s390/cpum_sf: do not register PMU if no sampling mode is authorized

hbrueckner · Martin Schwidefsky · commit 9232c3c74120 · 2017-11-16T15:06:10.000+01:00
Previously, the cpum_sf PMU was registered even if there is no
sampling mode authorized.  Add a check and register cpum_sf only
at least one sampling mode is authorized.

Signed-off-by: Hendrik Brueckner &lt;brueckner@linux.vnet.ibm.com&gt;
Signed-off-by: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
@@ -1938,6 +1938,9 @@ static int __init init_cpum_sampling_pmu(void)
 		return -ENODEV;
 	}
 
+	if (!si.as && !si.ad)
+		return -ENODEV;
+
 	if (si.bsdes != sizeof(struct hws_basic_entry)) {
 		pr_cpumsf_err(RS_INIT_FAILURE_BSDES);
 		return -EINVAL;

Original file line number	Diff line number	Diff line change
`@@ -1938,6 +1938,9 @@ static int __init init_cpum_sampling_pmu(void)`
`1938`	`1938`	`return -ENODEV;`
`1939`	`1939`	`}`
`1940`	`1940`
	`1941`	`+ if (!si.as && !si.ad)`
	`1942`	`+ return -ENODEV;`
	`1943`	`+`
`1941`	`1944`	`if (si.bsdes != sizeof(struct hws_basic_entry)) {`
`1942`	`1945`	`pr_cpumsf_err(RS_INIT_FAILURE_BSDES);`
`1943`	`1946`	`return -EINVAL;`