Re: [PATCH] selftests/livepatch: add test skip handling

[Miroslav Benes <mbenes@suse.cz>]

On Sun, 14 Jul 2019, Joe Lawrence wrote:

> On Sun, Jul 14, 2019 at 10:28:29AM -0400, Joe Lawrence wrote:
> > Before running a livpeatch self-test, first verify that we've built and
> > installed the livepatch self-test kernel modules by running a 'modprobe
> > --dry-run'.  This should catch a few environment issues, including
> > !CONFIG_LIVEPATCH and !CONFIG_TEST_LIVEPATCH.  In these cases, exit
> > gracefully with test-skip status rather than test-fail status.
> > 
> > Reported-by: Jiri Benc <jbenc@redhat.com>
> > Suggested-by: Shuah Khan <shuah@kernel.org>
> > Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
> > ---
> >  tools/testing/selftests/livepatch/functions.sh | 18 ++++++++++++++++++
> >  .../selftests/livepatch/test-callbacks.sh      |  5 +++++
> >  .../selftests/livepatch/test-livepatch.sh      |  3 +++
> >  .../selftests/livepatch/test-shadow-vars.sh    |  2 ++
> >  4 files changed, 28 insertions(+)
> > 
> > diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh
> > index 30195449c63c..92d6cfb49365 100644
> > --- a/tools/testing/selftests/livepatch/functions.sh
> > +++ b/tools/testing/selftests/livepatch/functions.sh
> > @@ -13,6 +13,14 @@ function log() {
> >  	echo "$1" > /dev/kmsg
> >  }
> >  
> > +# skip(msg) - testing can't proceed
> > +#	msg - explanation
> > +function skip() {
> > +	log "SKIP: $1"
> > +	echo "SKIP: $1" >&2
> > +	exit 4
> > +}
> > +
> >  # die(msg) - game over, man
> >  #	msg - dying words
> >  function die() {
> > @@ -43,6 +51,16 @@ function loop_until() {
> >  	done
> >  }
> >  
> > +function assert_mod() {
> > +	local mod="$1"
> > +
> > +	if ! modprobe --dry-run "$mod" &>/dev/null ; then
> > +		skip "Failed modprobe --dry-run of module: $mod"
> > +	fi
> > +
> > +	return 1
> > +}
> > +
> >  function is_livepatch_mod() {
> >  	local mod="$1"
> >  
> > diff --git a/tools/testing/selftests/livepatch/test-callbacks.sh b/tools/testing/selftests/livepatch/test-callbacks.sh
> > index e97a9dcb73c7..87a407cee7fd 100755
> > --- a/tools/testing/selftests/livepatch/test-callbacks.sh
> > +++ b/tools/testing/selftests/livepatch/test-callbacks.sh
> > @@ -9,6 +9,11 @@ MOD_LIVEPATCH2=test_klp_callbacks_demo2
> >  MOD_TARGET=test_klp_callbacks_mod
> >  MOD_TARGET_BUSY=test_klp_callbacks_busy
> >  
> > +assert_mod $MOD_LIVEPATCH
> > +assert_mod $MOD_LIVEPATCH2
> > +assert_mod $MOD_TARGET
> > +assert_mod $MOD_TARGET_BUSY
> > +
> >  set_dynamic_debug
> >  
> >  
> > diff --git a/tools/testing/selftests/livepatch/test-livepatch.sh b/tools/testing/selftests/livepatch/test-livepatch.sh
> > index f05268aea859..8d3b75ceeeff 100755
> > --- a/tools/testing/selftests/livepatch/test-livepatch.sh
> > +++ b/tools/testing/selftests/livepatch/test-livepatch.sh
> > @@ -7,6 +7,9 @@
> >  MOD_LIVEPATCH=test_klp_livepatch
> >  MOD_REPLACE=test_klp_atomic_replace
> >  
> > +assert_mod $MOD_LIVEPATCH
> > +assert_mod $MOD_REPLACE
> > +
> >  set_dynamic_debug
> >  
> >  
> > diff --git a/tools/testing/selftests/livepatch/test-shadow-vars.sh b/tools/testing/selftests/livepatch/test-shadow-vars.sh
> > index 04a37831e204..1ab09bc50363 100755
> > --- a/tools/testing/selftests/livepatch/test-shadow-vars.sh
> > +++ b/tools/testing/selftests/livepatch/test-shadow-vars.sh
> > @@ -6,6 +6,8 @@
> >  
> >  MOD_TEST=test_klp_shadow_vars
> >  
> > +assert_mod $MOD_TEST
> > +
> >  set_dynamic_debug
> >  
> >  
> > -- 
> > 2.21.0
> > 
> 
> Testing:
> 
> Here's the output if modprobe --dry-run doesn't like the modules (not
> built, etc.):
> 
>   TAP version 13
>   selftests: livepatch: test-livepatch.sh
>   ========================================
>   SKIP: Failed modprobe --dry-run of module: test_klp_livepatch
>   not ok 1..1 selftests: livepatch: test-livepatch.sh [SKIP]
>   selftests: livepatch: test-callbacks.sh
>   ========================================
>   SKIP: Failed modprobe --dry-run of module: test_klp_callbacks_demo
>   not ok 1..2 selftests: livepatch: test-callbacks.sh [SKIP]
>   selftests: livepatch: test-shadow-vars.sh
>   ========================================
>   SKIP: Failed modprobe --dry-run of module: test_klp_shadow_vars
>   not ok 1..3 selftests: livepatch: test-shadow-vars.sh [SKIP]
> 
> We could fold assert_mod() into __load_mod() if folks perfer.  I
> don't have strong opinion either way.

I think it would be better to move it there. Otherwise, we might forget to 
add assert_module call for new modules in the future.

Miroslav