137 lines
4.2 KiB
C
137 lines
4.2 KiB
C
/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2009 Free Software Foundation, Inc.
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*
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* GRUB 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 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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#define MAX_OVERHEAD ((RELOCATOR_SIZEOF (forward) + RELOCATOR_ALIGN) \
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+ (RELOCATOR_SIZEOF (backward) + RELOCATOR_ALIGN) \
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+ (RELOCATOR_SIZEOF (forward) + RELOCATOR_ALIGN) \
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+ (RELOCATOR_SIZEOF (backward) + RELOCATOR_ALIGN))
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#define PRE_REGION_SIZE (RELOCATOR_SIZEOF (backward) + RELOCATOR_ALIGN)
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void *
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PREFIX (alloc) (grub_size_t size)
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{
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char *playground;
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playground = grub_malloc (size + MAX_OVERHEAD);
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if (!playground)
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return 0;
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*(grub_size_t *) playground = size;
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return playground + PRE_REGION_SIZE;
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}
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void *
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PREFIX (realloc) (void *relocator, grub_size_t size)
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{
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char *playground;
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if (!relocator)
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return PREFIX (alloc) (size);
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playground = (char *) relocator - PRE_REGION_SIZE;
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playground = grub_realloc (playground, size + MAX_OVERHEAD);
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if (!playground)
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return 0;
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*(grub_size_t *) playground = size;
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return playground + PRE_REGION_SIZE;
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}
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void
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PREFIX(free) (void *relocator)
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{
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if (relocator)
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grub_free ((char *) relocator - PRE_REGION_SIZE);
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}
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grub_err_t
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PREFIX (boot) (void *relocator, grub_uint32_t dest,
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struct grub_relocator32_state state)
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{
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grub_size_t size;
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char *playground;
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playground = (char *) relocator - PRE_REGION_SIZE;
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size = *(grub_size_t *) playground;
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grub_dprintf ("relocator",
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"Relocator: source: %p, destination: 0x%x, size: 0x%lx\n",
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relocator, (unsigned) dest, (unsigned long) size);
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/* Very unlikely condition: Relocator may risk overwrite itself.
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Just move it a bit up. */
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if ((grub_uint8_t *) UINT_TO_PTR (dest) - (grub_uint8_t *) relocator
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< (signed) (RELOCATOR_SIZEOF (backward) + RELOCATOR_ALIGN)
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&& (grub_uint8_t *) UINT_TO_PTR (dest) - (grub_uint8_t *) relocator
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> - (signed) (RELOCATOR_SIZEOF (forward) + RELOCATOR_ALIGN))
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{
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void *relocator_new = ((grub_uint8_t *) relocator)
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+ (RELOCATOR_SIZEOF (forward) + RELOCATOR_ALIGN)
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+ (RELOCATOR_SIZEOF (backward) + RELOCATOR_ALIGN);
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grub_dprintf ("relocator", "Overwrite condition detected moving "
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"relocator from %p to %p\n", relocator, relocator_new);
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grub_memmove (relocator_new, relocator,
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(RELOCATOR_SIZEOF (forward) + RELOCATOR_ALIGN)
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+ size
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+ (RELOCATOR_SIZEOF (backward) + RELOCATOR_ALIGN));
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relocator = relocator_new;
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}
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if (UINT_TO_PTR (dest) >= relocator)
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{
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int overhead;
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overhead = dest -
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ALIGN_UP (dest - RELOCATOR_SIZEOF (backward) - RELOCATOR_ALIGN,
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RELOCATOR_ALIGN);
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grub_dprintf ("relocator",
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"Backward relocator: code %p, source: %p, "
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"destination: 0x%x, size: 0x%lx\n",
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(char *) relocator - overhead,
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(char *) relocator - overhead,
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(unsigned) dest - overhead,
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(unsigned long) size + overhead);
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write_call_relocator_bw ((char *) relocator - overhead,
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(char *) relocator - overhead,
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dest - overhead, size + overhead, state);
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}
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else
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{
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int overhead;
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overhead = ALIGN_UP (dest + size, RELOCATOR_ALIGN)
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+ RELOCATOR_SIZEOF (forward) - (dest + size);
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grub_dprintf ("relocator",
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"Forward relocator: code %p, source: %p, "
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"destination: 0x%x, size: 0x%lx\n",
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(char *) relocator + size + overhead
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- RELOCATOR_SIZEOF (forward),
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relocator, (unsigned) dest,
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(unsigned long) size + overhead);
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write_call_relocator_fw ((char *) relocator + size + overhead
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- RELOCATOR_SIZEOF (forward),
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relocator, dest, size + overhead, state);
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}
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/* Not reached. */
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return GRUB_ERR_NONE;
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}
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