perf: Validate cpu early in perf_event_alloc()
commit
66832eb4baaaa9abe4c993ddf9113a79e39b9915 upstream.
Starting from perf_event_alloc()->perf_init_event(), the kernel
assumes that event->cpu is either -1 or the valid CPU number.
Change perf_event_alloc() to validate this argument early. This
also means we can remove the similar check in
find_get_context().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
LKML-Reference: <
20110118161032.GC693@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>