grub/lib/relocator.c
Vladimir 'phcoder' Serbinenko 95c7fc3f55 First compileable newreloc
2010-01-10 00:30:33 +01:00

501 lines
13 KiB
C

/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/relocator.h>
#include <grub/relocator_private.h>
#include <grub/mm_private.h>
#include <grub/misc.h>
/* TODO: use more efficient data structures if necessary. */
struct grub_relocator *
grub_relocator_new (void)
{
struct grub_relocator *ret;
grub_cpu_relocator_init ();
ret = grub_zalloc (sizeof (struct grub_relocator));
if (!ret)
return NULL;
ret->postchunks = ~(grub_addr_t) 0;
ret->relocators_size = grub_relocator_jumper_size;
return ret;
}
static grub_mm_header_t
get_best_header (struct grub_relocator *rel,
grub_addr_t start, grub_addr_t end, grub_addr_t align,
grub_size_t size,
grub_mm_region_t rb, grub_mm_header_t *prev,
grub_addr_t *best_addr, int from_low_priv, int collisioncheck)
{
grub_mm_header_t h, hp;
grub_mm_header_t hb = NULL, hbp = NULL;
auto void try_addr (grub_addr_t allowable_start, grub_addr_t allowable_end);
void try_addr (grub_addr_t allowable_start, grub_addr_t allowable_end)
{
if (from_low_priv)
{
grub_addr_t addr;
addr = ALIGN_UP (allowable_start, align);
if (addr < start)
addr = ALIGN_UP (start, align);
if (collisioncheck)
while (1)
{
struct grub_relocator_chunk *chunk;
for (chunk = rel->chunks; chunk; chunk = chunk->next)
if ((chunk->target <= addr
&& addr < chunk->target + chunk->size)
|| (chunk->target <= addr + size
&& addr + size < chunk->target + chunk->size)
|| (addr <= chunk->target && chunk->target < addr + size)
|| (addr <= chunk->target + chunk->size
&& chunk->target + chunk->size < addr + size))
{
addr = ALIGN_UP (chunk->target + chunk->size, align);
break;
}
if (!chunk)
break;
}
if (allowable_end <= addr + size)
return;
if (addr > end)
return;
if (hb == NULL || *best_addr > addr)
{
hb = h;
hbp = hp;
*best_addr = addr;
}
}
else
{
grub_addr_t addr;
addr = ALIGN_DOWN (allowable_end - size, align);
if (addr > end)
addr = ALIGN_DOWN (end, align);
if (collisioncheck)
while (1)
{
struct grub_relocator_chunk *chunk;
for (chunk = rel->chunks; chunk; chunk = chunk->next)
if ((chunk->target <= addr
&& addr < chunk->target + chunk->size)
|| (chunk->target <= addr + size
&& addr + size < chunk->target + chunk->size)
|| (addr <= chunk->target && chunk->target < addr + size)
|| (addr <= chunk->target + chunk->size
&& chunk->target + chunk->size < addr + size))
{
addr = ALIGN_DOWN (chunk->target - size, align);
break;
}
if (!chunk)
break;
}
if (allowable_start > addr)
return;
if (addr < start)
return;
if (hb == NULL || *best_addr < addr)
{
hb = h;
hbp = hp;
*best_addr = addr;
}
}
}
for (hp = NULL, h = rb->first; h; hp = h, h = h->next)
{
grub_addr_t allowable_start, allowable_end;
allowable_start = (grub_addr_t) h;
allowable_end = (grub_addr_t) (h + 1 + h->size);
try_addr (allowable_start, allowable_end);
if ((grub_addr_t) h == (grub_addr_t) (rb + 1))
try_addr (allowable_start - sizeof (*rb) - rb->pre_size,
allowable_end - sizeof (*rb));
}
*prev = hbp;
return hb;
}
static int
malloc_in_range (struct grub_relocator *rel,
grub_addr_t start, grub_addr_t end, grub_addr_t align,
grub_size_t size, grub_addr_t *res, int from_low_priv,
int collisioncheck)
{
grub_mm_region_t rb = NULL, rbp = NULL;
grub_mm_header_t hb = NULL, hbp = NULL;
grub_addr_t best_addr;
again:
{
grub_mm_region_t r, rp;
for (rp = NULL, r = grub_mm_base; r; rp = r, r = r->next)
{
if ((grub_addr_t) r + r->size + sizeof (*r) > start
&& (grub_addr_t) r <= end && r->size + sizeof (*r) >= size
&& (rb == NULL || from_low_priv ? rb > r : rb < r))
{
rb = r;
rbp = rp;
}
}
}
if (!rb)
return 0;
hb = get_best_header (rel, start, end, align, size, rb, &hbp, &best_addr,
