Jiri Olsa 74cbb754d6 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 10:25:45 +01:00
..
bpf	bpf: fix inner map masking to prevent oob under speculation	2019-01-31 08:14:41 +01:00
cgroup	cgroup: fix parsing empty mount option string	2019-02-12 19:47:17 +01:00
configs
debug	kdb: Don't back trace on a cpu that didn't round up	2019-02-12 19:47:19 +01:00
dma
events	perf/x86: Add check_period PMU callback	2019-02-20 10:25:45 +01:00
gcov
irq	genirq/affinity: Spread IRQs to all available NUMA nodes	2019-02-12 19:46:57 +01:00
livepatch
locking	futex: Handle early deadlock return correctly	2019-02-12 19:47:24 +01:00
power
printk
rcu
sched	cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM	2019-02-12 19:47:25 +01:00
time	timekeeping: Use proper seqcount initializer	2019-02-12 19:47:05 +01:00
trace	tracing: uprobes: Fix typo in pr_fmt string	2019-02-15 08:10:11 +01:00
.gitignore
acct.c
async.c
audit_fsnotify.c
audit_tree.c
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c	cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM	2019-02-12 19:47:25 +01:00
crash_core.c
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c	kernel/exit.c: release ptraced tasks before zap_pid_ns_processes	2019-02-06 17:30:14 +01:00
extable.c
fail_function.c
fork.c
freezer.c
futex_compat.c
futex.c	futex: Handle early deadlock return correctly	2019-02-12 19:47:24 +01:00
groups.c
hung_task.c	kernel/hung_task.c: force console verbose before panic	2019-02-12 19:47:19 +01:00
iomem.c
irq_work.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kernel/kcov.c: mark write_comp_data() as notrace	2019-02-12 19:47:20 +01:00
kexec_core.c
kexec_file.c
kexec_internal.h
kexec.c
kmod.c
kprobes.c
ksysfs.c
kthread.c
latencytop.c
Makefile
memremap.c
module_signing.c
module-internal.h
module.c	kobject: return error code if writing /sys/.../uevent fails	2019-02-12 19:47:06 +01:00
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid_namespace.c
pid.c	Fix failure path in alloc_pid()	2019-01-13 09:51:06 +01:00
profile.c
ptrace.c
range.c
reboot.c
relay.c
resource.c
rseq.c
seccomp.c
signal.c	signal: Better detection of synchronous signals	2019-02-15 08:10:11 +01:00
smp.c	cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM	2019-02-12 19:47:25 +01:00
smpboot.c
smpboot.h
softirq.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c
sysctl_binary.c
sysctl.c	proc/sysctl: fix return error for proc_doulongvec_minmax()	2019-02-12 19:47:19 +01:00
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watchdog_hld.c
watchdog.c
workqueue_internal.h
workqueue.c