On Tue, Feb 23, 2021 at 3:34 PM Marco Elver <[email protected]> wrote: > > As with other ioctls (such as PERF_EVENT_IOC_{ENABLE,DISABLE}), fix up > handling of PERF_EVENT_IOC_MODIFY_ATTRIBUTES to also apply to children. > > Link: > https://lkml.kernel.org/r/[email protected] > Suggested-by: Dmitry Vyukov <[email protected]> > Signed-off-by: Marco Elver <[email protected]>
Reviewed-by: Dmitry Vyukov <[email protected]> > --- > kernel/events/core.c | 22 +++++++++++++++++++++- > 1 file changed, 21 insertions(+), 1 deletion(-) > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 129dee540a8b..37a8297be164 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -3179,16 +3179,36 @@ static int perf_event_modify_breakpoint(struct > perf_event *bp, > static int perf_event_modify_attr(struct perf_event *event, > struct perf_event_attr *attr) > { > + int (*func)(struct perf_event *, struct perf_event_attr *); > + struct perf_event *child; > + int err; > + > if (event->attr.type != attr->type) > return -EINVAL; > > switch (event->attr.type) { > case PERF_TYPE_BREAKPOINT: > - return perf_event_modify_breakpoint(event, attr); > + func = perf_event_modify_breakpoint; > + break; > default: > /* Place holder for future additions. */ > return -EOPNOTSUPP; > } > + > + WARN_ON_ONCE(event->ctx->parent_ctx); > + > + mutex_lock(&event->child_mutex); > + err = func(event, attr); > + if (err) > + goto out; > + list_for_each_entry(child, &event->child_list, child_list) { > + err = func(child, attr); > + if (err) > + goto out; > + } > +out: > + mutex_unlock(&event->child_mutex); > + return err; > } > > static void ctx_sched_out(struct perf_event_context *ctx, > -- > 2.30.0.617.g56c4b15f3c-goog >
