DynamicLoader: Don't do file backed mapping for filesz == 0

This is just to make memory mapping ELF files easier :D

kernel/kernel/Memory/FileBackedRegion.cpp

@@ -13,8 +13,20 @@ namespace Kernel
 
 		if (offset < 0 || offset % PAGE_SIZE || size == 0)
 			return BAN::Error::from_errno(EINVAL);
-		if (size > (size_t)inode->size() || (size_t)offset > (size_t)inode->size() - size)
+		switch (type)
+		{
+			case Type::PRIVATE:
+				if (offset >= inode->size())
 					return BAN::Error::from_errno(EOVERFLOW);
+				break;
+			case Type::SHARED:
+				if ((size > (size_t)inode->size() || (size_t)offset > (size_t)inode->size() - size))
+					return BAN::Error::from_errno(EOVERFLOW);
+				break;
+			default:
+				ASSERT_NOT_REACHED();
+				break;
+		}
 
 		auto* region_ptr = new FileBackedRegion(inode, page_table, offset, size, type, flags);
 		if (region_ptr == nullptr)
@@ -112,7 +124,7 @@ namespace Kernel
 		ASSERT(contains(address));
 
 		// Check if address is already mapped
-		vaddr_t vaddr = address & PAGE_ADDR_MASK;
+		const vaddr_t vaddr = address & PAGE_ADDR_MASK;
 		if (m_page_table.physical_address_of(vaddr) != 0)
 			return false;
 
@@ -126,10 +138,14 @@ namespace Kernel
 			// Temporarily force mapping to be writable so kernel can write to it
 			m_page_table.map_page_at(paddr, vaddr, m_flags | PageTable::Flags::ReadWrite);
 
-			size_t file_offset = m_offset + (vaddr - m_vaddr);
-			size_t bytes = BAN::Math::min<size_t>(m_size - file_offset, PAGE_SIZE);
-
 			ASSERT(&PageTable::current() == &m_page_table);
+			memset(reinterpret_cast<void*>(vaddr), 0x00, PAGE_SIZE);
+
+			const size_t file_offset = m_offset + (vaddr - m_vaddr);
+
+			if (file_offset < static_cast<size_t>(m_inode->size()))
+			{
+				const size_t bytes = BAN::Math::min<size_t>(BAN::Math::min<size_t>(m_offset + m_size, m_inode->size()) - file_offset, PAGE_SIZE);
 				auto read_ret = m_inode->read(file_offset, BAN::ByteSpan((uint8_t*)vaddr, bytes));
 
 				if (read_ret.is_error())
@@ -146,6 +162,7 @@ namespace Kernel
 					m_page_table.unmap_page(vaddr);
 					return BAN::Error::from_errno(EIO);
 				}
+			}
 
 			// Disable writable if not wanted
 			if (!(m_flags & PageTable::Flags::ReadWrite))
@@ -172,7 +189,8 @@ namespace Kernel
 				TRY(m_inode->read(offset, BAN::ByteSpan(m_shared_data->page_buffer, bytes)));
 
 				PageTable::with_fast_page(pages[page_index], [&] {
-					memcpy(PageTable::fast_page_as_ptr(), m_shared_data->page_buffer, PAGE_SIZE);
+					memcpy(PageTable::fast_page_as_ptr(), m_shared_data->page_buffer, bytes);
+					memset(PageTable::fast_page_as_ptr(bytes), 0x00, PAGE_SIZE - bytes);
 				});
 			}
 

ports/install.sh

@@ -36,6 +36,10 @@ if [ ! -f "$BANAN_SYSROOT/usr/lib/libc.a" ]; then
 	popd >/dev/null
 fi
 
+if [ "$BANAN_ARCH" = "i686" ]; then
+	export LDFLAGS="-shared-libgcc"
+fi
+
 clean() {
 	find . -mindepth 1 -maxdepth 1 -not -name 'patches' -not -name 'build.sh' -exec rm -rf {} +
 }

userspace/programs/DynamicLoader/main.cpp

@@ -622,7 +622,7 @@ static void load_program_header(const ElfNativeProgramHeader& program_header, in
 			return result;
 		}();
 
-	if ((program_header.p_vaddr & 0xFFF) || (program_header.p_offset & 0xFFF))
+	if ((program_header.p_vaddr & 0xFFF) || (program_header.p_offset & 0xFFF) || program_header.p_filesz == 0)
 	{
 		const uintptr_t aligned_addr = program_header.p_vaddr & ~(uintptr_t)0xFFF;