From cb9c6f007478abf491f598d4ce25c980542dd74a Mon Sep 17 00:00:00 2001
From: Damian Gryski <damian@gryski.com>
Date: Sun, 26 Mar 2023 17:47:11 -0700
Subject: [PATCH] runtime: zero map key/value on deletion to so GC doesn't see
 them

---
 src/runtime/hashmap.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/runtime/hashmap.go b/src/runtime/hashmap.go
index 62b4a7f59..f583d26b9 100644
--- a/src/runtime/hashmap.go
+++ b/src/runtime/hashmap.go
@@ -342,6 +342,11 @@ func hashmapDelete(m *hashmap, key unsafe.Pointer, hash uint32) {
 				if m.keyEqual(key, slotKey, m.keySize) {
 					// Found the key, delete it.
 					bucket.tophash[i] = 0
+					// Zero out the key and value so garbage collector doesn't pin the allocations.
+					memzero(slotKey, m.keySize)
+					slotValueOffset := unsafe.Sizeof(hashmapBucket{}) + m.keySize*8 + m.valueSize*uintptr(i)
+					slotValue := unsafe.Add(unsafe.Pointer(bucket), slotValueOffset)
+					memzero(slotValue, m.valueSize)
 					m.count--
 					return
 				}