From ac96652da2a760bbd8cb4dc74b6bf1c5d2c8babb Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 10 Dec 2014 21:23:50 +0100 Subject: perf/x86/intel/uncore: Make sure only uncore events are collected commit af91568e762d04931dcbdd6bef4655433d8b9418 upstream. The uncore_collect_events functions assumes that event group might contain only uncore events which is wrong, because it might contain any type of events. This bug leads to uncore framework touching 'not' uncore events, which could end up all sorts of bugs. One was triggered by Vince's perf fuzzer, when the uncore code touched breakpoint event private event space as if it was uncore event and caused BUG: BUG: unable to handle kernel paging request at ffffffff82822068 IP: [] uncore_assign_events+0x188/0x250 ... The code in uncore_assign_events() function was looking for event->hw.idx data while the event was initialized as a breakpoint with different members in event->hw union. This patch forces uncore_collect_events() to collect only uncore events. Reported-by: Vince Weaver Signed-off-by: Jiri Olsa Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Yan, Zheng Link: http://lkml.kernel.org/r/1418243031-20367-2-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/perf_event_intel_uncore.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c index 8aac56bda7dc..7185af255fb5 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c @@ -2657,6 +2657,17 @@ static struct intel_uncore_box *uncore_event_to_box(struct perf_event *event) return uncore_pmu_to_box(uncore_event_to_pmu(event), smp_processor_id()); } +/* + * Using uncore_pmu_event_init pmu event_init callback + * as a detection point for uncore events. + */ +static int uncore_pmu_event_init(struct perf_event *event); + +static bool is_uncore_event(struct perf_event *event) +{ + return event->pmu->event_init == uncore_pmu_event_init; +} + static int uncore_collect_events(struct intel_uncore_box *box, struct perf_event *leader, bool dogrp) { @@ -2671,13 +2682,18 @@ uncore_collect_events(struct intel_uncore_box *box, struct perf_event *leader, b return -EINVAL; n = box->n_events; - box->event_list[n] = leader; - n++; + + if (is_uncore_event(leader)) { + box->event_list[n] = leader; + n++; + } + if (!dogrp) return n; list_for_each_entry(event, &leader->sibling_list, group_entry) { - if (event->state <= PERF_EVENT_STATE_OFF) + if (!is_uncore_event(event) || + event->state <= PERF_EVENT_STATE_OFF) continue; if (n >= max_count) -- cgit v1.2.3