415 lines
13 KiB
C
415 lines
13 KiB
C
/*
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* arch/s390/kernel/module.c - Kernel module help for s390.
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*
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* S390 version
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* Copyright (C) 2002, 2003 IBM Deutschland Entwicklung GmbH,
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* IBM Corporation
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* Author(s): Arnd Bergmann (arndb@de.ibm.com)
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* Martin Schwidefsky (schwidefsky@de.ibm.com)
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*
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* based on i386 version
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* Copyright (C) 2001 Rusty Russell.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program 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
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/module.h>
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#include <linux/elf.h>
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#include <linux/vmalloc.h>
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#include <linux/fs.h>
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#include <linux/string.h>
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#include <linux/kernel.h>
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#include <linux/moduleloader.h>
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#include <linux/bug.h>
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#if 0
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#define DEBUGP printk
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#else
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#define DEBUGP(fmt , ...)
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#endif
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#ifndef CONFIG_64BIT
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#define PLT_ENTRY_SIZE 12
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#else /* CONFIG_64BIT */
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#define PLT_ENTRY_SIZE 20
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#endif /* CONFIG_64BIT */
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void *module_alloc(unsigned long size)
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{
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if (size == 0)
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return NULL;
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return vmalloc(size);
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}
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/* Free memory returned from module_alloc */
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void module_free(struct module *mod, void *module_region)
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{
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vfree(mod->arch.syminfo);
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mod->arch.syminfo = NULL;
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vfree(module_region);
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}
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static void
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check_rela(Elf_Rela *rela, struct module *me)
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{
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struct mod_arch_syminfo *info;
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info = me->arch.syminfo + ELF_R_SYM (rela->r_info);
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switch (ELF_R_TYPE (rela->r_info)) {
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case R_390_GOT12: /* 12 bit GOT offset. */
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case R_390_GOT16: /* 16 bit GOT offset. */
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case R_390_GOT20: /* 20 bit GOT offset. */
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case R_390_GOT32: /* 32 bit GOT offset. */
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case R_390_GOT64: /* 64 bit GOT offset. */
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case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */
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case R_390_GOTPLT12: /* 12 bit offset to jump slot. */
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case R_390_GOTPLT16: /* 16 bit offset to jump slot. */
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case R_390_GOTPLT20: /* 20 bit offset to jump slot. */
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case R_390_GOTPLT32: /* 32 bit offset to jump slot. */
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case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
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case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
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if (info->got_offset == -1UL) {
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info->got_offset = me->arch.got_size;
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me->arch.got_size += sizeof(void*);
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}
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break;
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case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
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case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */
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case R_390_PLT32: /* 32 bit PC relative PLT address. */
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case R_390_PLT64: /* 64 bit PC relative PLT address. */
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case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */
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case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
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case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
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if (info->plt_offset == -1UL) {
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info->plt_offset = me->arch.plt_size;
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me->arch.plt_size += PLT_ENTRY_SIZE;
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}
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break;
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case R_390_COPY:
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case R_390_GLOB_DAT:
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case R_390_JMP_SLOT:
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case R_390_RELATIVE:
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/* Only needed if we want to support loading of
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modules linked with -shared. */
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break;
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}
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}
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/*
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* Account for GOT and PLT relocations. We can't add sections for
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* got and plt but we can increase the core module size.
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*/
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int
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module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
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char *secstrings, struct module *me)
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{
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Elf_Shdr *symtab;
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Elf_Sym *symbols;
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Elf_Rela *rela;
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char *strings;
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int nrela, i, j;
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/* Find symbol table and string table. */
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symtab = NULL;
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for (i = 0; i < hdr->e_shnum; i++)
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switch (sechdrs[i].sh_type) {
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case SHT_SYMTAB:
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symtab = sechdrs + i;
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break;
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}
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if (!symtab) {
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printk(KERN_ERR "module %s: no symbol table\n", me->name);
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return -ENOEXEC;
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}
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/* Allocate one syminfo structure per symbol. */
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me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);
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me->arch.syminfo = vmalloc(me->arch.nsyms *
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sizeof(struct mod_arch_syminfo));
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if (!me->arch.syminfo)
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return -ENOMEM;
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symbols = (void *) hdr + symtab->sh_offset;
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strings = (void *) hdr + sechdrs[symtab->sh_link].sh_offset;
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for (i = 0; i < me->arch.nsyms; i++) {
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if (symbols[i].st_shndx == SHN_UNDEF &&
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strcmp(strings + symbols[i].st_name,
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"_GLOBAL_OFFSET_TABLE_") == 0)
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/* "Define" it as absolute. */
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symbols[i].st_shndx = SHN_ABS;
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me->arch.syminfo[i].got_offset = -1UL;
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me->arch.syminfo[i].plt_offset = -1UL;
