diff --git a/Kernel/Devices/HID/KeyboardDevice.cpp b/Kernel/Devices/HID/KeyboardDevice.cpp
index a95465228ed..7d490f85950 100644
--- a/Kernel/Devices/HID/KeyboardDevice.cpp
+++ b/Kernel/Devices/HID/KeyboardDevice.cpp
@@ -311,38 +311,38 @@ KResultOr<size_t> KeyboardDevice::write(FileDescription&, u64, const UserOrKerne
     return 0;
 }
 
-int KeyboardDevice::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
+KResult KeyboardDevice::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
 {
     switch (request) {
     case KEYBOARD_IOCTL_GET_NUM_LOCK: {
         auto output = static_ptr_cast<bool*>(arg);
         if (!copy_to_user(output, &m_num_lock_on))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     }
     case KEYBOARD_IOCTL_SET_NUM_LOCK: {
         // In this case we expect the value to be a boolean and not a pointer.
         auto num_lock_value = static_cast<u8>(arg.ptr());
         if (num_lock_value != 0 && num_lock_value != 1)
-            return -EINVAL;
+            return EINVAL;
         m_num_lock_on = !!num_lock_value;
-        return 0;
+        return KSuccess;
     }
     case KEYBOARD_IOCTL_GET_CAPS_LOCK: {
         auto output = static_ptr_cast<bool*>(arg);
         if (!copy_to_user(output, &m_caps_lock_on))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     }
     case KEYBOARD_IOCTL_SET_CAPS_LOCK: {
         auto caps_lock_value = static_cast<u8>(arg.ptr());
         if (caps_lock_value != 0 && caps_lock_value != 1)
-            return -EINVAL;
+            return EINVAL;
         m_caps_lock_on = !!caps_lock_value;
-        return 0;
+        return KSuccess;
     }
     default:
-        return -EINVAL;
+        return EINVAL;
     };
 }
 
diff --git a/Kernel/Devices/HID/KeyboardDevice.h b/Kernel/Devices/HID/KeyboardDevice.h
index 5bd43a97670..3269971a208 100644
--- a/Kernel/Devices/HID/KeyboardDevice.h
+++ b/Kernel/Devices/HID/KeyboardDevice.h
@@ -37,7 +37,7 @@ public:
     virtual mode_t required_mode() const override { return 0440; }
 
     // ^File
-    virtual int ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override;
+    virtual KResult ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override;
 
     virtual String device_name() const override { return String::formatted("keyboard{}", minor()); }
 
diff --git a/Kernel/FileSystem/File.cpp b/Kernel/FileSystem/File.cpp
index 29bc1fc5e94..355b6ed56df 100644
--- a/Kernel/FileSystem/File.cpp
+++ b/Kernel/FileSystem/File.cpp
@@ -35,9 +35,9 @@ KResult File::close()
     return KSuccess;
 }
 
-int File::ioctl(FileDescription&, unsigned, Userspace<void*>)
+KResult File::ioctl(FileDescription&, unsigned, Userspace<void*>)
 {
-    return -ENOTTY;
+    return ENOTTY;
 }
 
 KResultOr<Region*> File::mmap(Process&, FileDescription&, const Range&, u64, int, bool)
diff --git a/Kernel/FileSystem/File.h b/Kernel/FileSystem/File.h
index f51569897ea..6410d1e1cb2 100644
--- a/Kernel/FileSystem/File.h
+++ b/Kernel/FileSystem/File.h
@@ -87,7 +87,7 @@ public:
     virtual void did_seek(FileDescription&, off_t) { }
     virtual KResultOr<size_t> read(FileDescription&, u64, UserOrKernelBuffer&, size_t) = 0;
     virtual KResultOr<size_t> write(FileDescription&, u64, const UserOrKernelBuffer&, size_t) = 0;
-    virtual int ioctl(FileDescription&, unsigned request, Userspace<void*> arg);
+    virtual KResult ioctl(FileDescription&, unsigned request, Userspace<void*> arg);
     virtual KResultOr<Region*> mmap(Process&, FileDescription&, const Range&, u64 offset, int prot, bool shared);
     virtual KResult stat(::stat&) const { return EBADF; }
 
diff --git a/Kernel/FileSystem/InodeFile.cpp b/Kernel/FileSystem/InodeFile.cpp
index a0d657b88b6..c7462ac42e3 100644
--- a/Kernel/FileSystem/InodeFile.cpp
+++ b/Kernel/FileSystem/InodeFile.cpp
@@ -62,34 +62,34 @@ KResultOr<size_t> InodeFile::write(FileDescription& description, u64 offset, con
     return nwritten;
 }
 
