Fix dangling pointer in heapprofd API.

We would dlopen heapprofd_client.so, which has a static initializer [1]
that passes a pointer to of its functions to heapprofd_client_api.so.
If we dlclose heapprofd_client.so, this pointer is dangling.

[1]: https://cs.android.com/android/platform/superproject/+/master:external/perfetto/src/profiling/memory/malloc_interceptor_bionic_hooks.cc?q=symbol:g_heap_id

This is a cherry-pick of 85c7838bd9cb40949c08d957499357547c7cd687.

Bug: 189332777
Change-Id: Ia4a9d9dd7c89eceec86c6fac5f4b66de85d7604e

1 files changed, 3 insertions, 7 deletions

diff --git a/libc/bionic/malloc_heapprofd.cpp b/libc/bionic/malloc_heapprofd.cpp
index 198bcbab7..741b45e98 100644
--- a/libc/bionic/malloc_heapprofd.cpp
+++ b/libc/bionic/malloc_heapprofd.cpp
@@ -325,12 +325,12 @@ void HeapprofdRememberHookConflict() {
 
 static void CommonInstallHooks(libc_globals* globals) {
   void* impl_handle = atomic_load(&gHeapprofdHandle);
-  bool reusing_handle = impl_handle != nullptr;
-  if (!reusing_handle) {
+  if (impl_handle == nullptr) {
     impl_handle = LoadSharedLibrary(kHeapprofdSharedLib, kHeapprofdPrefix, &globals->malloc_dispatch_table);
     if (impl_handle == nullptr) {
       return;
     }
+    atomic_store(&gHeapprofdHandle, impl_handle);
   } else if (!InitSharedLibrary(impl_handle, kHeapprofdSharedLib, kHeapprofdPrefix, &globals->malloc_dispatch_table)) {
     return;
   }
@@ -341,11 +341,7 @@ static void CommonInstallHooks(libc_globals* globals) {
   // MaybeModifyGlobals locks at this point.
   atomic_store(&gPreviousDefaultDispatchTable, GetDefaultDispatchTable());
 
-  if (FinishInstallHooks(globals, nullptr, kHeapprofdPrefix)) {
-    atomic_store(&gHeapprofdHandle, impl_handle);
-  } else if (!reusing_handle) {
-    dlclose(impl_handle);
-  }
+  FinishInstallHooks(globals, nullptr, kHeapprofdPrefix);
 }
 
 void HeapprofdInstallHooksAtInit(libc_globals* globals) {