linux-stable/kernel
luca abeni 245a94a0ff sched/deadline: Correctly handle active 0-lag timers
commit 1b02cd6a2d upstream.

syzbot reported the following warning:

   [ ] WARNING: CPU: 4 PID: 17089 at kernel/sched/deadline.c:255 task_non_contending+0xae0/0x1950

line 255 of deadline.c is:

	WARN_ON(hrtimer_active(&dl_se->inactive_timer));

in task_non_contending().

Unfortunately, in some cases (for example, a deadline task
continuosly blocking and waking immediately) it can happen that
a task blocks (and task_non_contending() is called) while the
0-lag timer is still active.

In this case, the safest thing to do is to immediately decrease
the running bandwidth of the task, without trying to re-arm the 0-lag timer.

Signed-off-by: luca abeni <luca.abeni@santannapisa.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: chengjian (D) <cj.chengjian@huawei.com>
Link: https://lkml.kernel.org/r/20190325131530.34706-1-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-02 09:58:56 +02:00
..
bpf bpf: fix use after free in bpf_evict_inode 2019-04-20 09:16:05 +02:00
cgroup cgroup/pids: turn cgroup_subsys->free() into cgroup_subsys->release() to fix the accounting 2019-04-05 22:33:13 +02:00
configs kconfig: tinyconfig: remove stale stack protector fixups 2018-06-15 07:15:28 +09:00
debug kdb: Don't back trace on a cpu that didn't round up 2019-02-12 19:47:19 +01:00
dma dma-direct: do not include SME mask in the DMA supported check 2019-01-13 09:51:05 +01:00
events perf/core: Restore mmap record type correctly 2019-04-20 09:15:54 +02:00
gcov gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT 2018-06-08 18:56:02 +09:00
irq genirq: Initialize request_mutex if CONFIG_SPARSE_IRQ=n 2019-04-17 08:38:52 +02:00
livepatch Merge branch 'for-4.19/upstream' into for-linus 2018-08-20 18:33:50 +02:00
locking Revert "locking/lockdep: Add debug_locks check in __lock_downgrade()" 2019-04-27 09:36:41 +02:00
power Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2018-10-12 12:35:02 +02:00
printk printk: Fix panic caused by passing log_buf_len to command line 2018-11-13 11:08:48 -08:00
rcu kprobes: Prohibit probing on RCU debug routine 2019-04-05 22:33:08 +02:00
sched sched/deadline: Correctly handle active 0-lag timers 2019-05-02 09:58:56 +02:00
time timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze() 2019-04-27 09:36:38 +02:00
trace trace: Fix preempt_enable_no_resched() abuse 2019-05-02 09:58:54 +02:00
.gitignore
acct.c
async.c
audit.c audit: use ktime_get_coarse_real_ts64() for timestamps 2018-07-17 14:45:08 -04:00
audit.h
audit_fsnotify.c fsnotify: add fsnotify_add_inode_mark() wrappers 2018-05-18 14:58:22 +02:00
audit_tree.c \n 2018-08-17 09:41:28 -07:00
audit_watch.c audit: fix use-after-free in audit_add_watch 2018-07-18 11:43:36 -04:00
auditfilter.c audit: rename FILTER_TYPE to FILTER_EXCLUDE 2018-06-19 10:39:54 -04:00
auditsc.c audit/stable-4.18 PR 20180814 2018-08-15 10:46:54 -07:00
backtracetest.c
bounds.c kbuild: fix kernel/bounds.c 'W=1' warning 2018-11-13 11:08:47 -08:00
capability.c
compat.c time: Enable get/put_compat_itimerspec64 always 2018-06-24 14:39:47 +02:00
configs.c
context_tracking.c
cpu.c cpu/hotplug: Mute hotplug lockdep during init 2019-04-05 22:33:14 +02:00
cpu_pm.c
crash_core.c kernel/crash_core.c: print timestamp using time64_t 2018-08-22 10:52:47 -07:00
crash_dump.c
cred.c
delayacct.c delayacct: Use raw_spinlocks 2018-04-27 14:34:51 +02:00
dma.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
elfcore.c
exec_domain.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
exit.c cgroup/pids: turn cgroup_subsys->free() into cgroup_subsys->release() to fix the accounting 2019-04-05 22:33:13 +02:00
extable.c
fail_function.c bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe 2018-06-21 12:33:19 +02:00
fork.c fork: record start_time late 2019-01-13 09:51:04 +01:00
freezer.c PM / reboot: Eliminate race between reboot and suspend 2018-08-06 12:35:20 +02:00
futex.c futex: Ensure that futex address is aligned in handle_futex_death() 2019-03-27 14:14:40 +09:00
futex_compat.c
groups.c
hung_task.c kernel: hung_task.c: disable on suspend 2019-04-20 09:16:02 +02:00
