perf, x86: Restrict the ANY flag

The ANY flag can show SMT data of another task (like 'top'),
so we want to disable it when system-wide profiling is
disabled.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 18 insertions, 15 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 6531b4bdb22d..aab2e1ce9dee 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -503,6 +503,9 @@ static int __hw_perf_event_init(struct perf_event *event)
          */
         if (attr->type == PERF_TYPE_RAW) {
                 hwc->config |= x86_pmu.raw_event(attr->config);
+                if ((hwc->config & ARCH_PERFMON_EVENTSEL_ANY) &&
+                    perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
+                        return -EACCES;
                 return 0;
         }
 
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 04f06b4be297..90e0521b1690 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -857,6 +857,21 @@ extern int sysctl_perf_event_paranoid;
 extern int sysctl_perf_event_mlock;
 extern int sysctl_perf_event_sample_rate;
 
+static inline bool perf_paranoid_tracepoint_raw(void)
+{
+        return sysctl_perf_event_paranoid > -1;
+}
+
+static inline bool perf_paranoid_cpu(void)
+{
+        return sysctl_perf_event_paranoid > 0;
+}
+
+static inline bool perf_paranoid_kernel(void)
+{
+        return sysctl_perf_event_paranoid > 1;
+}
+
 extern void perf_event_init(void);
 extern void perf_tp_event(int event_id, u64 addr, u64 count, void *record, int entry_size);
 extern void perf_bp_event(struct perf_event *event, void *data);
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index a661e7991865..482d5e1d3764 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -56,21 +56,6 @@ static atomic_t nr_task_events __read_mostly;
  */
 int sysctl_perf_event_paranoid __read_mostly = 1;
 
-static inline bool perf_paranoid_tracepoint_raw(void)
-{
-        return sysctl_perf_event_paranoid > -1;
-}
-
-static inline bool perf_paranoid_cpu(void)
-{
-        return sysctl_perf_event_paranoid > 0;
-}
-
-static inline bool perf_paranoid_kernel(void)
-{
-        return sysctl_perf_event_paranoid > 1;
-}
-
 int sysctl_perf_event_mlock __read_mostly = 512; /* 'free' kb per user */
 
 /*