diff options
Diffstat (limited to 'sysdeps/nios2/dl-machine.h')
| -rw-r--r-- | sysdeps/nios2/dl-machine.h | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/sysdeps/nios2/dl-machine.h b/sysdeps/nios2/dl-machine.h new file mode 100644 index 0000000000..3efb0d7325 --- /dev/null +++ b/sysdeps/nios2/dl-machine.h @@ -0,0 +1,335 @@ +/* Machine-dependent ELF dynamic relocation inline functions. Nios II version. + Copyright (C) 1995-2015 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_machine_h +#define dl_machine_h + +#define ELF_MACHINE_NAME "nios2" + +#include <string.h> +#include <link.h> +#include <dl-tls.h> + +/* Return nonzero iff ELF header is compatible with the running host. */ +static inline int +elf_machine_matches_host (const Elf32_Ehdr *ehdr) +{ + return ehdr->e_machine == EM_ALTERA_NIOS2; +} + + +/* Return the link-time address of _DYNAMIC. Conveniently, this is the + first element of the GOT. */ +static inline Elf32_Addr +elf_machine_dynamic (void) +{ + Elf32_Addr *dynamic; + int tmp; + asm ("nextpc\t%0\n\t" + "1: movhi\t%1, %%hiadj(_GLOBAL_OFFSET_TABLE_ - 1b)\n\t" + "addi\t%1, %1, %%lo(_GLOBAL_OFFSET_TABLE_ - 1b)\n\t" + "add\t%0, %0, %1\n" + : "=r" (dynamic), "=r" (tmp)); + return *dynamic; +} + + +/* Return the run-time load address of the shared object. */ +static inline Elf32_Addr +elf_machine_load_address (void) +{ + Elf32_Addr result; + int tmp; + asm ("nextpc\t%0\n\t" + "1: movhi\t%1, %%hiadj(1b)\n\t" + "addi\t%1, %1, %%lo(1b)\n\t" + "sub\t%0, %0, %1\n" + : "=r" (result), "=r" (tmp)); + return result; +} + +/* 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__ ((always_inline)) +elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) +{ + extern void _dl_runtime_resolve (Elf32_Word); + + 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 load r15 with + an offset into the .got section, load r14 with + _GLOBAL_OFFSET_TABLE_[1], and then jump to _GLOBAL_OFFSET_TABLE[2]. + */ + Elf32_Addr *got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]); + got[1] = (Elf32_Addr) l; /* Identify this shared object. */ + + /* 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. */ + got[2] = (Elf32_Addr) &_dl_runtime_resolve; + } + + 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 ("\ +.text\n\ +.globl _start\n\ +.type _start, %function\n\ +_start:\n\ + /* At start time, all the args are on the stack. */\n\ + mov r4, sp\n\ +\n\ + /* Start the calculation of the GOT pointer. */\n\ + nextpc r22\n\ +1: movhi r8, %hiadj(_gp_got - 1b)\n\ + addi r8, r8, %lo(_gp_got - 1b)\n\ +\n\ + /* Figure out where _dl_start will need to return to. */\n\ + movhi ra, %hiadj(2f - 1b)\n\ + addi ra, ra, %lo(2f - 1b)\n\ + add ra, ra, r22\n\ +\n\ + /* Finish the calculation of the GOT pointer. */\n\ + add r22, r22, r8\n\ +\n\ + br _dl_start\n\ +\n\ + /* Save the returned user entry point. */\n\ +2: mov r16, r2\n\ +\n\ + /* Initialize gp. */\n\ + ldw r4, %got(_rtld_local)(r22)\n\ + ldw r4, 0(r4)\n\ + ldw r8, %call(_dl_nios2_get_gp_value)(r22)\n\ + callr r8\n\ + mov gp, r2\n\ +\n\ + /* Find the number of arguments to skip. */\n\ + ldw r8, %got(_dl_skip_args)(r22)\n\ + ldw r8, 0(r8)\n\ +\n\ + /* Find the main_map from the GOT. */\n\ + ldw r4, %got(_rtld_local)(r22)\n\ + ldw r4, 0(r4)\n\ +\n\ + /* Find argc. */\n\ + ldw r5, 0(sp)\n\ + sub r5, r5, r8\n\ + stw r5, 0(sp)\n\ +\n\ + /* Find the first unskipped argument. */\n\ + slli r8, r8, 2\n\ + addi r6, sp, 4\n\ + add r9, r6, r8\n\ + mov r10, r6\n\ +\n\ + /* Shuffle argv down. */\n\ +3: ldw r11, 0(r9)\n\ + stw r11, 0(r10)\n\ + addi r9, r9, 4\n\ + addi r10, r10, 4\n\ + bne r11, zero, 3b\n\ +\n\ + /* Shuffle envp down. */\n\ + mov r7, r10\n\ +4: ldw r11, 0(r9)\n\ + stw r11, 0(r10)\n\ + addi r9, r9, 4\n\ + addi r10, r10, 4\n\ + bne r11, zero, 4b\n\ +\n\ + /* Shuffle auxv down. */\n\ +5: ldw r11, 4(r9)\n\ + stw r11, 4(r10)\n\ + ldw r11, 0(r9)\n\ + stw r11, 0(r10)\n\ + addi r9, r9, 8\n\ + addi r10, r10, 8\n\ + bne r11, zero, 5b\n\ +\n\ + /* Update _dl_argv. */\n\ + ldw r2, %got(_dl_argv)(r22)\n\ + stw r6, 0(r2)\n\ +\n\ + /* Call _dl_init through the PLT. */\n\ + ldw r8, %call(_dl_init)(r22)\n\ + callr r8\n\ +\n\ + /* Find the finalization function. */\n\ + ldw r4, %got(_dl_fini)(r22)\n\ +\n\ + /* Jump to the user's entry point. */\n\ + jmp r16\n\ +"); + +/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so + PLT entries 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_NIOS2_JUMP_SLOT \ + || (type) == R_NIOS2_TLS_DTPMOD \ + || (type) == R_NIOS2_TLS_DTPREL \ + || (type) == R_NIOS2_TLS_TPREL) * ELF_RTYPE_CLASS_PLT) \ + | (((type) == R_NIOS2_COPY) * ELF_RTYPE_CLASS_COPY)) + +/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */ +#define ELF_MACHINE_JMP_SLOT R_NIOS2_JUMP_SLOT + +/* The Nios II never uses Elf32_Rel relocations. */ +#define ELF_MACHINE_NO_REL 1 +#define ELF_MACHINE_NO_RELA 0 + +/* Fixup a PLT entry to bounce directly to the function at VALUE. */ + +static inline Elf32_Addr +elf_machine_fixup_plt (struct link_map *map, lookup_t t, + const Elf32_Rela *reloc, + Elf32_Addr *reloc_addr, Elf32_Addr value) +{ + return *reloc_addr = value; +} + +/* Return the final value of a plt relocation. */ +static inline Elf32_Addr +elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc, + Elf32_Addr value) +{ + return value; +} + +/* Names of the architecture-specific auditing callback functions. */ +#define ARCH_LA_PLTENTER nios2_gnu_pltenter +#define ARCH_LA_PLTEXIT nios2_gnu_pltexit + +#endif /* dl_machine_h */ + +#ifdef RESOLVE_MAP + +/* Perform the relocation specified by RELOC and SYM (which is fully resolved). + LOADADDR is the load address of the object; INFO is an array indexed + by DT_* of the .dynamic section info. */ + +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) +{ + Elf32_Addr *const reloc_addr = reloc_addr_arg; + const unsigned int r_type = ELF32_R_TYPE (reloc->r_info); + + if (__glibc_unlikely (r_type == R_NIOS2_RELATIVE)) + *reloc_addr = map->l_addr + reloc->r_addend; + else if (__glibc_unlikely (r_type == R_NIOS2_NONE)) + return; + else + { + const Elf32_Sym *const refsym = sym; + struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type); + Elf32_Addr value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value; + + switch (r_type) + { + case R_NIOS2_COPY: + if (sym == NULL) + /* This can happen in trace mode if an object could not be + found. */ + break; + if (sym->st_size > refsym->st_size + || (sym->st_size < refsym->st_size && GLRO(dl_verbose))) + { + const char *strtab; + + strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]); + _dl_error_printf ("\ +%s: Symbol `%s' has different size in shared object, consider re-linking\n", + rtld_progname ?: "<program name unknown>", + strtab + refsym->st_name); + } + memcpy (reloc_addr_arg, (void *) value, + MIN (sym->st_size, refsym->st_size)); + break; + case R_NIOS2_GLOB_DAT: + case R_NIOS2_JUMP_SLOT: +# ifdef RTLD_BOOTSTRAP + /* Fix weak undefined references. */ + if (sym != NULL && sym->st_value == 0) + *reloc_addr = 0; + else +# endif + *reloc_addr = value; + break; +#ifndef RTLD_BOOTSTRAP + case R_NIOS2_TLS_DTPMOD: + /* Get the information from the link map returned by the + resolv function. */ + if (sym_map != NULL) + *reloc_addr = sym_map->l_tls_modid; + break; + + case R_NIOS2_TLS_DTPREL: + *reloc_addr = reloc->r_addend + TLS_DTPREL_VALUE(sym); + break; + + case R_NIOS2_TLS_TPREL: + if (sym != NULL) + { + CHECK_STATIC_TLS (map, sym_map); + *reloc_addr = reloc->r_addend + TLS_TPREL_VALUE(sym_map, sym); + } + break; +#endif + case R_NIOS2_BFD_RELOC_32: + *reloc_addr = value + reloc->r_addend; + break; + + default: + _dl_reloc_bad_type (map, r_type, 0); + break; + } + } +} + +auto inline void __attribute__((always_inline)) +elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc, + void *const reloc_addr_arg) +{ + Elf32_Addr *const reloc_addr = reloc_addr_arg; + *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) +{ + Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset); + if (ELF32_R_TYPE (reloc->r_info) == R_NIOS2_JUMP_SLOT) + *reloc_addr += l_addr; + else + _dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1); +} + +#endif /* RESOLVE_MAP */ |