chore: replace some naked pointers

The coding guidelines explicitly prohibit the use of "naked"/C-style
pointers. However, there were some prominent examples in the kapi and
the core kernel source. This changeset replaces them with the
appropriate smart pointer types.

19 files changed, 71 insertions, 61 deletions

diff --git a/kernel/kapi/boot_modules/device.cpp b/kernel/kapi/boot_modules/device.cpp
index dac24906..4bfce5f1 100644
--- a/kernel/kapi/boot_modules/device.cpp
+++ b/kernel/kapi/boot_modules/device.cpp
@@ -5,6 +5,7 @@
 #include <kapi/devices.hpp>
 
 #include <kstd/format.hpp>
+#include <kstd/memory.hpp>
 
 #include <cstddef>
 #include <string_view>
@@ -27,11 +28,11 @@ namespace kapi::boot_modules
     return m_module;
   }
 
-  auto device::query_facet(kapi::capabilities::facet_id facet) -> void *
+  auto device::query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void>
   {
     if (facet == boot_module_signature::id)
     {
-      return static_cast<boot_module_signature *>(this);
+      return kstd::make_observer<boot_module_signature>(this);
     }
 
     return kapi::devices::device::query_facet(facet);
diff --git a/kernel/kapi/devices/bus.cpp b/kernel/kapi/devices/bus.cpp
index 300151d5..d956c3b8 100644
--- a/kernel/kapi/devices/bus.cpp
+++ b/kernel/kapi/devices/bus.cpp
@@ -84,15 +84,15 @@ namespace kapi::devices
     return m_devices;
   }
 
-  auto bus::query_facet(kapi::capabilities::facet_id facet) -> void *
+  auto bus::query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void>
   {
     if (facet == bus::id)
     {
-      return this;
+      return kstd::observer_ptr(this);
     }
     else if (facet == bus_protocol::id)
     {
-      return m_protocol;
+      return kstd::observer_ptr{m_protocol};
     }
 
     return device::query_facet(facet);
diff --git a/kernel/kapi/devices/device.cpp b/kernel/kapi/devices/device.cpp
index 2576e20a..3a3b7cc1 100644
--- a/kernel/kapi/devices/device.cpp
+++ b/kernel/kapi/devices/device.cpp
@@ -23,12 +23,12 @@ namespace kapi::devices
       : m_name(name)
   {}
 
-  auto device::facet(kapi::capabilities::facet_id facet) noexcept -> void *
+  auto device::facet(kapi::capabilities::facet_id facet) noexcept -> kstd::observer_ptr<void>
   {
     return query_facet(facet);
   }
 
-  auto device::facet(kapi::capabilities::facet_id facet) const noexcept -> void const *
+  auto device::facet(kapi::capabilities::facet_id facet) const noexcept -> kstd::observer_ptr<void const>
   {
     return const_cast<device *>(this)->query_facet(facet);
   }
@@ -61,10 +61,10 @@ namespace kapi::devices
     m_state = state;
   }
 
-  auto device::bound_driver() const noexcept -> driver *
+  auto device::bound_driver() const noexcept -> kstd::shared_ptr<driver>
   {
     auto guard = kstd::lock_guard{m_lock};
-    return m_driver.lock().get();
+    return m_driver.lock();
   }
 
   auto device::bind_driver(kstd::weak_ptr<struct driver> driver) -> void
@@ -114,7 +114,7 @@ namespace kapi::devices
     m_resources = std::move(resources);
   }
 
-  auto device::query_facet(kapi::capabilities::facet_id) -> void *
+  auto device::query_facet(kapi::capabilities::facet_id) -> kstd::observer_ptr<void>
   {
     return nullptr;
   }
diff --git a/kernel/kapi/devices/driver.cpp b/kernel/kapi/devices/driver.cpp
index 5ca92dc8..0f103cbc 100644
--- a/kernel/kapi/devices/driver.cpp
+++ b/kernel/kapi/devices/driver.cpp
@@ -1,6 +1,7 @@
 #include <kapi/capabilities/facet_id.hpp>
 #include <kapi/devices.hpp>
 
+#include <kstd/memory.hpp>
 #include <kstd/result.hpp>
 
 #include <cstdint>
@@ -29,7 +30,7 @@ namespace kapi::devices
     return kstd::success();
   }
 
