perf/core: Need CAP_SYS_ADMIN to create k/uprobe with perf_event_open()

Non-root user cannot create kprobe or uprobe through the text-based
interface (kprobe_events, uprobe_events),so they should not be able
to create probes via perf_event_open() either.

Reported-by: Vince Weaver <[e-mail]>
Signed-off-by: Song Liu <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Fixes: 33ea4b24277b ("perf/core: Implement the 'perf_uprobe' PMU")
Fixes: e12f03d7031a ("perf/core: Implement the 'perf_kprobe' PMU")
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

kernel/events/core.c

···
 
 	if (event->attr.type != perf_kprobe.type)
 		return -ENOENT;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
 	/*
 	 * no branch sampling for probe events
 	 */
···
 
 	if (event->attr.type != perf_uprobe.type)
 		return -ENOENT;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
 	/*
 	 * no branch sampling for probe events
 	 */