/* yoinked from glibc/sysdeps/x86_64/dl-machine.h */ /* Machine-dependent ELF dynamic relocation inline functions. x86-64 version. Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Andreas Jaeger . 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 . */ /* Define this if the system uses RELOCA. */ #define ELF_USES_RELOCA #include #include /* Initialization sequence for the GOT. */ #define INIT_GOT(GOT_BASE,MODULE) \ do { \ GOT_BASE[2] = (unsigned long) _dl_linux_resolve; \ GOT_BASE[1] = (unsigned long) MODULE; \ } while(0) /* Here we define the magic numbers that this dynamic loader should accept */ #define MAGIC1 EM_X86_64 #undef MAGIC2 /* Used for error messages */ #define ELF_TARGET "x86_64" struct elf_resolve; extern unsigned long _dl_linux_resolver(struct elf_resolve * tpnt, int reloc_entry); /* 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_NOCOPY iff TYPE should not be allowed to resolve to one of the main executable's symbols, as for a COPY reloc. */ #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) \ * ELF_RTYPE_CLASS_PLT) \ | (((type) == R_X86_64_COPY) * ELF_RTYPE_CLASS_COPY)) /* 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 __always_inline Elf64_Addr __attribute__ ((unused)) elf_machine_dynamic (void) { Elf64_Addr addr; /* This works because we have our GOT address available in the small PIC model. */ addr = (Elf64_Addr) &_DYNAMIC; return addr; } /* Return the run-time load address of the shared object. */ static __always_inline Elf64_Addr __attribute__ ((unused)) elf_machine_load_address (void) { register Elf64_Addr addr, tmp; /* The easy way is just the same as on x86: leaq _dl_start, %0 leaq _dl_start(%%rip), %1 subq %0, %1 but this does not work with binutils since we then have a R_X86_64_32S relocation in a shared lib. Instead we store the address of _dl_start in the data section and compare it with the current value that we can get via an RIP relative addressing mode. */ __asm__ ("movq 1f(%%rip), %1\n" "0:\tleaq _dl_start(%%rip), %0\n\t" "subq %1, %0\n\t" ".section\t.data\n" "1:\t.quad _dl_start\n\t" ".previous\n\t" : "=r" (addr), "=r" (tmp) : : "cc"); return addr; } static __always_inline void elf_machine_relative(Elf64_Addr load_off, const Elf64_Addr rel_addr, Elf64_Word relative_count) { Elf64_Rela *rpnt = (Elf64_Rela*)rel_addr; --rpnt; do { Elf64_Addr *const reloc_addr = (Elf64_Addr*)(load_off + (++rpnt)->r_offset); *reloc_addr = load_off + rpnt->r_addend; } while (--relative_count); }