-  auto driver::query_facet(kapi::capabilities::facet_id) -> void *
+  auto driver::query_facet(kapi::capabilities::facet_id) -> kstd::observer_ptr<void>
   {
     return nullptr;
   }
diff --git a/kernel/kapi/devices/driver.tests.cpp b/kernel/kapi/devices/driver.tests.cpp
index ee3fe577..38d07ed9 100644
--- a/kernel/kapi/devices/driver.tests.cpp
+++ b/kernel/kapi/devices/driver.tests.cpp
@@ -36,8 +36,8 @@ namespace
     [[nodiscard]] auto match(kapi::devices::device const & dev, kapi::devices::driver const & drv) const
         -> kstd::result<std::uint32_t> override
     {
-      auto const * signature = dev.facet<controller_signature>();
-      auto const * claim = drv.facet<controller_claim>();
+      auto const signature = dev.facet<controller_signature>();
+      auto const claim = drv.facet<controller_claim>();
       if (!signature || !claim || !std::ranges::contains(claim->supported_names(), signature->controller_name()))
       {
         return kstd::failure(kapi::devices::driver_match_errc::no_match);
@@ -65,11 +65,11 @@ namespace
     }
 
   protected:
-    auto query_facet(kapi::capabilities::facet_id facet) -> void * override
+    auto query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void> override
     {
       if (facet == controller_signature::id)
       {
-        return static_cast<controller_signature *>(this);
+        return kstd::make_observer<controller_signature>(this);
       }
       return kapi::devices::bus::query_facet(facet);
     }
@@ -101,11 +101,11 @@ namespace
     }
 
   protected:
-    auto query_facet(kapi::capabilities::facet_id facet) -> void * override
+    auto query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void> override
     {
       if (facet == leaf_signature::id)
       {
-        return static_cast<leaf_signature *>(this);
+        return kstd::make_observer<leaf_signature>(this);
       }
       return kapi::devices::device::query_facet(facet);
     }
@@ -123,9 +123,9 @@ namespace
     [[nodiscard]] auto match(kapi::devices::device const & dev, kapi::devices::driver const & drv) const
         -> kstd::result<std::uint32_t> override
     {
-      auto const * ident = dev.facet<leaf_signature>();
-      auto const * claims = drv.facet<leaf_claim>();
-      if (!ident || !claims || !std::ranges::contains(claims->supported_names(), ident->leaf_name()))
+      auto const signature = dev.facet<leaf_signature>();
+      auto const claims = drv.facet<leaf_claim>();
+      if (!signature || !claims || !std::ranges::contains(claims->supported_names(), signature->leaf_name()))
       {
         return kstd::failure(kapi::devices::driver_match_errc::no_match);
       }
@@ -166,11 +166,11 @@ namespace
     }
 
   protected:
-    auto query_facet(kapi::capabilities::facet_id facet) -> void * override
+    auto query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void> override
     {
       if (facet == controller_claim::id)
       {
-        return static_cast<controller_claim *>(this);
+        return kstd::make_observer<controller_claim>(this);
       }
 
       return kapi::devices::driver::query_facet(facet);
@@ -198,11 +198,11 @@ namespace
     }
 
   protected:
-    auto query_facet(kapi::capabilities::facet_id facet) -> void * override
+    auto query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void> override
     {
       if (facet == leaf_claim::id)
       {
-        return static_cast<leaf_claim *>(this);
+        return kstd::make_observer<leaf_claim>(this);
       }
 
       return kapi::devices::driver::query_facet(facet);
@@ -213,7 +213,8 @@ namespace
 SCENARIO("a bound controller driver can attach a further, independently-typed bus protocol of its own",
          "[devices][driver][stacking]")
 {
-  GIVEN("a controller bus, a controller driver, and a leaf driver, none aware of each other's identification scheme")
+  GIVEN(
+      "a controller bus, a controller driver, and a leaf driver, none aware of each other's signatureification scheme")
   {
     auto outer_bus = kstd::make_shared<controller_bus>("stacking_test_controller_bus");
 
diff --git a/kernel/kapi/devices/driver_registry.tests.cpp b/kernel/kapi/devices/driver_registry.tests.cpp
index 02f5065f..7b08799c 100644
--- a/kernel/kapi/devices/driver_registry.tests.cpp
+++ b/kernel/kapi/devices/driver_registry.tests.cpp
@@ -40,7 +40,7 @@ namespace
     {
       ++*match_calls;
 
