diff options
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/events/core.c | 25 | ||||
-rw-r--r-- | kernel/stacktrace.c | 12 | ||||
-rw-r--r-- | kernel/time/tick-sched.c | 5 |
3 files changed, 24 insertions, 18 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index e5aaa806702d..e235bb991bdd 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3487,14 +3487,15 @@ struct perf_read_data { int ret; }; -static int find_cpu_to_read(struct perf_event *event, int local_cpu) +static int __perf_event_read_cpu(struct perf_event *event, int event_cpu) { - int event_cpu = event->oncpu; u16 local_pkg, event_pkg; if (event->group_caps & PERF_EV_CAP_READ_ACTIVE_PKG) { - event_pkg = topology_physical_package_id(event_cpu); - local_pkg = topology_physical_package_id(local_cpu); + int local_cpu = smp_processor_id(); + + event_pkg = topology_physical_package_id(event_cpu); + local_pkg = topology_physical_package_id(local_cpu); if (event_pkg == local_pkg) return local_cpu; @@ -3624,7 +3625,7 @@ u64 perf_event_read_local(struct perf_event *event) static int perf_event_read(struct perf_event *event, bool group) { - int ret = 0, cpu_to_read, local_cpu; + int event_cpu, ret = 0; /* * If event is enabled and currently active on a CPU, update the @@ -3637,21 +3638,25 @@ static int perf_event_read(struct perf_event *event, bool group) .ret = 0, }; - local_cpu = get_cpu(); - cpu_to_read = find_cpu_to_read(event, local_cpu); - put_cpu(); + event_cpu = READ_ONCE(event->oncpu); + if ((unsigned)event_cpu >= nr_cpu_ids) + return 0; + + preempt_disable(); + event_cpu = __perf_event_read_cpu(event, event_cpu); /* * Purposely ignore the smp_call_function_single() return * value. * - * If event->oncpu isn't a valid CPU it means the event got + * If event_cpu isn't a valid CPU it means the event got * scheduled out and that will have updated the event count. * * Therefore, either way, we'll have an up-to-date event count * after this. */ - (void)smp_call_function_single(cpu_to_read, __perf_event_read, &data, 1); + (void)smp_call_function_single(event_cpu, __perf_event_read, &data, 1); + preempt_enable(); ret = data.ret; } else if (event->state == PERF_EVENT_STATE_INACTIVE) { struct perf_event_context *ctx = event->ctx; diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c index b6e4c16377c7..9c15a9124e83 100644 --- a/kernel/stacktrace.c +++ b/kernel/stacktrace.c @@ -18,10 +18,8 @@ void print_stack_trace(struct stack_trace *trace, int spaces) if (WARN_ON(!trace->entries)) return; - for (i = 0; i < trace->nr_entries; i++) { - printk("%*c", 1 + spaces, ' '); - print_ip_sym(trace->entries[i]); - } + for (i = 0; i < trace->nr_entries; i++) + printk("%*c%pS\n", 1 + spaces, ' ', (void *)trace->entries[i]); } EXPORT_SYMBOL_GPL(print_stack_trace); @@ -29,7 +27,6 @@ int snprint_stack_trace(char *buf, size_t size, struct stack_trace *trace, int spaces) { int i; - unsigned long ip; int generated; int total = 0; @@ -37,9 +34,8 @@ int snprint_stack_trace(char *buf, size_t size, return 0; for (i = 0; i < trace->nr_entries; i++) { - ip = trace->entries[i]; - generated = snprintf(buf, size, "%*c[<%p>] %pS\n", - 1 + spaces, ' ', (void *) ip, (void *) ip); + generated = snprintf(buf, size, "%*c%pS\n", 1 + spaces, ' ', + (void *)trace->entries[i]); total += generated; diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 74e0388cc88d..fc6f740d0277 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -725,6 +725,11 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, */ if (delta == 0) { tick_nohz_restart(ts, now); + /* + * Make sure next tick stop doesn't get fooled by past + * clock deadline + */ + ts->next_tick = 0; goto out; } } |