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/* Copyright (C) 2007-2010 The Android Open Source Project
**
** This software is licensed under the terms of the GNU General Public
** License version 2, as published by the Free Software Foundation, and
** may be copied, distributed, and modified under those terms.
**
** This program 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.
*/
/*
* Contains implementation of routines that implement a red-black tree of
* memory mappings in the guest system.
*/
#include "memcheck_mmrange_map.h"
#include "memcheck_logging.h"
/* Memory range descriptor stored in the map. */
typedef struct MMRangeMapEntry {
/* R-B tree entry. */
RB_ENTRY(MMRangeMapEntry) rb_entry;
/* Memory range descriptor for this entry. */
MMRangeDesc desc;
} MMRangeMapEntry;
// =============================================================================
// R-B Tree implementation
// =============================================================================
/* Compare routine for the map.
* Param:
* d1 - First map entry to compare.
* d2 - Second map entry to compare.
* Return:
* 0 - Descriptors are equal. Note that descriptors are considered to be
* equal iff memory blocks they describe intersect in any part.
* 1 - d1 is greater than d2
* -1 - d1 is less than d2.
*/
static inline int
cmp_rb(MMRangeMapEntry* d1, MMRangeMapEntry* d2)
{
const target_ulong start1 = d1->desc.map_start;
const target_ulong start2 = d2->desc.map_start;
if (start1 < start2) {
return (d1->desc.map_end - 1) < start2 ? -1 : 0;
}
return (d2->desc.map_end - 1) < start1 ? 1 : 0;
}
/* Expands RB macros here. */
RB_GENERATE(MMRangeMap, MMRangeMapEntry, rb_entry, cmp_rb);
// =============================================================================
// Static routines
// =============================================================================
/* Inserts new (or replaces existing) entry into the map.
* See comments on mmrangemap_insert routine in the header file for details
* about this routine.
*/
static RBTMapResult
mmrangemap_insert_desc(MMRangeMap* map,
MMRangeMapEntry* rdesc,
MMRangeDesc* replaced)
{
MMRangeMapEntry* existing = MMRangeMap_RB_INSERT(map, rdesc);
if (existing == NULL) {
return RBT_MAP_RESULT_ENTRY_INSERTED;
}
// Matching entry exists. Lets see if we need to replace it.
if (replaced == NULL) {
return RBT_MAP_RESULT_ENTRY_ALREADY_EXISTS;
}
/* Copy existing entry to the provided buffer and replace it
* with the new one. */
memcpy(replaced, &existing->desc, sizeof(MMRangeDesc));
MMRangeMap_RB_REMOVE(map, existing);
qemu_free(existing);
MMRangeMap_RB_INSERT(map, rdesc);
return RBT_MAP_RESULT_ENTRY_REPLACED;
}
/* Finds an entry in the map that matches the given address range.
* Param:
* map - Map where to search for an entry.
* start - Starting address of a mapping range.
* end - Ending address of a mapping range.
* Return:
* Address of a map entry that matches the given range, or NULL if no
* such entry has been found.
*/
static inline MMRangeMapEntry*
mmrangemap_find_entry(const MMRangeMap* map,
target_ulong start,
target_ulong end)
{
MMRangeMapEntry rdesc;
rdesc.desc.map_start = start;
rdesc.desc.map_end = end;
return MMRangeMap_RB_FIND((MMRangeMap*)map, &rdesc);
}
// =============================================================================
// Map API
// =============================================================================
void
mmrangemap_init(MMRangeMap* map)
{
RB_INIT(map);
}
RBTMapResult
mmrangemap_insert(MMRangeMap* map,
const MMRangeDesc* desc,
MMRangeDesc* replaced)
{
RBTMapResult ret;
// Allocate and initialize new map entry.
MMRangeMapEntry* rdesc = qemu_malloc(sizeof(MMRangeMapEntry));
if (rdesc == NULL) {
ME("memcheck: Unable to allocate new MMRangeMapEntry on insert.");
return RBT_MAP_RESULT_ERROR;
}
memcpy(&rdesc->desc, desc, sizeof(MMRangeDesc));
// Insert new entry into the map.
ret = mmrangemap_insert_desc(map, rdesc, replaced);
if (ret == RBT_MAP_RESULT_ENTRY_ALREADY_EXISTS ||
ret == RBT_MAP_RESULT_ERROR) {
/* Another descriptor already exists for this block, or an error
* occurred. We have to free new descriptor, as it wasn't inserted. */
qemu_free(rdesc);
}
return ret;
}
MMRangeDesc*
mmrangemap_find(const MMRangeMap* map, target_ulong start, target_ulong end)
{
MMRangeMapEntry* rdesc = mmrangemap_find_entry(map, start, end);
return rdesc != NULL ? &rdesc->desc : NULL;
}
int
mmrangemap_pull(MMRangeMap* map,
target_ulong start,
target_ulong end,
MMRangeDesc* pulled)
{
MMRangeMapEntry* rdesc = mmrangemap_find_entry(map, start, end);
if (rdesc != NULL) {
memcpy(pulled, &rdesc->desc, sizeof(MMRangeDesc));
MMRangeMap_RB_REMOVE(map, rdesc);
qemu_free(rdesc);
return 0;
} else {
return -1;
}
}
int
mmrangemap_pull_first(MMRangeMap* map, MMRangeDesc* pulled)
{
MMRangeMapEntry* first = RB_MIN(MMRangeMap, map);
if (first != NULL) {
memcpy(pulled, &first->desc, sizeof(MMRangeDesc));
MMRangeMap_RB_REMOVE(map, first);
qemu_free(first);
return 0;
} else {
return -1;
}
}
int
mmrangemap_copy(MMRangeMap* to, const MMRangeMap* from)
{
MMRangeMapEntry* entry;
RB_FOREACH(entry, MMRangeMap, (MMRangeMap*)from) {
RBTMapResult ins_res;
MMRangeMapEntry* new_entry =
(MMRangeMapEntry*)qemu_malloc(sizeof(MMRangeMapEntry));
if (new_entry == NULL) {
ME("memcheck: Unable to allocate new MMRangeMapEntry on copy.");
return -1;
}
memcpy(new_entry, entry, sizeof(MMRangeMapEntry));
new_entry->desc.path = qemu_malloc(strlen(entry->desc.path) + 1);
if (new_entry->desc.path == NULL) {
ME("memcheck: Unable to allocate new path for MMRangeMapEntry on copy.");
qemu_free(new_entry);
return -1;
}
strcpy(new_entry->desc.path, entry->desc.path);
ins_res = mmrangemap_insert_desc(to, new_entry, NULL);
if (ins_res != RBT_MAP_RESULT_ENTRY_INSERTED) {
ME("memcheck: Unable to insert new range map entry on copy. Insert returned %u",
ins_res);
qemu_free(new_entry->desc.path);
qemu_free(new_entry);
return -1;
}
}
return 0;
}
int
mmrangemap_empty(MMRangeMap* map)
{
MMRangeDesc pulled;
int removed = 0;
while (!mmrangemap_pull_first(map, &pulled)) {
qemu_free(pulled.path);
removed++;
}
return removed;
}
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