-      auto const * identification = driver.facet<test_claim>();
+      auto const identification = driver.facet<test_claim>();
       if (!identification)
       {
         return kstd::failure(kapi::devices::driver_match_errc::no_match);
@@ -107,11 +107,11 @@ namespace
     mutable unsigned probe_calls;
 
   protected:
-    auto query_facet(kapi::capabilities::facet_id facet) -> void * override
+    auto query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void> override
     {
       if (facet == test_claim::id)
       {
-        return static_cast<test_claim *>(this);
+        return kstd::make_observer<test_claim>(this);
       }
 
       return kapi::devices::driver::query_facet(facet);
@@ -178,7 +178,7 @@ SCENARIO("Driver registry picks the highest-priority match", "[devices][driver_r
       {
         auto dev = kapi::devices::device_registry::get().find("driver_registry_priority_device");
         REQUIRE(dev != nullptr);
-        REQUIRE(dev->bound_driver() == high_priority.get());
+        REQUIRE(dev->bound_driver() == high_priority);
       }
     }
   }
@@ -203,7 +203,7 @@ SCENARIO("Driver registry breaks ties by registration order", "[devices][driver_
       {
         auto dev = kapi::devices::device_registry::get().find("driver_registry_tie_device");
         REQUIRE(dev != nullptr);
-        REQUIRE(dev->bound_driver() == registered_first.get());
+        REQUIRE(dev->bound_driver() == registered_first);
       }
     }
   }
@@ -255,7 +255,7 @@ SCENARIO("Driver registry leaves bound driver bound, even if better driver arriv
           auto dev = kapi::devices::device_registry::get().find("driver_probe_failure_device");
           REQUIRE(dev != nullptr);
           REQUIRE(dev->state() == kapi::devices::state::bound);
-          REQUIRE(dev->bound_driver() == lower.get());
+          REQUIRE(dev->bound_driver() == lower);
         }
       }
     }
diff --git a/kernel/kapi/devices/facet_registry.cpp b/kernel/kapi/devices/facet_registry.cpp
index 2974c71e..f2f5d03b 100644
--- a/kernel/kapi/devices/facet_registry.cpp
+++ b/kernel/kapi/devices/facet_registry.cpp
@@ -46,7 +46,7 @@ namespace kapi::devices
   }
 
   auto facet_registry::do_publish(kstd::shared_ptr<device> device, kstd::string name, kapi::capabilities::facet_id id,
-                                  void * facet) -> kstd::result<void>
+                                  kstd::observer_ptr<void> facet) -> kstd::result<void>
   {
     auto published = std::optional<entry>{};
 
@@ -169,7 +169,7 @@ namespace kapi::devices
     return filtered;
   }
 
-  auto facet_registry::resolve(kapi::capabilities::facet_id facet, std::string_view name) -> void *
+  auto facet_registry::resolve(kapi::capabilities::facet_id facet, std::string_view name) -> kstd::observer_ptr<void>
   {
     auto found_device = kstd::shared_ptr<device>{};
     {
@@ -193,7 +193,7 @@ namespace kapi::devices
     return resolve(facet, *found_device);
   }
 
-  auto facet_registry::resolve(kapi::capabilities::facet_id id, device & device) -> void *
+  auto facet_registry::resolve(kapi::capabilities::facet_id id, device & device) -> kstd::observer_ptr<void>
   {
     if (auto by_device = device.facet(id))
     {
diff --git a/kernel/kapi/devices/facet_registry.tests.cpp b/kernel/kapi/devices/facet_registry.tests.cpp
index 9396fc6c..f6735f01 100644
--- a/kernel/kapi/devices/facet_registry.tests.cpp
+++ b/kernel/kapi/devices/facet_registry.tests.cpp
@@ -50,15 +50,15 @@ namespace
       return m_value;
     }
 
-    auto query_facet(kapi::capabilities::facet_id facet) -> void * override
+    auto query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void> override
     {
       if (facet == probe_device::id)
       {
-        return static_cast<probe_device *>(this);
+        return kstd::make_observer<probe_device>(this);
       }
       if (facet == const_device::id)
       {
-        return m_const_device;
+        return kstd::observer_ptr{m_const_device};
       }
 
       return kapi::devices::device::query_facet(facet);
@@ -143,7 +143,7 @@ SCENARIO("Publishing and finding a device", "[kapi][devices][facet_registry]")
 
