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Diffstat (limited to 'REORG.TODO/sysdeps/powerpc/powerpc32/dl-machine.h')
| -rw-r--r-- | REORG.TODO/sysdeps/powerpc/powerpc32/dl-machine.h | 455 |
1 files changed, 455 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/powerpc/powerpc32/dl-machine.h b/REORG.TODO/sysdeps/powerpc/powerpc32/dl-machine.h new file mode 100644 index 0000000000..28eb50f92d --- /dev/null +++ b/REORG.TODO/sysdeps/powerpc/powerpc32/dl-machine.h @@ -0,0 +1,455 @@ +/* Machine-dependent ELF dynamic relocation inline functions. PowerPC version. + Copyright (C) 1995-2017 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 "powerpc" + +#include <assert.h> +#include <dl-tls.h> +#include <dl-irel.h> +#include <hwcapinfo.h> + +/* Translate a processor specific dynamic tag to the index + in l_info array. */ +#define DT_PPC(x) (DT_PPC_##x - DT_LOPROC + DT_NUM) + +/* 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_PPC; +} + +/* Return the value of the GOT pointer. */ +static inline Elf32_Addr * __attribute__ ((const)) +ppc_got (void) +{ + Elf32_Addr *got; + + asm ("bcl 20,31,1f\n" + "1: mflr %0\n" + " addis %0,%0,_GLOBAL_OFFSET_TABLE_-1b@ha\n" + " addi %0,%0,_GLOBAL_OFFSET_TABLE_-1b@l\n" + : "=b" (got) : : "lr"); + + return got; +} + +/* Return the link-time address of _DYNAMIC, stored as + the first value in the GOT. */ +static inline Elf32_Addr __attribute__ ((const)) +elf_machine_dynamic (void) +{ + return *ppc_got (); +} + +/* Return the run-time load address of the shared object. */ +static inline Elf32_Addr __attribute__ ((const)) +elf_machine_load_address (void) +{ + Elf32_Addr *branchaddr; + Elf32_Addr runtime_dynamic; + + /* This is much harder than you'd expect. Possibly I'm missing something. + The 'obvious' way: + + Apparently, "bcl 20,31,$+4" is what should be used to load LR + with the address of the next instruction. + I think this is so that machines that do bl/blr pairing don't + get confused. + + asm ("bcl 20,31,0f ;" + "0: mflr 0 ;" + "lis %0,0b@ha;" + "addi %0,%0,0b@l;" + "subf %0,%0,0" + : "=b" (addr) : : "r0", "lr"); + + doesn't work, because the linker doesn't have to (and in fact doesn't) + update the @ha and @l references; the loader (which runs after this + code) will do that. + + Instead, we use the following trick: + + The linker puts the _link-time_ address of _DYNAMIC at the first + word in the GOT. We could branch to that address, if we wanted, + by using an @local reloc; the linker works this out, so it's safe + to use now. We can't, of course, actually branch there, because + we'd cause an illegal instruction exception; so we need to compute + the address ourselves. That gives us the following code: */ + + /* Get address of the 'b _DYNAMIC@local'... */ + asm ("bcl 20,31,0f;" + "b _DYNAMIC@local;" + "0:" + : "=l" (branchaddr)); + + /* So now work out the difference between where the branch actually points, + and the offset of that location in memory from the start of the file. */ + runtime_dynamic = ((Elf32_Addr) branchaddr + + ((Elf32_Sword) (*branchaddr << 6 & 0xffffff00) >> 6)); + + return runtime_dynamic - elf_machine_dynamic (); +} + +#define ELF_MACHINE_BEFORE_RTLD_RELOC(dynamic_info) /* nothing */ + +/* The PLT uses Elf32_Rela relocs. */ +#define elf_machine_relplt elf_machine_rela + +/* Mask identifying addresses reserved for the user program, + where the dynamic linker should not map anything. */ +#define ELF_MACHINE_USER_ADDRESS_MASK 0xf0000000UL + +/* The actual _start code is in dl-start.S. Use a really + ugly bit of assembler to let dl-start.o see _dl_start. */ +#define RTLD_START asm (".globl _dl_start"); + +/* Decide where a relocatable object should be loaded. */ +extern ElfW(Addr) +__elf_preferred_address(struct link_map *loader, size_t maplength, + ElfW(Addr) mapstartpref); +#define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) \ + __elf_preferred_address (loader, maplength, mapstartpref) + +/* 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_COPY iff TYPE should not be allowed to resolve to one + of the main executable's symbols, as for a COPY reloc. */ +/* We never want to