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Diffstat (limited to 'sysdeps/s390/s390-64/dl-machine.h')
| -rw-r--r-- | sysdeps/s390/s390-64/dl-machine.h | 434 |
1 files changed, 434 insertions, 0 deletions
diff --git a/sysdeps/s390/s390-64/dl-machine.h b/sysdeps/s390/s390-64/dl-machine.h new file mode 100644 index 0000000000..fd1c752df9 --- /dev/null +++ b/sysdeps/s390/s390-64/dl-machine.h @@ -0,0 +1,434 @@ +/* Machine-dependent ELF dynamic relocation inline functions. + 64 bit S/390 Version. + Copyright (C) 2001 Free Software Foundation, Inc. + Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com). + 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 Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If + not, write to the Free Software Foundation, Inc., + 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#ifndef dl_machine_h +#define dl_machine_h + +#define ELF_MACHINE_NAME "s390x" + +#include <sys/param.h> +#include <string.h> +#include <link.h> + +/* This is an older, now obsolete value. */ +#define EM_S390_OLD 0xA390 + +/* Return nonzero iff E_MACHINE is compatible with the running host. */ +static inline int +elf_machine_matches_host (const Elf64_Ehdr *ehdr) +{ + return (ehdr->e_machine == EM_S390 || ehdr->e_machine == EM_S390_OLD) + && ehdr->e_ident[EI_CLASS] == ELFCLASS64; +} + +/* 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 Elf64_Addr +elf_machine_dynamic (void) +{ + register Elf64_Addr *got; + + asm( " larl %0,_GLOBAL_OFFSET_TABLE_\n" + : "=&a" (got) : : "0" ); + + return *got; +} + +/* Return the run-time load address of the shared object. */ +static inline Elf64_Addr +elf_machine_load_address (void) +{ + Elf64_Addr addr; + + asm( " larl %0,_dl_start\n" + " larl 1,_GLOBAL_OFFSET_TABLE_\n" + " lghi 2,_dl_start@GOT\n" + " slg %0,0(2,1)" + : "=&d" (addr) : : "1", "2" ); + 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 (Elf64_Word); + extern void _dl_runtime_profile (Elf64_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 push an + offset into the .rela.plt section, push _GLOBAL_OFFSET_TABLE_[1], + and then jump to _GLOBAL_OFFSET_TABLE[2]. */ + Elf64_Addr *got; + got = (Elf64_Addr *) D_PTR (l, l_info[DT_PLTGOT]); + got[1] = (Elf64_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 (__builtin_expect (profile, 0)) + { + got[2] = (Elf64_Addr) &_dl_runtime_profile; + + if (_dl_name_match_p (_dl_profile, l)) + /* This is the object we are looking for. Say that we really + want profiling and the timers are started. */ + _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] = (Elf64_Addr) &_dl_runtime_resolve; + } + + return lazy; +} + +/* This code is used in dl-runtime.c to call the `fixup' function + and then redirect to the address it returns. */ + +/* s390: + Arguments are in register. + r2 - r7 holds the original parameters for the function call, fixup + and trampoline code use r0-r5 and r14-15. For the correct function + call r2-r5 and r14-15 must be restored. + Arguments from the PLT are stored at 48(r15) and 56(r15) + and must be moved to r2 and r3 for the fixup call (see elf32-s390.c + in the binutils for the PLT code). + Fixup function address in r2. +*/ +#ifndef PROF +#define ELF_MACHINE_RUNTIME_TRAMPOLINE \ + asm ( "\ + .text\n\ + .globl _dl_runtime_resolve\n\ + .type _dl_runtime_resolve, @function\n\ + .align 16\n\ +_dl_runtime_resolve:\n\ + # save registers\n\ + stmg 2,5,64(15)\n\ + stg 14,96(15)\n\ + lgr 0,15\n\ + aghi 15,-160\n\ + stg 0,0(15)\n\ + # load args saved by PLT\n\ + lmg 2,3,208(15)\n\ + brasl 14,fixup # call fixup + lgr 1,2 # function addr returned in r2\n\ + # restore registers\n\ + aghi 15,160\n\ + lg 14,96(15)\n\ + lmg 2,5,64(15)\n\ + br 1\n\ + .size _dl_runtime_resolve, .