Date:   Fri, 27 Jan 2023 18:43:42 +0000
From:   Andrei Gherzan <andrei.gherzan@canonical.com>
To:     Maciej =?utf-8?Q?=C5=BBenczykowski?= <maze@google.com>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, Shuah Khan <shuah@kernel.org>,
        Lina Wang <lina.wang@mediatek.com>, netdev@vger.kernel.org,
        linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 3/3] selftests: net: Fix udpgro_frglist.sh shellcheck
 warnings and errors
Message-ID: <Y9QbXuMOV3BWSzt5@qwirkle>
References: <20230127140944.265135-1-andrei.gherzan@canonical.com>
 <20230127140944.265135-3-andrei.gherzan@canonical.com>
 <CANP3RGchqLRLRAxgWU69DzWfa9R2d0AhgeBdpJhmaE+c-Sszjw@mail.gmail.com>
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On 23/01/27 06:32AM, Maciej Żenczykowski wrote:
> On Fri, Jan 27, 2023 at 6:09 AM Andrei Gherzan
> <andrei.gherzan@canonical.com> wrote:
> >
> > This change fixes the following shellcheck warnings and errors:
> >
> > * SC2155 (warning): Declare and assign separately to avoid masking return
> >   values.
> > * SC2124 (warning): Assigning an array to a string! Assign as array, or use
> >   instead of @ to concatenate.
> > * SC2034 (warning): ipv4_args appears unused. Verify use (or export if used
> >   externally).
> > * SC2242 (error): Can only exit with status 0-255. Other data should be
> >   written to stdout/stderr.
> > * SC2068 (error): Double quote array expansions to avoid re-splitting
> >   elements.
> >
> > Fixes: edae34a3ed92 ("selftests net: add UDP GRO fraglist + bpf self-tests")
> > Signed-off-by: Andrei Gherzan <andrei.gherzan@canonical.com>
> > ---
> >  tools/testing/selftests/net/udpgro_frglist.sh | 20 +++++++++----------
> >  1 file changed, 10 insertions(+), 10 deletions(-)
> >
> > diff --git a/tools/testing/selftests/net/udpgro_frglist.sh b/tools/testing/selftests/net/udpgro_frglist.sh
> > index e1ca49de2491..97bf20e9afd8 100755
> > --- a/tools/testing/selftests/net/udpgro_frglist.sh
> > +++ b/tools/testing/selftests/net/udpgro_frglist.sh
> > @@ -3,7 +3,8 @@
> >  #
> >  # Run a series of udpgro benchmarks
> >
> > -readonly PEER_NS="ns-peer-$(mktemp -u XXXXXX)"
> > +PEER_NS="ns-peer-$(mktemp -u XXXXXX)"
> > +readonly PEER_NS
> >
> >  BPF_FILE="../bpf/xdp_dummy.bpf.o"
> >  BPF_NAT6TO4_FILE="nat6to4.o"
> > @@ -19,7 +20,7 @@ trap cleanup EXIT
> >
> >  run_one() {
> >         # use 'rx' as separator between sender args and receiver args
> > -       local -r all="$@"
> > +       local -r all="$*"
> 
> this should technically use arrays, something like
> 
> local -a -r args=("$@")
> 
> but perhaps just get rid of args and just use "$@" directly below

Using it directly would not work with the substitutions later because it
would try to apply it to each positional parameter in turn. Same when
using an intermediate array.

> 
> >         local -r tx_args=${all%rx*}
> >         local rx_args=${all#*rx}
> >
> > @@ -56,13 +57,13 @@ run_one() {
> >  }
> >
> >  run_in_netns() {
> > -       local -r args=$@
> > +       local -r args="$*"
> >    echo ${args}
> >         ./in_netns.sh $0 __subprocess ${args}
> 
> ie. here could just use "$@" directly twice instead of defining args.
> $0 should be doublequoted - though I guess it'll never be empty, and
> is unlikely to include spaces.

That sounds fine to me. I'll include it in v4.

> >  }
> >
> >  run_udp() {
> > -       local -r args=$@
> > +       local -r args="$*"
> >
> >         echo "udp gso - over veth touching data"
> >         run_in_netns ${args} -u -S 0 rx -4 -v
> > @@ -72,7 +73,7 @@ run_udp() {
> >  }
> >
> >  run_tcp() {
> > -       local -r args=$@
> > +       local -r args="$*"
> >
> >         echo "tcp - over veth touching data"
> >         run_in_netns ${args} -t rx -4 -t
> > @@ -80,7 +81,6 @@ run_tcp() {
> >
> >  run_all() {
> >         local -r core_args="-l 4"
> 
> is this still useful? embed directly in ipv6_args
> 
> > -       local -r ipv4_args="${core_args} -4  -D 192.168.1.1"
> 
> perhaps this should stay as a comment??

Well the way I see it is one or the other. We either embed and drop
ipv4_args or keep ipv4_args as a comment but also core_args. I'll do the
former in v4 if no other objections.

> 
> >         local -r ipv6_args="${core_args} -6  -D 2001:db8::1"
> >
> >         echo "ipv6"
> > @@ -90,19 +90,19 @@ run_all() {
> >
> >  if [ ! -f ${BPF_FILE} ]; then
> 
> double quote
> "${BPF_FILE}"
> in case space in file name

This change only targets warning/error issues. There are way more "info"
ones, but I didn't want to splash a big patch for all those.

> 
> >         echo "Missing ${BPF_FILE}. Build bpf selftest first"
> > -       exit -1
> > +       exit 1
> >  fi
> >
> >  if [ ! -f "$BPF_NAT6TO4_FILE" ]; then
> 
> there seems to be inconsistency around [ vs [[, use [[ if relying on bash anyway


> 
> >         echo "Missing nat6to4 helper. Build bpf nat6to4.o selftest first"
> > -       exit -1
> > +       exit 1
> >  fi
> >
> >  if [[ $# -eq 0 ]]; then
> >         run_all
> >  elif [[ $1 == "__subprocess" ]]; then
> 
> while this does indeed work, imho $1 should be "$1" to be less confusing

Agreed and again, there are a good set of other places where this is
needed. Should I just address them all in an extra patch? Again, this
one only scoped warnings/errors to avoid impact.

Thanks for the review.

-- 
Andrei Gherzan