396 lines
9.6 KiB
C
396 lines
9.6 KiB
C
/*
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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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* Copyright (C) 2001 Rusty Russell.
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* Copyright (C) 2003, 2004 Ralf Baechle (ralf@linux-mips.org)
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* Copyright (C) 2005 Thiemo Seufer
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*/
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#undef DEBUG
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#include <linux/moduleloader.h>
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#include <linux/elf.h>
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#include <linux/vmalloc.h>
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#include <linux/slab.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/module.h>
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#include <linux/spinlock.h>
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struct mips_hi16 {
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struct mips_hi16 *next;
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Elf_Addr *addr;
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Elf_Addr value;
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};
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static struct mips_hi16 *mips_hi16_list;
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static LIST_HEAD(dbe_list);
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static DEFINE_SPINLOCK(dbe_lock);
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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(module_region);
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/* FIXME: If module_region == mod->init_region, trim exception
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table entries. */
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}
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int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
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char *secstrings, struct module *mod)
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{
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return 0;
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}
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static int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
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{
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return 0;
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}
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static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v)
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{
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*location += v;
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return 0;
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}
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static int apply_r_mips_32_rela(struct module *me, u32 *location, Elf_Addr v)
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{
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*location = v;
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return 0;
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}
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static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
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{
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if (v % 4) {
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printk(KERN_ERR "module %s: dangerous relocation\n", me->name);
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return -ENOEXEC;
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}
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if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
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printk(KERN_ERR
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"module %s: relocation overflow\n",
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me->name);
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return -ENOEXEC;
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}
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*location = (*location & ~0x03ffffff) |
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((*location + (v >> 2)) & 0x03ffffff);
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return 0;
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}
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static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
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{
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if (v % 4) {
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printk(KERN_ERR "module %s: dangerous relocation\n", me->name);
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return -ENOEXEC;
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}
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if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
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printk(KERN_ERR
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"module %s: relocation overflow\n",
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me->name);
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return -ENOEXEC;
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}
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*location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
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return 0;
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}
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static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
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{
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struct mips_hi16 *n;
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/*
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* We cannot relocate this one now because we don't know the value of
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* the carry we need to add. Save the information, and let LO16 do the
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* actual relocation.
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*/
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n = kmalloc(sizeof *n, GFP_KERNEL);
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if (!n)
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return -ENOMEM;
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n->addr = (Elf_Addr *)location;
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n->value = v;
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n->next = mips_hi16_list;
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mips_hi16_list = n;
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return 0;
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}
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static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v)
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{
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*location = (*location & 0xffff0000) |
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((((long long) v + 0x8000LL) >> 16) & 0xffff);
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return 0;
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}
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static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
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{
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unsigned long insnlo = *location;
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Elf_Addr val, vallo;
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/* Sign extend the addend we extract from the lo insn. */
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vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
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if (mips_hi16_list != NULL) {
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struct mips_hi16 *l;
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l = mips_hi16_list;
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while (l != NULL) {
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struct mips_hi16 *next;
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unsigned long insn;
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/*
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* The value for the HI16 had best be the same.
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*/
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if (v != l->value)
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goto out_danger;
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/*
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* Do the HI16 relocation. Note that we actually don't
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* need to know anything about the LO16 itself, except
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* where to find the low 16 bits of the addend needed
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* by the LO16.
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*/
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insn = *l->addr;
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val = ((insn & 0xffff) << 16) + vallo;
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val += v;
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/*
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* Account for the sign extension that will happen in
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* the low bits.
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*/
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val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
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insn = (insn & ~0xffff) | val;
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*l->addr = insn;
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next = l->next;
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kfree(l);
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l = next;
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}
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mips_hi16_list = NULL;
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}
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/*
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* Ok, we're done with the HI16 relocs. Now deal with the LO16.
