmt = "\ +%s: Symbol `%s' causes overflow in R_X86_64_32 relocation\n"; +# ifndef RESOLVE_CONFLICT_FIND_MAP + print_err: +# endif + strtab = (const char *) D_PTR (map, l_info[DT_STRTAB]); + + _dl_error_printf (fmt, RTLD_PROGNAME, strtab + refsym->st_name); + } + break; +# ifndef RESOLVE_CONFLICT_FIND_MAP + /* Not needed for dl-conflict.c. */ + case R_X86_64_PC32: + value += reloc->r_addend - (ElfW(Addr)) reloc_addr; + *(unsigned int *) reloc_addr = value; + if (__glibc_unlikely (value != (int) value)) + { + fmt = "\ +%s: Symbol `%s' causes overflow in R_X86_64_PC32 relocation\n"; + goto print_err; + } + break; + case R_X86_64_COPY: + if (sym == NULL) + /* This can happen in trace mode if an object could not be + found. */ + break; + memcpy (reloc_addr_arg, (void *) value, + MIN (sym->st_size, refsym->st_size)); + if (__builtin_expect (sym->st_size > refsym->st_size, 0) + || (__builtin_expect (sym->st_size < refsym->st_size, 0) + && GLRO(dl_verbose))) + { + fmt = "\ +%s: Symbol `%s' has different size in shared object, consider re-linking\n"; + goto print_err; + } + break; +# endif + case R_X86_64_IRELATIVE: + value = map->l_addr + reloc->r_addend; + value = ((ElfW(Addr) (*) (void)) value) (); + *reloc_addr = value; + break; + default: + _dl_reloc_bad_type (map, r_type, 0); + break; +# endif + } + } +} + +auto inline void +__attribute ((always_inline)) +elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc, + void *const reloc_addr_arg) +{ + ElfW(Addr) *const reloc_addr = reloc_addr_arg; +#if !defined RTLD_BOOTSTRAP + /* l_addr + r_addend may be > 0xffffffff and R_X86_64_RELATIVE64 + relocation updates the whole 64-bit entry. */ + if (__glibc_unlikely (ELFW(R_TYPE) (reloc->r_info) == R_X86_64_RELATIVE64)) + *(Elf64_Addr *) reloc_addr = (Elf64_Addr) l_addr + reloc->r_addend; + else +#endif + { + assert (ELFW(R_TYPE) (reloc->r_info) == R_X86_64_RELATIVE); + *reloc_addr = l_addr + reloc->r_addend; + } +} + +auto inline void +__attribute ((always_inline)) +elf_machine_lazy_rel (struct link_map *map, + ElfW(Addr) l_addr, const ElfW(Rela) *reloc, + int skip_ifunc) +{ + ElfW(Addr) *const reloc_addr = (void *) (l_addr + reloc->r_offset); + const unsigned long int r_type = ELFW(R_TYPE) (reloc->r_info); + + /* Check for unexpected PLT reloc type. */ + if (__glibc_likely (r_type == R_X86_64_JUMP_SLOT)) + { + if (__builtin_expect (map->l_mach.plt, 0) == 0) + *reloc_addr += l_addr; + else + *reloc_addr = + map->l_mach.plt + + (((ElfW(Addr)) reloc_addr) - map->l_mach.gotplt) * 2; + } + else if (__glibc_likely (r_type == R_X86_64_TLSDESC)) + { + struct tlsdesc volatile * __attribute__((__unused__)) td = + (struct tlsdesc volatile *)reloc_addr; + + td->arg = (void*)reloc; + td->entry = (void*)(D_PTR (map, l_info[ADDRIDX (DT_TLSDESC_PLT)]) + + map->l_addr); + } + else if (__glibc_unlikely (r_type == R_X86_64_IRELATIVE)) + { + ElfW(Addr) value = map->l_addr + reloc->r_addend; + if (__glibc_likely (!skip_ifunc)) + value = ((ElfW(Addr) (*) (void)) value) (); + *reloc_addr = value; + } + else + _dl_reloc_bad_type (map, r_type, 1); +} + +#endif /* RESOLVE_MAP */ |