| /* Machine-dependent ELF dynamic relocation inline functions. S390 Version. |
| Copyright (C) 2000-2018 Free Software Foundation, Inc. |
| Contributed by Carl Pederson & Martin Schwidefsky. |
| 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 "s390" |
| |
| #include <sys/param.h> |
| #include <string.h> |
| #include <link.h> |
| #include <sysdeps/s390/dl-procinfo.h> |
| #include <dl-irel.h> |
| |
| /* This is an older, now obsolete value. */ |
| #define EM_S390_OLD 0xA390 |
| |
| /* Return nonzero iff ELF header is compatible with the running host. */ |
| static inline int |
| elf_machine_matches_host (const Elf32_Ehdr *ehdr) |
| { |
| /* Check if the kernel provides the high gpr facility if needed by |
| the binary. */ |
| if ((ehdr->e_flags & EF_S390_HIGH_GPRS) |
| && !(GLRO (dl_hwcap) & HWCAP_S390_HIGH_GPRS)) |
| return 0; |
| |
| return (ehdr->e_machine == EM_S390 || ehdr->e_machine == EM_S390_OLD) |
| && ehdr->e_ident[EI_CLASS] == ELFCLASS32; |
| } |
| |
| |
| /* 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 inline Elf32_Addr |
| elf_machine_dynamic (void) |
| { |
| register Elf32_Addr *got; |
| |
| __asm__( " bras %0,2f\n" |
| "1: .long _GLOBAL_OFFSET_TABLE_-1b\n" |
| "2: al %0,0(%0)" |
| : "=&a" (got) : : "0" ); |
| |
| return *got; |
| } |
| |
| |
| /* Return the run-time load address of the shared object. */ |
| static inline Elf32_Addr |
| elf_machine_load_address (void) |
| { |
| Elf32_Addr addr; |
| |
| __asm__( " bras 1,2f\n" |
| "1: .long _GLOBAL_OFFSET_TABLE_ - 1b\n" |
| " .long (_dl_start - 1b - 0x80000000) & 0x00000000ffffffff\n" |
| "2: l %0,4(1)\n" |
| " ar %0,1\n" |
| " al 1,0(1)\n" |
| " sl %0,_dl_start@GOT(1)" |
| : "=&d" (addr) : : "1" ); |
| return 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) |
| { |
| extern void _dl_runtime_resolve (Elf32_Word); |
| extern void _dl_runtime_profile (Elf32_Word); |
| #if defined HAVE_S390_VX_ASM_SUPPORT |
| extern void _dl_runtime_resolve_vx (Elf32_Word); |
| extern void _dl_runtime_profile_vx (Elf32_Word); |
| #endif |
| |
| |
| 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 push an |
| offset into the .rel.plt section, push _GLOBAL_OFFSET_TABLE_[1], |
| and then jump to _GLOBAL_OFFSET_TABLE[2]. */ |
| Elf32_Addr *got; |
| got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]); |
| /* If a library is prelinked but we have to relocate anyway, |
| we have to be able to undo the prelinking of .got.plt. |
| The prelinker saved us here address of .plt + 0x2c. */ |
| if (got[1]) |
| { |
| l->l_mach.plt = got[1] + l->l_addr; |
| l->l_mach.jmprel = (const Elf32_Rela *) D_PTR (l, l_info[DT_JMPREL]); |
| } |
| got[1] = (Elf32_Addr) l; /* Identify this shared object. */ |
| |
| /* 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 (__glibc_unlikely (profile)) |
| { |
| #if defined HAVE_S390_VX_ASM_SUPPORT |
| if (GLRO(dl_hwcap) & HWCAP_S390_VX) |
| got[2] = (Elf32_Addr) &_dl_runtime_profile_vx; |
| else |
| got[2] = (Elf32_Addr) &_dl_runtime_profile; |
| #else |
| got[2] = (Elf32_Addr) &_dl_runtime_profile; |
| #endif |
| |
| if (GLRO(dl_profile) != NULL |
| && _dl_name_match_p (GLRO(dl_profile), l)) |
| /* This is the object we are looking for. 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. */ |
| #if defined HAVE_S390_VX_ASM_SUPPORT |
| if (GLRO(dl_hwcap) & HWCAP_S390_VX) |
| got[2] = (Elf32_Addr) &_dl_runtime_resolve_vx; |
| else |
| got[2] = (Elf32_Addr) &_dl_runtime_resolve; |
