Import Cobalt 24.master.0.1032339
diff --git a/third_party/llvm-project/compiler-rt/test/tsan/map32bit.cpp b/third_party/llvm-project/compiler-rt/test/tsan/map32bit.cpp
new file mode 100644
index 0000000..e8bac22
--- /dev/null
+++ b/third_party/llvm-project/compiler-rt/test/tsan/map32bit.cpp
@@ -0,0 +1,49 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t 2>&1 | FileCheck %s
+#include "test.h"
+#include <stdint.h>
+#include <errno.h>
+#include <sys/mman.h>
+
+// Test for issue:
+// https://github.com/google/sanitizers/issues/412
+
+// MAP_32BIT flag for mmap is supported only for x86_64.
+// XFAIL: target=mips{{.*}}
+// XFAIL: target=aarch64{{.*}}
+// XFAIL: target=powerpc64{{.*}}
+// XFAIL: target=s390x{{.*}}
+// XFAIL: target=loongarch64{{.*}}
+
+// MAP_32BIT doesn't exist on OS X and NetBSD.
+// UNSUPPORTED: darwin,target={{.*netbsd.*}}
+
+void *Thread(void *ptr) {
+ *(int*)ptr = 42;
+ barrier_wait(&barrier);
+ return 0;
+}
+
+int main() {
+ barrier_init(&barrier, 2);
+ void *ptr = mmap(0, 128 << 10, PROT_READ|PROT_WRITE,
+ MAP_32BIT|MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+ fprintf(stderr, "ptr=%p\n", ptr);
+ if (ptr == MAP_FAILED) {
+ fprintf(stderr, "mmap failed: %d\n", errno);
+ return 1;
+ }
+ if ((uintptr_t)ptr >= (1ull << 32)) {
+ fprintf(stderr, "ptr is too high\n");
+ return 1;
+ }
+ pthread_t t;
+ pthread_create(&t, 0, Thread, ptr);
+ barrier_wait(&barrier);
+ *(int*)ptr = 42;
+ pthread_join(t, 0);
+ munmap(ptr, 128 << 10);
+ fprintf(stderr, "DONE\n");
+}
+
+// CHECK: WARNING: ThreadSanitizer: data race
+// CHECK: DONE
