[frameworks][native][vulkan] fix -Walloca

Alloca cannot be checked for failure. Replace alloca with dynamic memory
allocations.

Reapply a commit that was previously reverted.  The original commit
removed a call to enumerate_instance_layers() that it should not have.

Prefer std::vector to std::unique_ptr of an array.

Bug: 139945549
Bug: 142475221
Bug: 143156243
Test: mm && adb shell stop && adb sync && adb shell start && atest -it \
  CtsGpuToolsHostTestCases:android.gputools.cts.CtsRootlessGpuDebugHostTest#testDebugLayerLoadExternalVulkan,testMultipleExternalApps,testSystemPropertyIgnoreVulkan,testDebugLayerLoadVulkan,testSystemPropertyEnableVulkan
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

Change-Id: Ifdf747fdabc41ee6da8cd83bda5e3f030649030f

2 files changed, 20 insertions, 36 deletions

diff --git a/vulkan/libvulkan/driver.cpp b/vulkan/libvulkan/driver.cpp
index a544bc5ff8..d92f35ac23 100644
--- a/vulkan/libvulkan/driver.cpp
+++ b/vulkan/libvulkan/driver.cpp
@@ -151,15 +151,12 @@ class CreateInfoWrapper {
 Hal Hal::hal_;
 
 void* LoadLibrary(const android_dlextinfo& dlextinfo,
-                  const char* subname,
-                  int subname_len) {
+                  const std::string_view subname) {
     ATRACE_CALL();
 
-    const char kLibFormat[] = "vulkan.%*s.so";
-    char* name = static_cast<char*>(
-        alloca(sizeof(kLibFormat) + static_cast<size_t>(subname_len)));
-    sprintf(name, kLibFormat, subname_len, subname);
-    return android_dlopen_ext(name, RTLD_LOCAL | RTLD_NOW, &dlextinfo);
+    std::stringstream ss;
+    ss << "vulkan." << subname << ".so";
+    return android_dlopen_ext(ss.str().c_str(), RTLD_LOCAL | RTLD_NOW, &dlextinfo);
 }
 
 const std::array<const char*, 2> HAL_SUBNAME_KEY_PROPERTIES = {{
@@ -179,8 +176,9 @@ int LoadDriver(android_namespace_t* library_namespace,
     char prop[PROPERTY_VALUE_MAX];
     for (auto key : HAL_SUBNAME_KEY_PROPERTIES) {
         int prop_len = property_get(key, prop, nullptr);
-        if (prop_len > 0) {
-            so = LoadLibrary(dlextinfo, prop, prop_len);
+        if (prop_len > 0 && prop_len <= UINT_MAX) {
+            std::string_view lib_name(prop, static_cast<unsigned int>(prop_len));
+            so = LoadLibrary(dlextinfo, lib_name);
             if (so)
                 break;
         }
diff --git a/vulkan/libvulkan/layers_extensions.cpp b/vulkan/libvulkan/layers_extensions.cpp
index 2f33fee8ac..22f92d619d 100644
--- a/vulkan/libvulkan/layers_extensions.cpp
+++ b/vulkan/libvulkan/layers_extensions.cpp
@@ -95,9 +95,7 @@ class LayerLibrary {
     bool EnumerateLayers(size_t library_idx,
                          std::vector<Layer>& instance_layers) const;
 
-    void* GetGPA(const Layer& layer,
-                 const char* gpa_name,
-                 size_t gpa_name_len) const;
+    void* GetGPA(const Layer& layer, const std::string_view gpa_name) const;
 
     const std::string GetFilename() { return filename_; }
 
@@ -220,9 +218,8 @@ bool LayerLibrary::EnumerateLayers(size_t library_idx,
     }
 
     // get layer properties
-    VkLayerProperties* properties = static_cast<VkLayerProperties*>(alloca(
-        (num_instance_layers + num_device_layers) * sizeof(VkLayerProperties)));
-    result = enumerate_instance_layers(&num_instance_layers, properties);
+    std::vector<VkLayerProperties> properties(num_instance_layers + num_device_layers);
+    result = enumerate_instance_layers(&num_instance_layers, properties.data());
     if (result != VK_SUCCESS) {
         ALOGE("vkEnumerateInstanceLayerProperties failed for library '%s': %d",
               path_.c_str(), result);
@@ -230,7 +227,7 @@ bool LayerLibrary::EnumerateLayers(size_t library_idx,
     }
     if (num_device_layers > 0) {
         result = enumerate_device_layers(VK_NULL_HANDLE, &num_device_layers,
-                                         properties + num_instance_layers);
+                                         &properties[num_instance_layers]);
         if (result != VK_SUCCESS) {
             ALOGE(
                 "vkEnumerateDeviceLayerProperties failed for library '%s': %d",
@@ -315,21 +312,11 @@ bool LayerLibrary::EnumerateLayers(size_t library_idx,
     return true;
 }
 
-void* LayerLibrary::GetGPA(const Layer& layer,
-                           const char* gpa_name,
-                           size_t gpa_name_len) const {
-    void* gpa;
-    size_t layer_name_len =
-        std::max(size_t{2}, strlen(layer.properties.layerName));
-    char* name = static_cast<char*>(alloca(layer_name_len + gpa_name_len + 1));
-    strcpy(name, layer.properties.layerName);
-    strcpy(name + layer_name_len, gpa_name);
-    if (!(gpa = GetTrampoline(name))) {
-        strcpy(name, "vk");
-        strcpy(name + 2, gpa_name);
-        gpa = GetTrampoline(name);
-    }
-    return gpa;
+void* LayerLibrary::GetGPA(const Layer& layer, const std::string_view gpa_name) const {
+    std::string layer_name { layer.properties.layerName };
+    if (void* gpa = GetTrampoline((layer_name.append(gpa_name).c_str())))
+        return gpa;
+    return GetTrampoline((std::string {"vk"}.append(gpa_name)).c_str());
 }
 
 // ----------------------------------------------------------------------------
@@ -464,10 +451,9 @@ const VkExtensionProperties* FindExtension(
 }
 
 void* GetLayerGetProcAddr(const Layer& layer,
-                          const char* gpa_name,
-                          size_t gpa_name_len) {
+                          const std::string_view gpa_name) {
     const LayerLibrary& library = g_layer_libraries[layer.library_idx];
-    return library.GetGPA(layer, gpa_name, gpa_name_len);
+    return library.GetGPA(layer, gpa_name);
 }
 
 }  // anonymous namespace
@@ -550,13 +536,13 @@ LayerRef::LayerRef(LayerRef&& other) noexcept : layer_(other.layer_) {
 
 PFN_vkGetInstanceProcAddr LayerRef::GetGetInstanceProcAddr() const {
     return layer_ ? reinterpret_cast<PFN_vkGetInstanceProcAddr>(
-                        GetLayerGetProcAddr(*layer_, "GetInstanceProcAddr", 19))
+                        GetLayerGetProcAddr(*layer_, "GetInstanceProcAddr"))
                   : nullptr;
 }
 
 PFN_vkGetDeviceProcAddr LayerRef::GetGetDeviceProcAddr() const {
     return layer_ ? reinterpret_cast<PFN_vkGetDeviceProcAddr>(
-                        GetLayerGetProcAddr(*layer_, "GetDeviceProcAddr", 17))
+                        GetLayerGetProcAddr(*layer_, "GetDeviceProcAddr"))
                   : nullptr;
 }