-int InodeFile::ioctl(FileDescription& description, unsigned request, Userspace<void*> arg)
+KResult InodeFile::ioctl(FileDescription& description, unsigned request, Userspace<void*> arg)
 {
     (void)description;
 
     switch (request) {
     case FIBMAP: {
         if (!Process::current()->is_superuser())
-            return -EPERM;
+            return EPERM;
 
         auto user_block_number = static_ptr_cast<int*>(arg);
         int block_number = 0;
         if (!copy_from_user(&block_number, user_block_number))
-            return -EFAULT;
+            return EFAULT;
 
         if (block_number < 0)
-            return -EINVAL;
+            return EINVAL;
 
         auto block_address = inode().get_block_address(block_number);
         if (block_address.is_error())
             return block_address.error();
 
         if (!copy_to_user(user_block_number, &block_address.value()))
-            return -EFAULT;
+            return EFAULT;
 
-        return 0;
+        return KSuccess;
     }
     default:
-        return -EINVAL;
+        return EINVAL;
     }
 }
 
diff --git a/Kernel/FileSystem/InodeFile.h b/Kernel/FileSystem/InodeFile.h
index 2fb6a38d172..5fe928a21de 100644
--- a/Kernel/FileSystem/InodeFile.h
+++ b/Kernel/FileSystem/InodeFile.h
@@ -32,7 +32,7 @@ public:
 
     virtual KResultOr<size_t> read(FileDescription&, u64, UserOrKernelBuffer&, size_t) override;
     virtual KResultOr<size_t> write(FileDescription&, u64, const UserOrKernelBuffer&, size_t) override;
-    virtual int ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override;
+    virtual KResult ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override;
     virtual KResultOr<Region*> mmap(Process&, FileDescription&, const Range&, u64 offset, int prot, bool shared) override;
     virtual KResult stat(::stat& buffer) const override { return inode().metadata().stat(buffer); }
 
diff --git a/Kernel/Graphics/FramebufferDevice.cpp b/Kernel/Graphics/FramebufferDevice.cpp
index 435868ccb36..822db739513 100644
--- a/Kernel/Graphics/FramebufferDevice.cpp
+++ b/Kernel/Graphics/FramebufferDevice.cpp
@@ -143,7 +143,7 @@ size_t FramebufferDevice::framebuffer_size_in_bytes() const
     return m_framebuffer_pitch * m_framebuffer_height;
 }
 
-int FramebufferDevice::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
+KResult FramebufferDevice::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
 {
     REQUIRE_PROMISE(video);
     switch (request) {
@@ -151,26 +151,26 @@ int FramebufferDevice::ioctl(FileDescription&, unsigned request, Userspace<void*
         auto user_size = static_ptr_cast<size_t*>(arg);
         size_t value = framebuffer_size_in_bytes();
         if (!copy_to_user(user_size, &value))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     }
     case FB_IOCTL_GET_BUFFER: {
         auto user_index = static_ptr_cast<int*>(arg);
         int value = m_y_offset == 0 ? 0 : 1;
         if (!copy_to_user(user_index, &value))
-            return -EFAULT;
+            return EFAULT;
         if (!m_graphics_adapter->double_framebuffering_capable())
-            return -ENOTIMPL;
-        return 0;
+            return ENOTIMPL;
+        return KSuccess;
     }
     case FB_IOCTL_SET_BUFFER: {
         auto buffer = static_cast<int>(arg.ptr());
         if (buffer != 0 && buffer != 1)
-            return -EINVAL;
+            return EINVAL;
         if (!m_graphics_adapter->double_framebuffering_capable())
-            return -ENOTIMPL;
+            return ENOTIMPL;
         m_graphics_adapter->set_y_offset(m_output_port_index, buffer == 0 ? 0 : m_framebuffer_height);
-        return 0;
+        return KSuccess;
     }
     case FB_IOCTL_GET_RESOLUTION: {
         auto user_resolution = static_ptr_cast<FBResolution*>(arg);
@@ -179,24 +179,24 @@ int FramebufferDevice::ioctl(FileDescription&, unsigned request, Userspace<void*
         resolution.width = m_framebuffer_width;
         resolution.height = m_framebuffer_height;
         if (!copy_to_user(user_resolution, &resolution))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     }
     case FB_IOCTL_SET_RESOLUTION: {
         auto user_resolution = static_ptr_cast<FBResolution*>(arg);
         FBResolution resolution;
         if (!copy_from_user(&resolution, user_resolution))
-            return -EFAULT;
+            return EFAULT;
         if (resolution.width > MAX_RESOLUTION_WIDTH || resolution.height > MAX_RESOLUTION_HEIGHT)
-            return -EINVAL;
+            return EINVAL;
 
