Re: [RFC PATCH net-next 12/13] selftests: drivers/net: add knod tests

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] The tests hardcode relative paths to in-tree pyynl scripts and YAML specs, which breaks when tests are run from an installed directory.
- [Medium] The map lookup script uses the GNU awk extension strtonum(), causing the test to unconditionally fail on systems using non-GNU awk (like mawk).
--

--- Patch [12]: [RFC PATCH net-next 12/13] selftests: drivers/net: add knod tests ---
commit 8c1df38ed71ba173e2fb3bc36bc8224d06cad0df
Author: Taehee Yoo <ap420073@gmail.com>

selftests: drivers/net: add knod tests

Add attach/detach and XDP offload selftests for knod, exercising the
genetlink control plane and the BPF data path over a knod-capable NIC.

> diff --git a/tools/testing/selftests/drivers/net/knod/lib.sh b/tools/testing/selftests/drivers/net/knod/lib.sh
> new file mode 100755
> index 0000000000000..d0d9b03f109dc
> --- /dev/null
> +++ b/tools/testing/selftests/drivers/net/knod/lib.sh
> @@ -0,0 +1,181 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# lib.sh - KNOD XDP offload test utilities
> +#
> +# The KNOD control plane is the "knod" generic-netlink family; it is driven
> +# here through the in-tree ynl CLI (tools/net/ynl/pyynl/cli.py) so the tests
> +# need no dedicated user-space tool.
> +
> +KSRC=$(cd "$(dirname "${BASH_SOURCE[0]}")/../../../../../.." && pwd)
> +readonly KNOD_YNL="$KSRC/tools/net/ynl/pyynl/cli.py"
> +readonly KNOD_SPEC="$KSRC/Documentation/netlink/specs/knod.yaml"

[Severity: Medium]
Will this hardcoded relative path cause the tests to fail when run from an
installed directory?

When tests are installed (e.g., via make install) and run out-of-tree, these
paths to cli.py and the YAML specs will likely be invalid since they are not
copied to the install directory by default.

[ ... ]

> +knod_map_lookup_u64() {
> +	local map_id=$1
> +	local key=$2
> +	local hex
> +
> +	hex=$(bpftool map lookup id "$map_id" \
> +	      key $key 0 0 0 2>/dev/null | \
> +	      grep -o 'value:.*' | sed 's/value: //')
> +	if [ -z "$hex" ]; then
> +		echo 0
> +		return
> +	fi
> +
> +	printf '%d' "$(echo "$hex" | awk '{
> +		v = 0;
> +		for (i = 8; i >= 1; i--)
> +			v = v * 256 + strtonum("0x" $i);
> +		printf "0x%x", v;
> +	}')"

[Severity: Medium]
Does the use of the strtonum() function break this script on systems using
non-GNU awk? 

The strtonum() function is a gawk-specific extension. On systems where the
default awk is mawk or BusyBox awk, this may fail with an undefined function
error, causing the extracted map value to evaluate to 0 and the test to
falsely fail.

> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260719175857.4071636-1-ap420073@gmail.com?part=12