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Diffstat (limited to 'sysdeps/cris/dl-machine.h')
| -rw-r--r-- | sysdeps/cris/dl-machine.h | 392 |
1 files changed, 392 insertions, 0 deletions
diff --git a/sysdeps/cris/dl-machine.h b/sysdeps/cris/dl-machine.h new file mode 100644 index 0000000000..beec38184d --- /dev/null +++ b/sysdeps/cris/dl-machine.h @@ -0,0 +1,392 @@ +/* Machine-dependent ELF dynamic relocation inline functions. CRIS version. + Copyright (C) 1996,1997,1998,1999,2000,2001 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 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 "CRIS" + +#include <sys/param.h> + +#ifdef __PIC__ +# define CALL_FN(x) \ + "move.d $pc,$r9\n\t" \ + "add.d " #x " - .,$r9\n\t" \ + "jsr $r9" +#else +# define CALL_FN(x) "jsr " #x +#endif + +/* 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_CRIS; +} + +/* 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) +{ + /* Don't just set this to an asm variable "r0" since that's not logical + (like, the variable is uninitialized and the register is fixed) and + may make GCC trip over itself doing register allocation. Yes, I'm + paranoid. Why do you ask? */ + Elf32_Addr *got; + + __asm__ ("move.d $r0,%0" : "=rm" (got)); + return *got; +} + +/* Return the run-time load address of the shared object. We do it like + m68k and i386, by taking an arbitrary local symbol, forcing a GOT entry + for it, and peeking into the GOT table, which is set to the link-time + file-relative symbol value (regardless of whether the target is REL or + RELA). We subtract this link-time file-relative value from the "local" + value we calculate from GOT position and GOT offset. FIXME: Perhaps + there's some other symbol we could use, that we don't *have* to force a + GOT entry for. */ + +static inline Elf32_Addr +elf_machine_load_address (void) +{ + Elf32_Addr gotaddr_diff; + __asm__ ("sub.d [$r0+_dl_start:GOT16],$r0,%0\n\t" + "add.d _dl_start:GOTOFF,%0" : "=r" (gotaddr_diff)); + return gotaddr_diff; +} + +/* 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 +elf_machine_runtime_setup (struct link_map *l, int lazy, int profile) +{ + Elf32_Addr *got; + 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 .rela.plt section, push + _GLOBAL_OFFSET_TABLE_[1], and then jump to + _GLOBAL_OFFSET_TABLE_[2]. */ + 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. + + We get here with the offset into the relocation table pushed on stack, + and the link map in MOF. */ + +#define TRAMPOLINE_TEMPLATE(tramp_name, fixup_name) \ +"; Trampoline for " #fixup_name " + .globl " #tramp_name " + .type " #tramp_name ", @function +" #tramp_name ": + push $r13 + push $r12 + push $r11 + push $r10 + push $r9 + push $srp + move.d [$sp+6*4],$r11 + move $mof,$r10 + " CALL_FN (fixup_name) " + move.d $r10,[$sp+6*4] + pop $srp + pop $r9 + pop $r10 + pop $r11 + pop $r12 + pop $r13 + jump [$sp+] + .size " #tramp_name ", . - " #tramp_name "\n" +#ifndef PROF +#define ELF_MACHINE_RUNTIME_TRAMPOLINE \ +asm (TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup) \ + TRAMPOLINE_TEMPLATE (_dl_runtime_profile, profile_fixup)); +#else +#define ELF_MACHINE_RUNTIME_TRAMPOLINE \ +asm (TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup) \ + ".globl _dl_runtime_profile\n" \ + ".set _dl_runtime_profile, _dl_runtime_resolve"); +#endif + + +/* 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 ("\ + .text + .globl _start + .type _start,@function +_start: + move.d $sp,$r10 + " CALL_FN (_dl_start) " + /* FALLTHRU */ + + .globl _dl_start_user + .type _dl_start_user,@function +_dl_start_user: + ; Save the user entry point address in R1. + move.d $r10,$r1 + ; Point R0 at the GOT. + move.d $pc,$r0 + sub.d .:GOTOFF,$r0 + ; Remember the highest stack address. + move.d [$r0+__libc_stack_end:GOT16],$r13 + move.d $sp,[$r13] + ; See