diff options
| author | Hendrik Brueckner <brueckner@linux.vnet.ibm.com> | 2015-09-07 10:52:42 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2015-09-17 13:43:42 +0200 |
| commit | 58f8e9da33eb0104f5bee3e8b3ca44e1583c78b9 (patch) | |
| tree | d889d71b48c2f548740cdefa0a37c9410a14f915 | |
| parent | 8d4bd0ed0439dfc780aab801a085961925ed6838 (diff) | |
| download | linux-58f8e9da33eb0104f5bee3e8b3ca44e1583c78b9.tar.bz2 | |
s390/cpum_cf: Corrected return code for unauthorized counter sets
Previously, the cpum_cf PMU returned -EPERM if a counter is requested and
the counter set to which the counter belongs is not authorized. According
to the perf_event_open() system call manual, an error code of EPERM indicates
an unsupported exclude setting or CAP_SYS_ADMIN is missing.
Use ENOENT to indicate that particular counters are not available when the
counter set which contains the counter is not authorized. For generic events,
this might trigger a fall back, for example, to a software event.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/kernel/perf_cpum_cf.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c index 56fdad479115..a9563409c36e 100644 --- a/arch/s390/kernel/perf_cpum_cf.c +++ b/arch/s390/kernel/perf_cpum_cf.c @@ -157,10 +157,14 @@ static int validate_ctr_auth(const struct hw_perf_event *hwc) cpuhw = &get_cpu_var(cpu_hw_events); - /* check authorization for cpu counter sets */ + /* Check authorization for cpu counter sets. + * If the particular CPU counter set is not authorized, + * return with -ENOENT in order to fall back to other + * PMUs that might suffice the event request. + */ ctrs_state = cpumf_state_ctl[hwc->config_base]; if (!(ctrs_state & cpuhw->info.auth_ctl)) - err = -EPERM; + err = -ENOENT; put_cpu_var(cpu_hw_events); return err; @@ -536,7 +540,7 @@ static int cpumf_pmu_add(struct perf_event *event, int flags) */ if (!(cpuhw->flags & PERF_EVENT_TXN)) if (validate_ctr_auth(&event->hw)) - return -EPERM; + return -ENOENT; ctr_set_enable(&cpuhw->state, event->hw.config_base); event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED; @@ -611,7 +615,7 @@ static int cpumf_pmu_commit_txn(struct pmu *pmu) state = cpuhw->state & ~((1 << CPUMF_LCCTL_ENABLE_SHIFT) - 1); state >>= CPUMF_LCCTL_ENABLE_SHIFT; if ((state & cpuhw->info.auth_ctl) != state) - return -EPERM; + return -ENOENT; cpuhw->flags &= ~PERF_EVENT_TXN; perf_pmu_enable(pmu); |