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393 lines
12 KiB
C
393 lines
12 KiB
C
/* Machine-dependent ELF dynamic relocation inline functions. CRIS version.
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Copyright (C) 1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc.,
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59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#ifndef dl_machine_h
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#define dl_machine_h
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#define ELF_MACHINE_NAME "CRIS"
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#include <sys/param.h>
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#ifdef __PIC__
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# define CALL_FN(x) \
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"move.d $pc,$r9\n\t" \
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"add.d " #x " - .,$r9\n\t" \
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"jsr $r9"
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#else
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# define CALL_FN(x) "jsr " #x
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#endif
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/* Return nonzero iff ELF header is compatible with the running host. */
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static inline int
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elf_machine_matches_host (const Elf32_Ehdr *ehdr)
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{
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return ehdr->e_machine == EM_CRIS;
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}
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/* Return the link-time address of _DYNAMIC. Conveniently, this is the
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first element of the GOT. This must be inlined in a function which
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uses global data. */
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static inline Elf32_Addr
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elf_machine_dynamic (void)
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{
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/* Don't just set this to an asm variable "r0" since that's not logical
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(like, the variable is uninitialized and the register is fixed) and
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may make GCC trip over itself doing register allocation. Yes, I'm
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paranoid. Why do you ask? */
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Elf32_Addr *got;
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__asm__ ("move.d $r0,%0" : "=rm" (got));
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return *got;
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}
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/* Return the run-time load address of the shared object. We do it like
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m68k and i386, by taking an arbitrary local symbol, forcing a GOT entry
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for it, and peeking into the GOT table, which is set to the link-time
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file-relative symbol value (regardless of whether the target is REL or
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RELA). We subtract this link-time file-relative value from the "local"
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value we calculate from GOT position and GOT offset. FIXME: Perhaps
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there's some other symbol we could use, that we don't *have* to force a
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GOT entry for. */
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static inline Elf32_Addr
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elf_machine_load_address (void)
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{
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Elf32_Addr gotaddr_diff;
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__asm__ ("sub.d [$r0+_dl_start:GOT16],$r0,%0\n\t"
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"add.d _dl_start:GOTOFF,%0" : "=r" (gotaddr_diff));
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return gotaddr_diff;
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}
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/* Set up the loaded object described by L so its unrelocated PLT
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entries will jump to the on-demand fixup code in dl-runtime.c. */
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static inline int
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elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
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{
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Elf32_Addr *got;
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extern void _dl_runtime_resolve (Elf32_Word);
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extern void _dl_runtime_profile (Elf32_Word);
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if (l->l_info[DT_JMPREL] && lazy)
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{
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/* The GOT entries for functions in the PLT have not yet been
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filled in. Their initial contents will arrange when called
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to push an offset into the .rela.plt section, push
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_GLOBAL_OFFSET_TABLE_[1], and then jump to
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_GLOBAL_OFFSET_TABLE_[2]. */
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got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
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got[1] = (Elf32_Addr) l; /* Identify this shared object. */
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/* The got[2] entry contains the address of a function which gets
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called to get the address of a so far unresolved function and
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jump to it. The profiling extension of the dynamic linker allows
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to intercept the calls to collect information. In this case we
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don't store the address in the GOT so that all future calls also
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end in this function. */
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if (__builtin_expect (profile, 0))
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{
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got[2] = (Elf32_Addr) &_dl_runtime_profile;
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if (_dl_name_match_p (_dl_profile, l))
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{
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/* This is the object we are looking for. Say that we really
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want profiling and the timers are started. */
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_dl_profile_map = l;
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}
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}
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else
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/* This function will get called to fix up the GOT entry indicated by
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the offset on the stack, and then jump to the resolved address. */
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got[2] = (Elf32_Addr) &_dl_runtime_resolve;
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}
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return lazy;
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}
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/* This code is used in dl-runtime.c to call the `fixup' function
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and then redirect to the address it returns.
