From b8fd845885046d0333b6638b1b66d0eb3ad283a8 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Thu, 27 May 2021 21:23:56 +0200
Subject: [PATCH] LibJS: Update mmap name after recycling a HeapBlock :^)

Fixes #7507.
---
 Userland/Libraries/LibJS/Heap/BlockAllocator.cpp | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/Userland/Libraries/LibJS/Heap/BlockAllocator.cpp b/Userland/Libraries/LibJS/Heap/BlockAllocator.cpp
index d622623385c..50e0f096ba0 100644
--- a/Userland/Libraries/LibJS/Heap/BlockAllocator.cpp
+++ b/Userland/Libraries/LibJS/Heap/BlockAllocator.cpp
@@ -33,8 +33,16 @@ BlockAllocator::~BlockAllocator()
 
 void* BlockAllocator::allocate_block([[maybe_unused]] char const* name)
 {
-    if (!m_blocks.is_empty())
-        return m_blocks.take_last();
+    if (!m_blocks.is_empty()) {
+        auto* block = m_blocks.take_last();
+#ifdef __serenity__
+        if (set_mmap_name(block, HeapBlock::block_size, name) < 0) {
+            perror("set_mmap_name");
+            VERIFY_NOT_REACHED();
+        }
+#endif
+        return block;
+    }
 
 #ifdef __serenity__
     auto* block = (HeapBlock*)serenity_mmap(nullptr, HeapBlock::block_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_RANDOMIZED | MAP_PRIVATE, 0, 0, HeapBlock::block_size, name);