Linux breakpad_unittests: fix ThreadSanitizer problems

Some tests were failing because they had expectations about the number
of threads in a process, but TSan, and in some cases, ASan, introduce
their own threads. Where a sanitizer affects this, the expectations are
now used as minimum thread counts, not exact thread counts. See
https://www.brooklinen.com/blogs/brookliving/best-thread-count-for-sheets.

These problems were detected by ThreadSanitizer at
https://logs.chromium.org/logs/chromium/buildbucket/cr-buildbucket.appspot.com/8915151099544583616/+/steps/breakpad_unittests__with_patch_/0/stdout

Bug: chromium:949098
Change-Id: Ie40f1766bea27e9bcb112bf9e0b8b846fb343012
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/1585948
Reviewed-by: Robert Sesek <rsesek@chromium.org>

3 files changed, 18 insertions, 4 deletions

diff --git a/src/client/linux/minidump_writer/linux_core_dumper_unittest.cc b/src/client/linux/minidump_writer/linux_core_dumper_unittest.cc
index 212b151b..77448031 100644
--- a/src/client/linux/minidump_writer/linux_core_dumper_unittest.cc
+++ b/src/client/linux/minidump_writer/linux_core_dumper_unittest.cc
@@ -116,7 +116,11 @@ TEST(LinuxCoreDumperTest, VerifyDumpWithMultipleThreads) {
   EXPECT_EQ(crash_generator.GetThreadId(kCrashThread),
             dumper.crash_thread());
 
-  EXPECT_EQ(kNumOfThreads, dumper.threads().size());
+#if defined(THREAD_SANITIZER)
+  EXPECT_GE(dumper.threads().size(), kNumOfThreads);
+#else
+  EXPECT_EQ(dumper.threads().size(), kNumOfThreads);
+#endif
   for (unsigned i = 0; i < kNumOfThreads; ++i) {
     ThreadInfo info;
     EXPECT_TRUE(dumper.GetThreadInfoByIndex(i, &info));
diff --git a/src/client/linux/minidump_writer/linux_ptrace_dumper_unittest.cc b/src/client/linux/minidump_writer/linux_ptrace_dumper_unittest.cc
index 3060327f..8757563e 100644
--- a/src/client/linux/minidump_writer/linux_ptrace_dumper_unittest.cc
+++ b/src/client/linux/minidump_writer/linux_ptrace_dumper_unittest.cc
@@ -434,10 +434,15 @@ TEST(LinuxPtraceDumperTest, VerifyStackReadWithMultipleThreads) {
   // Children are ready now.
   LinuxPtraceDumper dumper(child_pid);
   ASSERT_TRUE(dumper.Init());
-  EXPECT_EQ((size_t)kNumberOfThreadsInHelperProgram, dumper.threads().size());
+#if defined(THREAD_SANITIZER)
+  EXPECT_GE(dumper.threads().size(), (size_t)kNumberOfThreadsInHelperProgram);
+#else
+  EXPECT_EQ(dumper.threads().size(), (size_t)kNumberOfThreadsInHelperProgram);
+#endif
   EXPECT_TRUE(dumper.ThreadsSuspend());
 
   ThreadInfo one_thread;
+  size_t matching_threads = 0;
   for (size_t i = 0; i < dumper.threads().size(); ++i) {
     EXPECT_TRUE(dumper.GetThreadInfoByIndex(i, &one_thread));
     const void* stack;
@@ -465,8 +470,9 @@ TEST(LinuxPtraceDumperTest, VerifyStackReadWithMultipleThreads) {
                            dumper.threads()[i],
                            process_tid_location,
                            4);
-    EXPECT_EQ(dumper.threads()[i], one_thread_id);
+    matching_threads += (dumper.threads()[i] == one_thread_id) ? 1 : 0;
   }
+  EXPECT_EQ(matching_threads, kNumberOfThreadsInHelperProgram);
   EXPECT_TRUE(dumper.ThreadsResume());
   kill(child_pid, SIGKILL);
 
diff --git a/src/client/linux/minidump_writer/minidump_writer_unittest.cc b/src/client/linux/minidump_writer/minidump_writer_unittest.cc
index 583ddda8..c951e69d 100644
--- a/src/client/linux/minidump_writer/minidump_writer_unittest.cc
+++ b/src/client/linux/minidump_writer/minidump_writer_unittest.cc
@@ -306,7 +306,11 @@ TEST(MinidumpWriterTest, MinidumpStacksSkippedIfRequested) {
       ++threads_with_stacks;
     }
   }
-  ASSERT_EQ(1, threads_with_stacks);
+#if defined(THREAD_SANITIZER) || defined(ADDRESS_SANITIZER)
+  ASSERT_GE(threads_with_stacks, 1);
+#else
+  ASSERT_EQ(threads_with_stacks, 1);
+#endif
   close(fds[1]);
   IGNORE_EINTR(waitpid(child, nullptr, 0));
 }