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me->arch.syminfo[i].got_initialized = 0;
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me->arch.syminfo[i].plt_initialized = 0;
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}
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/* Search for got/plt relocations. */
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me->arch.got_size = me->arch.plt_size = 0;
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for (i = 0; i < hdr->e_shnum; i++) {
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if (sechdrs[i].sh_type != SHT_RELA)
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continue;
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nrela = sechdrs[i].sh_size / sizeof(Elf_Rela);
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rela = (void *) hdr + sechdrs[i].sh_offset;
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for (j = 0; j < nrela; j++)
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check_rela(rela + j, me);
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}
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/* Increase core size by size of got & plt and set start
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offsets for got and plt. */
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me->core_size = ALIGN(me->core_size, 4);
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me->arch.got_offset = me->core_size;
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me->core_size += me->arch.got_size;
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me->arch.plt_offset = me->core_size;
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me->core_size += me->arch.plt_size;
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return 0;
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}
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int
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apply_relocate(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex,
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unsigned int relsec, struct module *me)
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{
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printk(KERN_ERR "module %s: RELOCATION unsupported\n",
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me->name);
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return -ENOEXEC;
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}
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static int
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apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
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struct module *me)
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{
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struct mod_arch_syminfo *info;
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Elf_Addr loc, val;
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int r_type, r_sym;
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/* This is where to make the change */
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loc = base + rela->r_offset;
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/* This is the symbol it is referring to. Note that all
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undefined symbols have been resolved. */
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r_sym = ELF_R_SYM(rela->r_info);
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r_type = ELF_R_TYPE(rela->r_info);
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info = me->arch.syminfo + r_sym;
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val = symtab[r_sym].st_value;
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switch (r_type) {
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case R_390_8: /* Direct 8 bit. */
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case R_390_12: /* Direct 12 bit. */
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case R_390_16: /* Direct 16 bit. */
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case R_390_20: /* Direct 20 bit. */
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case R_390_32: /* Direct 32 bit. */
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case R_390_64: /* Direct 64 bit. */
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val += rela->r_addend;
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if (r_type == R_390_8)
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*(unsigned char *) loc = val;
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else if (r_type == R_390_12)
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*(unsigned short *) loc = (val & 0xfff) |
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(*(unsigned short *) loc & 0xf000);
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else if (r_type == R_390_16)
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*(unsigned short *) loc = val;
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else if (r_type == R_390_20)
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*(unsigned int *) loc =
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(*(unsigned int *) loc & 0xf00000ff) |
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(val & 0xfff) << 16 | (val & 0xff000) >> 4;
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else if (r_type == R_390_32)
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*(unsigned int *) loc = val;
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else if (r_type == R_390_64)
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*(unsigned long *) loc = val;
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break;
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case R_390_PC16: /* PC relative 16 bit. */
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case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */
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case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */
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case R_390_PC32: /* PC relative 32 bit. */
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case R_390_PC64: /* PC relative 64 bit. */
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val += rela->r_addend - loc;
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if (r_type == R_390_PC16)
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*(unsigned short *) loc = val;
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else if (r_type == R_390_PC16DBL)
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*(unsigned short *) loc = val >> 1;
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else if (r_type == R_390_PC32DBL)
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*(unsigned int *) loc = val >> 1;
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else if (r_type == R_390_PC32)
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*(unsigned int *) loc = val;
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else if (r_type == R_390_PC64)
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*(unsigned long *) loc = val;
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break;
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case R_390_GOT12: /* 12 bit GOT offset. */
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case R_390_GOT16: /* 16 bit GOT offset. */
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case R_390_GOT20: /* 20 bit GOT offset. */
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case R_390_GOT32: /* 32 bit GOT offset. */
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case R_390_GOT64: /* 64 bit GOT offset. */
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case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */
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case R_390_GOTPLT12: /* 12 bit offset to jump slot. */
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case R_390_GOTPLT20: /* 20 bit offset to jump slot. */
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case R_390_GOTPLT16: /* 16 bit offset to jump slot. */
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case R_390_GOTPLT32: /* 32 bit offset to jump slot. */
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case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
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case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
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if (info->got_initialized == 0) {
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Elf_Addr *gotent;
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gotent = me->module_core + me->arch.got_offset +
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info->got_offset;
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*gotent = val;
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info->got_initialized = 1;
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}
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val = info->got_offset + rela->r_addend;
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if (r_type == R_390_GOT12 ||
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r_type == R_390_GOTPLT12)
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*(unsigned short *) loc = (val & 0xfff) |
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(*(unsigned short *) loc & 0xf000);
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else if (r_type == R_390_GOT16 ||
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r_type == R_390_GOTPLT16)
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*(unsigned short *) loc = val;
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else if (r_type == R_390_GOT20 ||
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r_type == R_390_GOTPLT20)
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*(unsigned int *) loc =
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(*(unsigned int *) loc & 0xf00000ff) |
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(val & 0xfff) << 16 | (val & 0xff000) >> 4;
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else if (r_type == R_390_GOT32 ||
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r_type == R_390_GOTPLT32)
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*(unsigned int *) loc = val;
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else if (r_type == R_390_GOTENT ||
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r_type == R_390_GOTPLTENT)
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*(unsigned int *) loc =
