[cfe-dev] i386 -faddress-sanitizer

[Carsten Mattner]

Just confirmed that manually passing the asan.a archive
in the ld command line fixes the issue but this should
of course happen automatically.

On Thu, Oct 18, 2012 at 5:00 PM, Carsten Mattner
<carstenmattner at gmail.com> wrote:
> On Thu, Oct 18, 2012 at 4:49 PM, Kostya Serebryany <kcc at google.com> wrote:
>> You are linking a shared object, asan.a should not be linked to it.
>
> What should happen instead?
>
>> Are these all the flags passed to ld?
>
> Yes it's all minus project-specific -l and *.a and *.o args
> I have omitted for the email.
>
>> On Thu, Oct 18, 2012 at 6:23 PM, Carsten Mattner <carstenmattner at gmail.com>
>> wrote:
>>>
>>> On Thu, Oct 18, 2012 at 3:36 PM, Alexander Potapenko <glider at google.com>
>>> wrote:
>>> > Can you append -v at the place it's being invoked to check whether the
>>> > contents of LDFLAGS are being actually passed?
>>>
>>> $ clang <INPUT_OBJECTS> -lstdc++ -v -faddress-sanitizer -shared
>>> <PROJECT_FLAGS> -o <SO_FILE>
>>> clang
>>> version 3.2 (http://llvm.org/git/clang.git
>>> 278eafa2cd8296f8128d13c6466a0ace3d03a872)
>>> (http://llvm.org/git/llvm.git
>>> 2360b7ad99eedecaae512373e7be49c2143550cf)
>>> Target: i386-pc-linux-gnu
>>> Thread model: posix
>>>
>>> "/usr/bin/ld" --eh-frame-hdr -m elf_i386 -shared -o <SO_FILE>
>>> /usr/lib/gcc/i686-pc-linux-gnu/4.7.2/../../../crti.o
>>> /usr/lib/gcc/i686-pc-linux-gnu/4.7.2/crtbeginS.o
>>> -L/usr/lib/gcc/i686-pc-linux-gnu/4.7.2
>>> -L/usr/lib/gcc/i686-pc-linux-gnu/4.7.2/../../.. -L/lib -L/usr/lib
>>> <INPUT_OBJECTS> -lstdc++ -lgcc --as-needed -lgcc_s --no-as-needed -lc
>>> -lgcc --as-needed -lgcc_s --no-as-needed
>>> /usr/lib/gcc/i686-pc-linux-gnu/4.7.2/crtendS.o
>>> /usr/lib/gcc/i686-pc-linux-gnu/4.7.2/../../../crtn.o
>>>
>>> I guess the libasan archive should be part of the above call to ld.
>>>
>>> > On Thu, Oct 18, 2012 at 5:33 PM, Carsten Mattner
>>> > <carstenmattner at gmail.com> wrote:
>>> >> On Thu, Oct 18, 2012 at 3:29 PM, Alexander Potapenko wrote:
>>> >>> Are you linking with ld or clang?
>>> >>> -faddress-sanitizer is a Clang flag, so if you're running `ld $LDFLAGS
>>> >>> ...` to link your program, it won't work.
>>> >>
>>> >> clang.
>>> >>
>>> >>> On Thu, Oct 18, 2012 at 5:12 PM, Carsten Mattner
>>> >>> <carstenmattner at gmail.com> wrote:
>>> >>>> On Thu, Oct 18, 2012 at 12:27 AM, Eli Friedman wrote:
>>> >>>>> On Wed, Oct 17, 2012 at 1:43 PM, Carsten Mattner
>>> >>>>> <carstenmattner at gmail.com> wrote:
>>> >>>>>> Is it expected that -faddress-sanitizer  does not work on i386 and
>>> >>>>>> fails
>>> >>>>>> to properly link resulting in errors like 'undefined symbol:
>>> >>>>>> __asan_init'
>>> >>>>>> at runtime?
>>> >>>>>>
>>> >>>>>> I have ./lib/clang/3.2/lib/linux/libclang_rt.asan-i386.a in llvm's
>>> >>>>>> installation,
>>> >>>>>> but it doesn't look like it's linked automatically into the
>>> >>>>>> executable.
>>> >>>>>>
>>> >>>>>> CFLAGS:
>>> >>>>>> -faddress-sanitizer -O1 -fno-omit-frame-pointer -g $PROJECT_FLAGS
>>> >>>>>
>>> >>>>> You need to pass in -faddress-sanitizer both when compiling and when
>>> >>>>> linking an application.  Try something like
>>> >>>>> "LDFLAGS=-faddress-sanitizer".
>>> >>>>
>>> >>>> Oh that makes a lot of sense and is kind of obvious in hindsight.
>>> >>>> Yet it didn't work in a quick test. Any options I flags to pass for
>>> >>>> verbose printfs to see what's happening you can suggest?
>>> >>>> In the next test I'll also try to explicitly link the libasan archive
>>> >>>> manually for ruling out issues with that archive.
>>> >>>> _______________________________________________
>>> >>>> cfe-dev mailing list
>>> >>>> cfe-dev at cs.uiuc.edu
>>> >>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>> >>>
>>> >>>
>>> >>>
>>> >>> --
>>> >>> Alexander Potapenko
>>> >>> Software Engineer
>>> >>> Google Moscow
>>> >
>>> >
>>> >
>>> > --
>>> > Alexander Potapenko
>>> > Software Engineer
>>> > Google Moscow
>>> _______________________________________________
>>> cfe-dev mailing list
>>> cfe-dev at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>
>>