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 fixes on the kernel side: fix an over-eager condition that failed
  larger perf ring-buffer sizes, plus fix crashes in the Intel BTS code
  for a corner case, found by fuzzing"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix impossible ring-buffer sizes warning
  perf/x86: Add check_period PMU callback

2 files changed, 17 insertions, 1 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index e5ede6918050..26d6edab051a 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4963,6 +4963,11 @@ static void __perf_event_period(struct perf_event *event,
         }
 }
 
+static int perf_event_check_period(struct perf_event *event, u64 value)
+{
+        return event->pmu->check_period(event, value);
+}
+
 static int perf_event_period(struct perf_event *event, u64 __user *arg)
 {
         u64 value;
@@ -4979,6 +4984,9 @@ static int perf_event_period(struct perf_event *event, u64 __user *arg)
         if (event->attr.freq && value > sysctl_perf_event_sample_rate)
                 return -EINVAL;
 
+        if (perf_event_check_period(event, value))
+                return -EINVAL;
+
         event_function_call(event, __perf_event_period, &value);
 
         return 0;
@@ -9391,6 +9399,11 @@ static int perf_pmu_nop_int(struct pmu *pmu)
         return 0;
 }
 
+static int perf_event_nop_int(struct perf_event *event, u64 value)
+{
+        return 0;
+}
+
 static DEFINE_PER_CPU(unsigned int, nop_txn_flags);
 
 static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags)
@@ -9691,6 +9704,9 @@ got_cpu_context:
                 pmu->pmu_disable = perf_pmu_nop_void;
         }
 
+        if (!pmu->check_period)
+                pmu->check_period = perf_event_nop_int;
+
         if (!pmu->event_idx)
                 pmu->event_idx = perf_event_idx_default;
 
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 309ef5a64af5..5ab4fe3b1dcc 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -734,7 +734,7 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
         size = sizeof(struct ring_buffer);
         size += nr_pages * sizeof(void *);
 
-        if (order_base_2(size) >= MAX_ORDER)
+        if (order_base_2(size) >= PAGE_SHIFT+MAX_ORDER)
                 goto fail;
 
         rb = kzalloc(size, GFP_KERNEL);