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b937534868
Resolves: #15465 The program name may be unavailable if the user application tampers with argc and argv[]. Some parts of the dynamic linker caters for this while others don't, so this patch consolidates the check and fallback into a single macro and updates all users.
299 lines
8.5 KiB
C
299 lines
8.5 KiB
C
/* Copyright (C) 1995-2013 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 Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 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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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef dl_machine_h
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#define dl_machine_h
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#define ELF_MACHINE_NAME "microblaze"
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#include <sys/param.h>
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#include <tls.h>
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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_MICROBLAZE);
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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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/* This produces a GOTOFF reloc that resolves to zero at link time, so in
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fact just loads from the GOT register directly. By doing it without
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an asm we can let the compiler choose any register. */
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Elf32_Addr got_entry_0;
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__asm__ __volatile__(
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"lwi %0,r20,0"
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:"=r"(got_entry_0)
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);
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return got_entry_0;
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}
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/* Return the run-time load address of the shared object. */
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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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/* Compute the difference between the runtime address of _DYNAMIC as seen
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by a GOTOFF reference, and the link-time address found in the special
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unrelocated first GOT entry. */
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Elf32_Addr dyn;
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__asm__ __volatile__ (
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"addik %0,r20,_DYNAMIC@GOTOFF"
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: "=r"(dyn)
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);
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return dyn - elf_machine_dynamic ();
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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 __attribute__ ((always_inline))
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elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
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{
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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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return lazy;
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}
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/* The PLT uses Elf32_Rela relocs. */
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#define elf_machine_relplt elf_machine_rela
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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 0x80000000UL
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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\n\
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.globl _start\n\
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.type _start,@function\n\
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_start:\n\
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addk r5,r0,r1\n\
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addk r3,r0,r0\n\
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1:\n\
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addik r5,r5,4\n\
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lw r4,r5,r0\n\
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bneid r4,1b\n\
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addik r3,r3,1\n\
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addik r3,r3,-1\n\
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addk r5,r0,r1\n\
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sw r3,r5,r0\n\
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addik r1,r1,-24\n\
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sw r15,r1,r0\n\
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brlid r15,_dl_start\n\
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nop\n\
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/* FALLTHRU. */\n\
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\n\
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.globl _dl_start_user\n\
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.type _dl_start_user,@function\n\
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_dl_start_user:\n\
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mfs r20,rpc\n\
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addik r20,r20,_GLOBAL_OFFSET_TABLE_+8\n\
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lwi r4,r20,_dl_skip_args@GOTOFF\n\
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lwi r5,r1,24\n\
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rsubk r5,r4,r5\n\
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addk r4,r4,r4\n\
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addk r4,r4,r4\n\
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addk r1,r1,r4\n\
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swi r5,r1,24\n\
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swi r3,r1,20\n\
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addk r6,r5,r0\n\
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addk r5,r5,r5\n\
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addk r5,r5,r5\n\
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addik r7,r1,28\n\
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addk r8,r7,r5\n\
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addik r8,r8,4\n\
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lwi r5,r20,_rtld_local@GOTOFF\n\
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brlid r15,_dl_init_internal\n\
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nop\n\
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lwi r5,r1,24\n\
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lwi r3,r1,20\n\
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addk r4,r5,r5\n\
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addk r4,r4,r4\n\
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addik r6,r1,28\n\
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addk r7,r6,r4\n\
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addik r7,r7,4\n\
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addik r15,r20,_dl_fini@GOTOFF\n\
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addik r15,r15,-8\n\
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brad r3\n\
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addik r1,r1,24\n\
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nop\n\
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.size _dl_start_user, . - _dl_start_user\n\
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.previous");
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/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or
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TLS variable, so undefined references should not be allowed to
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define the value.
