[android] Fix some tests for AOSP-master devices.

[hctim]

Summary

Some tests are broken at API level 30 on AOSP-master devices. When we
change the buildbuit to API level 30, the following tests get enabled.
They're currently broken due to various issues, and so fix up those
issues.

[hctim]

(changed some comment text).

[oontvoo]

compiler-rt/test/lsan/TestCases/stale_stack_leak.cpp

4–6

Just curious, can the instrumentation be changed? (to not stash arguments?)

[hctim]

compiler-rt/test/lsan/TestCases/stale_stack_leak.cpp

4–6

AFAICT, not really - the instrumentation is just a conditional branch with an IR call - it's the regalloc in the backend that would need to be tinkered with (which I'd rather not change the behaviour of the regalloc at -O0 to work around an lsan-in-asan false negative).

[oontvoo]

LGTM

compiler-rt/test/lsan/TestCases/stale_stack_leak.cpp

4–6

Got it! Thanks for the details!

[hctim]

Lost some of the patch in a comment fix, here's the rest of it.

[oontvoo]

compiler-rt/test/lsan/TestCases/stale_stack_leak.cpp

12

very nit: If this is an architecture-specific thing, then maybe Android (the OS) shouldn't have to be called out?

perhaps s/Android/aarch64 ?

[hctim]

compiler-rt/test/lsan/TestCases/stale_stack_leak.cpp

12

this line can actually be deleted, it's the same as above.

[hctim]

• Remove some dead comments.

compiler-rt/test/cfi/cross-dso/target_out_of_bounds.cpp

 // RUN: %clangxx_cfi_dso_diag -std=c++11 %s -o %t
 // RUN: %t zero 2>&1 | FileCheck --check-prefix=CHECK-ZERO %s
 // RUN: %t unaddressable 2>&1 | FileCheck --check-prefix=CHECK-UNADDR %s
 // RUN: %t 2>&1 | FileCheck --check-prefix=CHECK-TYPEINFO %s
 
 // RUN: %clangxx_cfi_diag -std=c++11 %s -o %t2
 // RUN: %t2 zero 2>&1 | FileCheck --check-prefix=CHECK-ZERO %s
 // RUN: %t2 unaddressable 2>&1 | FileCheck --check-prefix=CHECK-UNADDR %s
 // RUN: %t2 2>&1 | FileCheck --check-prefix=CHECK-TYPEINFO %s
 
 // REQUIRES: cxxabi
 
+// These checks are unsupported on newer versions of Android due to the
+// following patch that makes it harder to defeat ASLR by not mapping unused
+// shadow regions:
+// https://android-review.googlesource.com/c/platform/bionic/+/1333960
+// UNSUPPORTED: android
+
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mman.h>
 
 struct A {
   virtual void f();

compiler-rt/test/lsan/TestCases/Linux/use_tls_dynamic.cpp

 #include <stdio.h>
 #include <stdlib.h>
 #include <string>
 #include "sanitizer_common/print_address.h"
 
 int main(int argc, char *argv[]) {
   std::string path = std::string(argv[0]) + "-so.so";
 
+  // Clear any previous errors. On Android, the dynamic loader can have some
+  // left over dlerror() messages due to a missing symbol resolution for a
+  // deprecated malloc function.
+  dlerror();
+
   void *handle = dlopen(path.c_str(), RTLD_LAZY);
   assert(handle != 0);
   typedef void **(* store_t)(void *p);
   store_t StoreToTLS = (store_t)dlsym(handle, "StoreToTLS");
 
   // Sometimes dlerror() occurs when we broke the interceptors.
   // Add the message here to make the error more obvious.
   const char *dlerror_msg = dlerror();
-  assert(dlerror_msg == nullptr);
   if (dlerror_msg != nullptr) {
     fprintf(stderr, "DLERROR: %s\n", dlerror_msg);
     fflush(stderr);
+    abort();
   }
   void *p = malloc(1337);
   // If we don't  know about dynamic TLS, we will return a false leak above.
   void **p_in_tls = StoreToTLS(p);
   assert(*p_in_tls == p);
   print_address("Test alloc: ", 1, p);
   return 0;
 }

compiler-rt/test/lsan/TestCases/stale_stack_leak.cpp

 // Test that out-of-scope local variables are ignored by LSan.
 // RUN: LSAN_BASE="report_objects=1:use_registers=0:use_stacks=1"
-// RUN: %clangxx_lsan %s -o %t
+
+// LSan-in-ASan fails at -O0 on aarch64, because the stack use-after-return
+// instrumentation stashes the argument to `PutPointerOnStaleStack` on the stack
+// in order to conditionally call __asan_stack_malloc. This subverts our
+// expectations for this test, where we assume the pointer is never stashed
+// except at the bottom of the dead frame. Building at -O1 or greater solves
+// this problem, because the compiler is smart enough to stash the argument in a
+// callee-saved register for rematerialization instead.
+// RUN: %clangxx_lsan -O1 %s -o %t
+
 // RUN: %env_lsan_opts=$LSAN_BASE not %run %t 2>&1 | FileCheck %s
 // RUN: %env_lsan_opts=$LSAN_BASE":exitcode=0" %run %t 2>&1 | FileCheck --check-prefix=CHECK-sanity %s
 //
 // x86 passes parameters through stack that may lead to false negatives
 // The same applies to s390x register save areas.
 // UNSUPPORTED: x86,i686,powerpc64,arm,s390x
 
 #include <stdio.h>