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We get here with the offset into the relocation table pushed on stack,
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and the link map in MOF. */
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#define TRAMPOLINE_TEMPLATE(tramp_name, fixup_name) \
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"; Trampoline for " #fixup_name "
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.globl " #tramp_name "
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.type " #tramp_name ", @function
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" #tramp_name ":
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push $r13
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push $r12
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push $r11
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push $r10
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push $r9
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push $srp
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move.d [$sp+6*4],$r11
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move $mof,$r10
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" CALL_FN (fixup_name) "
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move.d $r10,[$sp+6*4]
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pop $srp
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pop $r9
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pop $r10
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pop $r11
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pop $r12
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pop $r13
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jump [$sp+]
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.size " #tramp_name ", . - " #tramp_name "\n"
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#ifndef PROF
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#define ELF_MACHINE_RUNTIME_TRAMPOLINE \
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asm (TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup) \
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TRAMPOLINE_TEMPLATE (_dl_runtime_profile, profile_fixup));
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#else
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#define ELF_MACHINE_RUNTIME_TRAMPOLINE \
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asm (TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup) \
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".globl _dl_runtime_profile\n" \
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".set _dl_runtime_profile, _dl_runtime_resolve");
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#endif
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/* Mask identifying addresses reserved for the user program,
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where the dynamic linker should not map anything. */
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#define ELF_MACHINE_USER_ADDRESS_MASK 0xf8000000UL
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/* Initial entry point code for the dynamic linker.
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The C function `_dl_start' is the real entry point;
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its return value is the user program's entry point. */
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#define RTLD_START asm ("\
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.text
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.globl _start
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.type _start,@function
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_start:
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move.d $sp,$r10
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" CALL_FN (_dl_start) "
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/* FALLTHRU */
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.globl _dl_start_user
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.type _dl_start_user,@function
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_dl_start_user:
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; Save the user entry point address in R1.
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move.d $r10,$r1
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; Point R0 at the GOT.
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move.d $pc,$r0
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sub.d .:GOTOFF,$r0
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; Remember the highest stack address.
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move.d [$r0+__libc_stack_end:GOT16],$r13
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move.d $sp,[$r13]
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; See if we were run as a command with the executable file
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; name as an extra leading argument.
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move.d [$r0+_dl_skip_args:GOT16],$r13
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move.d [$r13],$r9
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; Get the original argument count
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move.d [$sp],$r11
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; Subtract _dl_skip_args from it.
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sub.d $r9,$r11
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; Adjust the stack pointer to skip _dl_skip_args words.
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addi $r9.d,$sp
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; Put the new argc in place as expected by the user entry.
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move.d $r11,[$sp]
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; Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)
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; env: skip scaled argc and skip stored argc and NULL at end of argv[].
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move.d $sp,$r13
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addi $r11.d,$r13
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addq 8,$r13
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; argv: skip stored argc.
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move.d $sp,$r12
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addq 4,$r12
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; main_map: at _dl_loaded.
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move.d [$r0+_dl_loaded:GOT16],$r9
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move.d [$r9],$r10
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move.d _dl_init:PLTG,$r9
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add.d $r0,$r9
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jsr $r9
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; Pass our finalizer function to the user in R10.
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move.d [$r0+_dl_fini:GOT16],$r10
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; Terminate the frame-pointer.
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moveq 0,$r8
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; Cause SEGV if user entry returns.
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move $r8,$srp
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; Jump to the user's entry point.
