476 lines
15 KiB
C
476 lines
15 KiB
C
/* Machine-dependent ELF dynamic relocation inline functions. SPARC version.
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Copyright (C) 1996-2022 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
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License as published by the Free Software Foundation; either
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version 2.1 of the 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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<https://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 "sparc"
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#include <string.h>
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#include <sys/param.h>
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#include <ldsodefs.h>
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#include <sysdep.h>
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#include <tls.h>
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#include <dl-plt.h>
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#include <elf/dl-hwcaps.h>
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#include <dl-static-tls.h>
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#include <dl-machine-rel.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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if (ehdr->e_machine == EM_SPARC)
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return 1;
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else if (ehdr->e_machine == EM_SPARC32PLUS)
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{
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#if HAVE_TUNABLES || defined SHARED
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uint64_t hwcap_mask = GET_HWCAP_MASK();
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return GLRO(dl_hwcap) & hwcap_mask & HWCAP_SPARC_V9;
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#else
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return GLRO(dl_hwcap) & HWCAP_SPARC_V9;
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#endif
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}
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else
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return 0;
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}
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/* We have to do this because elf_machine_{dynamic,load_address} can be
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invoked from functions that have no GOT references, and thus the compiler
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has no obligation to load the PIC register. */
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#define LOAD_PIC_REG(PIC_REG) \
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do { register Elf32_Addr pc __asm("o7"); \
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__asm("sethi %%hi(_GLOBAL_OFFSET_TABLE_-4), %1\n\t" \
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"call 1f\n\t" \
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"add %1, %%lo(_GLOBAL_OFFSET_TABLE_+4), %1\n" \
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"1:\tadd %1, %0, %1" \
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: "=r" (pc), "=r" (PIC_REG)); \
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} while (0)
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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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register Elf32_Addr *got asm ("%l7");
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LOAD_PIC_REG (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. */
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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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register Elf32_Addr *pc __asm ("%o7"), *got __asm ("%l7");
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__asm ("sethi %%hi(_GLOBAL_OFFSET_TABLE_-4), %1\n\t"
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"call 1f\n\t"
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" add %1, %%lo(_GLOBAL_OFFSET_TABLE_+4), %1\n\t"
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"call _DYNAMIC\n\t"
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"call _GLOBAL_OFFSET_TABLE_\n"
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"1:\tadd %1, %0, %1\n\t" : "=r" (pc), "=r" (got));
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/* got is now l_addr + _GLOBAL_OFFSET_TABLE_
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*got is _DYNAMIC
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pc[2]*4 is l_addr + _DYNAMIC - (long)pc - 8
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pc[3]*4 is l_addr + _GLOBAL_OFFSET_TABLE_ - (long)pc - 12 */
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return (Elf32_Addr) got - *got + (pc[2] - pc[3]) * 4 - 4;
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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, struct r_scope_elem *scope[],
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int lazy, int profile)
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{
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Elf32_Addr *plt;
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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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Elf32_Addr rfunc;
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/* The entries for functions in the PLT have not yet been filled in.
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Their initial contents will arrange when called to set the high 22
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bits of %g1 with an offset into the .rela.plt section and jump to
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the beginning of the PLT. */
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plt = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
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if (__builtin_expect(profile, 0))
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{
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rfunc = (Elf32_Addr) &_dl_runtime_profile;
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if (GLRO(dl_profile) != NULL
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&& _dl_name_match_p (GLRO(dl_profile), l))
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GL(dl_profile_map) = l;
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}
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else
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{
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rfunc = (Elf32_Addr) &_dl_runtime_resolve;
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}
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/* The beginning of the PLT does:
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sethi %hi(_dl_runtime_{resolve,profile}), %g2
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pltpc: jmpl %g2 + %lo(_dl_runtime_{resolve,profile}), %g2
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nop
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.word MAP
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The PC value (pltpc) saved in %g2 by the jmpl points near the
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location where we store the link_map pointer for this object. */
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plt[0] = 0x05000000 | ((rfunc >> 10) & 0x003fffff);
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plt[1] = 0x85c0a000 | (rfunc & 0x3ff);
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plt[2] = OPCODE_NOP; /* Fill call delay slot. */
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plt[3] = (Elf32_Addr) l;
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}
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return lazy;
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}
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/* ELF_RTYPE_CLASS_PLT 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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ELF_RTYPE_CLASS_COPY 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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#define elf_machine_type_class(type) \
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((((type) == R_SPARC_JMP_SLOT \
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|| ((type) >= R_SPARC_TLS_GD_HI22 && (type) <= R_SPARC_TLS_TPOFF64)) \
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* ELF_RTYPE_CLASS_PLT) \
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| (((type) == R_SPARC_COPY) * ELF_RTYPE_CLASS_COPY))
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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_SPARC_JMP_SLOT
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/* Undo the sub %sp, 6*4, %sp; add %sp, 22*4, %o0 below to get at the
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value we want in __libc_stack_end. */
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#define DL_STACK_END(cookie) \
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((void *) (((long) (cookie)) - (22 - 6) * 4))
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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_GOT_ADDRESS(pic_reg, reg, symbol) \
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"sethi %gdop_hix22(" #symbol "), " #reg "\n\t" \
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"xor " #reg ", %gdop_lox10(" #symbol "), " #reg "\n\t" \
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"ld [" #pic_reg " + " #reg "], " #reg ", %gdop(" #symbol ")"
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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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.align 32\n\
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_start:\n\
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/* Allocate space for functions to drop their arguments. */\n\
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sub %sp, 6*4, %sp\n\
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/* Pass pointer to argument block to _dl_start. */\n\
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call _dl_start\n\
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add %sp, 22*4, %o0\n\
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/* FALTHRU */\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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/* Load the PIC register. */\n\
