[PATCH] kselftest/arm64: signal: Skip tests if required features are missing

[Cristian Marussi]

During initialization of a signal testcase, features declared as required
are properly checked against the running system but no action is then taken
to effectively skip such a testcase.

Fix core signals test logic to abort initialization and report such a
testcase as skipped to the KSelfTest framework.

Fixes: f96bf4340316 ("kselftest: arm64: mangle_pstate_invalid_compat_toggle and common utils")
Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
---
As a consequence KSelfTest TAP results will now report this when a signal-SVE
testcase run on a system missing SVE:

\# selftests: arm64: fake_sigreturn_sve_change_vl
\# Registered handlers for all signals.
\# Detected MINSTKSIGSZ:4720
\# Required Features: [ SVE ] NOT supported
\# ==>> completed. SKIP.
\# # FAKE_SIGRETURN_SVE_CHANGE :: Attempt to change SVE VL
\# ok 7 selftests: arm64: fake_sigreturn_sve_change_vl # SKIP
---
 tools/testing/selftests/arm64/signal/test_signals_utils.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/arm64/signal/test_signals_utils.c b/tools/testing/selftests/arm64/signal/test_signals_utils.c
index 6836510a522f..22722abc9dfa 100644
--- a/tools/testing/selftests/arm64/signal/test_signals_utils.c
+++ b/tools/testing/selftests/arm64/signal/test_signals_utils.c
@@ -266,16 +266,19 @@ int test_init(struct tdescr *td)
 			td->feats_supported |= FEAT_SSBS;
 		if (getauxval(AT_HWCAP) & HWCAP_SVE)
 			td->feats_supported |= FEAT_SVE;
-		if (feats_ok(td))
+		if (feats_ok(td)) {
 			fprintf(stderr,
 				"Required Features: [%s] supported\n",
 				feats_to_string(td->feats_required &
 						td->feats_supported));
-		else
+		} else {
 			fprintf(stderr,
 				"Required Features: [%s] NOT supported\n",
 				feats_to_string(td->feats_required &
 						~td->feats_supported));
+			td->result = KSFT_SKIP;
+			return 0;
+		}
 	}
 
 	/* Perform test specific additional initialization */
-- 
2.17.1