| #else |
| got[2] = (Elf32_Addr) &_dl_runtime_resolve; |
| #endif |
| } |
| } |
| |
| return lazy; |
| } |
| |
| /* Mask identifying addresses reserved for the user program, |
| where the dynamic linker should not map anything. */ |
| #define ELF_MACHINE_USER_ADDRESS_MASK 0xf8000000UL |
| |
| /* 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__ ("\n\ |
| .text\n\ |
| .align 4\n\ |
| .globl _start\n\ |
| .globl _dl_start_user\n\ |
| _start:\n\ |
| basr %r13,0\n\ |
| 0: ahi %r13,.Llit-0b\n\ |
| lr %r2,%r15\n\ |
| # Alloc stack frame\n\ |
| ahi %r15,-96\n\ |
| # Set the back chain to zero\n\ |
| xc 0(4,%r15),0(%r15)\n\ |
| # Call _dl_start with %r2 pointing to arg on stack\n\ |
| l %r14,.Ladr1-.Llit(%r13)\n\ |
| bas %r14,0(%r14,%r13) # call _dl_start\n\ |
| _dl_start_user:\n\ |
| # Save the user entry point address in %r8.\n\ |
| lr %r8,%r2\n\ |
| # Point %r12 at the GOT.\n\ |
| l %r12,.Ladr0-.Llit(%r13)\n\ |
| ar %r12,%r13\n\ |
| # See if we were run as a command with the executable file\n\ |
| # name as an extra leading argument.\n\ |
| l %r1,_dl_skip_args@GOT(%r12)\n\ |
| l %r1,0(%r1) # load _dl_skip_args\n\ |
| ltr %r1,%r1\n\ |
| je 4f # Skip the arg adjustment if there were none.\n\ |
| # Get the original argument count.\n\ |
| l %r0,96(%r15)\n\ |
| # Subtract _dl_skip_args from it.\n\ |
| sr %r0,%r1\n\ |
| # Store back the modified argument count.\n\ |
| st %r0,96(%r15)\n\ |
| # Copy argv and envp forward to account for skipped argv entries.\n\ |
| # We skipped at least one argument or we would not get here.\n\ |
| la %r6,100(%r15) # Destination pointer i.e. &argv[0]\n\ |
| lr %r5,%r6\n\ |
| lr %r0,%r1\n\ |
| sll %r0,2\n # Number of skipped bytes.\n\ |
| ar %r5,%r0 # Source pointer = Dest + Skipped args.\n\ |
| # argv copy loop:\n\ |
| 1: l %r7,0(%r5) # Load a word from the source.\n\ |
| st %r7,0(%r6) # Store the word in the destination.\n\ |
| ahi %r5,4\n\ |
| ahi %r6,4\n\ |
| ltr %r7,%r7\n\ |
| jne 1b # Stop after copying the NULL.\n\ |
| # envp copy loop:\n\ |
| 2: l %r7,0(%r5) # Load a word from the source.\n\ |
| st %r7,0(%r6) # Store the word in the destination.\n\ |
| ahi %r5,4\n\ |
| ahi %r6,4\n\ |
| ltr %r7,%r7\n\ |
| jne 2b # Stop after copying the NULL.\n\ |
| # Now we have to zero out the envp entries after NULL to allow\n\ |
| # start.S to properly find auxv by skipping zeroes.\n\ |
| # zero out loop:\n\ |
| lhi %r7,0\n\ |
| 3: st %r7,0(%r6) # Store zero.\n\ |
| ahi %r6,4 # Advance dest pointer.\n\ |
| ahi %r1,-1 # Subtract one from the word count.\n\ |
| ltr %r1,%r1\n\ |
| jne 3b # Keep copying if the word count is non-zero.\n\ |
| # Adjust _dl_argv\n\ |
| la %r6,100(%r15)\n\ |
| l %r1,_dl_argv@GOT(%r12)\n\ |
| st %r6,0(%r1)\n\ |
| # The special initializer gets called with the stack just\n\ |
| # as the application's entry point will see it; it can\n\ |
| # switch stacks if it moves these contents over.\n\ |
| " RTLD_START_SPECIAL_INIT "\n\ |
| # Call the function to run the initializers.\n\ |
| # Load the parameters:\n\ |
| # (%r2, %r3, %r4, %r5) = (_dl_loaded, argc, argv, envp)\n\ |
| 4: l %r2,_rtld_local@GOT(%r12)\n\ |
| l %r2,0(%r2)\n\ |
| l %r3,96(%r15)\n\ |
| la %r4,100(%r15)\n\ |
| lr %r5,%r3\n\ |
| sll %r5,2\n\ |
| la %r5,104(%r5,%r15)\n\ |
| l %r1,.Ladr4-.Llit(%r13)\n\ |
| bas %r14,0(%r1,%r13)\n\ |
| # Pass our finalizer function to the user in %r14, as per ELF ABI.\n\ |
| l %r14,_dl_fini@GOT(%r12)\n\ |
| # Free stack frame\n\ |
