diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp
--- a/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp
@@ -220,11 +220,9 @@
 // sizeof(struct pthread) from glibc.
 static atomic_uintptr_t thread_descriptor_size;
 
-uptr ThreadDescriptorSize() {
-  uptr val = atomic_load_relaxed(&thread_descriptor_size);
-  if (val)
-    return val;
-#if defined(__x86_64__) || defined(__i386__) || defined(__arm__)
+static uptr ThreadDescriptorSizeFallback() {
+  uptr val = 0;
+#    if defined(__x86_64__) || defined(__i386__) || defined(__arm__)
   int major;
   int minor;
   int patch;
@@ -285,12 +283,26 @@
 #elif defined(__powerpc64__)
   val = 1776; // from glibc.ppc64le 2.20-8.fc21
 #endif
+  return val;
+}
+
+uptr ThreadDescriptorSize() {
+  uptr val = atomic_load_relaxed(&thread_descriptor_size);
   if (val)
-    atomic_store_relaxed(&thread_descriptor_size, val);
+    return val;
+  // _thread_db_sizeof_pthread is a GLIBC_PRIVATE symbol that is
+  // exported in glibc 2.34 and later.
+  auto psizeof =
+      static_cast<unsigned *>(dlsym(RTLD_DEFAULT, "_thread_db_sizeof_pthread"));
+  if (psizeof != nullptr)
+    val = *psizeof;
+  if (!val)
+    val = ThreadDescriptorSizeFallback();
+  atomic_store_relaxed(&thread_descriptor_size, val);
   return val;
 }
 
-#if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64
+#    if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64
 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb
 // head structure. It lies before the static tls blocks.
 static uptr TlsPreTcbSize() {