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-rw-r--r--kernel/events/core.c25
-rw-r--r--kernel/stacktrace.c12
2 files changed, 19 insertions, 18 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index e5aaa80..e235bb9 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 b6e4c16..9c15a91 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;
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