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(svn r18634) -Revert (r16808): the fix doesn't work in all cases

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-Fix [FS#3421] (r16838): crash when invalid pointers are left due to saveload failing at e.g. decompressing the savegame
This commit is contained in:
rubidium 2009-12-25 23:14:12 +00:00
parent a7be7ebe80
commit 69f1db204e
1 changed files with 50 additions and 29 deletions
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79
src/saveload/saveload.cpp
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@ -64,6 +64,7 @@ enum SaveLoadAction {
SLA_LOAD, ///< loading
SLA_SAVE, ///< saving
SLA_PTRS, ///< fixing pointers
SLA_NULL, ///< null all pointers (on loading error)
};
enum NeedLength {
@ -106,6 +107,32 @@ struct SaveLoadParams {
static SaveLoadParams _sl;
/** Null all pointers (convert index -> NULL) */
static void SlNullPointers()
{
const ChunkHandler *ch;
const ChunkHandler * const *chsc;
_sl.action = SLA_NULL;
DEBUG(sl, 1, "Nulling pointers");
for (chsc = _sl.chs; (ch = *chsc++) != NULL;) {
while (true) {
if (ch->ptrs_proc != NULL) {
DEBUG(sl, 2, "Nulling pointers for %c%c%c%c", ch->id >> 24, ch->id >> 16, ch->id >> 8, ch->id);
ch->ptrs_proc();
}
if (ch->flags & CH_LAST) break;
ch++;
}
}
DEBUG(sl, 1, "All pointers nulled");
assert(_sl.action == SLA_NULL);
}
/** Error handler, calls longjmp to simulate an exception.
* @todo this was used to have a central place to handle errors, but it is
* pretty ugly, and seriously interferes with any multithreaded approaches */
@ -114,6 +141,11 @@ static void NORETURN SlError(StringID string, const char *extra_msg = NULL)
_sl.error_str = string;
free(_sl.extra_msg);
_sl.extra_msg = (extra_msg == NULL) ? NULL : strdup(extra_msg);
/* We have to NULL all pointers here; we might be in a state where
* the pointers are actually filled with indices, which means that
* when we access them during cleaning the pool dereferences of
* those indices will be made with segmentation faults as result. */
SlNullPointers();
throw std::exception();
}
@ -570,6 +602,7 @@ static void SlSaveLoadConv(void *ptr, VarType conv)
break;
}
case SLA_PTRS: break;
case SLA_NULL: break;
default: NOT_REACHED();
}
}
@ -678,6 +711,7 @@ static void SlString(void *ptr, size_t length, VarType conv)
break;
}
case SLA_PTRS: break;
case SLA_NULL: break;
default: NOT_REACHED();
}
}
@ -700,7 +734,7 @@ static inline size_t SlCalcArrayLen(size_t length, VarType conv)
*/
void SlArray(void *array, size_t length, VarType conv)
{
if (_sl.action == SLA_PTRS) return;
if (_sl.action == SLA_PTRS || _sl.action == SLA_NULL) return;
/* Automatically calculate the length? */
if (_sl.need_length != NL_NONE) {
@ -811,6 +845,9 @@ static void SlList(void *list, SLRefType conv)
}
break;
}
case SLA_NULL:
l->clear();
break;
default: NOT_REACHED();
}
}
@ -912,6 +949,9 @@ bool SlObjectMember(void *ptr, const SaveLoad *sld)
case SLA_PTRS:
*(void **)ptr = IntToReference(*(size_t *)ptr, (SLRefType)conv);
break;
case SLA_NULL:
*(void **)ptr = NULL;
break;
default: NOT_REACHED();
}
break;
@ -932,6 +972,7 @@ bool SlObjectMember(void *ptr, const SaveLoad *sld)
case SLA_SAVE: SlWriteByte(sld->version_to); break;
case SLA_LOAD: *(byte *)ptr = sld->version_from; break;
case SLA_PTRS: break;
case SLA_NULL: break;
default: NOT_REACHED();
}
break;
@ -1146,8 +1187,6 @@ static void SlLoadChunks()
}
}
static const char *_sl_ptrs_error; ///< error message if there was an error during fixing pointers, NULL otherwise
/** Fix all pointers (convert index -> pointer) */
static void SlFixPointers()
{
@ -1155,7 +1194,6 @@ static void SlFixPointers()
const ChunkHandler * const *chsc;
_sl.action = SLA_PTRS;
_sl_ptrs_error = NULL;
DEBUG(sl, 1, "Fixing pointers");
@ -1171,9 +1209,6 @@ static void SlFixPointers()
}
}
/* We need to fix all possible pointers even if there were invalid ones. This way pool cleaning will work fine. */
if (_sl_ptrs_error != NULL) SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, _sl_ptrs_error);
DEBUG(sl, 1, "All pointers fixed");
assert(_sl.action == SLA_PTRS);
@ -1537,55 +1572,41 @@ static void *IntToReference(size_t index, SLRefType rt)
switch (rt) {
case REF_ORDERLIST:
if (OrderList::IsValidID(index)) return OrderList::Get(index);
_sl_ptrs_error = "Referencing invalid OrderList";
break;
SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid OrderList");
case REF_ORDER:
if (Order::IsValidID(index)) return Order::Get(index);
/* in old versions, invalid order was used to mark end of order list */
if (CheckSavegameVersionOldStyle(5, 2)) return NULL;
_sl_ptrs_error = "Referencing invalid Order";
break;
SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid Order");
case REF_VEHICLE_OLD:
case REF_VEHICLE:
if (Vehicle::IsValidID(index)) return Vehicle::Get(index);
_sl_ptrs_error = "Referencing invalid Vehicle";
break;
SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid Vehicle");
case REF_STATION:
if (Station::IsValidID(index)) return Station::Get(index);
_sl_ptrs_error = "Referencing invalid Station";
break;
SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid Station");
case REF_TOWN:
if (Town::IsValidID(index)) return Town::Get(index);
_sl_ptrs_error = "Referencing invalid Town";
break;
SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid Town");
case REF_ROADSTOPS:
if (RoadStop::IsValidID(index)) return RoadStop::Get(index);
_sl_ptrs_error = "Referencing invalid RoadStop";
break;
SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid RoadStop");
case REF_ENGINE_RENEWS:
if (EngineRenew::IsValidID(index)) return EngineRenew::Get(index);
_sl_ptrs_error = "Referencing invalid EngineRenew";
break;
SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid EngineRenew");
case REF_CARGO_PACKET:
if (CargoPacket::IsValidID(index)) return CargoPacket::Get(index);
_sl_ptrs_error = "Referencing invalid CargoPacket";
break;
SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid CargoPacket");
default: NOT_REACHED();
}
/* Print a debug message about each invalid reference */
DEBUG(sl, 1, "%s (index = " PRINTF_SIZE ")", _sl_ptrs_error, index);
/* Return NULL for broken savegames */
return NULL;
}
/** The format for a reader/writer type of a savegame */