[lsan] Handle fork() correctly.

Update the main thread's os_id on every pthread_create, and before
initiating leak checking. This ensures that we have the correct os_id even if we
have forked after Init().

llvm-svn: 185815

2 files changed, 68 insertions, 0 deletions

diff --git a/compiler-rt/lib/lsan/lit_tests/TestCases/fork.cc b/compiler-rt/lib/lsan/lit_tests/TestCases/fork.cc
new file mode 100644
index 00000000000..69258d9a0c7
--- /dev/null
+++ b/compiler-rt/lib/lsan/lit_tests/TestCases/fork.cc
@@ -0,0 +1,24 @@
+// Test that thread local data is handled correctly after forking without exec().
+// RUN: %clangxx_lsan %s -o %t
+// RUN: %t 2>&1
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+__thread void *thread_local_var;
+
+int main() {
+  int status = 0;
+  thread_local_var = malloc(1337);
+  pid_t pid = fork();
+  assert(pid >= 0);
+  if (pid > 0) {
+    waitpid(pid, &status, 0);
+    assert(WIFEXITED(status));
+    return WEXITSTATUS(status);
+  }
+  return 0;
+}
diff --git a/compiler-rt/lib/lsan/lit_tests/TestCases/fork_threaded.cc b/compiler-rt/lib/lsan/lit_tests/TestCases/fork_threaded.cc
new file mode 100644
index 00000000000..b162de458b0
--- /dev/null
+++ b/compiler-rt/lib/lsan/lit_tests/TestCases/fork_threaded.cc
@@ -0,0 +1,44 @@
+// Test that thread local data is handled correctly after forking without
+// exec(). In this test leak checking is initiated from a non-main thread.
+// RUN: %clangxx_lsan %s -o %t
+// RUN: %t 2>&1
+
+#include <assert.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+__thread void *thread_local_var;
+
+void *exit_thread_func(void *arg) {
+  exit(0);
+}
+
+void ExitFromThread() {
+  pthread_t tid;
+  int res;
+  res = pthread_create(&tid, 0, exit_thread_func, 0);
+  assert(res == 0);
+  res = pthread_join(tid, 0);
+  assert(res == 0);
+}
+
+int main() {
+  int status = 0;
+  thread_local_var = malloc(1337);
+  pid_t pid = fork();
+  assert(pid >= 0);
+  if (pid > 0) {
+    waitpid(pid, &status, 0);
+    assert(WIFEXITED(status));
+    return WEXITSTATUS(status);
+  } else {
+    // Spawn a thread and call exit() from there, to check that we track main
+    // thread's pid correctly even if leak checking is initiated from another
+    // thread.
+    ExitFromThread();
+  }
+  return 0;
+}