         if (!m_graphics_adapter->modesetting_capable()) {
             resolution.pitch = m_framebuffer_pitch;
             resolution.width = m_framebuffer_width;
             resolution.height = m_framebuffer_height;
             if (!copy_to_user(user_resolution, &resolution))
-                return -EFAULT;
-            return -ENOTIMPL;
+                return EFAULT;
+            return ENOTIMPL;
         }
 
         if (!m_graphics_adapter->try_to_set_resolution(m_output_port_index, resolution.width, resolution.height)) {
@@ -210,8 +210,8 @@ int FramebufferDevice::ioctl(FileDescription&, unsigned request, Userspace<void*
             resolution.width = m_framebuffer_width;
             resolution.height = m_framebuffer_height;
             if (!copy_to_user(user_resolution, &resolution))
-                return -EFAULT;
-            return -EINVAL;
+                return EFAULT;
+            return EINVAL;
         }
         m_framebuffer_width = resolution.width;
         m_framebuffer_height = resolution.height;
@@ -222,25 +222,25 @@ int FramebufferDevice::ioctl(FileDescription&, unsigned request, Userspace<void*
         resolution.width = m_framebuffer_width;
         resolution.height = m_framebuffer_height;
         if (!copy_to_user(user_resolution, &resolution))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     }
     case FB_IOCTL_GET_BUFFER_OFFSET: {
         auto user_buffer_offset = static_ptr_cast<FBBufferOffset*>(arg);
         FBBufferOffset buffer_offset;
         if (!copy_from_user(&buffer_offset, user_buffer_offset))
-            return -EFAULT;
+            return EFAULT;
         if (buffer_offset.buffer_index != 0 && buffer_offset.buffer_index != 1)
-            return -EINVAL;
+            return EINVAL;
         buffer_offset.offset = (size_t)buffer_offset.buffer_index * m_framebuffer_pitch * m_framebuffer_height;
         if (!copy_to_user(user_buffer_offset, &buffer_offset))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     }
     case FB_IOCTL_FLUSH_BUFFERS:
-        return -ENOTSUP;
+        return ENOTSUP;
     default:
-        return -EINVAL;
+        return EINVAL;
     };
 }
 
diff --git a/Kernel/Graphics/FramebufferDevice.h b/Kernel/Graphics/FramebufferDevice.h
index bde59ddbe31..033c248dbb0 100644
--- a/Kernel/Graphics/FramebufferDevice.h
+++ b/Kernel/Graphics/FramebufferDevice.h
@@ -22,7 +22,7 @@ class FramebufferDevice : public BlockDevice {
 public:
     static NonnullRefPtr<FramebufferDevice> create(const GraphicsDevice&, size_t, PhysicalAddress, size_t, size_t, size_t);
 
-    virtual int ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override;
+    virtual KResult ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override;
     virtual KResultOr<Region*> mmap(Process&, FileDescription&, const Range&, u64 offset, int prot, bool shared) override;
 
     // ^Device
diff --git a/Kernel/Graphics/VirtIOGPU/FrameBufferDevice.cpp b/Kernel/Graphics/VirtIOGPU/FrameBufferDevice.cpp
index 126a1313a90..eb312811df2 100644
--- a/Kernel/Graphics/VirtIOGPU/FrameBufferDevice.cpp
+++ b/Kernel/Graphics/VirtIOGPU/FrameBufferDevice.cpp
@@ -140,7 +140,7 @@ void FrameBufferDevice::set_buffer(int buffer_index)
     buffer.dirty_rect = {};
 }
 
