Re: [PATCH 16/16] perf, persistent: Allow multiple users for an event

From: Jiri Olsa
Date: Tue Jun 04 2013 - 05:43:43 EST


On Tue, Jun 04, 2013 at 10:20:42AM +0200, Borislav Petkov wrote:
> On Mon, Jun 03, 2013 at 03:49:25PM +0200, Jiri Olsa wrote:
> > maybe check for valid cpu, since perf_get_persistent_event_fd is
> > called directly from syscall allowing anything in cpu
>
> That should be fine - we're traversing a per-cpu list of events there.

hum, can't see it:

perf SYSCALL:
...
return perf_get_persistent_event_fd(cpu, &attr);

...
int perf_get_persistent_event_fd(unsigned cpu, struct perf_event_attr *attr)
{
struct pers_event_desc *desc;
struct perf_event *event;
int event_fd = -ENODEV;

mutex_lock(&per_cpu(pers_events_lock, cpu));
...

'cpu' did not pass ay check here..

jirka
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