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jump $r1
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.size _dl_start_user, . - _dl_start_user
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.previous");
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/* Nonzero iff TYPE describes a relocation that should
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skip the executable when looking up the symbol value. */
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#define elf_machine_lookup_noexec_p(type) ((type) == R_CRIS_COPY)
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/* Nonzero iff TYPE describes relocation of a PLT entry, so
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PLT entries should not be allowed to define the value. */
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#define elf_machine_lookup_noplt_p(type) ((type) == R_CRIS_JUMP_SLOT)
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/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
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#define ELF_MACHINE_JMP_SLOT R_CRIS_JUMP_SLOT
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/* CRIS never uses Elf32_Rel relocations. */
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#define ELF_MACHINE_NO_REL 1
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/* We define an initialization functions. This is called very early in
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_dl_sysdep_start. */
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#define DL_PLATFORM_INIT dl_platform_init ()
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extern const char *_dl_platform;
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static inline void __attribute__ ((unused))
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dl_platform_init (void)
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{
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if (_dl_platform != NULL && *_dl_platform == '\0')
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/* Avoid an empty string which would disturb us. */
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_dl_platform = NULL;
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}
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static inline Elf32_Addr
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elf_machine_fixup_plt (struct link_map *map, lookup_t t,
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const Elf32_Rela *reloc,
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Elf32_Addr *reloc_addr, Elf32_Addr value)
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{
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return *reloc_addr = value;
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}
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/* Return the final value of a plt relocation. */
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static inline Elf32_Addr
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elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
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Elf32_Addr value)
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{
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return value + reloc->r_addend;
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}
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#endif /* !dl_machine_h */
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#ifdef RESOLVE
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/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
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MAP is the object containing the reloc. */
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static inline void
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elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
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const Elf32_Sym *sym, const struct r_found_version *version,
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Elf32_Addr *const reloc_addr)
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{
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#ifndef RTLD_BOOTSTRAP
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/* This is defined in rtld.c, but nowhere in the static libc.a; make the
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reference weak so static programs can still link. This declaration
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cannot be done when compiling rtld.c (i.e. #ifdef RTLD_BOOTSTRAP)
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because rtld.c contains the common defn for _dl_rtld_map, which is
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incompatible with a weak decl in the same file. */
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weak_extern (_dl_rtld_map);
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#endif
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if (ELF32_R_TYPE (reloc->r_info) == R_CRIS_RELATIVE)
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{
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#ifndef RTLD_BOOTSTRAP
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if (map != &_dl_rtld_map) /* Already done in rtld itself. */
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#endif
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*reloc_addr = map->l_addr + reloc->r_addend;
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}
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else
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{
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#ifndef RTLD_BOOTSTRAP
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const Elf32_Sym *const refsym = sym;
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#endif
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Elf32_Addr value;
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if (sym->st_shndx != SHN_UNDEF &&
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ELF32_ST_BIND (sym->st_info) == STB_LOCAL)
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value = map->l_addr;
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else
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{
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value = RESOLVE (&sym, version, ELF32_R_TYPE (reloc->r_info));
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if (sym)
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value += sym->st_value;
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}
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value += reloc->r_addend; /* Assume copy relocs have zero addend. */
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switch (ELF32_R_TYPE (reloc->r_info))
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{
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#ifndef RTLD_BOOTSTRAP
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case R_CRIS_COPY:
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if (sym == NULL)
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/* This can happen in trace mode if an object could not be
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found. */
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break;
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if (sym->st_size > refsym->st_size
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|| (_dl_verbose && sym->st_size < refsym->st_size))
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{
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extern char **_dl_argv;
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const char *strtab;
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strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
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_dl_error_printf ("\
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%s: Symbol `%s' has different size in shared object, consider re-linking\n",
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_dl_argv[0] ?: "<program name unknown>",
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strtab + refsym->st_name);
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}
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memcpy (reloc_addr, (void *) value, MIN (sym->st_size,
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refsym->st_size));
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break;
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case R_CRIS_32:
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#endif
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case R_CRIS_GLOB_DAT:
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case R_CRIS_JUMP_SLOT:
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*reloc_addr = value;
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break;
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#ifndef RTLD_BOOTSTRAP
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case R_CRIS_8:
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*(char *) reloc_addr = value;
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break;
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case R_CRIS_16:
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*(short *) reloc_addr = value;
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break;
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case R_CRIS_8_PCREL:
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*(char *) reloc_addr
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= value + reloc->r_addend - (Elf32_Addr) reloc_addr - 1;
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break;
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case R_CRIS_16_PCREL:
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*(short *) reloc_addr
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= value + reloc->r_addend - (Elf32_Addr) reloc_addr - 2;
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break;
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case R_CRIS_32_PCREL:
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*reloc_addr = value + reloc->r_addend - (Elf32_Addr) reloc_addr - 4;
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break;
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#endif
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case R_CRIS_NONE:
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break;
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#if !defined RTLD_BOOTSTRAP || defined _NDEBUG
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default:
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_dl_reloc_bad_type (map, ELFW(R_TYPE) (reloc->r_info), 0);
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break;
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#endif
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}
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}
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}
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static inline void
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elf_machine_lazy_rel (struct link_map *map,
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Elf32_Addr l_addr, const Elf32_Rela *reloc)
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{
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Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
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if (__builtin_expect (ELF32_R_TYPE (reloc->r_info), R_CRIS_JUMP_SLOT)
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== R_CRIS_JUMP_SLOT)
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*reloc_addr += l_addr;
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else
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_dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1);
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}
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#endif /* RESOLVE */
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