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

Fri Nov 11 16:24:25 UTC 2016

Hi,

I first searched the related patches, then tested them on 3.9. I wrote the
message without trying them on 3.8, I did not know if the first patch is
required.
Why didn't you run 'quilt push -a' before committing them? 😁

Am 11.11.2016 5:07 nachm. schrieb "Sylvestre Ledru" <s at mozilla.com>:

> 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=24e2b1ce
>>>>>>> de1952d7d4411a3cafd25dd8593dab9f
>>>>>>> [2] https://llvm.org/bugs/show_bug.cgi?id=27310
>>>>>>> [3]
>>>>>>> https://github.com/llvm-mirror/compiler-rt/commit/827ea206c1
>>>>>>> 078fc7c7da287984a7ba4563390589
>>>>>>> [4]
>>>>>>> https://github.com/llvm-mirror/compiler-rt/commit/570ee9dd7a
>>>>>>> 6f90b0370a86535cbde6738d0ccf67
>>>>>>>
>>>>>>> 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-lin
>>>>>>>> ux-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
>>>>>>>>
>>>>>>>
>>>
>>>
>
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