Bug#842642: clang-3.9: memory sanitizer segfaults immediately

Fri Nov 11 16:07:16 UTC 2016

Yeah, my bad. Why did you included the third patch btw?

thanks again

Le 11/11/2016 à 17:02, Norbert Lange a écrit :
> Hi, you messed up the order, look in the series file from the attachment.
> You only need those two patches (in this order), third is already
> included in 3.8.1:
>
> upstream-msan-prevent-initialization-failure.diff
> upstream-asan-msan-fix-reallocation-logic.diff
>
> if you want you can refresh them with quilt, but they apply cleanly
> for me (with some other linenumbers)
>
> 2016-11-11 16:23 GMT+01:00 Sylvestre Ledru <s at mozilla.com>:
>> I could apply upstream-msan-prevent-initialization-failure.diff  to 3.8 but
>> not the two others, could you share yours?
>> Thanks
>> S
>>
>>
>> Le 11/11/2016 à 09:52, Norbert Lange a écrit :
>>> The same 2 patches also apply to toolchain 3.8.1-15 (with some
>>> offsets), but I haven`t testing building it
>>>
>>> 2016-11-11 1:25 GMT+01:00 Norbert Lange <nolange79 at gmail.com>:
>>>> BTW. make check-sanitizer would have likely found this issue, might
>>>> want to enable it?
>>>> I believe it knows which sanitizers should work
>>>>
>>>> 2016-11-11 0:46 GMT+01:00 Norbert Lange <nolange79 at gmail.com>:
>>>>> Tags: patch
>>>>>
>>>>>
>>>>> Hi,
>>>>>
>>>>> I got it working, seems that from the 3 related patched, one is already
>>>>> applied.
>>>>> The attached archive is the 3 patches and a edited "series" file,
>>>>> it should be painless for you to integrate it into the debian/patches
>>>>> directory for 3.9
>>>>>
>>>>> I did not try with 3.8 yet (possibly more difficult), building llvm
>>>>> takes quite a while.
>>>>>
>>>>> Kind Regards,
>>>>> Norbert
>>>>>
>>>>> 2016-11-09 11:04 GMT+01:00 Norbert Lange <nolange79 at gmail.com>:
>>>>>> Hi,
>>>>>>
>>>>>> researched a bit further and the same compiled programm will run fine
>>>>>> on debian jessie.
>>>>>> I tracked it down to being caused by a newer glibc version [1][2],
>>>>>> apparently during loading of shared libs, glibc can now allocate
>>>>>> memory which messes up sanitzers (mostly in more subtile ways than the
>>>>>> memory sanitizer).
>>>>>>
>>>>>> The result is, that if stretch will ship with the current glibc, clang
>>>>>> and gcc (I dont think its patched there either), then the sanitizers
>>>>>> won`t be usable.
>>>>>> 1) revert the fix in glibc. Would have the advantage that "sanitized"
>>>>>> binaries compiled from current and older clang/gcc versions will work
>>>>>> 2) adopt the fixed from upstream [3][4] (possibly more) into clang
>>>>>> (and possibly gcc).
>>>>>> or maybe both?
>>>>>>
>>>>>> Kind Regards,
>>>>>> Norbert
>>>>>>
>>>>>> PS. shouldn`t the testsuite catch these bugs?
>>>>>>
>>>>>> [1]
>>>>>> https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=24e2b1cede1952d7d4411a3cafd25dd8593dab9f
>>>>>> [2] https://llvm.org/bugs/show_bug.cgi?id=27310
>>>>>> [3]
>>>>>> https://github.com/llvm-mirror/compiler-rt/commit/827ea206c1078fc7c7da287984a7ba4563390589
>>>>>> [4]
>>>>>> https://github.com/llvm-mirror/compiler-rt/commit/570ee9dd7a6f90b0370a86535cbde6738d0ccf67
>>>>>>
>>>>>> 2016-10-31 21:43 GMT+01:00 Norbert Lange <nolange79 at gmail.com>:
>>>>>>> On Mon, 31 Oct 2016 08:38:21 +0100 Sylvestre Ledru
>>>>>>> <sylvestre at debian.org> wrote:
>>>>>>>> Le 31/10/2016 à 00:39, Norbert Lange a écrit :
>>>>>>>>> Package: clang-3.9
>>>>>>>>> Version: 1:3.9-2
>>>>>>>>> Severity: normal
>>>>>>>>>
>>>>>>>>> Dear Maintainer,
>>>>>>>>>
>>>>>>>>> The memory sanitizer is unusable as it segfaults during
>>>>>>>>> initialization.
>>>>>>>>> To reproduce:
>>>>>>>>> echo 'int main() { return 0; }' >/tmp/test.c
>>>>>>>>> clang -fsanitize=memory -o test test.c
>>>>>>>> can you try with clang-3.9 instead?
>>>>>>> Same thing, output:
>>>>>>>
>>>>>>> $ clang-3.9 -fsanitize=memory -o test test.c -v
>>>>>>> clang version 3.9.0-2 (tags/RELEASE_390/final)
>>>>>>> Target: x86_64-pc-linux-gnu