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*/
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val = v + vallo;
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insnlo = (insnlo & ~0xffff) | (val & 0xffff);
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*location = insnlo;
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return 0;
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out_danger:
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printk(KERN_ERR "module %s: dangerous " "relocation\n", me->name);
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return -ENOEXEC;
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}
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static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v)
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{
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*location = (*location & 0xffff0000) | (v & 0xffff);
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return 0;
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}
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static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v)
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{
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*(Elf_Addr *)location = v;
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return 0;
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}
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static int apply_r_mips_higher_rela(struct module *me, u32 *location,
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Elf_Addr v)
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{
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*location = (*location & 0xffff0000) |
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((((long long) v + 0x80008000LL) >> 32) & 0xffff);
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return 0;
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}
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static int apply_r_mips_highest_rela(struct module *me, u32 *location,
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Elf_Addr v)
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{
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*location = (*location & 0xffff0000) |
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((((long long) v + 0x800080008000LL) >> 48) & 0xffff);
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return 0;
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}
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static int (*reloc_handlers_rel[]) (struct module *me, u32 *location,
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Elf_Addr v) = {
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[R_MIPS_NONE] = apply_r_mips_none,
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[R_MIPS_32] = apply_r_mips_32_rel,
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[R_MIPS_26] = apply_r_mips_26_rel,
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[R_MIPS_HI16] = apply_r_mips_hi16_rel,
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[R_MIPS_LO16] = apply_r_mips_lo16_rel
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};
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static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
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Elf_Addr v) = {
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[R_MIPS_NONE] = apply_r_mips_none,
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[R_MIPS_32] = apply_r_mips_32_rela,
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[R_MIPS_26] = apply_r_mips_26_rela,
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[R_MIPS_HI16] = apply_r_mips_hi16_rela,
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[R_MIPS_LO16] = apply_r_mips_lo16_rela,
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[R_MIPS_64] = apply_r_mips_64_rela,
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[R_MIPS_HIGHER] = apply_r_mips_higher_rela,
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[R_MIPS_HIGHEST] = apply_r_mips_highest_rela
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};
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int apply_relocate(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_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr;
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Elf_Sym *sym;
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u32 *location;
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unsigned int i;
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Elf_Addr v;
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int res;
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pr_debug("Applying relocate section %u to %u\n", relsec,
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sechdrs[relsec].sh_info);
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for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
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/* This is where to make the change */
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location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
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+ rel[i].r_offset;
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/* This is the symbol it is referring to */
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sym = (Elf_Sym *)sechdrs[symindex].sh_addr
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+ ELF_MIPS_R_SYM(rel[i]);
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if (!sym->st_value) {
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/* Ignore unresolved weak symbol */
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if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
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continue;
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printk(KERN_WARNING "%s: Unknown symbol %s\n",
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me->name, strtab + sym->st_name);
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return -ENOENT;
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}
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v = sym->st_value;
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res = reloc_handlers_rel[ELF_MIPS_R_TYPE(rel[i])](me, location, v);
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if (res)
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return res;
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}
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return 0;
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}
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int 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_Mips_Rela *rel = (void *) sechdrs[relsec].sh_addr;
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Elf_Sym *sym;
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u32 *location;
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unsigned int i;
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Elf_Addr v;
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int res;
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pr_debug("Applying relocate section %u to %u\n", relsec,
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sechdrs[relsec].sh_info);
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for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
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/* This is where to make the change */
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location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
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+ rel[i].r_offset;
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/* This is the symbol it is referring to */
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sym = (Elf_Sym *)sechdrs[symindex].sh_addr
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+ ELF_MIPS_R_SYM(rel[i]);
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if (!sym->st_value) {
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/* Ignore unresolved weak symbol */
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if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
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continue;
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printk(KERN_WARNING "%s: Unknown symbol %s\n",
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me->name, strtab + sym->st_name);
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return -ENOENT;
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}
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v = sym->st_value + rel[i].r_addend;
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res = reloc_handlers_rela[ELF_MIPS_R_TYPE(rel[i])](me, location, v);
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if (res)
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return res;
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}
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return 0;
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}
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/* Given an address, look for it in the module exception tables. */
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const struct exception_table_entry *search_module_dbetables(unsigned long addr)
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{
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unsigned long flags;
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const struct exception_table_entry *e = NULL;
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struct mod_arch_specific *dbe;
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spin_lock_irqsave(&dbe_lock, flags);
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list_for_each_entry(dbe, &dbe_list, dbe_list) {
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e = search_extable(dbe->dbe_start, dbe->dbe_end - 1, addr);
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if (e)
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break;
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}
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spin_unlock_irqrestore(&dbe_lock, flags);
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/* Now, if we found one, we are running inside it now, hence
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we cannot unload the module, hence no refcnt needed. */
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return e;
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}
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/* Put in dbe list if neccessary. */
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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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const Elf_Shdr *s;
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char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
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INIT_LIST_HEAD(&me->arch.dbe_list);
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for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
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if (strcmp("__dbe_table", secstrings + s->sh_name) != 0)
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continue;
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me->arch.dbe_start = (void *)s->sh_addr;
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me->arch.dbe_end = (void *)s->sh_addr + s->sh_size;
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spin_lock_irq(&dbe_lock);
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list_add(&me->arch.dbe_list, &dbe_list);
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spin_unlock_irq(&dbe_lock);
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}
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return 0;
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}
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void module_arch_cleanup(struct module *mod)
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{
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spin_lock_irq(&dbe_lock);
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list_del(&mod->arch.dbe_list);
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spin_unlock_irq(&dbe_lock);
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}
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