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(val + (Elf_Addr) me->module_core - loc) >> 1;
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else if (r_type == R_390_GOT64 ||
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r_type == R_390_GOTPLT64)
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*(unsigned long *) loc = val;
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break;
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case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
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case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */
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case R_390_PLT32: /* 32 bit PC relative PLT address. */
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case R_390_PLT64: /* 64 bit PC relative PLT address. */
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case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */
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case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
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case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
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if (info->plt_initialized == 0) {
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unsigned int *ip;
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ip = me->module_core + me->arch.plt_offset +
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info->plt_offset;
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#ifndef CONFIG_64BIT
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ip[0] = 0x0d105810; /* basr 1,0; l 1,6(1); br 1 */
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ip[1] = 0x100607f1;
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ip[2] = val;
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#else /* CONFIG_64BIT */
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ip[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */
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ip[1] = 0x100a0004;
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ip[2] = 0x07f10000;
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ip[3] = (unsigned int) (val >> 32);
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ip[4] = (unsigned int) val;
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#endif /* CONFIG_64BIT */
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info->plt_initialized = 1;
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}
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if (r_type == R_390_PLTOFF16 ||
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r_type == R_390_PLTOFF32 ||
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r_type == R_390_PLTOFF64)
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val = me->arch.plt_offset - me->arch.got_offset +
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info->plt_offset + rela->r_addend;
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else {
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if (!((r_type == R_390_PLT16DBL &&
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val - loc + 0xffffUL < 0x1ffffeUL) ||
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(r_type == R_390_PLT32DBL &&
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val - loc + 0xffffffffULL < 0x1fffffffeULL)))
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val = (Elf_Addr) me->module_core +
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me->arch.plt_offset +
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info->plt_offset;
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val += rela->r_addend - loc;
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}
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if (r_type == R_390_PLT16DBL)
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*(unsigned short *) loc = val >> 1;
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else if (r_type == R_390_PLTOFF16)
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*(unsigned short *) loc = val;
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else if (r_type == R_390_PLT32DBL)
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*(unsigned int *) loc = val >> 1;
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else if (r_type == R_390_PLT32 ||
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r_type == R_390_PLTOFF32)
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*(unsigned int *) loc = val;
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else if (r_type == R_390_PLT64 ||
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r_type == R_390_PLTOFF64)
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*(unsigned long *) loc = val;
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break;
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case R_390_GOTOFF16: /* 16 bit offset to GOT. */
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case R_390_GOTOFF32: /* 32 bit offset to GOT. */
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case R_390_GOTOFF64: /* 64 bit offset to GOT. */
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val = val + rela->r_addend -
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((Elf_Addr) me->module_core + me->arch.got_offset);
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if (r_type == R_390_GOTOFF16)
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*(unsigned short *) loc = val;
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else if (r_type == R_390_GOTOFF32)
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*(unsigned int *) loc = val;
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else if (r_type == R_390_GOTOFF64)
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*(unsigned long *) loc = val;
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break;
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case R_390_GOTPC: /* 32 bit PC relative offset to GOT. */
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case R_390_GOTPCDBL: /* 32 bit PC rel. off. to GOT shifted by 1. */
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val = (Elf_Addr) me->module_core + me->arch.got_offset +
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rela->r_addend - loc;
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if (r_type == R_390_GOTPC)
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*(unsigned int *) loc = val;
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else if (r_type == R_390_GOTPCDBL)
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*(unsigned int *) loc = val >> 1;
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break;
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case R_390_COPY:
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case R_390_GLOB_DAT: /* Create GOT entry. */
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case R_390_JMP_SLOT: /* Create PLT entry. */
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case R_390_RELATIVE: /* Adjust by program base. */
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/* Only needed if we want to support loading of
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modules linked with -shared. */
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break;
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default:
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printk(KERN_ERR "module %s: Unknown relocation: %u\n",
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me->name, r_type);
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return -ENOEXEC;
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}
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return 0;
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}
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int
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apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
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unsigned int symindex, unsigned int relsec,
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struct module *me)
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{
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Elf_Addr base;
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Elf_Sym *symtab;
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Elf_Rela *rela;
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unsigned long i, n;
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int rc;
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DEBUGP("Applying relocate section %u to %u\n",
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relsec, sechdrs[relsec].sh_info);
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base = sechdrs[sechdrs[relsec].sh_info].sh_addr;
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symtab = (Elf_Sym *) sechdrs[symindex].sh_addr;
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rela = (Elf_Rela *) sechdrs[relsec].sh_addr;
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n = sechdrs[relsec].sh_size / sizeof(Elf_Rela);
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for (i = 0; i < n; i++, rela++) {
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rc = apply_rela(rela, base, symtab, me);
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if (rc)
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return rc;
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}
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return 0;
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}
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int module_finalize(const Elf_Ehdr *hdr,
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const Elf_Shdr *sechdrs,
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struct module *me)
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{
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vfree(me->arch.syminfo);
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me->arch.syminfo = NULL;
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return module_bug_finalize(hdr, sechdrs, me);
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}
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void module_arch_cleanup(struct module *mod)
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{
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module_bug_cleanup(mod);
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}
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