       THEN("publishing a free standing second facet for the same device succeeds")
       {
-        REQUIRE(registry.publish(device, "probe0", &free_standing_facet));
+        REQUIRE(registry.publish(device, "probe0", kstd::make_observer(&free_standing_facet)));
       }
 
       AND_WHEN("getting all devices implementing that facet")
@@ -239,7 +239,7 @@ SCENARIO("Publishing and finding a device", "[kapi][devices][facet_registry]")
 
     THEN("publishing the facet for the device fails")
     {
-      REQUIRE_FALSE(registry.publish(device, "probe0", &facet));
+      REQUIRE_FALSE(registry.publish(device, "probe0", kstd::make_observer(&facet)));
     }
   }
 }
diff --git a/kernel/kernel/devices/pseudo.cpp b/kernel/kernel/devices/pseudo.cpp
index 13a8be3d..f5ee13c3 100644
--- a/kernel/kernel/devices/pseudo.cpp
+++ b/kernel/kernel/devices/pseudo.cpp
@@ -5,6 +5,7 @@
 #include <kapi/capabilities/facet_id.hpp>
 #include <kapi/devices.hpp>
 
+#include <kstd/memory.hpp>
 #include <kstd/string.hpp>
 
 #include <utility>
@@ -16,11 +17,11 @@ namespace kernel::devices
       : kapi::devices::device{std::move(name)}
   {}
 
-  auto pseudo::query_facet(kapi::capabilities::facet_id facet) -> void *
+  auto pseudo::query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void>
   {
     if (facet == kernel::bus::pseudo_signature::id)
     {
-      return &m_signature;
+      return kstd::make_observer(&m_signature);
     }
 
     return device::query_facet(facet);
diff --git a/kernel/kernel/devices/pseudo.hpp b/kernel/kernel/devices/pseudo.hpp
index efd504d5..eabe59b0 100644
--- a/kernel/kernel/devices/pseudo.hpp
+++ b/kernel/kernel/devices/pseudo.hpp
@@ -6,6 +6,7 @@
 #include <kapi/capabilities/facet_id.hpp>
 #include <kapi/devices.hpp>
 
+#include <kstd/memory.hpp>
 #include <kstd/string.hpp>
 
 #include <string_view>
@@ -33,7 +34,7 @@ namespace kernel::devices
     explicit pseudo(kstd::string name);
 
   protected:
-    auto query_facet(kapi::capabilities::facet_id facet) -> void * override;
+    auto query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void> override;
 
   private:
     pseudo_signature m_signature{*this};
diff --git a/kernel/kernel/drivers/pseudo/null.cpp b/kernel/kernel/drivers/pseudo/null.cpp
index 4c8bde12..9d8330b1 100644
--- a/kernel/kernel/drivers/pseudo/null.cpp
+++ b/kernel/kernel/drivers/pseudo/null.cpp
@@ -76,7 +76,7 @@ namespace kernel::drivers::pseudo
 
     auto implementation = kstd::make_shared<null_node>();
     auto published = kapi::devices::publish_facet<kapi::filesystem::character_special_file>(
-        device.shared_from_this(), "null", implementation.get());
+        device.shared_from_this(), "null", kstd::make_observer(implementation.get()));
 
     if (!published)
     {
@@ -117,11 +117,11 @@ namespace kernel::drivers::pseudo
     return names;
   }
 
-  auto null::query_facet(kapi::capabilities::facet_id facet) -> void *
+  auto null::query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void>
   {
     if (facet == kernel::bus::pseudo_claim::id)
     {
-      return static_cast<kernel::bus::pseudo_claim *>(this);
+      return kstd::make_observer<kernel::bus::pseudo_claim>(this);
     }
 
     return kapi::devices::driver::query_facet(facet);
diff --git a/kernel/kernel/drivers/pseudo/null.hpp b/kernel/kernel/drivers/pseudo/null.hpp
index 6a736c33..ab8affeb 100644
--- a/kernel/kernel/drivers/pseudo/null.hpp
+++ b/kernel/kernel/drivers/pseudo/null.hpp
@@ -6,6 +6,7 @@
 #include <kapi/devices.hpp>
 #include <kapi/filesystem.hpp>
 