iomem.c memremap: split devm_memremap_pages() and memremap() infrastructure 2018-05-15 23:08:33 -07:00
irq_work.c
jump_label.c jump_label: Fix typo in warning message 2018-09-10 10:15:48 +02:00
kallsyms.c kallsyms, x86: Export addresses of PTI entry trampolines 2018-08-14 19:12:29 -03:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt kconfig: include kernel/Kconfig.preempt from init/Kconfig 2018-08-02 08:06:54 +09:00
kcov.c kernel/kcov.c: mark write_comp_data() as notrace 2019-02-12 19:47:20 +01:00
kexec.c kexec: add call to LSM hook in original kexec_load syscall 2018-07-16 12:31:57 -07:00
kexec_core.c kexec: yield to scheduler when loading kimage segments 2018-06-15 07:55:24 +09:00
kexec_file.c treewide: Use array_size() in vzalloc() 2018-06-12 16:19:22 -07:00
kexec_internal.h
kmod.c
kprobes.c kprobes: Fix error check when reusing optimized probes 2019-04-27 09:36:37 +02:00
ksysfs.c
kthread.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-13 11:25:07 -07:00
latencytop.c
Makefile kbuild: move bin2c back to scripts/ from scripts/basic/ 2018-07-18 01:18:05 +09:00
memremap.c mm, devm_memremap_pages: add MEMORY_DEVICE_PRIVATE support 2019-01-13 09:51:04 +01:00
module-internal.h modsign: log module name in the event of an error 2018-07-02 11:36:17 +02:00
module.c kobject: return error code if writing /sys/.../uevent fails 2019-02-12 19:47:06 +01:00
module_signing.c modsign: log module name in the event of an error 2018-07-02 11:36:17 +02:00
notifier.c
nsproxy.c
padata.c
panic.c panic: avoid deadlocks in re-entrant console drivers 2018-12-29 13:37:57 +01:00
params.c kernel/params.c: downgrade warning for unsafe parameters 2018-04-11 10:28:37 -07:00
pid.c Fix failure path in alloc_pid() 2019-01-13 09:51:06 +01:00
pid_namespace.c
profile.c
ptrace.c ptrace: Remove unused ptrace_may_access_sched() and MODE_IBRS 2018-12-05 19:32:03 +01:00
range.c
reboot.c PM / reboot: Eliminate race between reboot and suspend 2018-08-06 12:35:20 +02:00
relay.c relay: check return of create_buf_file() properly 2019-03-13 14:02:35 -07:00
resource.c libnvdimm for 4.18 2018-06-08 17:21:52 -07:00
rseq.c rseq: uapi: Declare rseq_cs field as union, update includes 2018-07-10 22:18:52 +02:00
seccomp.c audit/stable-4.18 PR 20180605 2018-06-06 16:34:00 -07:00
signal.c signal: Restore the stop PTRACE_EVENT_EXIT 2019-02-20 10:25:48 +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: Remove cpumask from the API 2018-07-03 09:20:44 +02:00
smpboot.h
softirq.c nohz: Fix missing tick reprogram when interrupting an inline softirq 2018-08-03 15:52:10 +02:00
stacktrace.c
stop_machine.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-13 11:25:07 -07:00
sys.c kernel/sys.c: remove duplicated include 2018-09-20 22:01:11 +02:00
sys_ni.c Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-10 10:17:09 -07:00
sysctl.c kernel/sysctl.c: fix out-of-bounds access when setting file-max 2019-04-27 09:36:41 +02:00
sysctl_binary.c staging: irda: remove remaining remants of irda code removal 2018-04-16 11:26:49 +02:00
task_work.c
taskstats.c
test_kprobes.c kprobes: Remove jprobe API implementation 2018-06-21 12:33:05 +02:00
torture.c torture: Keep old-school dmesg format 2018-06-25 11:30:10 -07:00
tracepoint.c tracepoint: Fix tracepoint array element size mismatch 2018-10-17 15:35:29 -04:00
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c umh: fix race condition 2018-06-07 16:56:28 -04:00
up.c
user-return-notifier.c
user.c userns: use irqsave variant of refcount_dec_and_lock() 2018-08-22 10:52:47 -07:00
user_namespace.c userns: also map extents in the reverse map to kernel IDs 2018-11-13 11:09:00 -08:00
utsname.c uts: create "struct uts_namespace" from kmem_cache 2018-04-11 10:28:35 -07:00
utsname_sysctl.c sys: don't hold uts_sem while accessing userspace memory 2018-08-11 02:05:53 -05:00
watchdog.c watchdog: Respect watchdog cpumask on CPU hotplug 2019-04-03 06:26:29 +02:00
watchdog_hld.c watchdog: Mark watchdog touch functions as notrace 2018-08-30 12:56:40 +02:00
workqueue.c workqueue: Try to catch flush_work() without INIT_WORK(). 2019-05-02 09:58:56 +02:00
workqueue_internal.h workqueue: Set worker->desc to workqueue name by default 2018-05-18 08:47:13 -07:00