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

Pull perf fixes from Ingo Molnar:
 "A kernel crash fix plus three tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix crash in perf_event_read()
  perf callchain: Reference count maps
  perf diff: Fix -o/--order option behavior (again)
  perf diff: Fix segfault on 'perf diff -o N' option

7 files changed, 55 insertions, 13 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/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 9ff0db4e2d0c..933aeec46f4a 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -1199,7 +1199,7 @@ static int ui_init(void)
                 BUG_ON(1);
         }
 
-        perf_hpp__register_sort_field(fmt);
+        perf_hpp__prepend_sort_field(fmt);
         return 0;
 }
 
diff --git a/tools/perf/ui/hist.c b/tools/perf/ui/hist.c
index 37388397b5bc..18cfcdc90356 100644
--- a/tools/perf/ui/hist.c
+++ b/tools/perf/ui/hist.c
@@ -521,6 +521,12 @@ void perf_hpp_list__register_sort_field(struct perf_hpp_list *list,
         list_add_tail(&format->sort_list, &list->sorts);
 }
 
+void perf_hpp_list__prepend_sort_field(struct perf_hpp_list *list,
+                                       struct perf_hpp_fmt *format)
+{
+        list_add(&format->sort_list, &list->sorts);
+}
+
 void perf_hpp__column_unregister(struct perf_hpp_fmt *format)
 {
         list_del(&format->list);
@@ -560,6 +566,10 @@ void perf_hpp__setup_output_field(struct perf_hpp_list *list)
         perf_hpp_list__for_each_sort_list(list, fmt) {
                 struct perf_hpp_fmt *pos;
 
+                /* skip sort-only fields ("sort_compute" in perf diff) */
+                if (!fmt->entry && !fmt->color)
+                        continue;
+
                 perf_hpp_list__for_each_format(list, pos) {
                         if (fmt_equal(fmt, pos))
                                 goto next;
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 42922512c1c6..8b610dd9e2f6 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -437,7 +437,7 @@ fill_node(struct callchain_node *node, struct callchain_cursor *cursor)
                 }
                 call->ip = cursor_node->ip;
                 call->ms.sym = cursor_node->sym;
-                call->ms.map = cursor_node->map;
+                call->ms.map = map__get(cursor_node->map);
 
                 if (cursor_node->branch) {
                         call->branch_count = 1;
@@ -477,6 +477,7 @@ add_child(struct callchain_node *parent,
 
                 list_for_each_entry_safe(call, tmp, &new->val, list) {
                         list_del(&call->list);
+                        map__zput(call->ms.map);
                         free(call);
                 }
                 free(new);
@@ -761,6 +762,7 @@ merge_chain_branch(struct callchain_cursor *cursor,
                                         list->ms.map, list->ms.sym,
                                         false, NULL, 0, 0);
                 list_del(&list->list);
+                map__zput(list->ms.map);
                 free(list);
         }
 
@@ -811,7 +813,8 @@ int callchain_cursor_append(struct callchain_cursor *cursor,
         }
 
         node->ip = ip;
-        node->map = map;
+        map__zput(node->map);
+        node->map = map__get(map);
         node->sym = sym;
         node->branch = branch;
         node->nr_loop_iter = nr_loop_iter;
@@ -1142,11 +1145,13 @@ static void free_callchain_node(struct callchain_node *node)
 
         list_for_each_entry_safe(list, tmp, &node->parent_val, list) {
                 list_del(&list->list);
+                map__zput(list->ms.map);
                 free(list);
         }
 
         list_for_each_entry_safe(list, tmp, &node->val, list) {
                 list_del(&list->list);
+                map__zput(list->ms.map);
                 free(list);
         }
 
@@ -1210,6 +1215,7 @@ int callchain_node__make_parent_list(struct callchain_node *node)
                                 goto out;
                         *new = *chain;
                         new->has_children = false;
+                        map__get(new->ms.map);
                         list_add_tail(&new->list, &head);
                 }
                 parent = parent->parent;
@@ -1230,6 +1236,7 @@ int callchain_node__make_parent_list(struct callchain_node *node)
 out:
         list_for_each_entry_safe(chain, new, &head, list) {
                 list_del(&chain->list);
+                map__zput(chain->ms.map);
                 free(chain);
         }
         return -ENOMEM;
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index 35c8e379530f..4f4b60f1558a 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -5,6 +5,7 @@
 #include <linux/list.h>
 #include <linux/rbtree.h>
 #include "event.h"
+#include "map.h"
 #include "symbol.h"
 
 #define HELP_PAD "\t\t\t\t"
@@ -184,8 +185,13 @@ int callchain_merge(struct callchain_cursor *cursor,
  */
 static inline void callchain_cursor_reset(struct callchain_cursor *cursor)
 {
+        struct callchain_cursor_node *node;
+
         cursor->nr = 0;
         cursor->last = &cursor->first;
+
+        for (node = cursor->first; node != NULL; node = node->next)
+                map__zput(node->map);
 }
 
 int callchain_cursor_append(struct callchain_cursor *cursor, u64 ip,
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 6770a9645609..7d1b7d33e644 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -1,6 +1,7 @@
 #include "util.h"
 #include "build-id.h"
 #include "hist.h"
+#include "map.h"
 #include "session.h"
 #include "sort.h"
 #include "evlist.h"
@@ -1019,6 +1020,10 @@ int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
                          int max_stack_depth, void *arg)
 {
         int err, err2;
+        struct map *alm = NULL;
+
+        if (al && al->map)
+                alm = map__get(al->map);
 
         err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent,
                                         iter->evsel, al, max_stack_depth);
@@ -1058,6 +1063,8 @@ out:
         if (!err)
                 err = err2;
 
+        map__put(alm);
+
         return err;
 }
 
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index d4b6514eeef5..28c216e3d5b7 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -283,6 +283,8 @@ void perf_hpp_list__column_register(struct perf_hpp_list *list,
                                     struct perf_hpp_fmt *format);
 void perf_hpp_list__register_sort_field(struct perf_hpp_list *list,
                                         struct perf_hpp_fmt *format);
+void perf_hpp_list__prepend_sort_field(struct perf_hpp_list *list,
+                                       struct perf_hpp_fmt *format);
 
 static inline void perf_hpp__column_register(struct perf_hpp_fmt *format)
 {
@@ -294,6 +296,11 @@ static inline void perf_hpp__register_sort_field(struct perf_hpp_fmt *format)
         perf_hpp_list__register_sort_field(&perf_hpp_list, format);
 }
 
+static inline void perf_hpp__prepend_sort_field(struct perf_hpp_fmt *format)
+{
+        perf_hpp_list__prepend_sort_field(&perf_hpp_list, format);
+}
+
 #define perf_hpp_list__for_each_format(_list, format) \
         list_for_each_entry(format, &(_list)->fields, list)