+#include <kstd/memory.hpp>
 #include <kstd/result.hpp>
 
 #include <cstdint>
@@ -36,7 +37,7 @@ namespace kernel::drivers::pseudo
     [[nodiscard]] auto supported_names() const noexcept -> std::span<std::string_view const> override;
 
   protected:
-    auto query_facet(kapi::capabilities::facet_id facet) -> void * override;
+    auto query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void> override;
   };
 
 }  // namespace kernel::drivers::pseudo
diff --git a/kernel/kernel/drivers/pseudo/zero.cpp b/kernel/kernel/drivers/pseudo/zero.cpp
index 67ec2519..fda28d35 100644
--- a/kernel/kernel/drivers/pseudo/zero.cpp
+++ b/kernel/kernel/drivers/pseudo/zero.cpp
@@ -77,7 +77,7 @@ namespace kernel::drivers::pseudo
 
     auto implementation = kstd::make_shared<zero_node>();
     auto published = kapi::devices::publish_facet<kapi::filesystem::character_special_file>(
-        device.shared_from_this(), "zero", implementation.get());
+        device.shared_from_this(), "zero", kstd::make_observer(implementation.get()));
 
     if (!published)
     {
@@ -118,11 +118,11 @@ namespace kernel::drivers::pseudo
     return names;
   }
 
-  auto zero::query_facet(kapi::capabilities::facet_id facet) -> void *
+  auto zero::query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void>
   {
     if (facet == kernel::bus::pseudo_claim::id)
     {
-      return static_cast<kernel::bus::pseudo_claim *>(this);
+      return kstd::make_observer<kernel::bus::pseudo_claim>(this);
     }
 
     return kapi::devices::driver::query_facet(facet);
diff --git a/kernel/kernel/drivers/pseudo/zero.hpp b/kernel/kernel/drivers/pseudo/zero.hpp
index 7f26cc41..b5573e58 100644
--- a/kernel/kernel/drivers/pseudo/zero.hpp
+++ b/kernel/kernel/drivers/pseudo/zero.hpp
@@ -6,6 +6,7 @@
 #include <kapi/devices.hpp>
 #include <kapi/filesystem.hpp>
 
+#include <kstd/memory.hpp>
 #include <kstd/result.hpp>
 
 #include <cstdint>
@@ -31,7 +32,7 @@ namespace kernel::drivers::pseudo
     [[nodiscard]] auto supported_names() const noexcept -> std::span<std::string_view const> override;
 
   protected:
-    auto query_facet(kapi::capabilities::facet_id facet) -> void * override;
+    auto query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void> override;
   };
 
 }  // namespace kernel::drivers::pseudo
diff --git a/kernel/kernel/drivers/storage/ram_disk.cpp b/kernel/kernel/drivers/storage/ram_disk.cpp
index 80f7eedc..d33b7312 100644
--- a/kernel/kernel/drivers/storage/ram_disk.cpp
+++ b/kernel/kernel/drivers/storage/ram_disk.cpp
@@ -118,12 +118,12 @@ namespace kernel::drivers::storage
         std::ranges::count_if(kapi::devices::facet_registry::get().all(kapi::filesystem::block_special_file::id),
                               [this](auto const & published) {
                                 auto published_device = published.device();
-                                return published_device && published_device->bound_driver() == this;
+                                return published_device && published_device->bound_driver().get() == this;
                               });
     auto name = kstd::format("ram{}", next_index);
 
-    auto published = kapi::devices::publish_facet<kapi::filesystem::block_special_file>(device.shared_from_this(), name,
-                                                                                        implementation.get());
+    auto published = kapi::devices::publish_facet<kapi::filesystem::block_special_file>(
+        device.shared_from_this(), name, kstd::make_observer(implementation.get()));
     if (!published)
     {
       return published;
@@ -155,11 +155,11 @@ namespace kernel::drivers::storage
     return "Generic RAM Disk";
   }
 
