Em Fri, Feb 15, 2019 at 01:56:54PM +0200, Alexander Shishkin escreveu: > When a child event is allocated in the inherit_event() path, the VMA > based filter offsets are not copied from the parent, even though the > address space mapping of the new task remains the same, which leads > to no trace for the new task until exec.
Peter, I'm processing this one, ok? Ack? - Arnaldo > Signed-off-by: Alexander Shishkin <[email protected]> > Fixes: 375637bc5249 ("perf/core: Introduce address range filtering") > Reported-by: Mansour Alharthi <[email protected]> > --- > kernel/events/core.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 5aeb4c74fb99..2d89efc0a3e0 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -1255,6 +1255,7 @@ static void put_ctx(struct perf_event_context *ctx) > * perf_event_context::lock > * perf_event::mmap_mutex > * mmap_sem > + * perf_addr_filters_head::lock > * > * cpu_hotplug_lock > * pmus_lock > @@ -10312,6 +10313,20 @@ perf_event_alloc(struct perf_event_attr *attr, int > cpu, > goto err_per_task; > } > > + /* > + * Clone the parent's vma offsets: they are valid until exec() > + * even if the mm is not shared with the parent. > + */ > + if (event->parent) { > + struct perf_addr_filters_head *ifh = > perf_event_addr_filters(event); > + > + raw_spin_lock_irq(&ifh->lock); > + memcpy(event->addr_filters_offs, > + event->parent->addr_filters_offs, > + pmu->nr_addr_filters * sizeof(unsigned long)); > + raw_spin_unlock_irq(&ifh->lock); > + } > + > /* force hw sync on the address filters */ > event->addr_filters_gen = 1; > } > -- > 2.20.1
