From: Shouye Liu shouyeliu@tencent.com

In certain situations, the sysfs for uncore may not be present when all CPUs in a package are offlined and then brought back online after boot.

This issue can occur if there is an error in adding the sysfs entry due to a memory allocation failure. Retrying to bring the CPUs online will not resolve the issue, as the uncore_cpu_mask is already set for the package before the failure condition occurs.

This issue does not occur if the failure happens during module initialization, as the module will fail to load in the event of any error.

To address this, ensure that the uncore_cpu_mask is not set until the successful return of uncore_freq_add_entry().

Fixes: dbce412a7733 ("platform/x86/intel-uncore-freq: Split common and enumeration part") Signed-off-by: Shouye Liu shouyeliu@tencent.com Cc: stable@vger.kernel.org --- .../x86/intel/uncore-frequency/uncore-frequency.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c index 40bbf8e45fa4..bdee5d00f30b 100644 --- a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c +++ b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c @@ -146,15 +146,13 @@ static int uncore_event_cpu_online(unsigned int cpu) { struct uncore_data *data; int target; + int ret;

/* Check if there is an online cpu in the package for uncore MSR */ target = cpumask_any_and(&uncore_cpu_mask, topology_die_cpumask(cpu)); if (target < nr_cpu_ids) return 0;

- /* Use this CPU on this die as a control CPU */ - cpumask_set_cpu(cpu, &uncore_cpu_mask); - data = uncore_get_instance(cpu); if (!data) return 0; @@ -163,7 +161,14 @@ static int uncore_event_cpu_online(unsigned int cpu) data->die_id = topology_die_id(cpu); data->domain_id = UNCORE_DOMAIN_ID_INVALID;

- return uncore_freq_add_entry(data, cpu); + ret = uncore_freq_add_entry(data, cpu); + if (ret) + return ret; + + /* Use this CPU on this die as a control CPU */ + cpumask_set_cpu(cpu, &uncore_cpu_mask); + + return 0; }

static int uncore_event_cpu_offline(unsigned int cpu)