Re: [PATCH v6 16/16] scripts/oss-fuzz: remove the generic-fuzz target

[Darren Kenny <darren.kenny@oracle.com>]

On Thursday, 2020-10-22 at 09:01:23 -04, Alexander Bulekov wrote:
> On 201022 1032, Darren Kenny wrote:
>> Hi Alex,
>> 
>> On Wednesday, 2020-10-21 at 17:09:22 -04, Alexander Bulekov wrote:
>> > generic-fuzz is not a standalone fuzzer - it requires some env variables
>> > to be set. On oss-fuzz, we set these with some predefined
>> > generic-fuzz-{...} targets, that are thin wrappers around generic-fuzz.
>> > Remove generic-fuzz from the oss-fuzz build, so oss-fuzz does not treat
>> > it as a standalone fuzzer.
>> >
>> > Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
>> > ---
>> >  scripts/oss-fuzz/build.sh | 6 ++++++
>> >  1 file changed, 6 insertions(+)
>> >
>> > diff --git a/scripts/oss-fuzz/build.sh b/scripts/oss-fuzz/build.sh
>> > index 0c3ca9e06f..37cd7f9e25 100755
>> > --- a/scripts/oss-fuzz/build.sh
>> > +++ b/scripts/oss-fuzz/build.sh
>> > @@ -97,5 +97,11 @@ do
>> 
>
> Hi Darren,
>
>> I'm presuming that the target that you're removing is being created by
>> this line, maybe we should just specifically skip it here instead?
>
> Sounds good.
>
>> The comment below on the removal probably would still apply though.
>> 
>> >      cp qemu-fuzz-i386 "$DEST_DIR/qemu-fuzz-i386-target-$target"
>> 
>> Also, did you look into using hard-links, or even sym-links - they would
>> require less duplication of the binaries, which may be important, or may
>> not, and quicker creation too, e.g.
>> 
>>       ln qemu-fuzz-i386 "$DEST_DIR/qemu-fuzz-i386-target-$target"
>
> This is what I tried, when I was putting together the patch-series, and
> it raised an error when I was testing it in the oss-fuzz
> docker-containers. I blamed it on Docker, originally, but I just took a
> closer look, and the problem was that "qemu-fuzz-i386" isn't on the same
> file-system as $DEST_DIR in the oss-fuzz Docker. If I copy
> qemu-fuzz-i386 to $DEST_DIR/lib, and do 
>     ln "$DEST_DIR/lib/qemu-fuzz-i386" \
>        "$DEST_DIR/qemu-fuzz-i386-target-$target"
> everything works :)

Fair enough then!

Thanks,

Darren.

> Thanks
> -Alex
>
>> 
>> It's something that has been done for years, for example if you do:
>> 
>>       ls -il /sbin/{e2fsck,fsck.ext*}
>> 
>> you will see they share the same inode. Similarly for vi and ex, they
>> use symlinks (hardlinks on some OSes, but seems not Linux):
>> 
>>       ls -il /bin/{vi,ex}
>> 
>> The main point is that argv[0] will be the name of link itself, not the
>> thing pointed to.
>> 
>> Thanks,
>> 
>> Darren.
>> 
>> >  done
>> >  
>> > +# Remove the generic-fuzz target, as it requires some environment variables to
>> > +# be configured. We have some generic-fuzz-{pc-q35, floppy, ...} targets that
>> > +# are thin wrappers around this target that set the required environment
>> > +# variables according to predefined configs.
>> > +rm "$DEST_DIR/qemu-fuzz-i386-target-generic-fuzz"
>> > +
>> >  echo "Done. The fuzzers are located in $DEST_DIR"
>> >  exit 0
>> > -- 
>> > 2.28.0