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>

1 files changed, 23 insertions, 3 deletions

diff --git a/src/client/linux/handler/exception_handler_unittest.cc b/src/client/linux/handler/exception_handler_unittest.cc
index 2a080607..be49ef09 100644
--- a/src/client/linux/handler/exception_handler_unittest.cc
+++ b/src/client/linux/handler/exception_handler_unittest.cc
@@ -873,17 +873,37 @@ TEST(ExceptionHandlerTest, InstructionPointerMemoryNullPointer) {
   ASSERT_GT(st.st_size, 0);
 
   // Read the minidump. Locate the exception record and the
-  // memory list, and then ensure that there is a memory region
+  // memory list, and then ensure that there is no memory region
   // in the memory list that covers the instruction pointer from
   // the exception record.
   Minidump minidump(minidump_path);
   ASSERT_TRUE(minidump.Read());
 
   MinidumpException* exception = minidump.GetException();
-  MinidumpMemoryList* memory_list = minidump.GetMemoryList();
   ASSERT_TRUE(exception);
+
+  MinidumpContext* exception_context = exception->GetContext();
+  ASSERT_TRUE(exception_context);
+
+  uint64_t instruction_pointer;
+  ASSERT_TRUE(exception_context->GetInstructionPointer(&instruction_pointer));
+  EXPECT_EQ(instruction_pointer, 0);
+
+  MinidumpMemoryList* memory_list = minidump.GetMemoryList();
   ASSERT_TRUE(memory_list);
-  ASSERT_EQ(static_cast<unsigned int>(1), memory_list->region_count());
+
+  unsigned int region_count = memory_list->region_count();
+  ASSERT_GE(region_count, 1);
+
+  for (unsigned int region_index = 0;
+       region_index < region_count;
+       ++region_index) {
+    MinidumpMemoryRegion* region =
+        memory_list->GetMemoryRegionAtIndex(region_index);
+    uint64_t region_base = region->GetBase();
+    EXPECT_FALSE(instruction_pointer >= region_base &&
+                 instruction_pointer < region_base + region->GetSize());
+  }
 
   unlink(minidump_path.c_str());
 }