diff options
Diffstat (limited to 'sysdeps/x86_64')
| -rw-r--r-- | sysdeps/x86_64/dl-delayed-reloc-machine.h | 97 | ||||
| -rw-r--r-- | sysdeps/x86_64/dl-machine.h | 46 |
2 files changed, 128 insertions, 15 deletions
diff --git a/sysdeps/x86_64/dl-delayed-reloc-machine.h b/sysdeps/x86_64/dl-delayed-reloc-machine.h new file mode 100644 index 0000000000..d49e9ba27e --- /dev/null +++ b/sysdeps/x86_64/dl-delayed-reloc-machine.h @@ -0,0 +1,97 @@ +/* Delayed relocation processing. x86-64 version. + Copyright (C) 2001-2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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_DELAYED_RELOC_MACHINE_H +#define _DL_DELAYED_RELOC_MACHINE_H + +/* This needs to be kept in sync with elf_machine_rela in + dl-machine.h. */ +static inline void +_dl_delayed_reloc_machine (const struct dl_delayed_reloc *dr) +{ + const ElfW(Rela) *reloc = dr->reloc; + const unsigned long int r_type = ELFW(R_TYPE) (reloc->r_info); + ElfW(Addr) *const reloc_addr = dr->reloc_addr; + const ElfW(Sym) *refsym = dr->refsym; + const ElfW(Sym) *sym = dr->sym; + ElfW(Addr) value = SYMBOL_ADDRESS (dr->sym_map, sym, true); + + if (r_type == R_X86_64_IRELATIVE) + { + /* Special case: IRELATIVE relocations do not have an associated + symbol. */ + value = dr->map->l_addr + reloc->r_addend; + value = ((ElfW(Addr) (*) (void)) value) (); + *reloc_addr = value; + return; + } + + if (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC + && sym->st_shndx != SHN_UNDEF) + value = ((ElfW(Addr) (*) (void)) value) (); + + /* This switch statement needs to be kept in sync with the switch + statement in elf_machine_rela. */ + switch (r_type) + { + case R_X86_64_GLOB_DAT: + case R_X86_64_JUMP_SLOT: + *reloc_addr = value + reloc->r_addend; + break; + + 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; + 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"; + print_err: + strtab = (const char *) D_PTR (dr->map, l_info[DT_STRTAB]); + + _dl_error_printf (fmt, RTLD_PROGNAME, strtab + refsym->st_name); + } + break; + 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; + } + case R_X86_64_COPY: + memcpy (reloc_addr, (void *) value, + MIN (sym->st_size, refsym->st_size)); + break; + default: + _dl_reloc_bad_type (dr->map, r_type, 0); + } +} + +#endif /* _DL_DELAYED_RELOC_MACHINE_H */ diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h index 95a13b35b5..a1788e6998 100644 --- a/sysdeps/x86_64/dl-machine.h +++ b/sysdeps/x86_64/dl-machine.h @@ -27,6 +27,7 @@ #include <tls.h> #include <dl-tlsdesc.h> #include <cpu-features.c> +#include <dl-delayed-reloc.h> /* Return nonzero iff ELF header is compatible with the running host. */ static inline int __attribute__ ((unused)) @@ -314,22 +315,21 @@ elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc, && __glibc_likely (!skip_ifunc)) { # ifndef RTLD_BOOTSTRAP - if (sym_map != map - && sym_map->l_type != lt_executable - && !sym_map->l_relocated) + if (!sym_map->l_relocated || sym_map->l_delayed_relocations) { - 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); + /* If the target map has not yet been fully relocated, + delay the processing of the relocation until + later. */ + _dl_delayed_reloc_record + (map, refsym, reloc, reloc_addr, sym_map, sym); + return; } # endif value = ((ElfW(Addr) (*) (void)) value) (); } + /* This switch statement needs to be kept in sync with the + switch statement in _dl_delayed_reloc_machine. */ switch (r_type) { # ifndef RTLD_BOOTSTRAP @@ -498,8 +498,14 @@ elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc, /* 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 (sym_map->l_delayed_relocations) + /* The relocation result could depend on earlier delayed + relocations. */ + _dl_delayed_reloc_record + (map, refsym, reloc, reloc_addr, sym_map, sym); + else + memcpy (reloc_addr_arg, (void *) value, + MIN (sym->st_size, refsym->st_size)); if (__glibc_unlikely (sym->st_size > refsym->st_size) || (__glibc_unlikely (sym->st_size < refsym->st_size) && GLRO(dl_verbose))) @@ -511,9 +517,19 @@ elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc, break; # endif case R_X86_64_IRELATIVE: - value = map->l_addr + reloc->r_addend; - value = ((ElfW(Addr) (*) (void)) value) (); - *reloc_addr = value; + if (map->l_delayed_relocations) + /* We need to delay these IFUNC relocation because the + IFUNC resolver may pick up the address of a symbol + which in turn is determined by a (delayed) IFUNC + relocation. */ + _dl_delayed_reloc_record + (map, refsym, reloc, reloc_addr, map, NULL); + else + { + 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); |