llvm dev - Sep 2015 - LibFuzzer and platforms availability

Hi there.

I’m trying to use LibFuzzer on OSX and face some issues:
I checked out LibFuzzer documentation[1] and managed to proceed until the final
step of the first example.
Now I see linker errors related to dfsan, dfsan’s documentation[2] states
explicitly “DataFlowSanitizer is a work in progress, currently under development
for x86_64 Linux.”.

Does it mean that LibFuzzer available only on Linux platform? Can somebody
confirm or refute my conclusion?

[1] http://llvm.org/docs/LibFuzzer.html
[2] http://clang.llvm.org/docs/DataFlowSanitizer.html
--
AlexDenisov
Software Engineer, http://lowlevelbits.org

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On Wed, Sep 9, 2015 at 12:57 AM, AlexDenisov via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> Hi there.
>
> I’m trying to use LibFuzzer on OSX and face some issues:
> I checked out LibFuzzer documentation[1] and managed to proceed until the
> final step of the first example.
> Now I see linker errors related to dfsan, dfsan’s documentation[2] states
> explicitly “DataFlowSanitizer is a work in progress, currently under
> development for x86_64 Linux.”.
>
Yes, libFuzzer does not build on OSX today.
Marshall (CC-ed) has managed to make it work with a couple of #ifdefs
in FuzzerTraceState.cpp.

I'll try to commit such patches later this week, but I don't have a Mac
so
it will be harder for me to test.
If anyone wants it quicker -- patches are welcome.
I would also appreciate if someone can set up a build bot for libFuzzer on
Mac :)
(similar to lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fuzzer)

>
> Does it mean that LibFuzzer available only on Linux platform? Can somebody
> confirm or refute my conclusion?
>
> [1] http://llvm.org/docs/LibFuzzer.html
> [2] http://clang.llvm.org/docs/DataFlowSanitizer.html
> --
> AlexDenisov
> Software Engineer, http://lowlevelbits.org
>
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
>
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r247321 refactors the code so that it should build on Mac.
I haven't actually tested it on Mac -- so please help me and send follow up
patches if needed.

check-fuzzer will still fail because some of the libFuzzer tests require
dfsan.
I'd use some help from someone with a Mac to modify
lib/Fuzzer/test/CMakeLists.txt so that it does not run dfsan-dependent
tests on Mac.

Thanks,

--kcc

On Wed, Sep 9, 2015 at 9:41 AM, Kostya Serebryany <kcc at google.com>
wrote:
>
>
> On Wed, Sep 9, 2015 at 12:57 AM, AlexDenisov via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> Hi there.
>>
>> I’m trying to use LibFuzzer on OSX and face some issues:
>> I checked out LibFuzzer documentation[1] and managed to proceed until
the
>> final step of the first example.
>> Now I see linker errors related to dfsan, dfsan’s documentation[2]
states
>> explicitly “DataFlowSanitizer is a work in progress, currently under
>> development for x86_64 Linux.”.
>>
>
> Yes, libFuzzer does not build on OSX today.
> Marshall (CC-ed) has managed to make it work with a couple of #ifdefs
> in FuzzerTraceState.cpp.
>
> I'll try to commit such patches later this week, but I don't have a
Mac so
> it will be harder for me to test.
> If anyone wants it quicker -- patches are welcome.
> I would also appreciate if someone can set up a build bot for libFuzzer on
> Mac :)
> (similar to lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fuzzer)
>
>
>>
>> Does it mean that LibFuzzer available only on Linux platform? Can
>> somebody confirm or refute my conclusion?
>>
>> [1] http://llvm.org/docs/LibFuzzer.html
>> [2] http://clang.llvm.org/docs/DataFlowSanitizer.html
>> --
>> AlexDenisov
>> Software Engineer, http://lowlevelbits.org
>>
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
>>
>
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On Wed, Sep 9, 2015 at 9:41 AM, Kostya Serebryany <kcc at google.com>
wrote:
>
> On Wed, Sep 9, 2015 at 12:57 AM, AlexDenisov via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> Hi there.
>>
>> I’m trying to use LibFuzzer on OSX and face some issues:
>> I checked out LibFuzzer documentation[1] and managed to proceed until
the
>> final step of the first example.
>> Now I see linker errors related to dfsan, dfsan’s documentation[2]
states
>> explicitly “DataFlowSanitizer is a work in progress, currently under
>> development for x86_64 Linux.”.
>>
>
> Yes, libFuzzer does not build on OSX today.
> Marshall (CC-ed) has managed to make it work with a couple of #ifdefs
> in FuzzerTraceState.cpp.
>
>
Actually, all I did was implement an empty DF sanitizer :-)

extern "C" {

typedef uint16_t dfsan_label;

struct dfsan_label_info {
 // Fields for union labels, set to 0 for base labels.
 dfsan_label l1;
 dfsan_label l2;

 // Fields for base labels.
 const char *desc;
 void *userdata;
};

dfsan_label dfsan_create_label(const char *desc, void *userdata) { return
0; }

const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label) {
return NULL; }
dfsan_label dfsan_read_label(const void *addr, size_t size) { return 0; }
void dfsan_set_label(dfsan_label label, void *addr, size_t size) {}

}


extern "C" void LLVMFuzzerTestOneInput(const unsigned char *data,
size_t
size) {...}

-- Marshall
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