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ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
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of the main executable's symbols, as for a COPY reloc. */
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#ifndef RTLD_BOOTSTRAP
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# define elf_machine_type_class(type) \
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(((type) == R_MICROBLAZE_JUMP_SLOT || \
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(type) == R_MICROBLAZE_TLSDTPREL32 || \
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(type) == R_MICROBLAZE_TLSDTPMOD32 || \
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(type) == R_MICROBLAZE_TLSTPREL32) \
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* ELF_RTYPE_CLASS_PLT \
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| ((type) == R_MICROBLAZE_COPY) * ELF_RTYPE_CLASS_COPY)
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#else
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# define elf_machine_type_class(type) \
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(((type) == R_MICROBLAZE_JUMP_SLOT) * ELF_RTYPE_CLASS_PLT \
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| ((type) == R_MICROBLAZE_COPY) * ELF_RTYPE_CLASS_COPY)
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#endif
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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_MICROBLAZE_JUMP_SLOT
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/* The microblaze never uses Elf32_Rel relocations. */
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#define ELF_MACHINE_NO_REL 1
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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. Ignore the addend. */
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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;
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}
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#endif /* !dl_machine_h. */
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/* Names of the architecture-specific auditing callback functions. */
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#define ARCH_LA_PLTENTER microblaze_gnu_pltenter
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#define ARCH_LA_PLTEXIT microblaze_gnu_pltexit
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#ifdef RESOLVE_MAP
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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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/* Macro to put 32-bit relocation value into 2 words. */
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#define PUT_REL_64(rel_addr,val) \
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do { \
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((unsigned short *)(rel_addr))[1] = (val) >> 16; \
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((unsigned short *)(rel_addr))[3] = (val) & 0xffff; \
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} while (0)
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auto inline void __attribute__ ((always_inline))
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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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void *const reloc_addr_arg, int skip_ifunc)
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{
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Elf32_Addr *const reloc_addr = reloc_addr_arg;
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const int r_type = ELF32_R_TYPE (reloc->r_info);
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if (__builtin_expect (r_type == R_MICROBLAZE_64_PCREL, 0))
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PUT_REL_64 (reloc_addr, map->l_addr + reloc->r_addend);
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else if (r_type == R_MICROBLAZE_REL)
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*reloc_addr = map->l_addr + reloc->r_addend;
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else
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{
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const Elf32_Sym *const refsym = sym;
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struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
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Elf32_Addr value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value;
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value += reloc->r_addend;
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if (r_type == R_MICROBLAZE_GLOB_DAT ||
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r_type == R_MICROBLAZE_JUMP_SLOT ||
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r_type == R_MICROBLAZE_32)
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{
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*reloc_addr = value;
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}
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else if (r_type == R_MICROBLAZE_COPY)
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{
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if (sym != NULL && (sym->st_size > refsym->st_size
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|| (sym->st_size < refsym->st_size && GLRO (dl_verbose))) )
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{
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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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RTLD_PROGNAME, strtab + refsym->st_name);
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}
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memcpy (reloc_addr_arg, (void *) value,
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MIN (sym->st_size, refsym->st_size));
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}
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else if (r_type == R_MICROBLAZE_NONE)
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{
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}
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#if !defined RTLD_BOOTSTRAP
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else if (r_type == R_MICROBLAZE_TLSDTPMOD32)
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{
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if (sym_map != NULL)
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*reloc_addr = sym_map->l_tls_modid;
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}
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else if (r_type == R_MICROBLAZE_TLSDTPREL32)
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{
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if (sym != NULL)
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*reloc_addr = sym->st_value + reloc->r_addend;
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}
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else if (r_type == R_MICROBLAZE_TLSTPREL32)
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{
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if (sym != NULL)
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{
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CHECK_STATIC_TLS (map, sym_map);
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*reloc_addr = sym->st_value + sym_map->l_tls_offset + reloc->r_addend;
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}
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}
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#endif
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else
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{
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_dl_reloc_bad_type (map, r_type, 0);
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}
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}
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}
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auto inline void
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elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc,
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void *const reloc_addr_arg)
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{
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Elf32_Addr *const reloc_addr = reloc_addr_arg;
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PUT_REL_64 (reloc_addr, l_addr + reloc->r_addend);
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}
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auto 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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int skip_ifunc)
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{
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Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
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if (ELF32_R_TYPE (reloc->r_info) == R_MICROBLAZE_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_MAP. */
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