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authorOleg Nesterov <oleg@redhat.com>2011-01-18 17:10:32 +0100
committerIngo Molnar <mingo@elte.hu>2011-01-18 19:34:23 +0100
commit66832eb4baaaa9abe4c993ddf9113a79e39b9915 (patch)
treebc1b60069c5313231a5ddca0f0dcab953489bb1e
parent22a4ec729017ba613337a28f306f94ba5023fe2e (diff)
perf: Validate cpu early in perf_event_alloc()
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> Cc: gregkh@suse.de Cc: stable@kernel.org LKML-Reference: <20110118161032.GC693@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/perf_event.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index a962b1962eee..67d9bd70b746 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2233,9 +2233,6 @@ find_get_context(struct pmu *pmu, struct task_struct *task, int cpu)
if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
return ERR_PTR(-EACCES);
- if (cpu < 0 || cpu >= nr_cpumask_bits)
- return ERR_PTR(-EINVAL);
-
/*
* We could be clever and allow to attach a event to an
* offline CPU and activate it when the CPU comes up, but
@@ -5541,6 +5538,11 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
struct hw_perf_event *hwc;
long err;
+ if ((unsigned)cpu >= nr_cpu_ids) {
+ if (!task || cpu != -1)
+ return ERR_PTR(-EINVAL);
+ }
+
event = kzalloc(sizeof(*event), GFP_KERNEL);
if (!event)
return ERR_PTR(-ENOMEM);
@@ -5589,7 +5591,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
if (!overflow_handler && parent_event)
overflow_handler = parent_event->overflow_handler;
-
+
event->overflow_handler = overflow_handler;
if (attr->disabled)