From feb19646df0a95cbec7ef3fd1b692e96d6eab407 Mon Sep 17 00:00:00 2001
From: Peter Ross <pross@xvid.org>
Date: Tue, 1 Mar 2022 19:50:19 +1100
Subject: [PATCH] LibC: Increase alignment for malloc() BigAllocationBlocks to
 16 bytes

commit 5f3773b7150cbf113b5a0aabfe2b2670dc758d38 increased alignment
for ChunckedBlocks, but not for BigAllocationBlocks.

This is required to make SSE instructions work.
---
 Userland/Libraries/LibC/malloc.cpp   | 2 +-
 Userland/Libraries/LibC/mallocdefs.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Userland/Libraries/LibC/malloc.cpp b/Userland/Libraries/LibC/malloc.cpp
index b9afd147f4..f67dc0b4f3 100644
--- a/Userland/Libraries/LibC/malloc.cpp
+++ b/Userland/Libraries/LibC/malloc.cpp
@@ -528,7 +528,7 @@ size_t malloc_size(void const* ptr)
     auto* header = (const CommonHeader*)page_base;
     auto size = header->m_size;
     if (header->m_magic == MAGIC_BIGALLOC_HEADER)
-        size -= sizeof(CommonHeader);
+        size -= sizeof(BigAllocationBlock);
     else
         VERIFY(header->m_magic == MAGIC_PAGE_HEADER);
     return size;
diff --git a/Userland/Libraries/LibC/mallocdefs.h b/Userland/Libraries/LibC/mallocdefs.h
index ca7cf9a30f..63fd0071f3 100644
--- a/Userland/Libraries/LibC/mallocdefs.h
+++ b/Userland/Libraries/LibC/mallocdefs.h
@@ -46,7 +46,7 @@ struct BigAllocationBlock : public CommonHeader {
         m_magic = MAGIC_BIGALLOC_HEADER;
         m_size = size;
     }
-    unsigned char* m_slot[0];
+    alignas(16) unsigned char* m_slot[0];
 };
 
 struct FreelistEntry {