Re: [boost] Test failures on sanitize memory - are they caused by lightweight_test?

Subject: Re: [boost] Test failures on sanitize memory - are they caused by lightweight_test?
From: Ben Pope (benpope81_at_[hidden])
Date: 2015-03-11 07:18:37

On Wednesday, March 11, 2015 05:43 PM, Andrey Semashev wrote:
>   On Wed, Mar 11, 2015 at 12:32 PM, Fletcher, John P
> <j.p.fletcher_at_[hidden]> wrote:
>> There is a test set on develop called BenPope x86_64 Ubuntu - phoenix - adapt_function / clang-linux-3.6~msan~c14_libc++
>>
>> This runs this command line for example on the Phoenix test "adapt_function":
>>
>> "clang++-3.6" -c -x c++ -std=c++1y -stdlib=libc++ -fsanitize=memory -O0 -fno-inline -Wall -fPIC -m64  -DBOOST_ALL_NO_LIB=1 -I".." -o "/home/ben/development/boost/test/build/develop/results/boost/bin.v2/libs/phoenix/test/adapt_function.test/clang-linux-3.6~msan~c14_libc++/debug/address-model-64/architecture-x86/debug-symbols-off/function/adapt_function.o" "../libs/phoenix/test/function/adapt_function.cpp"
>>
>> There are numerous failures with this test set on Phoenix and I set out to find out why.
>>
>> Most of the failures are like this:
>>
>> SUMMARY: MemorySanitizer: use-of-uninitialized-value ??:0 std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long)
>> Exiting
>>
>> I think this is coming from the boost::report_errors function defined in boost/core/lightweight_test.hpp
>>
>> I have put some temporary tests on to develop for Phoenix which contain only various calls to test the lightweight test.  These are called aa_test0 to 3 so they will come at the top of the table.  Unfortunately tests are not reporting at the moment so I don't have any results.
>>
>> There are also failures on the testing of Boost Core with the same test set.
>>
>> I thought I would report this without waiting for the results in the hope that it can be sorted out for the 1.58.0 release.
>
> This looks like a string insertion operator implementation. I don't
> see how the string memory could be uninitialized since there are only
> literals used in report_errors(), as well as other functions, unless
> you use BOOST_ERROR with uninitialized buffer as the message string. I
> suspect a false positive. Does MSan report an error for this code
> sample:
>
>   #include <iostream>
>
>   int main()
>   {
>     std::cerr << "Hello, world!" << std::endl;
>     return 0;
>   }

Yes.

ben_at_yyls03:~/development/test$ ./a.out
==4752== WARNING: MemorySanitizer: use-of-uninitialized-value
     #0 0x7f0103b09f3f in std::__1::basic_ostream<char, 
std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, 
std::__1::char_traits<char> >(std::__1::basic_ostream<char, 
std::__1::char_traits<char> >&, char const*, unsigned long) 
(/home/ben/development/test/a.out+0x8bf3f)
     #1 0x7f0103b09602 in std::__1::basic_ostream<char, 
std::__1::char_traits<char> >& std::__1::operator<< 
<std::__1::char_traits<char> >(std::__1::basic_ostream<char, 
std::__1::char_traits<char> >&, char const*) 
(/home/ben/development/test/a.out+0x8b602)
     #2 0x7f0103b094d6 in main (/home/ben/development/test/a.out+0x8b4d6)
     #3 0x7f0102462ec4 in __libc_start_main 
/build/buildd/eglibc-2.19/csu/libc-start.c:287
     #4 0x7f0103ab4f7e in _start (/home/ben/development/test/a.out+0x36f7e)

SUMMARY: MemorySanitizer: use-of-uninitialized-value ??:0 
std::__1::basic_ostream<char, std::__1::char_traits<char> >& 
std::__1::__put_character_sequence<char, std::__1::char_traits<char> 
 >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char 
const*, unsigned long)
Exiting

I've added it to the blacklist now, hopefully I have the correct 
incantation and significantly reduce the false positives.

Ben