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

5 files changed, 21 insertions, 32 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index ef2d6ea10736..cfc227ccfceb 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -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) { }
diff --git a/tools/perf/builtin-buildid-list.c b/tools/perf/builtin-buildid-list.c
index 918b4de29de4..6419f57b0850 100644
--- a/tools/perf/builtin-buildid-list.c
+++ b/tools/perf/builtin-buildid-list.c
@@ -110,7 +110,7 @@ int cmd_buildid_list(int argc, const char **argv,
         setup_pager();
 
         if (show_kernel)
-                return sysfs__fprintf_build_id(stdout);
+                return !(sysfs__fprintf_build_id(stdout) > 0);
 
         return perf_session__list_build_ids(force, with_hits);
 }
diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index fa9eb92c9e24..81def6c3f24b 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -298,6 +298,9 @@ static bool hist_browser__toggle_fold(struct hist_browser *browser)
         struct callchain_list *cl = container_of(ms, struct callchain_list, ms);
         bool has_children;
 
+        if (!he || !ms)
+                return false;
+
         if (ms == &he->ms)
                 has_children = hist_entry__toggle_fold(he);
         else
@@ -928,6 +931,8 @@ static unsigned int hist_browser__refresh(struct ui_browser *browser)
         }
 
         ui_browser__hists_init_top(browser);
+        hb->he_selection = NULL;
+        hb->selection = NULL;
 
         for (nd = browser->top; nd; nd = rb_next(nd)) {
                 struct hist_entry *h = rb_entry(nd, struct hist_entry, rb_node);
@@ -1033,6 +1038,9 @@ static void ui_browser__hists_seek(struct ui_browser *browser,
          * and stop when we printed enough lines to fill the screen.
          */
 do_offset:
+        if (!nd)
+                return;
+
         if (offset > 0) {
                 do {
                         h = rb_entry(nd, struct hist_entry, rb_node);
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 217b5a60e2ab..6a7e273a514a 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -91,7 +91,7 @@ int build_id__sprintf(const u8 *build_id, int len, char *bf)
                 bid += 2;
         }
 
-        return raw - build_id;
+        return (bid - bf) + 1;
 }
 
 int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index e48d9da75707..6fc8cd753e1a 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -124,6 +124,10 @@ struct event_symbol event_symbols_sw[PERF_COUNT_SW_MAX] = {
                 .symbol = "dummy",
                 .alias  = "",
         },
+        [PERF_COUNT_SW_BPF_OUTPUT] = {
+                .symbol = "bpf-output",
+                .alias  = "",
+        },
 };
 
 #define __PERF_EVENT_FIELD(config, name) \
@@ -1879,7 +1883,7 @@ restart:
 
         for (i = 0; i < max; i++, syms++) {
 
-                if (event_glob != NULL &&
+                if (event_glob != NULL && syms->symbol != NULL &&
                     !(strglobmatch(syms->symbol, event_glob) ||
                       (syms->alias && strglobmatch(syms->alias, event_glob))))
                         continue;