use a PLT entry as the destination of a + reloc, when what is being relocated is a branch. This is + partly for efficiency, but mostly so we avoid loops. */ +#define elf_machine_type_class(type) \ + ((((type) == R_PPC_JMP_SLOT \ + || (type) == R_PPC_REL24 \ + || ((type) >= R_PPC_DTPMOD32 /* contiguous TLS */ \ + && (type) <= R_PPC_DTPREL32) \ + || (type) == R_PPC_ADDR24) * ELF_RTYPE_CLASS_PLT) \ + | (((type) == R_PPC_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_PPC_JMP_SLOT + +/* The PowerPC never uses REL relocations. */ +#define ELF_MACHINE_NO_REL 1 +#define ELF_MACHINE_NO_RELA 0 + +/* We define an initialization function to initialize HWCAP/HWCAP2 and + platform data so it can be copied into the TCB later. This is called + very early in _dl_sysdep_start for dynamically linked binaries. */ +#ifdef SHARED +# define DL_PLATFORM_INIT dl_platform_init () + +static inline void __attribute__ ((unused)) +dl_platform_init (void) +{ + __tcb_parse_hwcap_and_convert_at_platform (); +} +#endif + +/* Set up the loaded object described by MAP so its unrelocated PLT + entries will jump to the on-demand fixup code in dl-runtime.c. + Also install a small trampoline to be used by entries that have + been relocated to an address too far away for a single branch. */ +extern int __elf_machine_runtime_setup (struct link_map *map, + int lazy, int profile); + +static inline int +elf_machine_runtime_setup (struct link_map *map, + int lazy, int profile) +{ + if (map->l_info[DT_JMPREL] == 0) + return lazy; + + if (map->l_info[DT_PPC(GOT)] == 0) + /* Handle old style PLT. */ + return __elf_machine_runtime_setup (map, lazy, profile); + + /* New style non-exec PLT consisting of an array of addresses. */ + map->l_info[DT_PPC(GOT)]->d_un.d_ptr += map->l_addr; + if (lazy) + { + Elf32_Addr *plt, *got, glink; + Elf32_Word num_plt_entries; + void (*dlrr) (void); + extern void _dl_runtime_resolve (void); + extern void _dl_prof_resolve (void); + + if (__glibc_likely (!profile)) + dlrr = _dl_runtime_resolve; + else + { + if (GLRO(dl_profile) != NULL + &&_dl_name_match_p (GLRO(dl_profile), map)) + GL(dl_profile_map) = map; + dlrr = _dl_prof_resolve; + } + got = (Elf32_Addr *) map->l_info[DT_PPC(GOT)]->d_un.d_ptr; + glink = got[1]; + got[1] = (Elf32_Addr) dlrr; + got[2] = (Elf32_Addr) map; + + /* Relocate everything in .plt by the load address offset. */ + plt = (Elf32_Addr *) D_PTR (map, l_info[DT_PLTGOT]); + num_plt_entries = (map->l_info[DT_PLTRELSZ]->d_un.d_val + / sizeof (Elf32_Rela)); + + /* If a library is prelinked but we have to relocate anyway, + we have to be able to undo the prelinking of .plt section. + The prelinker saved us at got[1] address of .glink + section's start. */ + if (glink) + { + glink += map->l_addr; + while (num_plt_entries-- != 0) + *plt++ = glink, glink += 4; + } + else + while (num_plt_entries-- != 0) + *plt++ += map->l_addr; + } + return lazy; +} + +/* Change the PLT entry whose reloc is 'reloc' to call the actual routine. */ +extern Elf32_Addr __elf_machine_fixup_plt (struct link_map *map, + Elf32_Addr *reloc_addr, + Elf32_Addr finaladdr); + +static inline Elf32_Addr +elf_machine_fixup_plt (struct link_map *map, lookup_t t, + const Elf32_Rela *reloc, + Elf32_Addr *reloc_addr, Elf64_Addr finaladdr) +{ + if (map->l_info[DT_PPC(GOT)] == 0) + /* Handle old style PLT. */ + return __elf_machine_fixup_plt (map, reloc_addr, finaladdr); + + *reloc_addr = finaladdr; + return finaladdr; +} + +/* 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 + reloc->r_addend; +} + + +/* Names of the architecture-specific auditing callback functions. */ +#define ARCH_LA_PLTENTER ppc32_gnu_pltenter +#define ARCH_LA_PLTEXIT ppc32_gnu_pltexit + +#endif /* dl_machine_h */ + +#ifdef RESOLVE_MAP + +/* Do the actual processing of a reloc, once its target address + has been determined. */ +extern void __process_machine_rela (struct link_map *map, + const Elf32_Rela *reloc, + struct link_map *sym_map, + const Elf32_Sym *sym, + const Elf32_Sym *refsym, + Elf32_Addr *const reloc_addr, + Elf32_Addr finaladdr, + int rinfo) attribute_hidden; + +/* Call _dl_signal_error when a resolved value