-int FrameBufferDevice::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
+KResult FrameBufferDevice::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
 {
     REQUIRE_PROMISE(video);
     switch (request) {
@@ -148,20 +148,20 @@ int FrameBufferDevice::ioctl(FileDescription&, unsigned request, Userspace<void*
         auto out = static_ptr_cast<size_t*>(arg);
         size_t value = m_buffer_size * 2;
         if (!copy_to_user(out, &value))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     }
     case FB_IOCTL_SET_RESOLUTION: {
         auto user_resolution = static_ptr_cast<FBResolution*>(arg);
         FBResolution resolution;
         if (!copy_from_user(&resolution, user_resolution))
-            return -EFAULT;
+            return EFAULT;
         if (!try_to_set_resolution(resolution.width, resolution.height))
-            return -EINVAL;
+            return EINVAL;
         resolution.pitch = pitch();
         if (!copy_to_user(user_resolution, &resolution))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     }
     case FB_IOCTL_GET_RESOLUTION: {
         auto user_resolution = static_ptr_cast<FBResolution*>(arg);
@@ -170,33 +170,33 @@ int FrameBufferDevice::ioctl(FileDescription&, unsigned request, Userspace<void*
         resolution.width = width();
         resolution.height = height();
         if (!copy_to_user(user_resolution, &resolution))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     }
     case FB_IOCTL_SET_BUFFER: {
         auto buffer_index = static_cast<int>(arg.ptr());
         if (!is_valid_buffer_index(buffer_index))
-            return -EINVAL;
+            return EINVAL;
         if (m_last_set_buffer_index.exchange(buffer_index) != buffer_index && m_are_writes_active)
             set_buffer(buffer_index);
-        return 0;
+        return KSuccess;
     }
     case FB_IOCTL_FLUSH_BUFFERS: {
         auto user_flush_rects = static_ptr_cast<FBFlushRects*>(arg);
         FBFlushRects flush_rects;
         if (!copy_from_user(&flush_rects, user_flush_rects))
-            return -EFAULT;
+            return EFAULT;
         if (!is_valid_buffer_index(flush_rects.buffer_index))
-            return -EINVAL;
+            return EINVAL;
         if (Checked<unsigned>::multiplication_would_overflow(flush_rects.count, sizeof(FBRect)))
-            return -EFAULT;
+            return EFAULT;
         if (m_are_writes_active && flush_rects.count > 0) {
             auto& buffer = buffer_from_index(flush_rects.buffer_index);
             MutexLocker locker(m_gpu.operation_lock());
             for (unsigned i = 0; i < flush_rects.count; i++) {
                 FBRect user_dirty_rect;
                 if (!copy_from_user(&user_dirty_rect, &flush_rects.rects[i]))
-                    return -EFAULT;
+                    return EFAULT;
                 Protocol::Rect dirty_rect {
                     .x = user_dirty_rect.x,
                     .y = user_dirty_rect.y,
@@ -222,22 +222,22 @@ int FrameBufferDevice::ioctl(FileDescription&, unsigned request, Userspace<void*
                 }
             }
         }
-        return 0;
+        return KSuccess;
     }
     case FB_IOCTL_GET_BUFFER_OFFSET: {
         auto user_buffer_offset = static_ptr_cast<FBBufferOffset*>(arg);
         FBBufferOffset buffer_offset;
         if (!copy_from_user(&buffer_offset, user_buffer_offset))
-            return -EFAULT;
+            return EFAULT;
         if (!is_valid_buffer_index(buffer_offset.buffer_index))
-            return -EINVAL;
+            return EINVAL;
         buffer_offset.offset = (size_t)buffer_offset.buffer_index * m_buffer_size;
         if (!copy_to_user(user_buffer_offset, &buffer_offset))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     }
     default:
-        return -EINVAL;
+        return EINVAL;
     };
 }
 
diff --git a/Kernel/Graphics/VirtIOGPU/FrameBufferDevice.h b/Kernel/Graphics/VirtIOGPU/FrameBufferDevice.h
index e7bbae86249..54b765a40cb 100644
--- a/Kernel/Graphics/VirtIOGPU/FrameBufferDevice.h
+++ b/Kernel/Graphics/VirtIOGPU/FrameBufferDevice.h
@@ -60,7 +60,7 @@ private:
     void create_buffer(Buffer&, size_t, size_t);
     void set_buffer(int);
 
-    virtual int ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override;
+    virtual KResult ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override;
     virtual KResultOr<Region*> mmap(Process&, FileDescription&, const Range&, u64 offset, int prot, bool shared) override;
     virtual bool can_read(const FileDescription&, size_t) const override { return true; }
     virtual KResultOr<size_t> read(FileDescription&, u64, UserOrKernelBuffer&, size_t) override { return EINVAL; }
diff --git a/Kernel/Net/IPv4Socket.cpp b/Kernel/Net/IPv4Socket.cpp
index 9aa0fd61bc8..a539b4c5039 100644
--- a/Kernel/Net/IPv4Socket.cpp
+++ b/Kernel/Net/IPv4Socket.cpp
@@ -568,75 +568,75 @@ KResult IPv4Socket::getsockopt(FileDescription& description, int level, int opti
     }
 }
 
