[Openmp-commits] [PATCH] D116716: [OpenMP][Offloading] Fixed a crash caused by dereferencing nullptr

[Shilei Tian via Phabricator via Openmp-commits]

tianshilei1992 created this revision.
tianshilei1992 added reviewers: jdoerfert, ronlieb.
Herald added subscribers: guansong, yaxunl.
tianshilei1992 requested review of this revision.
Herald added subscribers: openmp-commits, sstefan1.
Herald added a project: OpenMP.

In function `DeviceTy::getTargetPointer`, `Entry` could be `nullptr` because of
zero length array section. We need to check if it is a valid iterator before
using it.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D116716

Files:
  openmp/libomptarget/src/device.cpp


Index: openmp/libomptarget/src/device.cpp
===================================================================
--- openmp/libomptarget/src/device.cpp
+++ openmp/libomptarget/src/device.cpp
@@ -305,7 +305,9 @@
     DataMapMtx.unlock();
     // If not a host pointer and no present modifier, we need to wait for the
     // event if it exists.
-    if (!IsHostPtr && !HasPresentModifier) {
+    // Note: Entry might be nullptr because of zero length array section.
+    if (Entry != HostDataToTargetListTy::iterator() && !IsHostPtr &&
+        !HasPresentModifier) {
       Entry->lock();
       void *Event = Entry->getEvent();
       if (Event) {


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