Kernel/Userspace: Replace my custom SHM system with SysV shm

This allows xbanan to use shm!

userspace/programs/WindowServer/Window.cpp

@@ -1,19 +1,16 @@
 #include "Window.h"
 
 #include <BAN/Debug.h>
-#include <BAN/ScopeGuard.h>
 
 #include <LibGUI/Window.h>
 
-#include <sys/banan-os.h>
-#include <sys/mman.h>
+#include <sys/shm.h>
 #include <sys/socket.h>
 #include <unistd.h>
 
 Window::~Window()
 {
-	munmap(m_fb_addr, client_width() * client_height() * 4);
-	smo_delete(m_smo_key);
+	shmdt(m_fb_addr);
 
 	LibGUI::EventPacket::DestroyWindowEvent packet;
 
@@ -45,16 +42,16 @@ BAN::ErrorOr<void> Window::resize(uint32_t width, uint32_t height)
 {
 	const size_t fb_bytes = width * height * 4;
 
-	long smo_key = smo_create(fb_bytes, PROT_READ | PROT_WRITE);
-	if (smo_key == -1)
+	const int shmid = shmget(IPC_PRIVATE, fb_bytes, 0666);
+	if (shmid == -1)
 		return BAN::Error::from_errno(errno);
-	BAN::ScopeGuard smo_deleter([&]() { smo_delete(smo_key); });
 
-	uint32_t* fb_addr = static_cast<uint32_t*>(smo_map(smo_key));
-	if (fb_addr == nullptr)
+	uint32_t* fb_addr = static_cast<uint32_t*>(shmat(shmid, nullptr, 0));
+	shmctl(shmid, IPC_RMID, nullptr);
+
+	if (fb_addr == SHM_FAILED)
 		return BAN::Error::from_errno(errno);
 	memset(fb_addr, 0xFF, fb_bytes);
-	BAN::ScopeGuard smo_unmapper([&]() { munmap(fb_addr, fb_bytes); });
 
 	{
 		const auto old_area = m_client_area;
@@ -65,19 +62,17 @@ BAN::ErrorOr<void> Window::resize(uint32_t width, uint32_t height)
 		m_client_area = old_area;
 
 		if (title_bar_ret.is_error())
+		{
+			shmdt(fb_addr);
 			return title_bar_ret.release_error();
+		}
 	}
 
-	smo_deleter.disable();
-	smo_unmapper.disable();
-
-	if (m_fb_addr)
-		munmap(m_fb_addr, client_width() * client_height() * 4);
-	if (m_smo_key)
-		smo_delete(m_smo_key);
+	if (m_fb_addr != nullptr)
+		shmdt(m_fb_addr);
 
 	m_fb_addr = fb_addr;
-	m_smo_key = smo_key;
+	m_shmid   = shmid;
 
 	m_client_area.max_x = m_client_area.min_x + width;
 	m_client_area.max_y = m_client_area.min_y + height;

userspace/programs/WindowServer/Window.h

@@ -42,7 +42,7 @@ public:
 	}
 
 	int client_fd() const { return m_client_fd; }
-	long smo_key() const { return m_smo_key; }
+	int shmid() const { return m_shmid; }
 
 	int32_t client_x() const { return m_client_area.min_x; }
 	int32_t client_y() const { return m_client_area.min_y; }
@@ -113,7 +113,7 @@ private:
 	Rectangle   m_client_area    { 0, 0, 0, 0 };
 	Rectangle   m_min_size       { 0, 0, m_title_bar_height, 0 };
 	Rectangle   m_max_size       { 0, 0, 10'000, 10'000 };
-	long        m_smo_key        { 0 };
+	int         m_shmid          { -1 };
 	uint32_t*   m_fb_addr        { nullptr };
 	BAN::String m_title;
 

userspace/programs/WindowServer/WindowServer.cpp

@@ -10,7 +10,6 @@
 #include <stdlib.h>
 #include <sys/banan-os.h>
 #include <sys/ioctl.h>
-#include <sys/mman.h>
 #include <sys/socket.h>
 #include <unistd.h>
 
@@ -128,7 +127,7 @@ void WindowServer::on_window_create(int fd, const LibGUI::WindowPacket::WindowCr
 	const LibGUI::EventPacket::ResizeWindowEvent event_packet {
 		.width  = static_cast<uint32_t>(window->client_width()),
 		.height = static_cast<uint32_t>(window->client_height()),
-		.smo_key = window->smo_key(),
+		.shmid  = window->shmid(),
 	};
 	if (auto ret = append_serialized_packet(event_packet, fd); ret.is_error())
 	{
@@ -731,7 +730,7 @@ void WindowServer::on_mouse_button(LibInput::MouseButtonEvent event)
 				const LibGUI::EventPacket::ResizeWindowEvent event_packet {
 					.width  = static_cast<uint32_t>(m_focused_window->client_width()),
 					.height = static_cast<uint32_t>(m_focused_window->client_height()),
-					.smo_key = m_focused_window->smo_key(),
+					.shmid  = m_focused_window->shmid(),
 				};
 				if (auto ret = append_serialized_packet(event_packet, m_focused_window->client_fd()); ret.is_error())
 				{
@@ -1771,7 +1770,7 @@ bool WindowServer::resize_window(BAN::RefPtr<Window> window, uint32_t width, uin
 	const LibGUI::EventPacket::ResizeWindowEvent event_packet {
 		.width  = static_cast<uint32_t>(window->client_width()),
 		.height = static_cast<uint32_t>(window->client_height()),
-		.smo_key = window->smo_key(),
+		.shmid  = window->shmid(),
 	};
 	if (auto ret = append_serialized_packet(event_packet, window->client_fd()); ret.is_error())
 	{