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1: call 2f\n\
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sethi %hi(_GLOBAL_OFFSET_TABLE_-(1b-.)), %l7\n\
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2: or %l7, %lo(_GLOBAL_OFFSET_TABLE_-(1b-.)), %l7\n\
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add %l7, %o7, %l7\n\
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/* Save the user entry point address in %l0 */\n\
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mov %o0, %l0\n\
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ld [%sp+22*4], %i5 /* load argc */\n\
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/* %o0 = _dl_loaded, %o1 = argc, %o2 = argv, %o3 = envp. */\n\
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" RTLD_GOT_ADDRESS(%l7, %o0, _rtld_local) "\n\
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add %sp, 23*4, %o2\n\
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sll %i5, 2, %o3\n\
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add %o3, 4, %o3\n\
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mov %i5, %o1\n\
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add %o2, %o3, %o3\n\
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call _dl_init\n\
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ld [%o0], %o0\n\
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/* Pass our finalizer function to the user in %g1. */\n\
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" RTLD_GOT_ADDRESS(%l7, %g1, _dl_fini) "\n\
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/* Jump to the user's entry point and deallocate the extra stack we got. */\n\
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jmp %l0\n\
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add %sp, 6*4, %sp\n\
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.size _dl_start_user, . - _dl_start_user\n\
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.previous");
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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 ElfW(Sym) *refsym, const ElfW(Sym) *sym,
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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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#ifdef __sparc_v9__
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/* Sparc v9 can assume flush is always present. */
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const int do_flush = 1;
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#else
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/* Note that we don't mask the hwcap here, as the flush is essential to
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functionality on those cpu's that implement it. */
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const int do_flush = GLRO(dl_hwcap) & HWCAP_SPARC_FLUSH;
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#endif
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return sparc_fixup_plt (reloc, reloc_addr, value, 1, do_flush);
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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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#define ARCH_LA_PLTENTER sparc32_gnu_pltenter
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#define ARCH_LA_PLTEXIT sparc32_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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static inline void
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__attribute__ ((always_inline))
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elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[],
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const Elf32_Rela *reloc, const Elf32_Sym *sym,
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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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#if !defined 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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const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
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struct link_map *sym_map = NULL;
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if (__glibc_unlikely (r_type == R_SPARC_NONE))
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return;
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if (__glibc_unlikely (r_type == R_SPARC_SIZE32))
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{
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*reloc_addr = sym->st_size + reloc->r_addend;
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return;
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}
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#if !defined RTLD_BOOTSTRAP
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if (__glibc_unlikely (r_type == R_SPARC_RELATIVE))
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{
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*reloc_addr += map->l_addr + reloc->r_addend;
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return;
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}
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#endif
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if (__builtin_expect (ELF32_ST_BIND (sym->st_info) == STB_LOCAL, 0)
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&& sym->st_shndx != SHN_UNDEF)
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{
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sym_map = map;
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value = map->l_addr;
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}
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else
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{
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sym_map = RESOLVE_MAP (map, scope, &sym, version, r_type);
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value = SYMBOL_ADDRESS (sym_map, sym, true);
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}
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value += reloc->r_addend; /* Assume copy relocs have zero addend. */
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if (sym != NULL
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&& __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC, 0)
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&& __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
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&& __builtin_expect (!skip_ifunc, 1))
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{
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value = ((Elf32_Addr (*) (int)) value) (GLRO(dl_hwcap));
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}
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switch (r_type)
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{
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#if !defined RTLD_BOOTSTRAP
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case R_SPARC_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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|| (GLRO(dl_verbose) && sym->st_size < refsym->st_size))
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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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break;
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#endif
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case R_SPARC_GLOB_DAT:
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case R_SPARC_32:
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*reloc_addr = value;
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break;
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case R_SPARC_IRELATIVE:
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if (__glibc_likely (!skip_ifunc))
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value = ((Elf32_Addr (*) (int)) value) (GLRO(dl_hwcap));
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*reloc_addr = value;
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break;
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case R_SPARC_JMP_IREL:
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if (__glibc_likely (!skip_ifunc))
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value = ((Elf32_Addr (*) (int)) value) (GLRO(dl_hwcap));
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/* Fall thru */
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case R_SPARC_JMP_SLOT:
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{
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#if !defined RTLD_BOOTSTRAP && !defined __sparc_v9__
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/* Note that we don't mask the hwcap here, as the flush is
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essential to functionality on those cpu's that implement
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it. For sparcv9 we can assume flush is present. */
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const int do_flush = GLRO(dl_hwcap) & HWCAP_SPARC_FLUSH;
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#else
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/* Unfortunately, this is necessary, so that we can ensure
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ld.so will not execute corrupt PLT entry instructions. */
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const int do_flush = 1;
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#endif
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/* At this point we don't need to bother with thread safety,
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so we can optimize the first instruction of .plt out. */
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sparc_fixup_plt (reloc, reloc_addr, value, 0, do_flush);
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}
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break;
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case R_SPARC_TLS_DTPMOD32:
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/* Get the information from the link map returned by the
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resolv function. */
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if (sym_map != NULL)
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*reloc_addr = sym_map->l_tls_modid;
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break;
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case R_SPARC_TLS_DTPOFF32:
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/* During relocation all TLS symbols are defined and used.
