On Thu, Feb 10, 2022 at 04:23:15PM +0100, Petr Mladek wrote:
> OK, what about the following change:
>
> 1. Store only the value (number) in $result
> 2. Add optional --fail parameter
I'm fine with this approach. I agree that it's probably less confusing than
"$2" == "$1". I don't think the elif check I proposed is strictly necessary
either, and in any case the way you've rewired the patch address that.
>
> Hmm, the 1st step is not needed after several iterations here ;-)
> Anyway, it should be easier to maintain it in the long term when the
> sysctl output might change. We should probably do it in a separate patch.
>
>
> diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh
> index 846c7ed71556..7b624d0fd7c0 100644
> --- a/tools/testing/selftests/livepatch/functions.sh
> +++ b/tools/testing/selftests/livepatch/functions.sh
> @@ -75,9 +75,25 @@ function set_dynamic_debug() {
> }
>
> function set_ftrace_enabled() {
> - result=$(sysctl -q kernel.ftrace_enabled="$1" 2>&1 && \
> - sysctl kernel.ftrace_enabled 2>&1)
> - echo "livepatch: $result" > /dev/kmsg
> + can_fail=0
Can you make this variable a local?
> + if [[ "$1" == "--fail" ]] ; then
> + can_fail=1
> + shift
> + fi
> +
> + err=$(sysctl -q kernel.ftrace_enabled="$1" 2>&1)
> + result=$(sysctl --values kernel.ftrace_enabled)
> +
> + if [[ "$result" != "$1" ]] ; then
> + if [[ $can_fail -eq 1 ]] ; then
> + echo "livepatch: $err" > /dev/kmsg
> + return
> + fi
> +
> + skip "failed to set kernel.ftrace_enabled = $1"
> + fi
> +
> + echo "livepatch: kernel.ftrace_enabled = $result" > /dev/kmsg
> }
>
> function cleanup() {
> diff --git a/tools/testing/selftests/livepatch/test-ftrace.sh b/tools/testing/selftests/livepatch/test-ftrace.sh
> index 552e165512f4..825540a5194d 100755
> --- a/tools/testing/selftests/livepatch/test-ftrace.sh
> +++ b/tools/testing/selftests/livepatch/test-ftrace.sh
> @@ -25,7 +25,8 @@ if [[ "$(cat /proc/cmdline)" != "$MOD_LIVEPATCH: this has been live patched" ]]
> die "livepatch kselftest(s) failed"
> fi
>
> -set_ftrace_enabled 0
> +# Check that ftrace could not get disabled when a livepatch is enabled
> +set_ftrace_enabled --fail 0
> if [[ "$(cat /proc/cmdline)" != "$MOD_LIVEPATCH: this has been live patched" ]] ; then
> echo -e "FAIL\n\n"
> die "livepatch kselftest(s) failed"
Patch looks great otherwise and works fine after testing on my end. Do you
want me to send it out as a v3? Or would you prefer to just apply it as is?
Assuming it's the latter, then:
Reviewed-by: David Vernet <void@xxxxxxxxxxxxx>
Thanks,
David
