On Fri, Jan 16, 2015 at 12:26:03PM +0000, Mark Rutland wrote: > On Wed, Jan 07, 2015 at 02:56:51PM +0000, Mark Rutland wrote: > > When initialising an event, perf_init_event will call try_module_get to > > ensure that the PMU's module cannot be removed for the lifetime of the > > event, with __free_event dropping the reference when the event is > > finally destroyed. If something fails after the event has been > > initialised, but before the event is installed, perf_event_alloc will > > drop the reference on the module. > > > > However, if we fail to initialise an event for some reason (e.g. we ask > > an uncore PMU to perform sampling, and it refuses to initialise the > > event), we do not drop the refcount. If we try to open such a bogus > > event without a precise IDR type, we will loop over each PMU in the pmus > > list, incrementing each of their refcounts without decrementing them. > > > > This patch adds a module_put when pmu->event_init(event) fails, ensuring > > that the refcounts are balanced in failure cases. As the innards of the > > precise and search based initialisation look very similar, this logic is > > hoisted out into a new helper function. While the early return for the > > failed try_module_get is removed from the search case, this is handled > > by the remaining return when ret is not -ENOENT. > > I hate to ping, but is anyone going to look at this? >
Thanks for reminding me; the inbox is still a horrid mess. Looks good, thanks! -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
