drm_hwcomposer: Wrap libdrm drmMode*{Get|Free}* into RAII

This should elliminate chance of any leaks in the future.
Fix drmModePropertyBlobPtr leak in DrmHwcTwo.cpp.

Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
diff --git a/drm/DrmConnector.cpp b/drm/DrmConnector.cpp
index 0468527..b3179c7 100644
--- a/drm/DrmConnector.cpp
+++ b/drm/DrmConnector.cpp
@@ -90,20 +90,19 @@
   return ret;
 }
 
-int DrmConnector::GetEdidBlob(drmModePropertyBlobPtr &blob) {
+auto DrmConnector::GetEdidBlob() -> DrmModePropertyBlobUnique {
   uint64_t blob_id = 0;
   int ret = UpdateEdidProperty();
-  if (ret) {
-    return ret;
+  if (ret != 0) {
+    return DrmModePropertyBlobUnique();
   }
 
   std::tie(ret, blob_id) = edid_property().value();
-  if (ret) {
-    return ret;
+  if (ret != 0) {
+    return DrmModePropertyBlobUnique();
   }
 
-  blob = drmModeGetPropertyBlob(drm_->fd(), blob_id);
-  return !blob;
+  return MakeDrmModePropertyBlobUnique(drm_->fd(), blob_id);
 }
 
 uint32_t DrmConnector::id() const {
diff --git a/drm/DrmConnector.h b/drm/DrmConnector.h
index 3bc18c8..e2789ea 100644
--- a/drm/DrmConnector.h
+++ b/drm/DrmConnector.h
@@ -26,6 +26,7 @@
 #include "DrmEncoder.h"
 #include "DrmMode.h"
 #include "DrmProperty.h"
+#include "DrmUnique.h"
 
 namespace android {
 
@@ -41,7 +42,7 @@
 
   int Init();
   int UpdateEdidProperty();
-  int GetEdidBlob(drmModePropertyBlobPtr &blob);
+  auto GetEdidBlob() -> DrmModePropertyBlobUnique;
 
   uint32_t id() const;
 
diff --git a/drm/DrmDevice.cpp b/drm/DrmDevice.cpp
index 570b676..bd4b1e4 100644
--- a/drm/DrmDevice.cpp
+++ b/drm/DrmDevice.cpp
@@ -161,7 +161,7 @@
     return std::make_tuple(-EACCES, 0);
   }
 
-  drmModeResPtr res = drmModeGetResources(fd());
+  auto res = MakeDrmModeResUnique(fd());
   if (!res) {
     ALOGE("Failed to get DrmDevice resources");
     return std::make_tuple(-ENODEV, 0);
@@ -177,15 +177,14 @@
   bool found_primary = num_displays != 0;
 
   for (int i = 0; !ret && i < res->count_crtcs; ++i) {
-    drmModeCrtcPtr c = drmModeGetCrtc(fd(), res->crtcs[i]);
+    auto c = MakeDrmModeCrtcUnique(fd(), res->crtcs[i]);
     if (!c) {
       ALOGE("Failed to get crtc %d", res->crtcs[i]);
       ret = -ENODEV;
       break;
     }
 
-    std::unique_ptr<DrmCrtc> crtc(new DrmCrtc(this, c, i));
-    drmModeFreeCrtc(c);
+    std::unique_ptr<DrmCrtc> crtc(new DrmCrtc(this, c.get(), i));
 
     ret = crtc->Init();
     if (ret) {
@@ -197,7 +196,7 @@
 
   std::vector<uint32_t> possible_clones;
   for (int i = 0; !ret && i < res->count_encoders; ++i) {
-    drmModeEncoderPtr e = drmModeGetEncoder(fd(), res->encoders[i]);
+    auto e = MakeDrmModeEncoderUnique(fd(), res->encoders[i]);
     if (!e) {
       ALOGE("Failed to get encoder %d", res->encoders[i]);
       ret = -ENODEV;
@@ -215,9 +214,8 @@
     }
 
     std::unique_ptr<DrmEncoder> enc(
-        new DrmEncoder(e, current_crtc, possible_crtcs));
+        new DrmEncoder(e.get(), current_crtc, possible_crtcs));
     possible_clones.push_back(e->possible_clones);
-    drmModeFreeEncoder(e);
 
     encoders_.emplace_back(std::move(enc));
   }
@@ -229,7 +227,7 @@
   }
 
   for (int i = 0; !ret && i < res->count_connectors; ++i) {
-    drmModeConnectorPtr c = drmModeGetConnector(fd(), res->connectors[i]);
+    auto c = MakeDrmModeConnectorUnique(fd(), res->connectors[i]);
     if (!c) {
       ALOGE("Failed to get connector %d", res->connectors[i]);
       ret = -ENODEV;
@@ -248,9 +246,7 @@
     }
 
     std::unique_ptr<DrmConnector> conn(
-        new DrmConnector(this, c, current_encoder, possible_encoders));
-
-    drmModeFreeConnector(c);
+        new DrmConnector(this, c.get(), current_encoder, possible_encoders));
 
     ret = conn->Init();
     if (ret) {
@@ -299,30 +295,25 @@
     }
   }
 
-  if (res)
-    drmModeFreeResources(res);
-
   // Catch-all for the above loops
   if (ret)
     return std::make_tuple(ret, 0);
 
