Merge branch 'mpi-master' into wip-k-fmlpwip-k-fmlp

Conflicts:
	litmus/sched_cedf.c

1 files changed, 46 insertions, 13 deletions

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 31cc4cb0dbf2..19a359d5e6d5 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -9,7 +9,7 @@
 #include <linux/kprobes.h>
 #include "trace.h"
 
-static char *perf_trace_buf[4];
+static char __percpu *perf_trace_buf[PERF_NR_CONTEXTS];
 
 /*
  * Force it to be aligned to unsigned long to avoid misaligned accesses
@@ -21,17 +21,46 @@ typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)])
 /* Count the events in use (per event id, not per instance) */
 static int      total_ref_count;
 
+static int perf_trace_event_perm(struct ftrace_event_call *tp_event,
+                                 struct perf_event *p_event)
+{
+        /* No tracing, just counting, so no obvious leak */
+        if (!(p_event->attr.sample_type & PERF_SAMPLE_RAW))
+                return 0;
+
+        /* Some events are ok to be traced by non-root users... */
+        if (p_event->attach_state == PERF_ATTACH_TASK) {
+                if (tp_event->flags & TRACE_EVENT_FL_CAP_ANY)
+                        return 0;
+        }
+
+        /*
+         * ...otherwise raw tracepoint data can be a severe data leak,
+         * only allow root to have these.
+         */
+        if (perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        return 0;
+}
+
 static int perf_trace_event_init(struct ftrace_event_call *tp_event,
                                  struct perf_event *p_event)
 {
-        struct hlist_head *list;
-        int ret = -ENOMEM;
+        struct hlist_head __percpu *list;
+        int ret;
         int cpu;
 
+        ret = perf_trace_event_perm(tp_event, p_event);
+        if (ret)
+                return ret;
+
         p_event->tp_event = tp_event;
         if (tp_event->perf_refcount++ > 0)
                 return 0;
 
+        ret = -ENOMEM;
+
         list = alloc_percpu(struct hlist_head);
         if (!list)
                 goto fail;
@@ -42,11 +71,11 @@ static int perf_trace_event_init(struct ftrace_event_call *tp_event,
         tp_event->perf_events = list;
 
         if (!total_ref_count) {
-                char *buf;
+                char __percpu *buf;
                 int i;
 
-                for (i = 0; i < 4; i++) {
-                        buf = (char *)alloc_percpu(perf_trace_t);
+                for (i = 0; i < PERF_NR_CONTEXTS; i++) {
+                        buf = (char __percpu *)alloc_percpu(perf_trace_t);
                         if (!buf)
                                 goto fail;
 
@@ -65,7 +94,7 @@ fail:
         if (!total_ref_count) {
                 int i;
 
-                for (i = 0; i < 4; i++) {
+                for (i = 0; i < PERF_NR_CONTEXTS; i++) {
                         free_percpu(perf_trace_buf[i]);
                         perf_trace_buf[i] = NULL;
                 }
@@ -101,22 +130,26 @@ int perf_trace_init(struct perf_event *p_event)
         return ret;
 }
 
-int perf_trace_enable(struct perf_event *p_event)
+int perf_trace_add(struct perf_event *p_event, int flags)
 {
         struct ftrace_event_call *tp_event = p_event->tp_event;
+        struct hlist_head __percpu *pcpu_list;
         struct hlist_head *list;
 
-        list = tp_event->perf_events;
-        if (WARN_ON_ONCE(!list))
+        pcpu_list = tp_event->perf_events;
+        if (WARN_ON_ONCE(!pcpu_list))
                 return -EINVAL;
 
-        list = this_cpu_ptr(list);
+        if (!(flags & PERF_EF_START))
+                p_event->hw.state = PERF_HES_STOPPED;
+
+        list = this_cpu_ptr(pcpu_list);
         hlist_add_head_rcu(&p_event->hlist_entry, list);
 
         return 0;
 }
 
-void perf_trace_disable(struct perf_event *p_event)
+void perf_trace_del(struct perf_event *p_event, int flags)
 {
         hlist_del_rcu(&p_event->hlist_entry);
 }
@@ -142,7 +175,7 @@ void perf_trace_destroy(struct perf_event *p_event)
         tp_event->perf_events = NULL;
 
         if (!--total_ref_count) {
-                for (i = 0; i < 4; i++) {
+                for (i = 0; i < PERF_NR_CONTEXTS; i++) {
                         free_percpu(perf_trace_buf[i]);
                         perf_trace_buf[i] = NULL;
                 }