rts/RetainerProfile: Handle BLOCKING_QUEUES

push() considers BLOCKING_QUEUES to be an invalid closure type which
should never be present on the stack. However, retainClosure made no
accomodation for this and ended up pushing such a closure. This lead
to #14947.

Test Plan: Validate

Reviewers: simonmar, erikd

Reviewed By: simonmar

Subscribers: thomie, carter, RyanGlScott

GHC Trac Issues: #14947

Differential Revision: https://phabricator.haskell.org/D4538

1 files changed, 10 insertions, 1 deletions

diff --git a/rts/RetainerProfile.c b/rts/RetainerProfile.c
index 79bb7e3cfb..67a6da93cd 100644
--- a/rts/RetainerProfile.c
+++ b/rts/RetainerProfile.c
@@ -424,7 +424,7 @@ find_srt( stackPos *info )
  *  push() pushes a stackElement representing the next child of *c
  *  onto the traverse stack. If *c has no child, *first_child is set
  *  to NULL and nothing is pushed onto the stack. If *c has only one
- *  child, *c_chlid is set to that child and nothing is pushed onto
+ *  child, *c_child is set to that child and nothing is pushed onto
  *  the stack.  If *c has more than two children, *first_child is set
  *  to the first child and a stackElement representing the second
  *  child is pushed onto the stack.
@@ -1695,6 +1695,15 @@ inner_loop:
         goto loop;
     }
 
+    case BLOCKING_QUEUE:
+    {
+        StgBlockingQueue *bq = (StgBlockingQueue *)c;
+        retainClosure((StgClosure*) bq->link,           c, c_child_r);
+        retainClosure((StgClosure*) bq->bh,             c, c_child_r);
+        retainClosure((StgClosure*) bq->owner,          c, c_child_r);
+        goto loop;
+    }
+
     case PAP:
     {
         StgPAP *pap = (StgPAP *)c;