if we were run as a command with the executable file + ; name as an extra leading argument. + move.d [$r0+_dl_skip_args:GOT16],$r13 + move.d [$r13],$r9 + ; Get the original argument count + move.d [$sp],$r11 + ; Subtract _dl_skip_args from it. + sub.d $r9,$r11 + ; Adjust the stack pointer to skip _dl_skip_args words. + addi $r9.d,$sp + ; Put the new argc in place as expected by the user entry. + move.d $r11,[$sp] + ; Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) + ; env: skip scaled argc and skip stored argc and NULL at end of argv[]. + move.d $sp,$r13 + addi $r11.d,$r13 + addq 8,$r13 + ; argv: skip stored argc. + move.d $sp,$r12 + addq 4,$r12 + ; main_map: at _dl_loaded. + move.d [$r0+_dl_loaded:GOT16],$r9 + move.d [$r9],$r10 + move.d _dl_init:PLTG,$r9 + add.d $r0,$r9 + jsr $r9 + ; Pass our finalizer function to the user in R10. + move.d [$r0+_dl_fini:GOT16],$r10 + ; Terminate the frame-pointer. + moveq 0,$r8 + ; Cause SEGV if user entry returns. + move $r8,$srp + ; Jump to the user's entry point. + jump $r1 + .size _dl_start_user, . - _dl_start_user + .previous"); + +/* Nonzero iff TYPE describes a relocation that should + skip the executable when looking up the symbol value. */ +#define elf_machine_lookup_noexec_p(type) ((type) == R_CRIS_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_CRIS_JUMP_SLOT) + +/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */ +#define ELF_MACHINE_JMP_SLOT R_CRIS_JUMP_SLOT + +/* CRIS never uses Elf32_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 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 + reloc->r_addend; +} + +#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) +{ +#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); +#endif + + if (ELF32_R_TYPE (reloc->r_info) == R_CRIS_RELATIVE) + { +#ifndef RTLD_BOOTSTRAP + if (map != &_dl_rtld_map) /* Already done in rtld itself. */ +#endif + *reloc_addr = map->l_addr + reloc->r_addend; + } + else + { +#ifndef RTLD_BOOTSTRAP + const Elf32_Sym *const refsym = sym; +#endif + Elf32_Addr value; + if (sym->st_shndx != SHN_UNDEF && + ELF32_ST_BIND (sym->st_info) == STB_LOCAL) + value = map->l_addr; + else + { + value = RESOLVE (&sym, version, ELF32_R_TYPE (reloc->r_info)); + if (sym) + value += sym->st_value; + } + value += reloc->r_addend; /* Assume copy relocs have zero addend. */ + + switch (ELF32_R_TYPE (reloc->r_info)) + { +#ifndef RTLD_BOOTSTRAP + case R_CRIS_COPY: + if (sym == NULL) + /* This can happen in trace mode if an object could not be + found. */ + break; + if (sym->st_size > refsym->st_size + || (_dl_verbose && sym->st_size < refsym->st_size)) + { + extern char **_dl_argv; + 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", + _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_CRIS_32: +#endif + case R_CRIS_GLOB_DAT: + case R_CRIS_JUMP_SLOT: + *reloc_addr = value; + break; +#ifndef RTLD_BOOTSTRAP + case R_CRIS_8: + *(char *) reloc_addr = value; + break; + case R_CRIS_16: + *(short *) reloc_addr = value; + break; + case R_CRIS_8_PCREL: + *(char *) reloc_addr + = value + reloc->r_addend - (Elf32_Addr) reloc_addr - 1; + break; + case R_CRIS_16_PCREL: + *(short *) reloc_addr + = value + reloc->r_addend - (Elf32_Addr) reloc_addr - 2; + break; + case R_CRIS_32_PCREL: + *reloc_addr = value + reloc->r_addend - (Elf32_Addr) reloc_addr - 4; + break; +#endif + case R_CRIS_NONE: + break; +#if !defined RTLD_BOOTSTRAP || defined _NDEBUG + default: + _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, + Elf32_Addr l_addr, const Elf32_Rela *reloc) +{ + Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset); + if (__builtin_expect (ELF32_R_TYPE (reloc->r_info), R_CRIS_JUMP_SLOT) + == R_CRIS_JUMP_SLOT) + *reloc_addr += l_addr; + else + _dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1); +} + +#endif /* RESOLVE */ |