From 3af976e41ea62a2b65fa276f77bc2bf0a9ee6b65 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Wed, 28 Mar 2018 19:55:24 -0400
Subject: [PATCH] ncch_container: Get rid of pointer casts in
LZSS_GetDecompressedSize() and LZSS_Decompress()
These kinds of casts invoke undefined behavior, due to both the aliasing
rule, and from an alignment point-of-view. Use the way that's guaranteed
to always work instead.
---
src/core/file_sys/ncch_container.cpp | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/src/core/file_sys/ncch_container.cpp b/src/core/file_sys/ncch_container.cpp
index 82cc07c95..b26e366ac 100644
--- a/src/core/file_sys/ncch_container.cpp
+++ b/src/core/file_sys/ncch_container.cpp
@@ -26,7 +26,8 @@ static const int kBlockSize = 0x200; ///< Size of ExeFS blocks (in bytes)
* @return Size of decompressed buffer
*/
static u32 LZSS_GetDecompressedSize(const u8* buffer, u32 size) {
- u32 offset_size = *(u32*)(buffer + size - 4);
+ u32 offset_size;
+ std::memcpy(&offset_size, buffer + size - sizeof(u32), sizeof(u32));
return offset_size + size;
}
@@ -41,7 +42,10 @@ static u32 LZSS_GetDecompressedSize(const u8* buffer, u32 size) {
static bool LZSS_Decompress(const u8* compressed, u32 compressed_size, u8* decompressed,
u32 decompressed_size) {
const u8* footer = compressed + compressed_size - 8;
- u32 buffer_top_and_bottom = *reinterpret_cast<const u32*>(footer);
+
+ u32 buffer_top_and_bottom;
+ std::memcpy(&buffer_top_and_bottom, footer, sizeof(u32));
+
u32 out = decompressed_size;
u32 index = compressed_size - ((buffer_top_and_bottom >> 24) & 0xFF);
u32 stop_index = compressed_size - (buffer_top_and_bottom & 0xFFFFFF);