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

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

Bug: 139945549
Bug: 142475221
Test: mm
Change-Id: I1a154b479c8da66e25d20dced6bf9ae269b906f8
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

1 files changed, 10 insertions, 9 deletions

diff --git a/vulkan/libvulkan/driver.cpp b/vulkan/libvulkan/driver.cpp
index c3c19ecdff..2f6747dd70 100644
--- a/vulkan/libvulkan/driver.cpp
+++ b/vulkan/libvulkan/driver.cpp
@@ -37,7 +37,10 @@
 
 #include <algorithm>
 #include <array>
+#include <climits>
 #include <new>
+#include <string_view>
+#include <sstream>
 #include <vector>
 
 #include "stubhal.h"
@@ -148,15 +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 = {{
@@ -176,8 +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;
         }