| /* Copyright (C) 1995-2014 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 "aarch64" |
| |
| #include <tls.h> |
| #include <dl-tlsdesc.h> |
| #include <dl-irel.h> |
| |
| /* 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_AARCH64; |
| } |
| |
| /* Return the link-time address of _DYNAMIC. Conveniently, this is the |
| first element of the GOT. */ |
| static inline ElfW(Addr) __attribute__ ((unused)) |
| elf_machine_dynamic (void) |
| { |
| 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) |
| { |
| /* To figure out the load address we use the definition that for any symbol: |
| dynamic_addr(symbol) = static_addr(symbol) + load_addr |
| |
| The choice of symbol is arbitrary. The static address we obtain |
| by constructing a non GOT reference to the symbol, the dynamic |
| address of the symbol we compute using adrp/add to compute the |
| symbol's address relative to the PC. */ |
| |
| ElfW(Addr) static_addr; |
| ElfW(Addr) dynamic_addr; |
| |
| asm (" \n\ |
| adrp %1, _dl_start; \n\ |
| add %1, %1, #:lo12:_dl_start \n\ |
| ldr %w0, 1f \n\ |
| b 2f \n\ |
| 1: .word _dl_start \n\ |
| 2: \n\ |
| " : "=r" (static_addr), "=r" (dynamic_addr)); |
| return dynamic_addr - static_addr; |
| } |
| |
| /* 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)) |
| elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) |
| { |
| if (l->l_info[DT_JMPREL] && lazy) |
| { |
| ElfW(Addr) *got; |
| extern void _dl_runtime_resolve (ElfW(Word)); |
| extern void _dl_runtime_profile (ElfW(Word)); |
| |
| got = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]); |
| if (got[1]) |
| { |
| l->l_mach.plt = got[1] + l->l_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 ( profile) |
| { |
| got[2] = (ElfW(Addr)) &_dl_runtime_profile; |
| |
| if (GLRO(dl_profile) != NULL |
| && _dl_name_match_p (GLRO(dl_profile), l)) |
| /* 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. */ |
| got[2] = (ElfW(Addr)) &_dl_runtime_resolve; |
| } |
| } |
| |
| if (l->l_info[ADDRIDX (DT_TLSDESC_GOT)] && lazy) |
| *(Elf64_Addr*)(D_PTR (l, l_info[ADDRIDX (DT_TLSDESC_GOT)]) + l->l_addr) |
| = (Elf64_Addr) &_dl_tlsdesc_resolve_rela; |
| |
| return lazy; |
| } |
| |
| /* Initial entry point 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\ |
| .globl _dl_start_user \n\ |
| .type _dl_start_user, %function \n\ |
| _start: \n\ |
| mov x0, sp \n\ |
| bl _dl_start \n\ |
| // returns user entry point in x0 \n\ |
| mov x21, x0 \n\ |
| _dl_start_user: \n\ |
| // get the original arg count \n\ |
| ldr x1, [sp] \n\ |
| // get the argv address \n\ |
| add x2, sp, #8 \n\ |
| // get _dl_skip_args to see if we were \n\ |
| // invoked as an executable \n\ |
| adrp x4, _dl_skip_args \n\ |
| ldr w4, [x4, #:lo12:_dl_skip_args] \n\ |
| // do we need to adjust argc/argv \n\ |
| cmp w4, 0 \n\ |
| beq .L_done_stack_adjust \n\ |
| // subtract _dl_skip_args from original arg count \n\ |
| sub x1, x1, x4 \n\ |
| // store adjusted argc back to stack \n\ |
| str x1, [sp] \n\ |
| // find the first unskipped argument \n\ |
| mov x3, x2 \n\ |
| add x4, x2, x4, lsl #3 \n\ |
| // shuffle argv down \n\ |
| 1: ldr x5, [x4], #8 \n\ |
| str x5, [x3], #8 \n\ |
| cmp x5, #0 \n\ |
| bne 1b \n\ |
| // shuffle envp down \n\ |
| 1: ldr x5, [x4], #8 \n\ |
| str x5, [x3], #8 \n\ |
| cmp x5, #0 \n\ |
| bne 1b \n\ |
| // shuffle auxv down \n\ |
| 1: ldp x0, x5, [x4, #16]! \n\ |
| stp x0, x5, [x3], #16 \n\ |
| cmp x0, #0 \n\ |
| bne 1b \n\ |
| // Update _dl_argv \n\ |
| adrp x3, _dl_argv \n\ |
| str x2, [x3, #:lo12:_dl_argv] \n\ |
| .L_done_stack_adjust: \n\ |
| // compute envp \n\ |
| add x3, x2, x1, lsl #3 \n\ |
| add x3, x3, #8 \n\ |
| adrp x16, _rtld_local \n\ |
| add x16, x16, #:lo12:_rtld_local \n\ |
| ldr x0, [x16] \n\ |
| bl _dl_init_internal \n\ |
| // load the finalizer function \n\ |
| adrp x0, _dl_fini \n\ |
| add x0, x0, #:lo12:_dl_fini \n\ |
| // jump to the user_s entry point \n\ |