| ahi %r15,96\n\ |
| # Jump to the user's entry point (saved in %r8).\n\ |
| br %r8\n\ |
| .Llit:\n\ |
| .Ladr0: .long _GLOBAL_OFFSET_TABLE_-.Llit\n\ |
| .Ladr1: .long _dl_start-.Llit\n\ |
| .Ladr4: .long _dl_init@PLT-.Llit\n\ |
| "); |
| |
| #ifndef RTLD_START_SPECIAL_INIT |
| #define RTLD_START_SPECIAL_INIT /* nothing */ |
| #endif |
| |
| /* 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_COPY 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_390_JMP_SLOT || (type) == R_390_TLS_DTPMOD \ |
| || (type) == R_390_TLS_DTPOFF || (type) == R_390_TLS_TPOFF) \ |
| * ELF_RTYPE_CLASS_PLT) \ |
| | (((type) == R_390_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_390_JMP_SLOT |
| |
| /* The S390 never uses Elf32_Rel relocations. */ |
| #define ELF_MACHINE_NO_REL 1 |
| #define ELF_MACHINE_NO_RELA 0 |
| |
| /* We define an initialization functions. This is called very early in |
| _dl_sysdep_start. */ |
| #define DL_PLATFORM_INIT dl_platform_init () |
| |
| static inline void __attribute__ ((unused)) |
| dl_platform_init (void) |
| { |
| if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0') |
| /* Avoid an empty string which would disturb us. */ |
| GLRO(dl_platform) = NULL; |
| } |
| |
| static inline Elf32_Addr |
| elf_machine_fixup_plt (struct link_map *map, lookup_t t, |
| const ElfW(Sym) *refsym, const ElfW(Sym) *sym, |
| 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 s390_32_gnu_pltenter |
| #define ARCH_LA_PLTEXIT s390_32_gnu_pltexit |
| |
| #endif /* !dl_machine_h */ |
| |
| |
| #ifdef RESOLVE_MAP |
| |
| /* Perform the relocation specified by RELOC and SYM (which is fully resolved). |
| MAP is the object containing the reloc. */ |
| |
| 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 unsigned int r_type = ELF32_R_TYPE (reloc->r_info); |
| |
| #if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC |
| if (__glibc_unlikely (r_type == R_390_RELATIVE)) |
| { |
| # if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC |
| /* This is defined in rtld.c, but nowhere in the static libc.a; |
| make the reference weak so static programs can still link. |
| This declaration cannot be done when compiling rtld.c |
| (i.e. #ifdef RTLD_BOOTSTRAP) because rtld.c contains the |
| common defn for _dl_rtld_map, which is incompatible with a |
| weak decl in the same file. */ |
| # ifndef SHARED |
| weak_extern (GL(dl_rtld_map)); |
| # endif |
| if (map != &GL(dl_rtld_map)) /* Already done in rtld itself. */ |
| # endif |
| *reloc_addr = map->l_addr + reloc->r_addend; |
| } |
| else |
| #endif |
| if (__glibc_unlikely (r_type == R_390_NONE)) |
| return; |
| else |
| { |
| #if !defined RTLD_BOOTSTRAP && !defined RESOLVE_CONFLICT_FIND_MAP |
| /* Only needed for R_390_COPY below. */ |
| const Elf32_Sym *const refsym = sym; |
| #endif |
| struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type); |
| Elf32_Addr value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value; |
| |
| 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); |
| |
| switch (r_type) |
| { |
| case R_390_IRELATIVE: |
| value = map->l_addr + reloc->r_addend; |
| if (__glibc_likely (!skip_ifunc)) |
| value = elf_ifunc_invoke (value); |
| *reloc_addr = value; |
| break; |
| |
| case R_390_GLOB_DAT: |
| case R_390_JMP_SLOT: |
| *reloc_addr = value + reloc->r_addend; |
| break; |
| |
| #ifndef RESOLVE_CONFLICT_FIND_MAP |
| case R_390_TLS_DTPMOD: |
| # ifdef RTLD_BOOTSTRAP |
