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Diffstat (limited to 'sysdeps/s390/dl-machine.h')
| -rw-r--r-- | sysdeps/s390/dl-machine.h | 464 |
1 files changed, 464 insertions, 0 deletions
diff --git a/sysdeps/s390/dl-machine.h b/sysdeps/s390/dl-machine.h new file mode 100644 index 0000000000..3cab824ce2 --- /dev/null +++ b/sysdeps/s390/dl-machine.h @@ -0,0 +1,464 @@ +/* Machine-dependent ELF dynamic relocation inline functions. S390 Version. + Copyright (C) 2000 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 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 "s390" + +#include <sys/param.h> +#include <string.h> +#include <link.h> + + +/* Return nonzero iff E_MACHINE is compatible with the running host. */ +static inline int +elf_machine_matches_host (Elf32_Half e_machine) +{ + switch (e_machine) + { + case EM_S390: + return 1; + default: + return 0; + } +} + + +/* 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\n" + "2: l %0,4(1)\n" + " ar %0,1\n" + " al 1,0(1)\n" + " sl %0,_dl_start@GOT12(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 (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]); + 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 (__builtin_expect (profile, 0)) + { + got[2] = (Elf32_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] = (Elf32_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 24(r15) and 28(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\ + stm 2,5,32(15)\n\ + st 14,48(15)\n\ + lr 0,15\n\ + ahi 15,-96\n\ + st 0,0(15)\n\ + # load args saved by PLT\n\ + lm 2,3,120(15)\n\ + basr 1,0\n\ +0: ahi 1,1f-0b\n\ + l 14,0(1)\n\ + bas 14,0(14,1) # call fixup\n\ + lr 1,2 # function addr returned in r2\n\ + # restore registers\n\ + ahi 15,96\n\ + l 14,48(15)\n\ + lm 2,5,32(15)\n\ + br 1\n\ +1: .long fixup-1b\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\ + stm 2,5,32(15)\n\ + st 14,48(15)\n\ + lr 0,15\n\ + ahi 15,-96\n\ + st 0,0(15)\n\ + # load args saved by PLT\n\ + lm 2,3,120(15)\n\ + # load return address as third parameter\n\ + lr 4,14\n\ + basr 1,0\n\ +0: ahi 1,1f-0b\n\ + l 14,0(1)\n\ + bas 14,0(14,1) # call fixup\n\ + lr 1,2 # function addr returned in r2\n\ + # restore registers\n\ + ahi 15,96\n\ + l 14,48(15)\n\ + lm 2,5,32(15)\n\ + br 1\n\ +1: .long profile_fixup-1b\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\ + stm 2,5,32(15)\n\ + st 14,48(15)\n\ + lr 0,15\n\ + ahi 15,-96\n\ + st 0,0(15)\n\ + # load args saved by PLT\n\ + lm 2,3,120(15)\n\ + # load return address as third parameter\n\ + lr 4,14\n\ + basr 1,0\n\ +0: ahi 1,1f-0b\n\ + l 14,0(1)\n\ + bas 14,0(14,1) # call fixup\n\ + lr 1,2 # function addr returned in r2\n\ + # restore registers\n\ + ahi 15,96\n\ + l 14,48(15)\n\ + lm 2,5,32(15)\n\ + br 1\n\ +1: .long fixup-1b\n\ + .size _dl_runtime_resolve, .-_dl_runtime_resolve\n\ + .size _dl_runtime_profile, .-_dl_runtime_profile\n\ +"); +#endif + +/* 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 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\ +.L0: ahi %r13,.Llit-.L0\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\ + # Store the highest stack address\n\ + l %r1,__libc_stack_end@GOT(%r12)\n\ + st %r15, 0(%r1)\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@GOT12(0,%r12)\n\ + l %r1,0(%r1) # load _dl_skip_args\n\ + # Get the original argument count.\n\ + l %r0,96(%r15)\n\ + # Subtract _dl_skip_args from it.\n\ + sr %r0,%r1\n\ + # Adjust the stack pointer to skip _dl_skip_args words.\n\ + sll %r1,2\n\ + ar %r15,%r1\n\ + # Set the back chain to zero again\n\ + xc 0(4,%r15),0(%r15)\n\ + # Store back the modified argument count.\n\ + st %r0,96(%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\ + l %r2,_dl_loaded@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 + +/* Nonzero iff TYPE describes relocation of a PLT entry, so + PLT entries should not be allowed to define the value. */ +#define elf_machine_pltrel_p(type) ((type) == R_390_JMP_SLOT) + +/* 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 S390 never uses Elf32_Rel relocations. */ +#define ELF_MACHINE_NO_REL 1 + +/* The S390 overlaps DT_RELA and DT_PLTREL. */ +#define ELF_MACHINE_PLTREL_OVERLAP 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 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; +} + +#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 Elf32_Rela *reloc, + const Elf32_Sym *sym, const struct r_found_version *version, + Elf32_Addr *const reloc_addr) +{ + if (ELF32_R_TYPE (reloc->r_info) == R_390_RELATIVE) { +#ifndef RTLD_BOOTSTRAP + if (map != &_dl_rtld_map) /* Already done in rtld itself. */ +#endif + *reloc_addr = map->l_addr + reloc->r_addend; + } + else if (ELF32_R_TYPE (reloc->r_info) != R_390_NONE) + { + const Elf32_Sym *const refsym = sym; + Elf32_Addr value = RESOLVE (&sym, version, ELF32_R_TYPE (reloc->r_info)); + if (sym) + value += sym->st_value; + + switch (ELF32_R_TYPE (reloc->r_info)) + { + 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_sysdep_error (_dl_argv[0] ?: "<program name unknown>", + ": Symbol `", strtab + refsym->st_name, + "' has different size in shared object, " + "consider re-linking\n", NULL); + } + memcpy (reloc_addr, (void *) value, MIN (sym->st_size, + refsym->st_size)); + break; + case R_390_GLOB_DAT: + case R_390_JMP_SLOT: + *reloc_addr = value; + break; + case R_390_32: + { +#ifndef RTLD_BOOTSTRAP + /* 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. */ + weak_extern (_dl_rtld_map); + if (map == &_dl_rtld_map) + /* Undo the relocation done here during bootstrapping. + Now we will relocate it anew, possibly using a + binding found in the user program or a loaded library + rather than the dynamic linker's built-in definitions + used while loading those libraries. */ + value -= map->l_addr + refsym->st_value; +#endif + *reloc_addr = value + reloc->r_addend; + break; + } + + case R_390_PC32: + *reloc_addr = value +reloc->r_addend - (Elf32_Addr) reloc_addr; + break; + case R_390_NONE: + break; + default: + _dl_reloc_bad_type (map, ELFW(R_TYPE) (reloc->r_info), 0); + break; + } + } +} + + +static inline void +elf_machine_lazy_rel (struct link_map *map, + Elf32_Addr l_addr, const Elf32_Rela *reloc) +{ + Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset); + /* Check for unexpected PLT reloc type. */ + if (__builtin_expect (ELF32_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 */ |