[scudo] Additional modifications for Android tests support

[cryptoad]

Summary

With the recent move of android_commands to sanitizer_common, some things
have to be updated with regard to Scudo on Android.

Notably:

• config.android is dealt with in the common code
• config.compile_wrapper can be prepended to allow for the use of the android commands
• SCUDO_OPTIONS must be passed with the environment when running a test
• preinit.cpp fails with some API levels, not sure why, I will have to dig into this later.

Note that check-scudo is not enabled yet in the bots. It's all local testing
for now until everything looks good.

[vitalybuka]

test/scudo/preinit.cpp

9

XFAIL means that test is going to fail if it passes
if it's inconsistent it must be UNSUPPORTED

[cryptoad]

s/XFAIL/UNSUPPORTED for the preinit.cpp test.

[cryptoad]

Updating the description of preinit.cpp.
For some API levels on my emulator, calling mmap from a preinit function
ends up in a NULL dereference in __mmap2.S (without Scudo).

test/sanitizer_common/android_commands/android_run.py

 #!/usr/bin/python
 
 import os, signal, sys, subprocess, tempfile
 from android_common import *
 
 ANDROID_TMPDIR = '/data/local/tmp/Output'
 
 here = os.path.abspath(os.path.dirname(sys.argv[0]))
 device_binary = os.path.join(ANDROID_TMPDIR, os.path.basename(sys.argv[0]))
 
 def build_env():
     args = []
     # Android linker ignores RPATH. Set LD_LIBRARY_PATH to Output dir.
     args.append('LD_LIBRARY_PATH=%s' % (ANDROID_TMPDIR,))
     for (key, value) in os.environ.items():
-        if key in ['ASAN_OPTIONS', 'ASAN_ACTIVATION_OPTIONS']:
+        if key in ['ASAN_OPTIONS', 'ASAN_ACTIVATION_OPTIONS', 'SCUDO_OPTIONS']:
             args.append('%s="%s"' % (key, value))
     return ' '.join(args)
 
 is_64bit = (subprocess.check_output(['file', sys.argv[0] + '.real']).find('64-bit') != -1)
 
 device_env = build_env()
 device_args = ' '.join(sys.argv[1:]) # FIXME: escape?
 device_stdout = device_binary + '.stdout'

test/scudo/lit.cfg

c_flags = ([config.target_cflags] +
            "-ldl",
            "-Wl,--gc-sections"])
 
 # Android doesn't want -lrt.
 if not config.android:
   c_flags += ["-lrt"]
 
 def build_invocation(compile_flags):                                            
-  return " " + " ".join([config.clang] + compile_flags) + " "                   
+  return " " + " ".join([config.compile_wrapper, config.clang] + compile_flags) + " "                   
 
 # Add clang substitutions.
 config.substitutions.append(("%clang_scudo ",
                              build_invocation(c_flags) + whole_archive))
 
 # Platform-specific default SCUDO_OPTIONS for lit tests.
 default_scudo_opts = ''
 if config.android:

test/scudo/lit.site.cfg.in

 @LIT_SITE_CFG_IN_HEADER@
 
 config.name_suffix = "@SCUDO_TEST_CONFIG_SUFFIX@"
 config.target_arch = "@SCUDO_TEST_TARGET_ARCH@"
 config.target_cflags = "@SCUDO_TEST_TARGET_CFLAGS@"
-config.android = "@ANDROID@"
 
 # Load common config for all compiler-rt lit tests.
 lit_config.load_config(config, "@COMPILER_RT_BINARY_DIR@/test/lit.common.configured")
 
 # Load tool-specific config that would do the real work.
 lit_config.load_config(config, "@SCUDO_LIT_SOURCE_DIR@/lit.cfg")

test/scudo/preinit.cpp

 // RUN: %clang_scudo %s -o %t
 // RUN: %run %t 2>&1
 
 // Verifies that calling malloc in a preinit_array function succeeds, and that
 // the resulting pointer can be freed at program termination.
 
+// On some Android versions, calling mmap() from a preinit function segfaults.
+// It looks like __mmap2.S ends up calling a NULL function pointer.
+// UNSUPPORTED: android
+
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>
 
 static void *global_p = nullptr;
 
 void __init(void) {
   global_p = malloc(1);