linux-kernel - Re: [PATCH v2 16/23] test_firmware: enable custom fallback testing on limited kernel configs

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Date:   Wed, 29 Nov 2017 11:22:35 +0100
From:   Greg KH <gregkh@...uxfoundation.org>
To:     "Luis R. Rodriguez" <mcgrof@...nel.org>
Cc:     akpm@...ux-foundation.org, keescook@...omium.org,
        mfuzzey@...keon.com, zohar@...ux.vnet.ibm.com, dhowells@...hat.com,
        pali.rohar@...il.com, tiwai@...e.de, arend.vanspriel@...adcom.com,
        zajec5@...il.com, nbroeking@...com, markivx@...eaurora.org,
        stephen.boyd@...aro.org, broonie@...nel.org,
        dmitry.torokhov@...il.com, dwmw2@...radead.org,
        torvalds@...ux-foundation.org, Abhay_Salunke@...l.com,
        bjorn.andersson@...aro.org, jewalt@...innovations.com,
        linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH v2 16/23] test_firmware: enable custom fallback testing
 on limited kernel configs

On Mon, Nov 20, 2017 at 10:24:02AM -0800, Luis R. Rodriguez wrote:
> When a kernel is not built with:
> 
> CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y
> 
> We don't currently enable testing fw_fallback.sh. For kernels that
> still enable the fallback mechanism, its possible to use the async
> request firmware API call request_firmware_nowait() using the custom
> interface to use the fallback mechanism, so we should be able to test
> this but we currently cannot.
> 
> We can enable testing without CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y
> by relying on /proc/config.gz (CONFIG_IKCONFIG_PROC), if present. If you
> don't have this we'll have no option but to rely on old heuristics for now.
> 
> Signed-off-by: Luis R. Rodriguez <mcgrof@...nel.org>
> ---
>  tools/testing/selftests/firmware/config         |  4 +++
>  tools/testing/selftests/firmware/fw_fallback.sh | 45 ++++++++++++++++++++++++-
>  2 files changed, 48 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/firmware/config b/tools/testing/selftests/firmware/config
> index c8137f70e291..bf634dda0720 100644
> --- a/tools/testing/selftests/firmware/config
> +++ b/tools/testing/selftests/firmware/config
> @@ -1 +1,5 @@
>  CONFIG_TEST_FIRMWARE=y
> +CONFIG_FW_LOADER=y
> +CONFIG_FW_LOADER_USER_HELPER=y
> +CONFIG_IKCONFIG=y
> +CONFIG_IKCONFIG_PROC=y
> diff --git a/tools/testing/selftests/firmware/fw_fallback.sh b/tools/testing/selftests/firmware/fw_fallback.sh
> index 722cad91df74..a42e437363d9 100755
> --- a/tools/testing/selftests/firmware/fw_fallback.sh
> +++ b/tools/testing/selftests/firmware/fw_fallback.sh
> @@ -6,7 +6,46 @@
>  # won't find so that we can do the load ourself manually.
>  set -e
>  
> +PROC_CONFIG="/proc/config.gz"
> +TEST_DIR=$(dirname $0)
> +
>  modprobe test_firmware
> +if [ ! -f $PROC_CONFIG ]; then
> +	if modprobe configs 2>/dev/null; then
> +		echo "Loaded configs module"
> +		if [ ! -f $PROC_CONFIG ]; then
> +			echo "You must have the following enabled in your kernel:" >&2
> +			cat $TEST_DIR/config >&2
> +			echo "Resorting to old heuristics" >&2
> +		fi
> +	else
> +		echo "Failed to load configs module, using old heuristics" >&2
> +	fi
> +fi
> +
> +kconfig_has()
> +{
> +	if [ -f $PROC_CONFIG ]; then
> +		if zgrep -q $1 $PROC_CONFIG 2>/dev/null; then
> +			echo "yes"
> +		else
> +			echo "no"
> +		fi
> +	else
> +		# We currently don't have easy heuristics to infer this
> +		# so best we can do is just try to use the kernel assuming
> +		# you had enabled it. This matches the old behaviour.
> +		if [ "$1" = "CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y" ]; then
> +			echo "yes"
> +		elif [ "$1" = "CONFIG_FW_LOADER_USER_HELPER=y" ]; then
> +			if [ -d /sys/class/firmware/ ]; then
> +				echo yes
> +			else
> +				echo no
> +			fi
> +		fi
> +	fi
> +}

Shouldn't these functions be part of the kselftest core so that all
tests can take advantage of them instead of having to hand-roll them for
every individual test?

And is there no way at runtime to tell what the options are and just
not run that type of test?

thanks,

greg k-h