[NFC][scudo] Add reference to a QEMU bug

D101031 added workaround for the bug.

diff --git a/compiler-rt/lib/scudo/standalone/linux.cpp b/compiler-rt/lib/scudo/standalone/linux.cpp
index 63a8e43..7ec6987 100644 (file)
--- a/compiler-rt/lib/scudo/standalone/linux.cpp
+++ b/compiler-rt/lib/scudo/standalone/linux.cpp
@@ -122,6 +122,7 @@ void releasePagesToOS(uptr BaseAddress, uptr Offset, uptr Size,
   if (madviseNeedsMemsetCached()) {
     // Workaround for QEMU-user ignoring MADV_DONTNEED.
     // https://github.com/qemu/qemu/blob/b1cffefa1b163bce9aebc3416f562c1d3886eeaa/linux-user/syscall.c#L11941
+    // https://bugs.launchpad.net/qemu/+bug/1926521
     memset(Addr, 0, Size);
   }
   while (madvise(Addr, Size, MADV_DONTNEED) == -1 && errno == EAGAIN) {