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Date:   Thu, 17 Nov 2022 16:54:33 -0800
From:   Kees Cook <keescook@chromium.org>
To:     sdf@google.com
Cc:     wangkailong@jari.cn, linux-kernel@vger.kernel.org,
        bpf@vger.kernel.org
Subject: Re: [PATCH] samples/seccomp: fix array_size.cocci warning
Message-ID: <202211171653.0E3BA8E71B@keescook>
References: <2b3f2420.130.184706d34e6.Coremail.wangkailong@jari.cn>
 <Y3J3t/ieGaOG8Qjl@google.com>
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On Mon, Nov 14, 2022 at 09:15:35AM -0800, sdf@google.com wrote:
> On 11/13, wangkailong@jari.cn wrote:
> > Fix following coccicheck warning:
> 
> > samples/seccomp/bpf-fancy.c:83:39-40: WARNING: Use ARRAY_SIZE
> > samples/seccomp/bpf-fancy.c:86:44-45: WARNING: Use ARRAY_SIZE
> 
> Not sure this should go via bpf tree. CC'ed Kees
> 
> > Signed-off-by: KaiLong Wang <wangkailong@jari.cn>
> > ---
> >   samples/seccomp/bpf-fancy.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> > diff --git a/samples/seccomp/bpf-fancy.c b/samples/seccomp/bpf-fancy.c
> > index 1ccb435025b6..548f038924d6 100644
> > --- a/samples/seccomp/bpf-fancy.c
> > +++ b/samples/seccomp/bpf-fancy.c
> > @@ -80,10 +80,10 @@ int main(int argc, char **argv)
> >   	};
> >   	struct sock_fprog prog = {
> >   		.filter = filter,
> > -		.len = (unsigned short)(sizeof(filter)/sizeof(filter[0])),
> > +		.len = (unsigned short)(ARRAY_SIZE(filter)),
> >   	};
> >   	ssize_t bytes;
> > -	bpf_resolve_jumps(&l, filter, sizeof(filter)/sizeof(*filter));
> > +	bpf_resolve_jumps(&l, filter, ARRAY_SIZE(filter));

Hm, this is the "samples" tree, so this was intentionally avoiding these
kinds of kernel-isms, but perhaps that doesn't realistically matter?

-Kees

> 
> >   	if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
> >   		perror("prctl(NO_NEW_PRIVS)");
> > --
> > 2.25.1

-- 
Kees Cook