1 files changed, 50 insertions, 0 deletions
diff --git a/compiler-rt/test/tsan/Darwin/write-interpose.c b/compiler-rt/test/tsan/Darwin/write-interpose.c
new file mode 100644
index 0000000..cbd9a08
--- /dev/null
+++ b/compiler-rt/test/tsan/Darwin/write-interpose.c
@@ -0,0 +1,50 @@
+// Test that dylibs interposing write, and then calling functions intercepted
+// by TSan don't deadlock (self-lock)
+
+// RUN: %clang_tsan %s -o %t
+// RUN: %clang_tsan %s -o %t.dylib -fno-sanitize=thread -dynamiclib -DSHARED_LIB
+
+// Note that running the below command with out `lock_during_write` should
+// deadlock (self-lock)
+// RUN: env DYLD_INSERT_LIBRARIES=%t.dylib TSAN_OPTIONS=verbosity=2:lock_during_write=disable_for_current_process %run %t 2>&1 | FileCheck %s
+
+#include <stdio.h>
+
+#if defined(SHARED_LIB)
+
+// dylib implementation - interposes write() calls
+#  include <os/lock.h>
+#  include <unistd.h>
+
+struct interpose_substitution {
+  const void *replacement;
+  const void *original;
+};
+
+#  define INTERPOSE(replacement, original)                                     \
+    __attribute__((used)) static const struct interpose_substitution           \
+        substitution_##original[]                                              \
+        __attribute__((section("__DATA, __interpose"))) = {                    \
+            {(const void *)(replacement), (const void *)(original)}}
+
+static ssize_t my_write(int fd, const void *buf, size_t count) {
+  struct os_unfair_lock_s lock = OS_UNFAIR_LOCK_INIT;
+  os_unfair_lock_lock(&lock);
+  printf("Interposed write called: fd=%d, count=%zu\n", fd, count);
+  ssize_t res = write(fd, buf, count);
+  os_unfair_lock_unlock(&lock);
+  return res;
+}
+INTERPOSE(my_write, write);
+
+#else // defined(SHARED_LIB)
+
+int main() {
+  printf("Write test completed\n");
+  return 0;
+}
+
+#endif // defined(SHARED_LIB)
+
+// CHECK: Interposed write called: fd={{[0-9]+}}, count={{[0-9]+}}
+// CHECK: Write test completed