-int IPv4Socket::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
+KResult IPv4Socket::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
 {
     REQUIRE_PROMISE(inet);
 
-    auto ioctl_route = [request, arg]() {
+    auto ioctl_route = [request, arg]() -> KResult {
         auto user_route = static_ptr_cast<rtentry*>(arg);
         rtentry route;
         if (!copy_from_user(&route, user_route))
-            return -EFAULT;
+            return EFAULT;
 
         auto copied_ifname = copy_string_from_user(route.rt_dev, IFNAMSIZ);
         if (copied_ifname.is_null())
-            return -EFAULT;
+            return EFAULT;
 
         auto adapter = NetworkingManagement::the().lookup_by_name(copied_ifname);
         if (!adapter)
-            return -ENODEV;
+            return ENODEV;
 
         switch (request) {
         case SIOCADDRT:
             if (!Process::current()->is_superuser())
-                return -EPERM;
+                return EPERM;
             if (route.rt_gateway.sa_family != AF_INET)
-                return -EAFNOSUPPORT;
+                return EAFNOSUPPORT;
             if ((route.rt_flags & (RTF_UP | RTF_GATEWAY)) != (RTF_UP | RTF_GATEWAY))
-                return -EINVAL; // FIXME: Find the correct value to return
+                return EINVAL; // FIXME: Find the correct value to return
             adapter->set_ipv4_gateway(IPv4Address(((sockaddr_in&)route.rt_gateway).sin_addr.s_addr));
-            return 0;
+            return KSuccess;
 
         case SIOCDELRT:
             // FIXME: Support gateway deletion
-            return 0;
+            return KSuccess;
         }
 
-        return -EINVAL;
+        return EINVAL;
     };
 
-    auto ioctl_arp = [request, arg]() {
+    auto ioctl_arp = [request, arg]() -> KResult {
         auto user_req = static_ptr_cast<arpreq*>(arg);
         arpreq arp_req;
         if (!copy_from_user(&arp_req, user_req))
-            return -EFAULT;
+            return EFAULT;
 
         switch (request) {
         case SIOCSARP:
             if (!Process::current()->is_superuser())
-                return -EPERM;
+                return EPERM;
             if (arp_req.arp_pa.sa_family != AF_INET)
-                return -EAFNOSUPPORT;
+                return EAFNOSUPPORT;
             update_arp_table(IPv4Address(((sockaddr_in&)arp_req.arp_pa).sin_addr.s_addr), *(MACAddress*)&arp_req.arp_ha.sa_data[0], UpdateArp::Set);
-            return 0;
+            return KSuccess;
 
         case SIOCDARP:
             if (!Process::current()->is_superuser())
-                return -EPERM;
+                return EPERM;
             if (arp_req.arp_pa.sa_family != AF_INET)
-                return -EAFNOSUPPORT;
+                return EAFNOSUPPORT;
             update_arp_table(IPv4Address(((sockaddr_in&)arp_req.arp_pa).sin_addr.s_addr), *(MACAddress*)&arp_req.arp_ha.sa_data[0], UpdateArp::Delete);
-            return 0;
+            return KSuccess;
         }
 
-        return -EINVAL;
+        return EINVAL;
     };
 
-    auto ioctl_interface = [request, arg]() {
+    auto ioctl_interface = [request, arg]() -> KResult {
         auto user_ifr = static_ptr_cast<ifreq*>(arg);
         ifreq ifr;
         if (!copy_from_user(&ifr, user_ifr))
-            return -EFAULT;
+            return EFAULT;
 
         char namebuf[IFNAMSIZ + 1];
         memcpy(namebuf, ifr.ifr_name, IFNAMSIZ);
@@ -644,24 +644,24 @@ int IPv4Socket::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
 
         auto adapter = NetworkingManagement::the().lookup_by_name(namebuf);
         if (!adapter)
-            return -ENODEV;
+            return ENODEV;
 