-  auto ram_disk::query_facet(kapi::capabilities::facet_id facet) -> void *
+  auto ram_disk::query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void>
   {
     if (facet == kapi::boot_modules::boot_module_claim::id)
     {
-      return static_cast<kapi::boot_modules::boot_module_claim *>(this);
+      return kstd::make_observer<kapi::boot_modules::boot_module_claim>(this);
     }
 
     return kapi::devices::driver::query_facet(facet);
diff --git a/kernel/kernel/drivers/storage/ram_disk.hpp b/kernel/kernel/drivers/storage/ram_disk.hpp
index a526435b..1f7d5774 100644
--- a/kernel/kernel/drivers/storage/ram_disk.hpp
+++ b/kernel/kernel/drivers/storage/ram_disk.hpp
@@ -5,6 +5,7 @@
 #include <kapi/capabilities/facet_id.hpp>
 #include <kapi/devices.hpp>
 
+#include <kstd/memory.hpp>
 #include <kstd/result.hpp>
 
 #include <cstdint>
@@ -28,7 +29,7 @@ namespace kernel::drivers::storage
     [[nodiscard]] auto name() const noexcept -> std::string_view override;
 
   protected:
-    auto query_facet(kapi::capabilities::facet_id facet) -> void * override;
+    auto query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void> override;
   };
 
 }  // namespace kernel::drivers::storage
diff --git a/kernel/kernel/test_support/devices/block_device.cpp b/kernel/kernel/test_support/devices/block_device.cpp
index 462dc79d..fa834122 100644
--- a/kernel/kernel/test_support/devices/block_device.cpp
+++ b/kernel/kernel/test_support/devices/block_device.cpp
@@ -3,6 +3,7 @@
 #include <kapi/devices.hpp>
 #include <kapi/filesystem.hpp>
 
+#include <kstd/memory.hpp>
 #include <kstd/result.hpp>
 #include <kstd/string.hpp>
 #include <kstd/units.hpp>
@@ -68,11 +69,11 @@ namespace kernel::tests::devices
     return kstd::bytes{data.size()};
   }
 
-  auto block_device::query_facet(kapi::capabilities::facet_id facet) -> void *
+  auto block_device::query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void>
   {
     if (facet == kapi::filesystem::block_special_file::id)
     {
-      return static_cast<kapi::filesystem::block_special_file *>(this);
+      return kstd::make_observer<kapi::filesystem::block_special_file>(this);
     }
 
     return kapi::devices::device::query_facet(facet);
diff --git a/kernel/kernel/test_support/devices/block_device.hpp b/kernel/kernel/test_support/devices/block_device.hpp
index 9e64ed18..94c9a58d 100644
--- a/kernel/kernel/test_support/devices/block_device.hpp
+++ b/kernel/kernel/test_support/devices/block_device.hpp
@@ -4,6 +4,7 @@
 #include <kapi/devices.hpp>
 #include <kapi/filesystem.hpp>
 
+#include <kstd/memory.hpp>
 #include <kstd/result.hpp>
 #include <kstd/string.hpp>
 #include <kstd/units.hpp>
@@ -29,7 +30,7 @@ namespace kernel::tests::devices
     kstd::vector<std::uint8_t> data{};
 
   private:
-    [[nodiscard]] auto query_facet(kapi::capabilities::facet_id facet) -> void * override;
+    [[nodiscard]] auto query_facet(kapi::capabilities::facet_id facet) -> kstd::observer_ptr<void> override;
 
     kstd::bytes m_block_size{};
   };
diff --git a/kernel/kernel/vfs/device_inode.cpp b/kernel/kernel/vfs/device_inode.cpp
index e9c70f15..75ed03d6 100644
--- a/kernel/kernel/vfs/device_inode.cpp
+++ b/kernel/kernel/vfs/device_inode.cpp
@@ -89,12 +89,12 @@ namespace kernel::vfs
 
   auto device_inode::is_block_device() const -> bool
   {
-    return kapi::devices::facet_registry::get().resolve<kapi::filesystem::block_special_file>(*m_device);
+    return !!kapi::devices::facet_registry::get().resolve<kapi::filesystem::block_special_file>(*m_device);
   }
 
   auto device_inode::is_character_device() const -> bool
   {
-    return kapi::devices::facet_registry::get().resolve<kapi::filesystem::character_special_file>(*m_device);
+    return !!kapi::devices::facet_registry::get().resolve<kapi::filesystem::character_special_file>(*m_device);
   }
 
   auto device_inode::status() const -> kstd::result<kapi::filesystem::file_status>