From 1f373479b8e31a4febb954533f52615088859223 Mon Sep 17 00:00:00 2001
From: Nicolas Werner <nicolas.werner@hotmail.de>
Date: Thu, 25 Feb 2021 15:15:59 +0100
Subject: [PATCH] Fix unaligned reads
---
src/Cache.cpp | 46 ++++++++++++++++++++++++++++++----------------
1 file changed, 30 insertions(+), 16 deletions(-)
diff --git a/src/Cache.cpp b/src/Cache.cpp
index 8cf66d212..c81840c66 100644
--- a/src/Cache.cpp
+++ b/src/Cache.cpp
@@ -102,6 +102,20 @@ namespace {
std::unique_ptr<Cache> instance_ = nullptr;
}
+template<class T>
+static T
+to(lmdb::val &value)
+{
+ static_assert(std::is_trivial_v<T>, "Can only convert to trivial types!");
+ T temp;
+
+ if (value.size() < sizeof(T))
+ throw lmdb::runtime_error(__func__, MDB_BAD_VALSIZE);
+
+ std::memcpy(&temp, value.data(), sizeof(T));
+ return temp;
+}
+
bool
Cache::isHiddenEvent(lmdb::txn &txn,
mtx::events::collections::TimelineEvents e,
@@ -1667,14 +1681,14 @@ Cache::getTimelineMessages(lmdb::txn &txn, const std::string &room_id, uint64_t
auto cursor = lmdb::cursor::open(txn, orderDb);
if (index == std::numeric_limits<uint64_t>::max()) {
if (cursor.get(indexVal, event_id, forward ? MDB_FIRST : MDB_LAST)) {
- index = *indexVal.data<uint64_t>();
+ index = to<uint64_t>(indexVal);
} else {
messages.end_of_cache = true;
return messages;
}
} else {
if (cursor.get(indexVal, event_id, MDB_SET)) {
- index = *indexVal.data<uint64_t>();
+ index = to<uint64_t>(indexVal);
} else {
messages.end_of_cache = true;
return messages;
@@ -1708,7 +1722,7 @@ Cache::getTimelineMessages(lmdb::txn &txn, const std::string &room_id, uint64_t
cursor.close();
// std::reverse(timeline.events.begin(), timeline.events.end());
- messages.next_index = *indexVal.data<uint64_t>();
+ messages.next_index = to<uint64_t>(indexVal);
messages.end_of_cache = !ret;
return messages;
@@ -1861,12 +1875,12 @@ Cache::getTimelineRange(const std::string &room_id)
}
TimelineRange range{};
- range.last = *indexVal.data<uint64_t>();
+ range.last = to<uint64_t>(indexVal);
if (!cursor.get(indexVal, val, MDB_FIRST)) {
return {};
}
- range.first = *indexVal.data<uint64_t>();
+ range.first = to<uint64_t>(indexVal);
return range;
}
@@ -1892,7 +1906,7 @@ Cache::getTimelineIndex(const std::string &room_id, std::string_view event_id)
return {};
}
- return *val.data<uint64_t>();
+ return to<uint64_t>(val);
}
std::optional<uint64_t>
@@ -1920,7 +1934,7 @@ Cache::getEventIndex(const std::string &room_id, std::string_view event_id)
return {};
}
- return *val.data<uint64_t>();
+ return to<uint64_t>(val);
}
std::optional<std::pair<uint64_t, std::string>>
@@ -1951,7 +1965,7 @@ Cache::lastInvisibleEventAfter(const std::string &room_id, std::string_view even
if (!success) {
return {};
}
- uint64_t prevIdx = *indexVal.data<uint64_t>();
+ uint64_t prevIdx = to<uint64_t>(indexVal);
std::string prevId{eventIdVal.data(), eventIdVal.size()};
auto cursor = lmdb::cursor::open(txn, eventOrderDb);
@@ -1964,7 +1978,7 @@ Cache::lastInvisibleEventAfter(const std::string &room_id, std::string_view even
if (lmdb::dbi_get(txn, timelineDb, lmdb::val(evId.data(), evId.size()), temp)) {
return std::pair{prevIdx, std::string(prevId)};
} else {
- prevIdx = *indexVal.data<uint64_t>();
+ prevIdx = to<uint64_t>(indexVal);
prevId = std::move(evId);
}
}
@@ -1994,7 +2008,7 @@ Cache::getArrivalIndex(const std::string &room_id, std::string_view event_id)
return {};
}
- return *val.data<uint64_t>();
+ return to<uint64_t>(val);
}
std::optional<std::string>
@@ -2775,13 +2789,13 @@ Cache::saveTimelineMessages(lmdb::txn &txn,
uint64_t index = std::numeric_limits<uint64_t>::max() / 2;
auto cursor = lmdb::cursor::open(txn, orderDb);
if (cursor.get(indexVal, val, MDB_LAST)) {
- index = *indexVal.data<int64_t>();
+ index = to<uint64_t>(indexVal);
}
uint64_t msgIndex = std::numeric_limits<uint64_t>::max() / 2;
auto msgCursor = lmdb::cursor::open(txn, order2msgDb);
if (msgCursor.get(indexVal, val, MDB_LAST)) {
- msgIndex = *indexVal.data<uint64_t>();
+ msgIndex = to<uint64_t>(indexVal);
}
bool first = true;
@@ -2942,7 +2956,7 @@ Cache::saveOldMessages(const std::string &room_id, const mtx::responses::Message
{
auto cursor = lmdb::cursor::open(txn, orderDb);
if (cursor.get(indexVal, val, MDB_FIRST)) {
- index = *indexVal.data<uint64_t>();
+ index = to<uint64_t>(indexVal);
}
}
@@ -2950,7 +2964,7 @@ Cache::saveOldMessages(const std::string &room_id, const mtx::responses::Message
{
auto msgCursor = lmdb::cursor::open(txn, order2msgDb);
if (msgCursor.get(indexVal, val, MDB_FIRST)) {
- msgIndex = *indexVal.data<uint64_t>();
+ msgIndex = to<uint64_t>(indexVal);
}
}
@@ -3258,12 +3272,12 @@ Cache::deleteOldMessages()
uint64_t first, last;
if (cursor.get(indexVal, val, MDB_LAST)) {
- last = *indexVal.data<uint64_t>();
+ last = to<uint64_t>(indexVal);
} else {
continue;
}
if (cursor.get(indexVal, val, MDB_FIRST)) {
- first = *indexVal.data<uint64_t>();
+ first = to<uint64_t>(indexVal);
} else {
continue;
}
--
GitLab