from_low_priv, collisioncheck);
if (!hb)
{
if (from_low_priv)
start = (grub_addr_t) (rb + rb->size + sizeof (*rb));
else
end = (grub_addr_t) rb - 1;
goto again;
}
/* Special case: relocating region start. */
if (best_addr < (grub_addr_t) hbp)
{
grub_addr_t newreg_start, newreg_raw_start = best_addr + size;
grub_addr_t newreg_size, newreg_presize;
grub_mm_header_t new_header;
newreg_start = ALIGN_UP (newreg_raw_start, GRUB_MM_ALIGN);
newreg_presize = newreg_start - newreg_raw_start;
newreg_size = rb->size - (newreg_start - (grub_addr_t) rb);
if ((hb->size << GRUB_MM_ALIGN_LOG2) >= newreg_start
+ (grub_addr_t) rb)
{
grub_mm_header_t newhnext = hb->next;
grub_size_t newhsize = ((hb->size << GRUB_MM_ALIGN_LOG2)
- newreg_start
- (grub_addr_t) rb) >> GRUB_MM_ALIGN_LOG2;
new_header = (void *) (newreg_start + sizeof (*rb));
new_header->next = newhnext;
new_header->size = newhsize;
new_header->magic = GRUB_MM_FREE_MAGIC;
}
else
{
new_header = hb->next;
}
if (hbp || new_header)
{
struct grub_mm_header *newregfirst = rb->first;
struct grub_mm_region *newregnext = rb->next;
struct grub_mm_region *newreg = (void *) newreg_start;
if (hbp)
hbp->next = new_header;
else
newregfirst = new_header;
newreg->first = newregfirst;
newreg->next = newregnext;
newreg->pre_size = newreg_presize;
newreg->size = newreg_size;
if (rbp)
rbp->next = newreg;
else
grub_mm_base = newreg;
}
else
{
if (rbp)
rbp->next = rb->next;
else
grub_mm_base = rb->next;
}
*res = best_addr;
return 1;
}
{
struct grub_mm_header *foll = NULL;
if (best_addr + size <= (grub_addr_t) (hb + hb->size))
{
foll = (void *) ALIGN_UP (best_addr + size, GRUB_MM_ALIGN);
foll->magic = GRUB_MM_FREE_MAGIC;
foll->size = hb->size - (foll - hb);
}
if (best_addr - (grub_addr_t) hb >= sizeof (*hb))
{
hb->size = (best_addr - (grub_addr_t) hb) >> GRUB_MM_ALIGN_LOG2;
if (foll)
{
foll->next = hb;
if (hbp)
hbp->next = foll;
else
rb->first = foll;
}
}
else
{
if (foll)
foll->next = hb->next;
else
foll = hb->next;
if (hbp)
hbp->next = foll;
else
rb->first = foll;
}
*res = best_addr;
return 1;
}
}
grub_err_t
grub_relocator_alloc_chunk_addr (struct grub_relocator *rel, void **src,
grub_addr_t target, grub_size_t size)
{
struct grub_relocator_chunk *chunk;
grub_addr_t start;
grub_addr_t min_addr = 0, max_addr;
max_addr = rel->postchunks;
/* Keep chunks in memory in the same order as they'll be after relocation. */
for (chunk = rel->chunks; chunk; chunk = chunk->next)
{
if (chunk->target > target && chunk->src > max_addr)
max_addr = chunk->src;
if (chunk->target + chunk->size <= target
&& chunk->src + chunk->size < min_addr
&& chunk->src < rel->postchunks)
min_addr = chunk->src + chunk->size;
if ((chunk->target <= target && target < chunk->target + chunk->size)
|| (target <= chunk->target && chunk->target < target + size))
{
return grub_error (GRUB_ERR_BAD_ARGUMENT, "overlap detected");
}
}
chunk = grub_malloc (sizeof (struct grub_relocator_chunk));
if (!chunk)
return grub_errno;
do
{
/* A trick to improve Linux allocation. */
#if defined (__i386__) || defined (__x86_64__)
if (target < 0x100000)
if (malloc_in_range (rel, rel->highestnonpostaddr, ~(grub_addr_t)0, 0,
size, &start, 1, 0))
{
if (rel->postchunks < start)
rel->postchunks = start;
break;
}
#endif
if (malloc_in_range (rel, target, max_addr, 1, size, &start, 1, 0))
break;
if (malloc_in_range (rel, min_addr, target, 0, size, &start, 1, 0))
break;
grub_free (chunk);
return grub_error (GRUB_ERR_OUT_OF_MEMORY, "out of memory");
}
while (0);
if (rel->highestaddr < target + size)
rel->highestaddr = target + size;
if (rel->highestaddr < start + size)
rel->highestaddr = start + size;
if (start < rel->postchunks)
{
if (rel->highestnonpostaddr < target + size)