| br x21 \n\ |
| "); |
| |
| #define elf_machine_type_class(type) \ |
| ((((type) == R_AARCH64_JUMP_SLOT || \ |
| (type) == R_AARCH64_TLS_DTPMOD64 || \ |
| (type) == R_AARCH64_TLS_DTPREL64 || \ |
| (type) == R_AARCH64_TLS_TPREL64 || \ |
| (type) == R_AARCH64_TLSDESC) * ELF_RTYPE_CLASS_PLT) \ |
| | (((type) == R_AARCH64_COPY) * ELF_RTYPE_CLASS_COPY)) |
| |
| #define ELF_MACHINE_JMP_SLOT R_AARCH64_JUMP_SLOT |
| |
| /* AArch64 uses RELA not REL */ |
| #define ELF_MACHINE_NO_REL 1 |
| |
| 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. */ |
| static inline ElfW(Addr) |
| elf_machine_plt_value (struct link_map *map, |
| const ElfW(Rela) *reloc, |
| ElfW(Addr) value) |
| { |
| return value; |
| } |
| |
| #endif |
| |
| /* Names of the architecture-specific auditing callback functions. */ |
| #define ARCH_LA_PLTENTER aarch64_gnu_pltenter |
| #define ARCH_LA_PLTEXIT aarch64_gnu_pltexit |
| |
| #ifdef RESOLVE_MAP |
| |
| 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 int r_type = ELF64_R_TYPE (reloc->r_info); |
| |
| if (__builtin_expect (r_type == R_AARCH64_RELATIVE, 0)) |
| *reloc_addr = map->l_addr + reloc->r_addend; |
| else if (__builtin_expect (r_type == R_AARCH64_NONE, 0)) |
| return; |
| else |
| { |
| const ElfW(Sym) *const refsym = sym; |
| struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type); |
| ElfW(Addr) value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value; |
| |
| if (sym != NULL |
| && __glibc_unlikely (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC) |
| && __glibc_likely (sym->st_shndx != SHN_UNDEF) |
| && __glibc_likely (!skip_ifunc)) |
| value = elf_ifunc_invoke (value); |
| |
| switch (r_type) |
| { |
| case R_AARCH64_COPY: |
| if (sym == NULL) |
| break; |
| |
| if (sym->st_size > refsym->st_size |
| || (GLRO(dl_verbose) && sym->st_size < refsym->st_size)) |
| { |
| 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, strtab + refsym->st_name); |
| } |
| memcpy (reloc_addr_arg, (void *) value, |
| MIN (sym->st_size, refsym->st_size)); |
| break; |
| |
| case R_AARCH64_RELATIVE: |
| case R_AARCH64_GLOB_DAT: |
| case R_AARCH64_JUMP_SLOT: |
| case R_AARCH64_ABS32: |
| case R_AARCH64_ABS64: |
| *reloc_addr = value + reloc->r_addend; |
| break; |
| |
| case R_AARCH64_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_AARCH64_TLS_DTPMOD64: |
| #ifdef RTLD_BOOTSTRAP |
| *reloc_addr = 1; |
| #else |
| if (sym_map != NULL) |
| { |
| *reloc_addr = sym_map->l_tls_modid; |
| } |
| #endif |
| break; |
| |
| case R_AARCH64_TLS_DTPREL64: |
| if (sym) |
| *reloc_addr = sym->st_value + reloc->r_addend; |
| break; |
| |
| case R_AARCH64_TLS_TPREL64: |
| if (sym) |
| { |
| CHECK_STATIC_TLS (map, sym_map); |
| *reloc_addr = |
| sym->st_value + reloc->r_addend + sym_map->l_tls_offset; |
| } |
| break; |
| |
| case R_AARCH64_IRELATIVE: |
| value = map->l_addr + reloc->r_addend; |
| value = elf_ifunc_invoke (value); |
| *reloc_addr = value; |
| break; |
| |
| default: |
| _dl_reloc_bad_type (map, r_type, 0); |
| break; |
| } |
| } |
| } |
| |
| 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; |
| *reloc_addr = l_addr + reloc->r_addend; |
| } |
| |
| 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 int r_type = ELF64_R_TYPE (reloc->r_info); |
| /* Check for unexpected PLT reloc type. */ |
| if (__builtin_expect (r_type == R_AARCH64_JUMP_SLOT, 1)) |
| { |
| if (__builtin_expect (map->l_mach.plt, 0) == 0) |
| *reloc_addr += l_addr; |
| else |
| *reloc_addr = map->l_mach.plt; |
| } |
| else if (__builtin_expect (r_type == R_AARCH64_TLSDESC, 1)) |
| { |
| struct tlsdesc volatile *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_AARCH64_IRELATIVE)) |
| { |
| ElfW(Addr) value = map->l_addr + reloc->r_addend; |
| if (__glibc_likely (!skip_ifunc)) |
| value = elf_ifunc_invoke (value); |
| *reloc_addr = value; |
| } |
| else |
| _dl_reloc_bad_type (map, r_type, 1); |
| } |
| |
| #endif |