         switch (request) {
         case SIOCSIFADDR:
             if (!Process::current()->is_superuser())
-                return -EPERM;
+                return EPERM;
             if (ifr.ifr_addr.sa_family != AF_INET)
-                return -EAFNOSUPPORT;
+                return EAFNOSUPPORT;
             adapter->set_ipv4_address(IPv4Address(((sockaddr_in&)ifr.ifr_addr).sin_addr.s_addr));
-            return 0;
+            return KSuccess;
 
         case SIOCSIFNETMASK:
             if (!Process::current()->is_superuser())
-                return -EPERM;
+                return EPERM;
             if (ifr.ifr_addr.sa_family != AF_INET)
-                return -EAFNOSUPPORT;
+                return EAFNOSUPPORT;
             adapter->set_ipv4_netmask(IPv4Address(((sockaddr_in&)ifr.ifr_netmask).sin_addr.s_addr));
-            return 0;
+            return KSuccess;
 
         case SIOCGIFADDR: {
             auto ip4_addr = adapter->ipv4_address().to_u32();
@@ -669,8 +669,8 @@ int IPv4Socket::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
             socket_address_in.sin_family = AF_INET;
             socket_address_in.sin_addr.s_addr = ip4_addr;
             if (!copy_to_user(user_ifr, &ifr))
-                return -EFAULT;
-            return 0;
+                return EFAULT;
+            return KSuccess;
         }
 
         case SIOCGIFNETMASK: {
@@ -681,8 +681,8 @@ int IPv4Socket::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
             socket_address_in.sin_addr.s_addr = ip4_netmask;
 
             if (!copy_to_user(user_ifr, &ifr))
-                return -EFAULT;
-            return 0;
+                return EFAULT;
+            return KSuccess;
         }
 
         case SIOCGIFHWADDR: {
@@ -690,8 +690,8 @@ int IPv4Socket::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
             ifr.ifr_hwaddr.sa_family = AF_INET;
             mac_address.copy_to(Bytes { ifr.ifr_hwaddr.sa_data, sizeof(ifr.ifr_hwaddr.sa_data) });
             if (!copy_to_user(user_ifr, &ifr))
-                return -EFAULT;
-            return 0;
+                return EFAULT;
+            return KSuccess;
         }
 
         case SIOCGIFBRDADDR: {
@@ -703,8 +703,8 @@ int IPv4Socket::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
             socket_address_in.sin_family = AF_INET;
             socket_address_in.sin_addr.s_addr = broadcast_addr;
             if (!copy_to_user(user_ifr, &ifr))
-                return -EFAULT;
-            return 0;
+                return EFAULT;
+            return KSuccess;
         }
 
         case SIOCGIFMTU: {
@@ -713,8 +713,8 @@ int IPv4Socket::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
             ifr.ifr_addr.sa_family = AF_INET;
             ifr.ifr_metric = ip4_metric;
             if (!copy_to_user(user_ifr, &ifr))
-                return -EFAULT;
-            return 0;
+                return EFAULT;
+            return KSuccess;
         }
 
         case SIOCGIFFLAGS: {
@@ -723,17 +723,17 @@ int IPv4Socket::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
             ifr.ifr_addr.sa_family = AF_INET;
             ifr.ifr_flags = flags;
             if (!copy_to_user(user_ifr, &ifr))
-                return -EFAULT;
-            return 0;
+                return EFAULT;
+            return KSuccess;
         }
 
         case SIOCGIFCONF: {
             // FIXME: stub!
-            return -EINVAL;
+            return EINVAL;
         }
         }
 
-        return -EINVAL;
+        return EINVAL;
     };
 
     switch (request) {
@@ -757,7 +757,7 @@ int IPv4Socket::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
         return ioctl_arp();
     }
 
-    return -EINVAL;
+    return EINVAL;
 }
 
 KResult IPv4Socket::close()
diff --git a/Kernel/Net/IPv4Socket.h b/Kernel/Net/IPv4Socket.h
index 1eed0a4d09f..3d47160aba8 100644
--- a/Kernel/Net/IPv4Socket.h
+++ b/Kernel/Net/IPv4Socket.h
@@ -46,7 +46,7 @@ public:
     virtual KResult setsockopt(int level, int option, Userspace<const void*>, socklen_t) override;
     virtual KResult getsockopt(FileDescription&, int level, int option, Userspace<void*>, Userspace<socklen_t*>) override;
 
