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References: <20190515134731.12611-1-krzesimir@kinvolk.io> <20190515134731.12611-4-krzesimir@kinvolk.io>
 <20190515145037.6918f626@cakuba.netronome.com>
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From:   Krzesimir Nowak <krzesimir@kinvolk.io>
Date:   Thu, 16 May 2019 11:31:04 +0200
Message-ID: <CAGGp+cHqJZFfYt9VUAuQ7SpCZZ9ijoreKVBumc+wnGfw7pAXTA@mail.gmail.com>
Subject: Re: [PATCH bpf v1 3/3] selftests/bpf: Avoid a clobbering of errno
To:     Jakub Kicinski <jakub.kicinski@netronome.com>
Cc:     bpf@vger.kernel.org,
        =?UTF-8?Q?Iago_L=C3=B3pez_Galeiras?= <iago@kinvolk.io>,
        "Alban Crequy (Kinvolk)" <alban@kinvolk.io>,
        Shuah Khan <shuah@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        Andrey Ignatov <rdna@fb.com>,
        Jiong Wang <jiong.wang@netronome.com>,
        linux-kselftest@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
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On Wed, May 15, 2019 at 11:51 PM Jakub Kicinski
<jakub.kicinski@netronome.com> wrote:
>
> On Wed, 15 May 2019 15:47:28 +0200, Krzesimir Nowak wrote:
> > Save errno right after bpf_prog_test_run returns, so we later check
> > the error code actually set by bpf_prog_test_run, not by some libcap
> > function.
> >
> > Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
> > Fixes: 5a8d5209ac022 ("selftests: bpf: add trivial JSET tests")
>
> This commit (of mine) just moved this code into a helper, the bug is
> older:
>
> Fixes: 832c6f2c29ec ("bpf: test make sure to run unpriv test cases in tes=
t_verifier")

Oops, ok. Will fix it. Thanks.

>
> > Signed-off-by: Krzesimir Nowak <krzesimir@kinvolk.io>
> > ---
> >  tools/testing/selftests/bpf/test_verifier.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testin=
g/selftests/bpf/test_verifier.c
> > index bf0da03f593b..514e17246396 100644
> > --- a/tools/testing/selftests/bpf/test_verifier.c
> > +++ b/tools/testing/selftests/bpf/test_verifier.c
> > @@ -818,15 +818,17 @@ static int do_prog_test_run(int fd_prog, bool unp=
riv, uint32_t expected_val,
> >       __u32 size_tmp =3D sizeof(tmp);
> >       uint32_t retval;
> >       int err;
> > +     int saved_errno;
> >
> >       if (unpriv)
> >               set_admin(true);
> >       err =3D bpf_prog_test_run(fd_prog, 1, data, size_data,
> >                               tmp, &size_tmp, &retval, NULL);
> > +     saved_errno =3D errno;
> >       if (unpriv)
> >               set_admin(false);
> >       if (err) {
> > -             switch (errno) {
> > +             switch (saved_errno) {
> >               case 524/*ENOTSUPP*/:
> >                       printf("Did not run the program (not supported) "=
);
> >                       return 0;
>


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