5 files changed, 61 insertions, 26 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 437a74a7524a..d190664f25ff 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2326,6 +2326,18 @@ static void find_module_sections(struct module *mod, struct load_info *info)
 	kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
 			   mod->num_trace_events, GFP_KERNEL);
 #endif
+#ifdef CONFIG_TRACING
+	mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
+					 sizeof(*mod->trace_bprintk_fmt_start),
+					 &mod->num_trace_bprintk_fmt);
+	/*
+	 * This section contains pointers to allocated objects in the trace
+	 * code and not scanning it leads to false positives.
+	 */
+	kmemleak_scan_area(mod->trace_bprintk_fmt_start,
+			   sizeof(*mod->trace_bprintk_fmt_start) *
+			   mod->num_trace_bprintk_fmt, GFP_KERNEL);
+#endif
 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 	/* sechdrs[0].sh_size is always zero */
 	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index cb6c0d2af68f..40c3aab648a1 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -4773,15 +4773,6 @@ static int perf_tp_event_init(struct perf_event *event)
 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
 		return -ENOENT;
 
-	/*
-	 * Raw tracepoint data is a severe data leak, only allow root to
-	 * have these.
-	 */
-	if ((event->attr.sample_type & PERF_SAMPLE_RAW) &&
-			perf_paranoid_tracepoint_raw() &&
-			!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
 	err = perf_trace_init(event);
 	if (err)
 		return err;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 5abfa1518554..cbd97da7a613 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -746,22 +746,6 @@ static struct ctl_table kern_table[] = {
 		.extra2		= &one,
 	},
 #endif
-#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) && !defined(CONFIG_LOCKUP_DETECTOR)
-	{
-		.procname       = "unknown_nmi_panic",
-		.data           = &unknown_nmi_panic,
-		.maxlen         = sizeof (int),
-		.mode           = 0644,
-		.proc_handler   = proc_dointvec,
-	},
-	{
-		.procname       = "nmi_watchdog",
-		.data           = &nmi_watchdog_enabled,
-		.maxlen         = sizeof (int),
-		.mode           = 0644,
-		.proc_handler   = proc_nmi_enabled,
-	},
-#endif
 #if defined(CONFIG_X86)
 	{
 		.procname	= "panic_on_unrecovered_nmi",
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 042084157980..c380612273bf 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1283,6 +1283,8 @@ void trace_dump_stack(void)
 	__ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count());
 }
 
+static DEFINE_PER_CPU(int, user_stack_count);
+
 void
 ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
 {
@@ -1301,6 +1303,18 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
 	if (unlikely(in_nmi()))
 		return;
 
+	/*
+	 * prevent recursion, since the user stack tracing may
+	 * trigger other kernel events.
+	 */
+	preempt_disable();
+	if (__this_cpu_read(user_stack_count))
+		goto out;
+
+	__this_cpu_inc(user_stack_count);
+
+
+
 	event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
 					  sizeof(*entry), flags, pc);
 	if (!event)
@@ -1318,6 +1332,11 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
 	save_stack_trace_user(&trace);
 	if (!filter_check_discard(call, entry, buffer, event))
 		ring_buffer_unlock_commit(buffer, event);
+
+	__this_cpu_dec(user_stack_count);
+
+ out:
+	preempt_enable();
 }
 
 #ifdef UNUSED
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 39c059ca670e..19a359d5e6d5 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -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 __percpu *list;
-	int ret = -ENOMEM;
+	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;