-    virtual int ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override;
+    virtual KResult ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override;
 
     bool did_receive(const IPv4Address& peer_address, u16 peer_port, ReadonlyBytes, const Time&);
 
diff --git a/Kernel/TTY/MasterPTY.cpp b/Kernel/TTY/MasterPTY.cpp
index 6cf84f2c9ff..2179d7c90fd 100644
--- a/Kernel/TTY/MasterPTY.cpp
+++ b/Kernel/TTY/MasterPTY.cpp
@@ -106,14 +106,14 @@ KResult MasterPTY::close()
     return KSuccess;
 }
 
-int MasterPTY::ioctl(FileDescription& description, unsigned request, Userspace<void*> arg)
+KResult MasterPTY::ioctl(FileDescription& description, unsigned request, Userspace<void*> arg)
 {
     REQUIRE_PROMISE(tty);
     if (!m_slave)
-        return -EIO;
+        return EIO;
     if (request == TIOCSWINSZ || request == TIOCGPGRP)
         return m_slave->ioctl(description, request, arg);
-    return -EINVAL;
+    return EINVAL;
 }
 
 String MasterPTY::absolute_path(const FileDescription&) const
diff --git a/Kernel/TTY/MasterPTY.h b/Kernel/TTY/MasterPTY.h
index 96fcadea7aa..a1c92740465 100644
--- a/Kernel/TTY/MasterPTY.h
+++ b/Kernel/TTY/MasterPTY.h
@@ -40,7 +40,7 @@ private:
     virtual bool can_write(const FileDescription&, size_t) const override;
     virtual KResult close() override;
     virtual bool is_master_pty() const override { return true; }
-    virtual int ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override;
+    virtual KResult ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override;
     virtual StringView class_name() const override { return "MasterPTY"; }
 
     RefPtr<SlavePTY> m_slave;
diff --git a/Kernel/TTY/TTY.cpp b/Kernel/TTY/TTY.cpp
index c5a78021332..db7962bdb13 100644
--- a/Kernel/TTY/TTY.cpp
+++ b/Kernel/TTY/TTY.cpp
@@ -360,9 +360,9 @@ void TTY::flush_input()
     evaluate_block_conditions();
 }
 
-int TTY::set_termios(const termios& t)
+KResult TTY::set_termios(const termios& t)
 {
-    int rc = 0;
+    KResult rc = KSuccess;
     m_termios = t;
 
     dbgln_if(TTY_DEBUG, "{} set_termios: ECHO={}, ISIG={}, ICANON={}, ECHOE={}, ECHOK={}, ECHONL={}, ISTRIP={}, ICRNL={}, INLCR={}, IGNCR={}, OPOST={}, ONLCR={}",
@@ -402,7 +402,7 @@ int TTY::set_termios(const termios& t)
     for (auto flag : unimplemented_iflags) {
         if (m_termios.c_iflag & flag.value) {
             dbgln("FIXME: iflag {} unimplemented", flag.name);
-            rc = -ENOTIMPL;
+            rc = ENOTIMPL;
         }
     }
 
@@ -416,7 +416,7 @@ int TTY::set_termios(const termios& t)
     for (auto flag : unimplemented_oflags) {
         if (m_termios.c_oflag & flag.value) {
             dbgln("FIXME: oflag {} unimplemented", flag.name);
-            rc = -ENOTIMPL;
+            rc = ENOTIMPL;
         }
     }
 
@@ -436,7 +436,7 @@ int TTY::set_termios(const termios& t)
     for (auto flag : unimplemented_cflags) {
         if (m_termios.c_cflag & flag.value) {
             dbgln("FIXME: cflag {} unimplemented", flag.name);
-            rc = -ENOTIMPL;
+            rc = ENOTIMPL;
         }
     }
 
@@ -447,14 +447,14 @@ int TTY::set_termios(const termios& t)
     for (auto flag : unimplemented_lflags) {
         if (m_termios.c_lflag & flag.value) {
             dbgln("FIXME: lflag {} unimplemented", flag.name);
-            rc = -ENOTIMPL;
+            rc = ENOTIMPL;
         }
     }
 
     return rc;
 }
 
-int TTY::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
+KResult TTY::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
 {
     REQUIRE_PROMISE(tty);
     auto& current_process = *Process::current();
@@ -473,42 +473,42 @@ int TTY::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
         auto user_pgid = static_ptr_cast<pid_t*>(arg);
         auto pgid = this->pgid().value();
         if (!copy_to_user(user_pgid, &pgid))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     }
     case TIOCSPGRP: {
         ProcessGroupID pgid = static_cast<pid_t>(arg.ptr());
         if (pgid <= 0)
-            return -EINVAL;
+            return EINVAL;
         InterruptDisabler disabler;
         auto process_group = ProcessGroup::from_pgid(pgid);
         // Disallow setting a nonexistent PGID.
         if (!process_group)
-            return -EINVAL;
+            return EINVAL;
 