overflows a relocated area. */ +extern void _dl_reloc_overflow (struct link_map *map, + const char *name, + Elf32_Addr *const reloc_addr, + const Elf32_Sym *refsym) attribute_hidden; + +/* 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 Elf32_Rela *reloc, + const Elf32_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 Elf32_Sym *const refsym = sym; + Elf32_Addr value; + const int r_type = ELF32_R_TYPE (reloc->r_info); + struct link_map *sym_map = NULL; + +#ifndef RESOLVE_CONFLICT_FIND_MAP + if (r_type == R_PPC_RELATIVE) + { + *reloc_addr = map->l_addr + reloc->r_addend; + return; + } + + if (__glibc_unlikely (r_type == R_PPC_NONE)) + return; + + /* binutils on ppc32 includes st_value in r_addend for relocations + against local symbols. */ + if (__builtin_expect (ELF32_ST_BIND (sym->st_info) == STB_LOCAL, 0) + && sym->st_shndx != SHN_UNDEF) + value = map->l_addr; + else + { + sym_map = RESOLVE_MAP (&sym, version, r_type); + value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value; + } + value += reloc->r_addend; +#else + value = reloc->r_addend; +#endif + + 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)) + value = elf_ifunc_invoke (value); + + /* A small amount of code is duplicated here for speed. In libc, + more than 90% of the relocs are R_PPC_RELATIVE; in the X11 shared + libraries, 60% are R_PPC_RELATIVE, 24% are R_PPC_GLOB_DAT or + R_PPC_ADDR32, and 16% are R_PPC_JMP_SLOT (which this routine + wouldn't usually handle). As an bonus, doing this here allows + the switch statement in __process_machine_rela to work. */ + switch (r_type) + { + case R_PPC_GLOB_DAT: + case R_PPC_ADDR32: + *reloc_addr = value; + break; + +#ifndef RESOLVE_CONFLICT_FIND_MAP +# ifdef RTLD_BOOTSTRAP +# define NOT_BOOTSTRAP 0 +# else +# define NOT_BOOTSTRAP 1 +# endif + + case R_PPC_DTPMOD32: + if (map->l_info[DT_PPC(OPT)] + && (map->l_info[DT_PPC(OPT)]->d_un.d_val & PPC_OPT_TLS)) + { + if (!NOT_BOOTSTRAP) + { + reloc_addr[0] = 0; + reloc_addr[1] = (sym_map->l_tls_offset - TLS_TP_OFFSET + + TLS_DTV_OFFSET); + break; + } + else if (sym_map != NULL) + { +# ifndef SHARED + CHECK_STATIC_TLS (map, sym_map); +# else + if (TRY_STATIC_TLS (map, sym_map)) +# endif + { + reloc_addr[0] = 0; + /* Set up for local dynamic. */ + reloc_addr[1] = (sym_map->l_tls_offset - TLS_TP_OFFSET + + TLS_DTV_OFFSET); + break; + } + } + } + if (!NOT_BOOTSTRAP) + /* During startup the dynamic linker is always index 1. */ + *reloc_addr = 1; + else if (sym_map != NULL) + /* Get the information from the link map returned by the + RESOLVE_MAP function. */ + *reloc_addr = sym_map->l_tls_modid; + break; + case R_PPC_DTPREL32: + if (map->l_info[DT_PPC(OPT)] + && (map->l_info[DT_PPC(OPT)]->d_un.d_val & PPC_OPT_TLS)) + { + if (!NOT_BOOTSTRAP) + { + *reloc_addr = TLS_TPREL_VALUE (sym_map, sym, reloc); + break; + } + else if (sym_map != NULL) + { + /* This reloc is always preceded by R_PPC_DTPMOD32. */ +# ifndef SHARED + assert (HAVE_STATIC_TLS (map, sym_map)); +# else + if (HAVE_STATIC_TLS (map, sym_map)) +# endif + { + *reloc_addr = TLS_TPREL_VALUE (sym_map, sym, reloc); + break; + } + } + } + /* During relocation all TLS symbols are defined and used. + Therefore the offset is already correct. */ + if (NOT_BOOTSTRAP && sym_map != NULL) + *reloc_addr = TLS_DTPREL_VALUE (sym, reloc); + break; + case R_PPC_TPREL32: + if (!NOT_BOOTSTRAP || sym_map != NULL) + { + if (NOT_BOOTSTRAP) + CHECK_STATIC_TLS (map, sym_map); + *reloc_addr = TLS_TPREL_VALUE (sym_map, sym, reloc); + } + break; +#endif + + case R_PPC_JMP_SLOT: +#ifdef RESOLVE_CONFLICT_FIND_MAP + RESOLVE_CONFLICT_FIND_MAP (map, reloc_addr); +#endif + if (map->l_info[DT_PPC(GOT)] != 0) + { + *reloc_addr = value; + break; + } + /* FALLTHROUGH */ + + default: + __process_machine_rela (map, reloc, sym_map, sym, refsym, + reloc_addr, value, r_type); + } +} + +auto inline void __attribute__ ((always_inline)) +elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_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, + Elf32_Addr l_addr, const Elf32_Rela *reloc, + int skip_ifunc) +{ + /* elf_machine_runtime_setup handles this. */ +} + +#endif /* RESOLVE_MAP */ |