-_dl_runtime_resolve\n\ +\n\ + .globl _dl_runtime_profile\n\ + .type _dl_runtime_profile, @function\n\ + .align 16\n\ +_dl_runtime_profile:\n\ + # save registers\n\ + stmg 2,5,64(15)\n\ + stg 14,96(15)\n\ + lgr 0,15\n\ + aghi 15,-160\n\ + stg 0,0(15)\n\ + # load args saved by PLT\n\ + lmg 2,3,208(15)\n\ + # load return address as third parameter\n\ + lgr 4,14\n\ + brasl 14,profile_fixup # call fixup\n\ + lgr 1,2 # function addr returned in r2\n\ + # restore registers\n\ + aghi 15,160\n\ + lg 14,96(15)\n\ + lmg 2,5,64(15)\n\ + br 1\n\ + .size _dl_runtime_profile, .-_dl_runtime_profile\n\ +"); +#else +#define ELF_MACHINE_RUNTIME_TRAMPOLINE \ + asm ( "\ + .text\n\ + .globl _dl_runtime_resolve\n\ + .globl _dl_runtime_profile\n\ + .type _dl_runtime_resolve, @function\n\ + .type _dl_runtime_profile, @function\n\ + .align 16\n\ +_dl_runtime_resolve:\n\ +_dl_runtime_profile:\n\ + # save registers\n\ + stmg 2,5,64(15)\n\ + stg 14,96(15)\n\ + lgr 0,15\n\ + aghi 15,-160\n\ + stg 0,0(15)\n\ + # load args saved by PLT\n\ + lmg 2,3,208(15)\n\ + # load return address as third parameter\n\ + lgr 4,14\n\ + brasl 14,profile_fixup # call fixup\n\ + lgr 1,2 # function addr returned in r2\n\ + # restore registers\n\ + aghi 15,160\n\ + lg 14,96(15)\n\ + lmg 2,5,64(15)\n\ + br 1\n\ + .size _dl_runtime_resolve, .-_dl_runtime_resolve\n\ + .size _dl_runtime_profile, .-_dl_runtime_profile\n\ +"); +#endif + +/* 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\ + lgr %r2,%r15\n\ + # Alloc stack frame\n\ + aghi %r15,-160\n\ + # Set the back chain to zero\n\ + xc 0(8,%r15),0(%r15)\n\ + # Call _dl_start with %r2 pointing to arg on stack\n\ + brasl %r14,_dl_start # call _dl_start\n\ +_dl_start_user:\n\ + # Save the user entry point address in %r8.\n\ + lgr %r8,%r2\n\ + # Point %r12 at the GOT.\n\ + larl %r12,_GLOBAL_OFFSET_TABLE_\n\ + # Store the highest stack address\n\ + lghi %r1,__libc_stack_end@GOT + lg %r1,0(%r1,%r12)\n\ + stg %r15, 0(%r1)\n\ + # See if we were run as a command with the executable file\n\ + # name as an extra leading argument.\n\ + lghi %r1,_dl_skip_args@GOT + lg %r1,0(%r1,%r12)\n\ + lgf %r1,0(%r1) # load _dl_skip_args\n\ + # Get the original argument count.\n\ + lg %r0,160(%r15)\n\ + # Subtract _dl_skip_args from it.\n\ + sgr %r0,%r1\n\ + # Adjust the stack pointer to skip _dl_skip_args words.\n\ + sllg %r1,%r1,3\n\ + agr %r15,%r1\n\ + # Set the back chain to zero again\n\ + xc 0(8,%r15),0(%r15)\n\ + # Store back the modified argument count.\n\ + stg %r0,160(%r15)\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\ + lghi %r2,_dl_loaded@GOT + lg %r2,0(%r2,%r12)\n\ + lg %r2,0(%r2)\n\ + lg %r3,160(%r15)\n\ + la %r4,168(%r15)\n\ + lgr %r5,%r3\n\ + sllg %r5,%r5,3\n\ + la %r5,176(%r5,%r15)\n\ + brasl %r14,_dl_init@PLT\n + # Pass our finalizer function to the user in %r14, as per ELF ABI.\n\ + lghi %r14,_dl_fini@GOT + lg %r14,0(%r14,%r12)\n\ + # Free stack frame\n\ + aghi %r15,160\n\ + # Jump to the user's entry point (saved in %r8).