gcc-asan doesn't work on android/arm32

[ramosian-glider]

Originally reported on Google Code with ID 407

What steps will reproduce the problem?
1.built the testcase invalid-free.cc with cross-compile toolchain gcc-asan

2.upload libasan.so and binary
sudo adb root
sudo adb remount
sudo adb push libasan.so.2 /system/lib
sudo adb push invalid-free /data/local

3.running the invalid-free on Android Phone
sudo adb shell
/data/local/invalid-free

What is the expected output? What do you see instead?

the expected output should be:

running case 1:  ./TestCases/x86_binary/invalid-free 

=================================================================
==14369==ERROR: AddressSanitizer: attempting free on address which was not malloc()-ed:
0x60200000eff5 in thread T0
    #0 0x43be57 in __interceptor_free /tmp/AOSP-toolchain/build/../gcc/gcc-4.9.2/libsanitizer/asan/asan_malloc_linux.cc:62
    #1 0x444a00 in main (TestCases/x86_binary/invalid-free+0x4
44a00)
    #2 0x7f45f75ce76c in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2176c)
    #3 0x408c18 (TestCases/x86_binary/invalid-free+0x408c18)

0x60200000eff5 is located 5 bytes inside of 10-byte region [0x60200000eff0,0x60200000effa)
allocated by thread T0 here:
    #0 0x43c01f in __interceptor_malloc /tmp/AOSP-toolchain/build/../gcc/gcc-4.9.2/libsanitizer/asan/asan_malloc_linux.cc:72
    #1 0x44491f in main (TestCases/x86_binary/invalid-free+0x4
4491f)   
    #2 0x7f45f75ce76c in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2176c)

SUMMARY: AddressSanitizer: bad-free /tmp/AOSP-toolchain/build/../gcc/gcc-4.9.2/libsanitizer/asan/asan_malloc_linux.cc:62
__intercept
or_free
==14369==ABORTING

when running the testcase on android, the testcase will SEGV as following:


[1m[31m==3909==ERROR: AddressSanitizer: SEGV on unknown address 0x369a00fe (pc 0xb6f51662
bp 0xbeb58a1c sp 0xbeb589e0 T0)
[1m[0m    #0 0xb6f51661 in main TestCases/invalid-free.cc:14
    #1 0xb69c0e09  (/system/lib/libc.so+0x12e09)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV TestCases/invalid-free.cc:14 main
==3909==ABORTING


What version of the product are you using? On what operating system?

Android 5.0

Please provide any additional information below.

made a gcc-based cross-compile toolchain for Android 5.0 with AddressSanitizer feature
enabled; then use the customzied toolchain to built the testcase in external/compiler-rt/test/asan/TestCases,
and running the testcase on Android phone.

this bug had been fixed and validated with gcc4.9.2 and gcc5.2.0 in our development
environment:


1.
modify function 

static unsigned HOST_WIDE_INT arm_asan_shadow_offset(void) 

in the gcc-4.9.2/config/arm/arm.c  

from 

static unsigned HOST_WIDE_INT
 arm_asan_shadow_offset (void)
{
 return (unsigned HOST_WIDE_INT) 1 << 29;
}

to

static unsigned HOST_WIDE_INT
 arm_asan_shadow_offset (void)
{
#ifdef TARGET_ANDROID
 return 0;
#else
 return (unsigned HOST_WIDE_INT) 1 << 29;
#endif
}

 because the process's memory layout in Android is different in x86. so the shadow
offset should be zero in Android when instrument the check code.

2.disable -Os optimization options in Android build system; becase the asan pass  

should be called in the GCC's internal to handle GENERIC/GIMPLY transformation,otherwise
the check code wouldn't be instrumented during compile stage.

Reported by zhouweiguo2008 on 2015-08-21 08:41:12

---

- _Attachment: [gcc-asan_ut-on-android-after-fixbug.log](https://storage.googleapis.com/google-code-attachments/address-sanitizer/issue-407/comment-0/gcc-asan_ut-on-android-after-fixbug.log)_

[ramosian-glider]

I submitted the same bugs on gcc's bugzilla system. the following is the URL.


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67286

I got my manager's approval before submitted the bug.

because I think our debug tool base on the Google's AddressSanitizer and GCC,
we should feedback the result to open-source community.

Thanks the powerful AddressSanitizer and excellent creator of the AddressSanitizer,
especially the kcc in Google. I think he is an greate and excellent engineer.

I can only access code.google.com via company's VPN because the people in Mainland
China couldn't access goolge  and Google's powerful search engine.

Reported by zhouweiguo2008 on 2015-08-21 08:49:47

[kcc]

Not working on gcc-asan-android