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Therefore the offset is already correct. */
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*reloc_addr = (sym == NULL ? 0 : sym->st_value) + reloc->r_addend;
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break;
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case R_SPARC_TLS_TPOFF32:
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/* The offset is negative, forward from the thread pointer. */
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/* We know the offset of object the symbol is contained in.
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It is a negative value which will be added to the
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thread pointer. */
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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
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+ reloc->r_addend;
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}
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break;
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#ifndef RTLD_BOOTSTRAP
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case R_SPARC_TLS_LE_HIX22:
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case R_SPARC_TLS_LE_LOX10:
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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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value = sym->st_value - sym_map->l_tls_offset
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+ reloc->r_addend;
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if (r_type == R_SPARC_TLS_LE_HIX22)
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*reloc_addr = (*reloc_addr & 0xffc00000) | ((~value) >> 10);
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else
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*reloc_addr = (*reloc_addr & 0xffffe000) | (value & 0x3ff)
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| 0x1c00;
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}
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break;
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#endif
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#ifndef RTLD_BOOTSTRAP
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case R_SPARC_8:
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*(char *) reloc_addr = value;
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break;
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case R_SPARC_16:
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*(short *) reloc_addr = value;
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break;
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case R_SPARC_DISP8:
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*(char *) reloc_addr = (value - (Elf32_Addr) reloc_addr);
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break;
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case R_SPARC_DISP16:
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*(short *) reloc_addr = (value - (Elf32_Addr) reloc_addr);
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break;
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case R_SPARC_DISP32:
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*reloc_addr = (value - (Elf32_Addr) reloc_addr);
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break;
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case R_SPARC_LO10:
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*reloc_addr = (*reloc_addr & ~0x3ff) | (value & 0x3ff);
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break;
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case R_SPARC_WDISP30:
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*reloc_addr = ((*reloc_addr & 0xc0000000)
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| ((value - (unsigned int) reloc_addr) >> 2));
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break;
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case R_SPARC_HI22:
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*reloc_addr = (*reloc_addr & 0xffc00000) | (value >> 10);
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break;
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case R_SPARC_UA16:
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((unsigned char *) reloc_addr_arg) [0] = value >> 8;
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((unsigned char *) reloc_addr_arg) [1] = value;
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break;
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case R_SPARC_UA32:
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((unsigned char *) reloc_addr_arg) [0] = value >> 24;
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((unsigned char *) reloc_addr_arg) [1] = value >> 16;
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((unsigned char *) reloc_addr_arg) [2] = value >> 8;
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((unsigned char *) reloc_addr_arg) [3] = value;
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break;
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#endif
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#if !defined RTLD_BOOTSTRAP || defined _NDEBUG
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default:
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_dl_reloc_bad_type (map, r_type, 0);
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break;
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#endif
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}
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}
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static inline void
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__attribute__ ((always_inline))
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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;
|
|
*reloc_addr += l_addr + reloc->r_addend;
|
|
}
|
|
|
|
static inline void
|
|
__attribute__ ((always_inline))
|
|
elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
|
|
Elf32_Addr l_addr, const Elf32_Rela *reloc,
|
|
int skip_ifunc)
|
|
{
|
|
Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
|
|
const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
|
|
|
|
if (__glibc_likely (r_type == R_SPARC_JMP_SLOT))
|
|
;
|
|
else if (r_type == R_SPARC_JMP_IREL)
|
|
{
|
|
Elf32_Addr value = map->l_addr + reloc->r_addend;
|
|
if (__glibc_likely (!skip_ifunc))
|
|
value = ((Elf32_Addr (*) (int)) value) (GLRO(dl_hwcap));
|
|
sparc_fixup_plt (reloc, reloc_addr, value, 1, 1);
|
|
}
|
|
else if (r_type == R_SPARC_NONE)
|
|
;
|
|
else
|
|
_dl_reloc_bad_type (map, r_type, 1);
|
|
}
|
|
|
|
#endif /* RESOLVE_MAP */
|