         auto process = Process::from_pid(ProcessID(pgid.value()));
         SessionID new_sid = process ? process->sid() : Process::get_sid_from_pgid(pgid);
         if (!new_sid || new_sid != current_process.sid())
-            return -EPERM;
+            return EPERM;
         if (process && pgid != process->pgid())
-            return -EPERM;
+            return EPERM;
         m_pg = process_group;
 
         if (process) {
             if (auto parent = Process::from_pid(process->ppid())) {
                 m_original_process_parent = *parent;
-                return 0;
+                return KSuccess;
             }
         }
 
         m_original_process_parent = nullptr;
-        return 0;
+        return KSuccess;
     }
     case TCGETS: {
         user_termios = static_ptr_cast<termios*>(arg);
         if (!copy_to_user(user_termios, &m_termios))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     }
     case TCSETS:
     case TCSETSF:
@@ -516,8 +516,8 @@ int TTY::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
         user_termios = static_ptr_cast<termios*>(arg);
         termios termios;
         if (!copy_from_user(&termios, user_termios))
-            return -EFAULT;
-        int rc = set_termios(termios);
+            return EFAULT;
+        auto rc = set_termios(termios);
         if (request == TCSETSF)
             flush_input();
         return rc;
@@ -528,9 +528,9 @@ int TTY::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
         if (operation == TCIFLUSH || operation == TCIOFLUSH) {
             flush_input();
         } else if (operation != TCOFLUSH) {
-            return -EINVAL;
+            return EINVAL;
         }
-        return 0;
+        return KSuccess;
     }
     case TIOCGWINSZ:
         user_winsize = static_ptr_cast<winsize*>(arg);
@@ -540,30 +540,30 @@ int TTY::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
         ws.ws_xpixel = 0;
         ws.ws_ypixel = 0;
         if (!copy_to_user(user_winsize, &ws))
-            return -EFAULT;
-        return 0;
+            return EFAULT;
+        return KSuccess;
     case TIOCSWINSZ: {
         user_winsize = static_ptr_cast<winsize*>(arg);
         winsize ws;
         if (!copy_from_user(&ws, user_winsize))
-            return -EFAULT;
+            return EFAULT;
         if (ws.ws_col == m_columns && ws.ws_row == m_rows)
-            return 0;
+            return KSuccess;
         m_rows = ws.ws_row;
         m_columns = ws.ws_col;
         generate_signal(SIGWINCH);
-        return 0;
+        return KSuccess;
     }
     case TIOCSCTTY:
         current_process.set_tty(this);
-        return 0;
+        return KSuccess;
     case TIOCSTI:
-        return -EIO;
+        return EIO;
     case TIOCNOTTY:
         current_process.set_tty(nullptr);
-        return 0;
+        return KSuccess;
     }
-    return -EINVAL;
+    return EINVAL;
 }
 
 void TTY::set_size(unsigned short columns, unsigned short rows)
diff --git a/Kernel/TTY/TTY.h b/Kernel/TTY/TTY.h
index 6d611b3332b..678e835605a 100644
--- a/Kernel/TTY/TTY.h
+++ b/Kernel/TTY/TTY.h
@@ -25,7 +25,7 @@ public:
     virtual KResultOr<size_t> write(FileDescription&, u64, const UserOrKernelBuffer&, size_t) override;
     virtual bool can_read(const FileDescription&, size_t) const override;
     virtual bool can_write(const FileDescription&, size_t) const override;
-    virtual int ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override final;
+    virtual KResult ioctl(FileDescription&, unsigned request, Userspace<void*> arg) override final;
     virtual String absolute_path(const FileDescription&) const override { return tty_name(); }
 
     virtual String const& tty_name() const = 0;
@@ -40,7 +40,7 @@ public:
         return 0;
     }
 
-    int set_termios(const termios&);
+    KResult set_termios(const termios&);
     bool should_generate_signals() const { return m_termios.c_lflag & ISIG; }
     bool should_flush_on_signal() const { return !(m_termios.c_lflag & NOFLSH); }
     bool should_echo_input() const { return m_termios.c_lflag & ECHO; }