>>>>>>> Thread model: posix
>>>>>>> InstalledDir: /usr/bin
>>>>>>> Found candidate GCC installation: /usr/bin/../lib/gcc/i686-linux-gnu/6
>>>>>>> Found candidate GCC installation:
>>>>>>> /usr/bin/../lib/gcc/i686-linux-gnu/6.2.0
>>>>>>> Found candidate GCC installation:
>>>>>>> /usr/bin/../lib/gcc/x86_64-linux-gnu/5
>>>>>>> Found candidate GCC installation:
>>>>>>> /usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.1
>>>>>>> Found candidate GCC installation:
>>>>>>> /usr/bin/../lib/gcc/x86_64-linux-gnu/6
>>>>>>> Found candidate GCC installation:
>>>>>>> /usr/bin/../lib/gcc/x86_64-linux-gnu/6.2.0
>>>>>>> Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/6
>>>>>>> Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/6.2.0
>>>>>>> Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
>>>>>>> Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.4.1
>>>>>>> Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
>>>>>>> Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.2.0
>>>>>>> Selected GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/6.2.0
>>>>>>> Candidate multilib: .;@m64
>>>>>>> Candidate multilib: 32;@m32
>>>>>>> Candidate multilib: x32;@mx32
>>>>>>> Selected multilib: .;@m64
>>>>>>>    "/usr/lib/llvm-3.9/bin/clang" -cc1 -triple x86_64-pc-linux-gnu
>>>>>>> -emit-obj -mrelax-all -disable-free -disable-llvm-verifier
>>>>>>> -discard-value-names -main-file-name test.c -mrelocation-model static
>>>>>>> -mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose
>>>>>>> -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu
>>>>>>> x86-64 -v -dwarf-column-info -debugger-tuning=gdb -resource-dir
>>>>>>> /usr/lib/llvm-3.9/bin/../lib/clang/3.9.0 -internal-isystem
>>>>>>> /usr/local/include -internal-isystem
>>>>>>> /usr/lib/llvm-3.9/bin/../lib/clang/3.9.0/include
>>>>>>> -internal-externc-isystem /usr/include/x86_64-linux-gnu
>>>>>>> -internal-externc-isystem /include -internal-externc-isystem
>>>>>>> /usr/include -fdebug-compilation-dir /tmp -ferror-limit 19
>>>>>>> -fmessage-length 135 -fsanitize=memory
>>>>>>>
>>>>>>> -fsanitize-blacklist=/usr/lib/llvm-3.9/bin/../lib/clang/3.9.0/msan_blacklist.txt
>>>>>>> -fno-assume-sane-operator-new -fobjc-runtime=gcc
>>>>>>> -fdiagnostics-show-option -fcolor-diagnostics -o /tmp/test-2d4d2c.o -x
>>>>>>> c test.c
>>>>>>> clang -cc1 version 3.9.0 based upon LLVM 3.9.0 default target
>>>>>>> x86_64-pc-linux-gnu
>>>>>>> ignoring nonexistent directory "/include"
>>>>>>> #include "..." search starts here:
>>>>>>> #include <...> search starts here:
>>>>>>>    /usr/local/include
>>>>>>>    /usr/lib/llvm-3.9/bin/../lib/clang/3.9.0/include
>>>>>>>    /usr/include/x86_64-linux-gnu
>>>>>>>    /usr/include
>>>>>>> End of search list.
>>>>>>>    "/usr/bin/ld" --hash-style=both --eh-frame-hdr -m elf_x86_64
>>>>>>> -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o test
>>>>>>>
>>>>>>> /usr/bin/../lib/gcc/x86_64-linux-gnu/6.2.0/../../../x86_64-linux-gnu/crt1.o
>>>>>>>
>>>>>>> /usr/bin/../lib/gcc/x86_64-linux-gnu/6.2.0/../../../x86_64-linux-gnu/crti.o
>>>>>>> /usr/bin/../lib/gcc/x86_64-linux-gnu/6.2.0/crtbegin.o
>>>>>>> -L/usr/bin/../lib/gcc/x86_64-linux-gnu/6.2.0
>>>>>>> -L/usr/bin/../lib/gcc/x86_64-linux-gnu/6.2.0/../../../x86_64-linux-gnu
>>>>>>> -L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu
>>>>>>> -L/usr/bin/../lib/gcc/x86_64-linux-gnu/6.2.0/../../..
>>>>>>> -L/usr/lib/llvm-3.9/bin/../lib -L/lib -L/usr/lib -whole-archive
>>>>>>>
>>>>>>> /usr/lib/llvm-3.9/bin/../lib/clang/3.9.0/lib/linux/libclang_rt.msan-x86_64.a
>>>>>>> -no-whole-archive
>>>>>>>
>>>>>>> --dynamic-list=/usr/lib/llvm-3.9/bin/../lib/clang/3.9.0/lib/linux/libclang_rt.msan-x86_64.a.syms
>>>>>>> /tmp/test-2d4d2c.o --no-as-needed -lpthread -lrt -lm -ldl -lgcc
>>>>>>> --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s
>>>>>>> --no-as-needed /usr/bin/../lib/gcc/x86_64-linux-gnu/6.2.0/crtend.o
>>>>>>>
>>>>>>> /usr/bin/../lib/gcc/x86_64-linux-gnu/6.2.0/../../../x86_64-linux-gnu/crtn.o
>>
>>