\n\ + br %r8\n\ +"); + +#ifndef RTLD_START_SPECIAL_INIT +#define RTLD_START_SPECIAL_INIT /* nothing */ +#endif + +/* Nonzero iff TYPE should not be allowed to resolve to one of + the main executable's symbols, as for a COPY reloc. */ +#define elf_machine_lookup_noexec_p(type) ((type) == R_390_COPY) + +/* Nonzero iff TYPE describes relocation of a PLT entry, so + PLT entries should not be allowed to define the value. */ +#define elf_machine_lookup_noplt_p(type) ((type) == R_390_JMP_SLOT) + +/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */ +#define ELF_MACHINE_JMP_SLOT R_390_JMP_SLOT + +/* The 64 bit S/390 never uses Elf64_Rel relocations. */ +#define ELF_MACHINE_NO_REL 1 + +/* We define an initialization functions. This is called very early in + _dl_sysdep_start. */ +#define DL_PLATFORM_INIT dl_platform_init () + +extern const char *_dl_platform; + +static inline void __attribute__ ((unused)) +dl_platform_init (void) +{ + if (_dl_platform != NULL && *_dl_platform == '\0') + /* Avoid an empty string which would disturb us. */ + _dl_platform = NULL; +} + +static inline Elf64_Addr +elf_machine_fixup_plt (struct link_map *map, lookup_t t, + const Elf64_Rela *reloc, + Elf64_Addr *reloc_addr, Elf64_Addr value) +{ + return *reloc_addr = value; +} + +/* Return the final value of a plt relocation. */ +static inline Elf64_Addr +elf_machine_plt_value (struct link_map *map, const Elf64_Rela *reloc, + Elf64_Addr value) +{ + return value; +} + +#endif /* !dl_machine_h */ + +#ifdef RESOLVE + +/* Perform the relocation specified by RELOC and SYM (which is fully resolved). + MAP is the object containing the reloc. */ + +static inline void +elf_machine_rela (struct link_map *map, const Elf64_Rela *reloc, + const Elf64_Sym *sym, const struct r_found_version *version, + Elf64_Addr *const reloc_addr) +{ + if (ELF64_R_TYPE (reloc->r_info) == R_390_RELATIVE) { +#ifndef RTLD_BOOTSTRAP + weak_extern (_dl_rtld_map); + if (map != &_dl_rtld_map) /* Already done in rtld itself. */ +#endif + *reloc_addr = map->l_addr + reloc->r_addend; + } + else if (ELF64_R_TYPE (reloc->r_info) != R_390_NONE) + { + const Elf64_Sym *const refsym = sym; + Elf64_Addr value = RESOLVE (&sym, version, ELF64_R_TYPE (reloc->r_info)); + if (sym) + value += sym->st_value; + + switch (ELF64_R_TYPE (reloc->r_info)) + { + case R_390_GLOB_DAT: + case R_390_JMP_SLOT: + *reloc_addr = value + reloc->r_addend; + break; +#ifndef RTLD_BOOTSTRAP + 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 (_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", + _dl_argv[0] ?: "<program name unknown>", + strtab + refsym->st_name); + } + memcpy (reloc_addr, (void *) value, MIN (sym->st_size, + refsym->st_size)); + break; + case R_390_64: + *reloc_addr = value + reloc->r_addend; + break; + case R_390_32: + *(unsigned int *) 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; + case R_390_PC64: + *reloc_addr = value +reloc->r_addend - (Elf64_Addr) reloc_addr; + break; + case R_390_PC32DBL: + case R_390_PLT32DBL: + *(unsigned int *) reloc_addr = (unsigned int) + ((int) (value + reloc->r_addend - (Elf64_Addr) reloc_addr) >> 1); + break; + case R_390_PC32: + *(unsigned int *) reloc_addr = + value + reloc->r_addend - (Elf64_Addr) reloc_addr; + break; + case R_390_PC16DBL: + case R_390_PLT16DBL: + *(unsigned short *) reloc_addr = (unsigned short) + ((short) (value + reloc->r_addend - (Elf64_Addr) reloc_addr) >> 1); + break; + case R_390_PC16: + *(unsigned short *) reloc_addr = + value + reloc->r_addend - (Elf64_Addr) reloc_addr; + break; +#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, ELFW(R_TYPE) (reloc->r_info), 0); + break; +#endif + } + } +} + +static inline void +elf_machine_lazy_rel (struct link_map *map, + Elf64_Addr l_addr, const Elf64_Rela *reloc) +{ + Elf64_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset); + /* Check for unexpected PLT reloc type. */ + if (__builtin_expect (ELF64_R_TYPE (reloc->r_info), R_390_JMP_SLOT) + == R_390_JMP_SLOT) + *reloc_addr += l_addr; + else + _dl_reloc_bad_type (map, ELFW(R_TYPE) (reloc->r_info), 1); +} + +#endif /* RESOLVE */ |