rel->highestnonpostaddr = target + size;
if (rel->highestnonpostaddr < start + size)
rel->highestnonpostaddr = start + size;
}
if (start < target)
rel->relocators_size += grub_relocator_backward_size;
if (start > target)
rel->relocators_size += grub_relocator_forward_size;
chunk->src = start;
chunk->target = target;
chunk->size = size;
chunk->next = rel->chunks;
rel->chunks = chunk;
*src = (void *) start;
return GRUB_ERR_NONE;
}
grub_err_t
grub_relocator_alloc_chunk_align (struct grub_relocator *rel, void **src,
grub_addr_t *target,
grub_addr_t min_addr, grub_addr_t max_addr,
grub_size_t size, grub_size_t align)
{
grub_addr_t min_addr2 = 0, max_addr2;
struct grub_relocator_chunk *chunk;
grub_addr_t start;
chunk = grub_malloc (sizeof (struct grub_relocator_chunk));
if (!chunk)
return grub_errno;
if (malloc_in_range (rel, min_addr, max_addr, align,
size, &start, 1, 1))
{
chunk->src = start;
chunk->target = start;
chunk->size = size;
chunk->next = rel->chunks;
rel->chunks = chunk;
*src = (void *) start;
*target = start;
return GRUB_ERR_NONE;
}
max_addr2 = rel->postchunks;
/* Keep chunks in memory in the same order as they'll be after
relocation. */
for (chunk = rel->chunks; chunk; chunk = chunk->next)
{
if (chunk->target > max_addr && chunk->src > max_addr2)
max_addr2 = chunk->src;
if (chunk->target + chunk->size <= min_addr
&& chunk->src + chunk->size < min_addr2
&& chunk->src < rel->postchunks)
min_addr2 = chunk->src + chunk->size;
}
if (!malloc_in_range (rel, min_addr2, max_addr2, align,
size, &start, 1, 1))
{
grub_free (chunk);
return grub_error (GRUB_ERR_OUT_OF_MEMORY, "out of memory");
}
chunk->target = ALIGN_UP (min_addr, align);
while (1)
{
struct grub_relocator_chunk *chunk2;
for (chunk2 = rel->chunks; chunk2; chunk2 = chunk2->next)
if ((chunk2->target <= chunk->target
&& chunk->target < chunk2->target + chunk2->size)
|| (chunk2->target <= chunk->target + size
&& chunk->target + size < chunk2->target + chunk2->size)
|| (chunk->target <= chunk2->target && chunk2->target
< chunk->target + size)
|| (chunk->target <= chunk2->target + chunk2->size
&& chunk2->target + chunk2->size < chunk->target + size))
{
chunk->target = ALIGN_UP (chunk2->target + chunk2->size, align);
break;
}
if (!chunk2)
break;
}
if (start < chunk->target)
rel->relocators_size += grub_relocator_backward_size;
if (start > chunk->target)
rel->relocators_size += grub_relocator_forward_size;
chunk->src = start;
chunk->size = size;
chunk->next = rel->chunks;
rel->chunks = chunk;
*src = (void *) start;
*target = chunk->target;
return GRUB_ERR_NONE;
}
void
grub_relocator_unload (struct grub_relocator *rel)
{
struct grub_relocator_chunk *chunk, *next;
for (chunk = rel->chunks; chunk; chunk = next)
{
grub_fatal ("Relocator unloading isn't implemented yet");
next = chunk->next;
grub_free (chunk);
}
}
grub_err_t
grub_relocator_prepare_relocs (struct grub_relocator *rel, grub_addr_t addr,
grub_addr_t *relstart)
{
struct grub_relocator_chunk *chunk;
grub_addr_t rels;
grub_addr_t rels0;
if (!malloc_in_range (rel, 0, ~(grub_addr_t)0, grub_relocator_align,
rel->relocators_size, &rels0, 1, 1))
return grub_error (GRUB_ERR_OUT_OF_MEMORY, "out of memory");
rels = rels0;
for (chunk = rel->chunks; chunk; chunk = chunk->next)
{
if (chunk->src < chunk->target)
{
grub_cpu_relocator_backward ((void *) rels,
(void *) chunk->src,
(void *) chunk->target,
chunk->size);
rels += grub_relocator_backward_size;
}
if (chunk->src > chunk->target)
{
grub_cpu_relocator_forward ((void *) rels,
(void *) chunk->src,
(void *) chunk->target,
chunk->size);
rels += grub_relocator_forward_size;
}
}
grub_cpu_relocator_jumper ((void *) rels, addr);
*relstart = rels0;
return GRUB_ERR_NONE;
}