![Paul Gortmaker](/assets/img/avatar_default.png)
These files were only including module.h for exception table related functions. We've now separated that content out into its own file "extable.h" so now move over to that and avoid all the extra header content in module.h that we don't really need to compile these files. In the case of traps.c we can't dump the module.h include since it is also used to provide "print_modules". Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13934/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
361 lines
8.9 KiB
C
361 lines
8.9 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/extable.h>
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#include <linux/moduleloader.h>
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#include <linux/elf.h>
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#include <linux/mm.h>
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#include <linux/numa.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/spinlock.h>
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#include <linux/jump_label.h>
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#include <asm/pgtable.h> /* MODULE_START */
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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 LIST_HEAD(dbe_list);
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static DEFINE_SPINLOCK(dbe_lock);
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#ifdef MODULE_START
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void *module_alloc(unsigned long size)
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{
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return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
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GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
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__builtin_return_address(0));
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}
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#endif
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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_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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pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
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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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pr_err("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_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 = me->arch.r_mips_hi16_list;
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me->arch.r_mips_hi16_list = n;
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return 0;
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}
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static void free_relocation_chain(struct mips_hi16 *l)
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{
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struct mips_hi16 *next;
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while (l) {
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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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}
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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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struct mips_hi16 *l;
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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 (me->arch.r_mips_hi16_list != NULL) {
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l = me->arch.r_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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me->arch.r_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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free_relocation_chain(l);
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me->arch.r_mips_hi16_list = NULL;
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pr_err("module %s: dangerous R_MIPS_LO16 REL relocation\n", me->name);
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return -ENOEXEC;
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}
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static int apply_r_mips_pc_rel(struct module *me, u32 *location, Elf_Addr v,
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unsigned bits)
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{
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unsigned long mask = GENMASK(bits - 1, 0);
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unsigned long se_bits;
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long offset;
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if (v % 4) {
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pr_err("module %s: dangerous R_MIPS_PC%u REL relocation\n",
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me->name, bits);
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return -ENOEXEC;
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}
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/* retrieve & sign extend implicit addend */
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offset = *location & mask;
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offset |= (offset & BIT(bits - 1)) ? ~mask : 0;
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offset += ((long)v - (long)location) >> 2;
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/* check the sign bit onwards are identical - ie. we didn't overflow */
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se_bits = (offset & BIT(bits - 1)) ? ~0ul : 0;
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if ((offset & ~mask) != (se_bits & ~mask)) {
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pr_err("module %s: relocation overflow\n", me->name);
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return -ENOEXEC;
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}
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*location = (*location & ~mask) | (offset & mask);
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return 0;
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}
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static int apply_r_mips_pc16_rel(struct module *me, u32 *location, Elf_Addr v)
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{
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return apply_r_mips_pc_rel(me, location, v, 16);
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}
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static int apply_r_mips_pc21_rel(struct module *me, u32 *location, Elf_Addr v)
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{
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return apply_r_mips_pc_rel(me, location, v, 21);
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}
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static int apply_r_mips_pc26_rel(struct module *me, u32 *location, Elf_Addr v)
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{
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return apply_r_mips_pc_rel(me, location, v, 26);
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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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[R_MIPS_PC16] = apply_r_mips_pc16_rel,
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[R_MIPS_PC21_S2] = apply_r_mips_pc21_rel,
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[R_MIPS_PC26_S2] = apply_r_mips_pc26_rel,
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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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int (*handler)(struct module *me, u32 *location, Elf_Addr v);
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Elf_Sym *sym;
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u32 *location;
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unsigned int i, type;
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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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me->arch.r_mips_hi16_list = NULL;
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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 >= -MAX_ERRNO) {
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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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pr_warn("%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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type = ELF_MIPS_R_TYPE(rel[i]);
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if (type < ARRAY_SIZE(reloc_handlers_rel))
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handler = reloc_handlers_rel[type];
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else
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handler = NULL;
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if (!handler) {
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pr_err("%s: Unknown relocation type %u\n",
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me->name, type);
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return -EINVAL;
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}
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v = sym->st_value;
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res = handler(me, location, v);
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if (res)
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return res;
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}
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/*
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* Normally the hi16 list should be deallocated at this point. A
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* malformed binary however could contain a series of R_MIPS_HI16
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* relocations not followed by a R_MIPS_LO16 relocation. In that
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* case, free up the list and return an error.
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*/
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if (me->arch.r_mips_hi16_list) {
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free_relocation_chain(me->arch.r_mips_hi16_list);
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me->arch.r_mips_hi16_list = NULL;
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return -ENOEXEC;
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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 necessary. */
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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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/* Make jump label nops. */
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jump_label_apply_nops(me);
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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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