-  drmModePlaneResPtr plane_res = drmModeGetPlaneResources(fd());
+  auto plane_res = MakeDrmModePlaneResUnique(fd());
   if (!plane_res) {
     ALOGE("Failed to get plane resources");
     return std::make_tuple(-ENOENT, 0);
   }
 
   for (uint32_t i = 0; i < plane_res->count_planes; ++i) {
-    drmModePlanePtr p = drmModeGetPlane(fd(), plane_res->planes[i]);
+    auto p = MakeDrmModePlaneUnique(fd(), plane_res->planes[i]);
     if (!p) {
       ALOGE("Failed to get plane %d", plane_res->planes[i]);
       ret = -ENODEV;
       break;
     }
 
-    std::unique_ptr<DrmPlane> plane(new DrmPlane(this, p));
-
-    drmModeFreePlane(p);
+    std::unique_ptr<DrmPlane> plane(new DrmPlane(this, p.get()));
 
     ret = plane->Init();
     if (ret) {
@@ -332,7 +323,6 @@
 
     planes_.emplace_back(std::move(plane));
   }
-  drmModeFreePlaneResources(plane_res);
   if (ret)
     return std::make_tuple(ret, 0);
 
diff --git a/drm/DrmUnique.h b/drm/DrmUnique.h
new file mode 100644
index 0000000..4d248bf
--- /dev/null
+++ b/drm/DrmUnique.h
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef DRM_UNIQUE_H_
+#define DRM_UNIQUE_H_
+
+#include <xf86drmMode.h>
+
+#include <functional>
+#include <memory>
+
+template <typename T>
+using DUniquePtr = std::unique_ptr<T, std::function<void(T *)>>;
+
+using DrmModeAtomicReqUnique = DUniquePtr<drmModeAtomicReq>;
+auto inline MakeDrmModeAtomicReqUnique() {
+  return DrmModeAtomicReqUnique(drmModeAtomicAlloc(), [](drmModeAtomicReq *it) {
+    drmModeAtomicFree(it);
+  });
+};
+
+using DrmModeConnectorUnique = DUniquePtr<drmModeConnector>;
+auto inline MakeDrmModeConnectorUnique(int fd, uint32_t connector_id) {
+  return DrmModeConnectorUnique(drmModeGetConnector(fd, connector_id),
+                                [](drmModeConnector *it) {
+                                  drmModeFreeConnector(it);
+                                });
+}
+
+using DrmModeCrtcUnique = DUniquePtr<drmModeCrtc>;
+auto inline MakeDrmModeCrtcUnique(int fd, uint32_t crtc_id) {
+  return DrmModeCrtcUnique(drmModeGetCrtc(fd, crtc_id),
+                           [](drmModeCrtc *it) { drmModeFreeCrtc(it); });
+}
+
+using DrmModeEncoderUnique = DUniquePtr<drmModeEncoder>;
+auto inline MakeDrmModeEncoderUnique(int fd, uint32_t encoder_id) {
+  return DrmModeEncoderUnique(drmModeGetEncoder(fd, encoder_id),
+                              [](drmModeEncoder *it) {
+                                drmModeFreeEncoder(it);
+                              });
+}
+
+using DrmModePlaneUnique = DUniquePtr<drmModePlane>;
+auto inline MakeDrmModePlaneUnique(int fd, uint32_t plane_id) {
+  return DrmModePlaneUnique(drmModeGetPlane(fd, plane_id),
+                            [](drmModePlane *it) { drmModeFreePlane(it); });
+}
+
+using DrmModePlaneResUnique = DUniquePtr<drmModePlaneRes>;
+auto inline MakeDrmModePlaneResUnique(int fd) {
+  return DrmModePlaneResUnique(drmModeGetPlaneResources(fd),
+                               [](drmModePlaneRes *it) {
+                                 drmModeFreePlaneResources(it);
+                               });
+}
+
+using DrmModePropertyBlobUnique = DUniquePtr<drmModePropertyBlobRes>;
+auto inline MakeDrmModePropertyBlobUnique(int fd, uint32_t blob_id) {
+  return DrmModePropertyBlobUnique(drmModeGetPropertyBlob(fd, blob_id),
+                                   [](drmModePropertyBlobRes *it) {
+                                     drmModeFreePropertyBlob(it);
+                                   });
+}
+
+using DrmModeResUnique = DUniquePtr<drmModeRes>;
+auto inline MakeDrmModeResUnique(int fd) {
+  return DrmModeResUnique(drmModeGetResources(fd),
+                          [](drmModeRes *it) { drmModeFreeResources(it); });
+}
+
+#endif
diff --git a/drm/ResourceManager.cpp b/drm/ResourceManager.cpp
index ef44180..224e709 100644
--- a/drm/ResourceManager.cpp
+++ b/drm/ResourceManager.cpp
@@ -103,22 +103,19 @@
 }
 
 bool ResourceManager::IsKMSDev(const char *path) {
-  int fd = open(path, O_RDWR | O_CLOEXEC);
-  if (fd < 0)
+  auto fd = UniqueFd(open(path, O_RDWR | O_CLOEXEC));
+  if (!fd) {
     return false;
+  }
 
-  auto *res = drmModeGetResources(fd);
+  auto res = MakeDrmModeResUnique(fd.Get());
   if (!res) {
-    close(fd);
     return false;
   }
 
   bool is_kms = res->count_crtcs > 0 && res->count_connectors > 0 &&
                 res->count_encoders > 0;
 
-  drmModeFreeResources(res);
-  close(fd);
-
   return is_kms;
 }