From 5756ff0b168b5646731d9f520d6de8da40a9dab1 Mon Sep 17 00:00:00 2001
From: Justin Weiss <justin@justinweiss.com>
Date: Mon, 28 Sep 2020 19:12:15 -0700
Subject: [PATCH] [3DS] Free memory in 1MB blocks

When freeing large blocks of memory, the 3DS may kernel panic. Freeing
in smaller blocks seems to avoid the crashes.
---
 ctr/ctr_memory.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/ctr/ctr_memory.c b/ctr/ctr_memory.c
index 2a7722dc75..bb84ff8f7d 100644
--- a/ctr/ctr_memory.c
+++ b/ctr/ctr_memory.c
@@ -141,9 +141,12 @@ void* _sbrk_r(struct _reent *ptr, ptrdiff_t incr)
 
    __heap_size += diff;
 
-   if (diff < 0)
-      svcControlMemory(&tmp, __heapBase + __heap_size,
-            0x0, -diff, MEMOP_FREE, MEMPERM_READ | MEMPERM_WRITE);
+   while (diff < 0) {
+      int size = -diff < 0x100000 ? -diff : 0x100000;
+      diff += size;
+      svcControlMemory(&tmp, __heapBase + __heap_size - diff,
+            0x0, size, MEMOP_FREE, 0);
+   }
 
    sbrk_top += incr;