| /* During startup the dynamic linker is always the module |
| with index 1. |
| XXX If this relocation is necessary move before RESOLVE |
| call. */ |
| *reloc_addr = 1; |
| # else |
| /* Get the information from the link map returned by the |
| resolv function. */ |
| if (sym_map != NULL) |
| *reloc_addr = sym_map->l_tls_modid; |
| # endif |
| break; |
| case R_390_TLS_DTPOFF: |
| # ifndef RTLD_BOOTSTRAP |
| /* During relocation all TLS symbols are defined and used. |
| Therefore the offset is already correct. */ |
| if (sym != NULL) |
| *reloc_addr = sym->st_value + reloc->r_addend; |
| # endif |
| break; |
| case R_390_TLS_TPOFF: |
| /* The offset is negative, forward from the thread pointer. */ |
| # ifdef RTLD_BOOTSTRAP |
| *reloc_addr = sym->st_value + reloc->r_addend - map->l_tls_offset; |
| # else |
| /* We know the offset of the object the symbol is contained in. |
| It is a negative value which will be added to the |
| thread pointer. */ |
| if (sym != NULL) |
| { |
| CHECK_STATIC_TLS (map, sym_map); |
| *reloc_addr = (sym->st_value + reloc->r_addend |
| - sym_map->l_tls_offset); |
| } |
| #endif |
| break; |
| #endif /* use TLS */ |
| |
| #ifndef RTLD_BOOTSTRAP |
| # ifndef RESOLVE_CONFLICT_FIND_MAP |
| /* Not needed in dl-conflict.c. */ |
| case R_390_COPY: |
| if (sym == NULL) |
| /* This can happen in trace mode if an object could not be |
| found. */ |
| break; |
| if (__builtin_expect (sym->st_size > refsym->st_size, 0) |
| || (__builtin_expect (sym->st_size < refsym->st_size, 0) |
| && __builtin_expect (GLRO(dl_verbose), 0))) |
| { |
| const char *strtab; |
| |
| strtab = (const char *) 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; |
| # endif |
| case R_390_32: |
| *reloc_addr = value + reloc->r_addend; |
| break; |
| case R_390_16: |
| *(unsigned short *) reloc_addr = value + reloc->r_addend; |
| break; |
| case R_390_8: |
| *(char *) reloc_addr = value + reloc->r_addend; |
| break; |
| # ifndef RESOLVE_CONFLICT_FIND_MAP |
| case R_390_PC32: |
| *reloc_addr = value + reloc->r_addend - (Elf32_Addr) reloc_addr; |
| break; |
| case R_390_PC16DBL: |
| *(unsigned short *) reloc_addr = (unsigned short) |
| ((short) (value + reloc->r_addend - (Elf32_Addr) reloc_addr) >> 1); |
| break; |
| case R_390_PC32DBL: |
| *(unsigned int *) reloc_addr = (unsigned int) |
| ((int) (value + reloc->r_addend - (Elf32_Addr) reloc_addr) >> 1); |
| break; |
| case R_390_PC16: |
| *(unsigned short *) reloc_addr = |
| value + reloc->r_addend - (Elf32_Addr) reloc_addr; |
| break; |
| case R_390_NONE: |
| break; |
| # endif |
| #endif |
| #if !defined(RTLD_BOOTSTRAP) || defined(_NDEBUG) |
| default: |
| /* We add these checks in the version to relocate ld.so only |
| if we are still debugging. */ |
| _dl_reloc_bad_type (map, r_type, 0); |
| break; |
| #endif |
| } |
| } |
| } |
| |
| 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) |
| { |
| Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset); |
| const unsigned int r_type = ELF32_R_TYPE (reloc->r_info); |
| /* Check for unexpected PLT reloc type. */ |
| if (__glibc_likely (r_type == R_390_JMP_SLOT)) |
| { |
| if (__builtin_expect (map->l_mach.plt, 0) == 0) |
| *reloc_addr += l_addr; |
| else |
| *reloc_addr = map->l_mach.plt + (reloc - map->l_mach.jmprel) * 32; |
| } |
| else if (__glibc_likely (r_type == R_390_IRELATIVE)) |
| { |
| Elf32_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 /* RESOLVE_MAP */ |