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

Pull perf fixes from Ingo Molnar:
 "Assorted standalone fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Add model number for Avoton Silvermont
  perf: Fix capabilities bitfield compatibility in 'struct perf_event_mmap_page'
  perf/x86/intel/uncore: Don't use smp_processor_id() in validate_group()
  perf: Update ABI comment
  tools lib lk: Uninclude linux/magic.h in debugfs.c
  perf tools: Fix old GCC build error in trace-event-parse.c:parse_proc_kallsyms()
  perf probe: Fix finder to find lines of given function
  perf session: Check for SIGINT in more loops
  perf tools: Fix compile with libelf without get_phdrnum
  perf tools: Fix buildid cache handling of kallsyms with kcore
  perf annotate: Fix objdump line parsing offset validation
  perf tools: Fill in new definitions for madvise()/mmap() flags
  perf tools: Sharpen the libaudit dependencies test

1 files changed, 21 insertions, 0 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index dd236b66ca3a..cb4238e85b38 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3660,6 +3660,26 @@ static void calc_timer_values(struct perf_event *event,
 	*running = ctx_time - event->tstamp_running;
 }
 
+static void perf_event_init_userpage(struct perf_event *event)
+{
+	struct perf_event_mmap_page *userpg;
+	struct ring_buffer *rb;
+
+	rcu_read_lock();
+	rb = rcu_dereference(event->rb);
+	if (!rb)
+		goto unlock;
+
+	userpg = rb->user_page;
+
+	/* Allow new userspace to detect that bit 0 is deprecated */
+	userpg->cap_bit0_is_deprecated = 1;
+	userpg->size = offsetof(struct perf_event_mmap_page, __reserved);
+
+unlock:
+	rcu_read_unlock();
+}
+
 void __weak arch_perf_update_userpage(struct perf_event_mmap_page *userpg, u64 now)
 {
 }
@@ -4044,6 +4064,7 @@ again:
 	ring_buffer_attach(event, rb);
 	rcu_assign_pointer(event->rb, rb);
 
+	perf_event_init_userpage(event);
 	perf_event_update_userpage(event);
 
 unlock: