[WIP] Fix a rosalloc verification crash.
Bug: 18960494
Change-Id: Ia7a11f06b3fc8207f6304ae881539251d6b1de24
diff --git a/runtime/gc/collector/semi_space.cc b/runtime/gc/collector/semi_space.cc
index cb9f111..681bfaa 100644
--- a/runtime/gc/collector/semi_space.cc
+++ b/runtime/gc/collector/semi_space.cc
@@ -251,10 +251,13 @@
// Note: Freed bytes can be negative if we copy form a compacted space to a free-list backed
// space.
RecordFree(ObjectBytePair(from_objects - to_objects, from_bytes - to_bytes));
- // Clear and protect the from space.
+ // Clear the from space. Protect it with PROT_READ here and if
+ // kProtectFromSpace is true, will protect it with PROT_NONE later
+ // in FinishPhase() so the rosalloc verification works (can read the
+ // metadata magic number.)
from_space_->Clear();
- VLOG(heap) << "Protecting from_space_: " << *from_space_;
- from_space_->GetMemMap()->Protect(kProtectFromSpace ? PROT_NONE : PROT_READ);
+ VLOG(heap) << "Protecting from_space_ with PROT_READ : " << *from_space_;
+ from_space_->GetMemMap()->Protect(PROT_READ);
heap_->PreSweepingGcVerification(this);
if (swap_semi_spaces_) {
heap_->SwapSemiSpaces();
@@ -749,6 +752,10 @@
void SemiSpace::FinishPhase() {
TimingLogger::ScopedTiming t(__FUNCTION__, GetTimings());
+ if (kProtectFromSpace) {
+ VLOG(heap) << "Protecting from_space_ with PROT_NONE : " << *from_space_;
+ from_space_->GetMemMap()->Protect(PROT_NONE);
+ }
// Null the "to" and "from" spaces since compacting from one to the other isn't valid until
// further action is done by the heap.
to_space_ = nullptr;
diff --git a/runtime/gc/heap.cc b/runtime/gc/heap.cc
index 2575676..8eeaeec 100644
--- a/runtime/gc/heap.cc
+++ b/runtime/gc/heap.cc
@@ -1592,8 +1592,6 @@
// Make sure that we will have enough room to copy.
CHECK_GE(to_space->GetFootprintLimit(), from_space->GetFootprintLimit());
Compact(to_space, from_space, kGcCauseHomogeneousSpaceCompact);
- // Leave as prot read so that we can still run ROSAlloc verification on this space.
- from_space->GetMemMap()->Protect(PROT_READ);
const uint64_t space_size_after_compaction = to_space->Size();
main_space_ = to_space;
main_space_backup_.reset(from_space);
