From df77fc8de8cf8aa17ce98e8a09e478e2688359bf Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Wed, 2 Aug 2023 14:47:58 +0200
Subject: [PATCH] libluna: Remove make_array() and destroy_array()

Placement new on arrays is a bit unreliable and could cause out-of-bounds data accesses.
---
 kernel/src/arch/x86_64/disk/ATA.cpp |  4 ++--
 kernel/src/fs/GPT.cpp               |  4 ++--
 kernel/src/fs/ext2/Inode.cpp        |  4 ++--
 libluna/include/luna/Alloc.h        | 12 ------------
 libos/src/FileSystem.cpp            |  5 ++---
 5 files changed, 8 insertions(+), 21 deletions(-)

diff --git a/kernel/src/arch/x86_64/disk/ATA.cpp b/kernel/src/arch/x86_64/disk/ATA.cpp
index a0026c3f..7dc03484 100644
--- a/kernel/src/arch/x86_64/disk/ATA.cpp
+++ b/kernel/src/arch/x86_64/disk/ATA.cpp
@@ -754,8 +754,8 @@ Result<u64> ATADevice::read(u8* buf, usize offset, usize size) const
     ScopedKMutexLock<100> lock(m_drive->channel()->lock());
 
     // FIXME: Don't always allocate this if we don't need it.
-    auto* temp = TRY(make_array<u8>(block_size));
-    auto guard = make_scope_guard([temp] { delete[] temp; });
+    auto* temp = (u8*)TRY(malloc_impl(block_size));
+    auto guard = make_scope_guard([temp] { free_impl(temp); });
 
     if (offset % block_size)
     {
diff --git a/kernel/src/fs/GPT.cpp b/kernel/src/fs/GPT.cpp
index 9a5c1d78..e3556a5f 100644
--- a/kernel/src/fs/GPT.cpp
+++ b/kernel/src/fs/GPT.cpp
@@ -41,8 +41,8 @@ namespace GPT
 
         u32 partition_index = 1;
 
-        auto* table = TRY(make_array<PartitionEntry>(header.num_partitions));
-        auto guard = make_scope_guard([table] { delete[] table; });
+        auto* table = (PartitionEntry*)TRY(calloc_impl(header.num_partitions, sizeof(PartitionEntry)));
+        auto guard = make_scope_guard([table] { free_impl(table); });
 
         nread = TRY(device->read((u8*)table, partition_table_start, sizeof(PartitionEntry) * header.num_partitions));
         check(nread == sizeof(PartitionEntry) * header.num_partitions);
diff --git a/kernel/src/fs/ext2/Inode.cpp b/kernel/src/fs/ext2/Inode.cpp
index 261adcab..872195c5 100644
--- a/kernel/src/fs/ext2/Inode.cpp
+++ b/kernel/src/fs/ext2/Inode.cpp
@@ -91,8 +91,8 @@ namespace Ext2
         const usize inode_size = m_metadata.size;
         const usize block_size = m_fs->m_block_size;
 
-        u8* const buf = TRY(make_array<u8>(block_size));
-        auto guard = make_scope_guard([buf] { delete[] buf; });
+        u8* const buf = (u8*)TRY(calloc_impl(block_size, 1));
+        auto guard = make_scope_guard([buf] { free_impl(buf); });
 
         m_entries.clear();
 
diff --git a/libluna/include/luna/Alloc.h b/libluna/include/luna/Alloc.h
index 1e89feb6..a6e0dfb5 100644
--- a/libluna/include/luna/Alloc.h
+++ b/libluna/include/luna/Alloc.h
@@ -10,19 +10,7 @@ template <typename T, class... Args> [[nodiscard]] Result<T*> make(Args... args)
     return result;
 }
 
-template <typename T> [[nodiscard]] Result<T*> make_array(usize count)
-{
-    T* const result = (T*)TRY(calloc_impl(count, sizeof(T)));
-    new (result) T[count];
-    return result;
-}
-
 template <typename T> void destroy(T* item)
 {
     delete item;
 }
-
-template <typename T> void destroy_array(T* item)
-{
-    delete[] item;
-}
diff --git a/libos/src/FileSystem.cpp b/libos/src/FileSystem.cpp
index 4c753d45..1c2e4a9d 100644
--- a/libos/src/FileSystem.cpp
+++ b/libos/src/FileSystem.cpp
@@ -82,12 +82,11 @@ namespace os::FileSystem
         TRY(stat(path, st, false));
         if (!S_ISLNK(st.st_mode)) return String {};
 
-        char* buf = TRY(make_array<char>(st.st_size + 1));
-        auto guard = make_scope_guard([buf] { delete[] buf; });
+        char* buf = (char*)TRY(calloc_impl(st.st_size + 1, 1));
+        auto guard = make_scope_guard([buf] { free_impl(buf); });
         usize nread = TRY(
             Result<usize>::from_syscall(syscall(SYS_readlinkat, path.dirfd(), path.name().chars(), buf, st.st_size)));
 
-        buf[nread] = '\0';
         guard.deactivate();
 
         return String { buf, nread };