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Jiri Olsa b1b0ca701b 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 10:20:52 +01:00
arch perf/x86: Add check_period PMU callback 2019-02-20 10:20:52 +01:00
block blk-mq: fix a hung issue when fsync 2019-02-20 10:20:44 +01:00
certs Replace magic for trusting the secondary keyring with #define 2018-09-09 19:55:54 +02:00
crypto crypto: aes_ti - disable interrupts while accessing S-box 2019-02-12 19:45:57 +01:00
Documentation dt-bindings: eeprom: at24: add "atmel,24c2048" compatible string 2019-02-20 10:20:44 +01:00
drivers Input: elan_i2c - add ACPI ID for touchpad in Lenovo V330-15ISK 2019-02-20 10:20:51 +01:00
firmware License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs cifs: Limit memory used by lock request calls to a page 2019-02-20 10:20:51 +01:00
include perf/x86: Add check_period PMU callback 2019-02-20 10:20:52 +01:00
init init: rename and re-order boot_cpu_state_init() 2018-08-15 18:12:48 +02:00
ipc ipc/sem.c: prevent queue.status tearing in semop 2018-09-05 09:26:30 +02:00
kernel perf/x86: Add check_period PMU callback 2019-02-20 10:20:52 +01:00
lib seq_buf: Make seq_buf_puts() null-terminate the buffer 2019-02-12 19:46:08 +01:00
mm percpu: convert spin_lock_irq to spin_lock_irqsave. 2019-02-12 19:46:05 +01:00
net net: create skb_gso_validate_mac_len() 2019-02-20 10:20:48 +01:00
samples samples: mei: use /dev/mei0 instead of /dev/mei 2019-02-15 08:09:12 +01:00
scripts scripts/gdb: fix lx-version string output 2019-02-12 19:46:10 +01:00
security smack: fix access permissions for keyring 2019-02-12 19:46:01 +01:00
sound ALSA: hda - Serialize codec registrations 2019-02-12 19:46:11 +01:00
tools perf test shell: Use a fallback to get the pathname in vfs_getname 2019-02-20 10:20:48 +01:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974) 2019-02-12 19:46:13 +01:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: rpm-pkg: keep spec file until make mrproper 2018-02-13 10:19:46 +01:00
.mailmap .mailmap: Add Maciej W. Rozycki's Imagination e-mail address 2017-11-10 12:16:15 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS MAINTAINERS: Add Sasha as a stable branch maintainer 2018-12-01 09:42:50 +01:00
Makefile Linux 4.14.101 2019-02-15 09:08:56 +01:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.