Files
linux/include/linux
Jiri Olsa e62e3b61e3 perf/x86: Add check_period PMU callback
commit 81ec3f3c4c upstream.

Vince (and later on Ravi) reported crashes in the BTS code during
fuzzing with the following backtrace:

  general protection fault: 0000 [#1] SMP PTI
  ...
  RIP: 0010:perf_prepare_sample+0x8f/0x510
  ...
  Call Trace:
   <IRQ>
   ? intel_pmu_drain_bts_buffer+0x194/0x230
   intel_pmu_drain_bts_buffer+0x160/0x230
   ? tick_nohz_irq_exit+0x31/0x40
   ? smp_call_function_single_interrupt+0x48/0xe0
   ? call_function_single_interrupt+0xf/0x20
   ? call_function_single_interrupt+0xa/0x20
   ? x86_schedule_events+0x1a0/0x2f0
   ? x86_pmu_commit_txn+0xb4/0x100
   ? find_busiest_group+0x47/0x5d0
   ? perf_event_set_state.part.42+0x12/0x50
   ? perf_mux_hrtimer_restart+0x40/0xb0
   intel_pmu_disable_event+0xae/0x100
   ? intel_pmu_disable_event+0xae/0x100
   x86_pmu_stop+0x7a/0xb0
   x86_pmu_del+0x57/0x120
   event_sched_out.isra.101+0x83/0x180
   group_sched_out.part.103+0x57/0xe0
   ctx_sched_out+0x188/0x240
   ctx_resched+0xa8/0xd0
   __perf_event_enable+0x193/0x1e0
   event_function+0x8e/0xc0
   remote_function+0x41/0x50
   flush_smp_call_function_queue+0x68/0x100
   generic_smp_call_function_single_interrupt+0x13/0x30
   smp_call_function_single_interrupt+0x3e/0xe0
   call_function_single_interrupt+0xf/0x20
   </IRQ>

The reason is that while event init code does several checks
for BTS events and prevents several unwanted config bits for
BTS event (like precise_ip), the PERF_EVENT_IOC_PERIOD allows
to create BTS event without those checks being done.

Following sequence will cause the crash:

If we create an 'almost' BTS event with precise_ip and callchains,
and it into a BTS event it will crash the perf_prepare_sample()
function because precise_ip events are expected to come
in with callchain data initialized, but that's not the
case for intel_pmu_drain_bts_buffer() caller.

Adding a check_period callback to be called before the period
is changed via PERF_EVENT_IOC_PERIOD. It will deny the change
if the event would become BTS. Plus adding also the limit_period
check as well.

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20190204123532.GA4794@krava
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-20 10:18:31 +01:00
..
2015-10-07 18:08:15 +01:00
2016-07-08 16:23:11 +02:00
2016-08-25 11:26:48 -04:00
2017-10-08 10:26:06 +02:00
2018-04-24 09:34:18 +02:00
2016-09-14 09:18:06 -06:00
2016-06-07 13:41:38 -06:00
2016-08-11 09:41:35 -06:00
2017-06-14 15:06:00 +02:00
2018-02-28 10:18:33 +01:00
2017-07-15 12:16:11 +02:00
2016-06-07 13:41:38 -06:00
2016-05-17 15:48:12 -04:00
2017-05-14 14:00:22 +02:00
2017-07-12 15:01:02 +02:00
2017-08-06 18:59:43 -07:00
2018-04-24 09:34:12 +02:00
2016-07-22 09:07:02 +02:00
2016-09-24 10:48:18 +02:00
2015-05-05 13:40:42 -06:00
2015-11-25 09:22:00 -07:00
2016-02-11 09:59:22 -05:00
2016-10-20 15:51:28 +11:00
2016-09-16 09:34:15 +01:00
2016-09-14 09:18:09 -06:00
2016-05-11 22:37:54 +02:00
2015-06-25 12:06:45 +02:00
2016-01-28 14:19:12 -08:00
2018-10-10 08:53:18 +02:00
2016-03-22 15:36:02 -07:00
2016-08-10 11:23:44 -04:00
2016-03-22 15:36:02 -07:00
2015-07-28 08:50:42 +01:00
2016-01-15 17:56:32 -08:00
2016-09-15 16:49:39 +02:00
2015-04-29 17:17:17 -05:00
2016-09-14 12:57:43 -07:00
2016-09-27 12:33:47 +02:00
2017-08-24 17:12:19 -07:00
2015-06-24 17:49:41 -07:00
2015-07-21 10:39:05 -07:00
2016-07-29 12:17:52 -07:00
2016-08-28 23:32:41 -04:00
2016-06-03 19:37:21 -04:00
2016-04-25 15:09:11 -04:00
2016-02-16 13:04:58 -05:00
2016-10-19 11:36:22 -06:00
2016-05-02 09:00:56 -05:00
2018-09-09 20:01:20 +02:00
2015-04-12 21:03:31 +02:00
2016-02-11 18:35:48 -08:00
2016-03-14 15:43:11 -04:00
2017-08-24 17:12:21 -07:00
2016-10-14 11:36:59 -07:00
2016-07-12 19:25:38 -07:00
2016-09-27 21:52:00 -04:00
2016-09-08 15:01:10 -07:00
2016-03-17 15:09:34 -07:00
2016-07-06 10:51:14 +01:00
2016-03-22 15:36:02 -07:00
2016-07-26 16:19:19 -07:00
2016-09-08 22:15:25 -07:00
2017-08-30 10:21:40 +02:00
2016-08-28 23:44:55 -04:00
2016-05-08 23:46:14 -04:00
2016-10-05 18:23:36 -04:00
2017-01-19 20:17:59 +01:00
2015-06-25 17:00:39 -07:00
2018-11-13 11:17:02 -08:00
2016-06-20 12:47:15 -07:00
2015-10-01 09:57:59 -07:00
2016-07-19 17:43:38 +03:00
2016-05-23 17:04:14 -07:00
2018-11-27 16:09:41 +01:00
2016-04-07 16:53:29 -04:00
2017-04-21 09:31:21 +02:00
2015-11-23 09:44:58 +01:00
2016-07-26 16:19:19 -07:00
2016-05-20 17:58:30 -07:00
2017-12-25 14:23:37 +01:00
2016-06-25 09:04:48 -07:00
2016-09-30 10:54:03 +02:00
2015-12-03 07:24:29 -08:00
2018-12-05 19:42:42 +01:00
2015-09-08 15:35:28 -07:00