Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:
 "Two core subsystem fixes, plus a handful of tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix race in swevent hash
  perf: Fix race in perf_event_exec()
  perf list: Robustify event printing routine
  perf list: Add support for PERF_COUNT_SW_BPF_OUT
  perf hists browser: Fix segfault if use symbol filter in cmdline
  perf hists browser: Reset selection when refresh
  perf hists browser: Add NULL pointer check to prevent crash
  perf buildid-list: Fix return value of perf buildid-list -k
  perf buildid-list: Show running kernel build id fix
This commit is contained in:
Linus Torvalds 2016-01-08 13:52:59 -08:00
commit 3ab6d1ebd5
5 changed files with 21 additions and 32 deletions

View file

@ -3154,15 +3154,16 @@ static int event_enable_on_exec(struct perf_event *event,
* Enable all of a task's events that have been marked enable-on-exec.
* This expects task == current.
*/
static void perf_event_enable_on_exec(struct perf_event_context *ctx)
static void perf_event_enable_on_exec(int ctxn)
{
struct perf_event_context *clone_ctx = NULL;
struct perf_event_context *ctx, *clone_ctx = NULL;
struct perf_event *event;
unsigned long flags;
int enabled = 0;
int ret;
local_irq_save(flags);
ctx = current->perf_event_ctxp[ctxn];
if (!ctx || !ctx->nr_events)
goto out;
@ -3205,17 +3206,11 @@ out:
void perf_event_exec(void)
{
struct perf_event_context *ctx;
int ctxn;
rcu_read_lock();
for_each_task_context_nr(ctxn) {
ctx = current->perf_event_ctxp[ctxn];
if (!ctx)
continue;
perf_event_enable_on_exec(ctx);
}
for_each_task_context_nr(ctxn)
perf_event_enable_on_exec(ctxn);
rcu_read_unlock();
}
@ -6493,9 +6488,6 @@ struct swevent_htable {
/* Recursion avoidance in each contexts */
int recursion[PERF_NR_CONTEXTS];
/* Keeps track of cpu being initialized/exited */
bool online;
};
static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
@ -6753,14 +6745,8 @@ static int perf_swevent_add(struct perf_event *event, int flags)
hwc->state = !(flags & PERF_EF_START);
head = find_swevent_head(swhash, event);
if (!head) {
/*
* We can race with cpu hotplug code. Do not
* WARN if the cpu just got unplugged.
*/
WARN_ON_ONCE(swhash->online);
if (WARN_ON_ONCE(!head))
return -EINVAL;
}
hlist_add_head_rcu(&event->hlist_entry, head);
perf_event_update_userpage(event);
@ -6828,7 +6814,6 @@ static int swevent_hlist_get_cpu(struct perf_event *event, int cpu)
int err = 0;
mutex_lock(&swhash->hlist_mutex);
if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) {
struct swevent_hlist *hlist;
@ -9291,7 +9276,6 @@ static void perf_event_init_cpu(int cpu)
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
mutex_lock(&swhash->hlist_mutex);
swhash->online = true;
if (swhash->hlist_refcount > 0) {
struct swevent_hlist *hlist;
@ -9333,14 +9317,7 @@ static void perf_event_exit_cpu_context(int cpu)
static void perf_event_exit_cpu(int cpu)
{
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
perf_event_exit_cpu_context(cpu);
mutex_lock(&swhash->hlist_mutex);
swhash->online = false;
swevent_hlist_release(swhash);
mutex_unlock(&swhash->hlist_mutex);
}
#else
static inline void perf_event_exit_cpu(int cpu) { }