Juri Lelli e852bdcce9 sched/core: Fix PI boosting between RT and DEADLINE tasks ... [ Upstream commit 740797ce3a124b7dd22b7fb832d87bc8fba1cf6f ] syzbot reported the following warning: WARNING: CPU: 1 PID: 6351 at kernel/sched/deadline.c:628 enqueue_task_dl+0x22da/0x38a0 kernel/sched/deadline.c:1504 At deadline.c:628 we have: 623 static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se) 624 { 625 struct dl_rq *dl_rq = dl_rq_of_se(dl_se); 626 struct rq *rq = rq_of_dl_rq(dl_rq); 627 628 WARN_ON(dl_se->dl_boosted); 629 WARN_ON(dl_time_before(rq_clock(rq), dl_se->deadline)); [...] } Which means that setup_new_dl_entity() has been called on a task currently boosted. This shouldn't happen though, as setup_new_dl_entity() is only called when the 'dynamic' deadline of the new entity is in the past w.r.t. rq_clock and boosted tasks shouldn't verify this condition. Digging through the PI code I noticed that what above might in fact happen if an RT tasks blocks on an rt_mutex hold by a DEADLINE task. In the first branch of boosting conditions we check only if a pi_task 'dynamic' deadline is earlier than mutex holder's and in this case we set mutex holder to be dl_boosted. However, since RT 'dynamic' deadlines are only initialized if such tasks get boosted at some point (or if they become DEADLINE of course), in general RT 'dynamic' deadlines are usually equal to 0 and this verifies the aforementioned condition. Fix it by checking that the potential donor task is actually (even if temporary because in turn boosted) running at DEADLINE priority before using its 'dynamic' deadline value. Fixes: 2d3d891d33 ("sched/deadline: Add SCHED_DEADLINE inheritance logic") Reported-by: syzbot+119ba87189432ead09b4@syzkaller.appspotmail.com Signed-off-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Tested-by: Daniel Wagner <dwagner@suse.de> Link: https://lkml.kernel.org/r/20181119153201.GB2119@localhost.localdomain Signed-off-by: Sasha Levin <sashal@kernel.org>		2020-06-30 23:17:13 -04:00
..
bpf	cpumap: Avoid warning when CONFIG_DEBUG_PER_CPU_MAPS is enabled	2020-05-02 17:25:53 +02:00
cgroup	Revert "cgroup: Add memory barriers to plug cgroup_rstat_updated() race window"	2020-06-07 13:17:53 +02:00
configs	kconfig: tinyconfig: remove stale stack protector fixups	2018-06-15 07:15:28 +09:00
debug	kgdb: Prevent infinite recursive entries to the debugger	2020-06-22 09:05:11 +02:00
dma	dma-debug: add a schedule point in debug_dma_dump_mappings()	2020-01-04 19:12:43 +01:00
events	perf: Add cond_resched() to task_function_call()	2020-06-22 09:05:08 +02:00
gcov	kernel/gcov/fs.c: gcov_seq_next() should increase position index	2020-04-29 16:31:12 +02:00
irq	genirq/irqdomain: Check pointer in irq_domain_alloc_irqs_hierarchy()	2020-04-17 10:48:41 +02:00
livepatch	livepatch: Nullify obj->mod in klp_module_coming()'s error path	2019-10-07 18:57:10 +02:00
locking	locktorture: Print ratio of acquisitions, not failures	2020-04-23 10:30:23 +02:00
power	PM: hibernate: Freeze kernel threads in software_resume()	2020-05-06 08:13:28 +02:00
printk	printk: fix exclusive_console replaying	2020-02-11 04:33:51 -08:00
rcu	rcu: Avoid data-race in rcu_gp_fqs_check_wake()	2020-02-11 04:33:55 -08:00
sched	sched/core: Fix PI boosting between RT and DEADLINE tasks	2020-06-30 23:17:13 -04:00
time	clocksource: Prevent double add_timer_on() for watchdog_timer	2020-02-11 04:34:18 -08:00
trace	blktrace: fix endianness for blk_log_remap()	2020-06-25 15:33:03 +02:00
.gitignore
acct.c	acct_on(): don't mess with freeze protection	2019-05-31 06:46:05 -07:00
async.c
audit.c	audit: fix a net reference leak in audit_list_rules_send()	2020-06-22 09:05:13 +02:00
audit.h	audit: fix a net reference leak in audit_list_rules_send()	2020-06-22 09:05:13 +02:00
audit_fsnotify.c	fsnotify: add fsnotify_add_inode_mark() wrappers	2018-05-18 14:58:22 +02:00
audit_tree.c	audit: Embed key into chunk	2019-12-13 08:51:11 +01:00
audit_watch.c	audit_get_nd(): don't unlock parent too early	2019-12-13 08:51:02 +01:00
auditfilter.c	audit: fix a net reference leak in audit_list_rules_send()	2020-06-22 09:05:13 +02:00
auditsc.c	audit: print empty EXECVE args	2019-12-01 09:17:17 +01:00
backtracetest.c
bounds.c	kbuild: fix kernel/bounds.c 'W=1' warning	2018-11-13 11:08:47 -08:00
capability.c	LSM: generalize flag passing to security_capable	2020-01-23 08:21:29 +01:00
compat.c	make 'user_access_begin()' do 'access_ok()'	2020-06-22 09:04:58 +02:00
configs.c
context_tracking.c
cpu.c	sched/core: Fix illegal RCU from offline CPUs	2020-06-22 09:05:14 +02:00
cpu_pm.c	kernel/cpu_pm: Fix uninitted local in cpu_pm	2020-06-22 09:05:28 +02:00
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	memcg: account security cred as well to kmemcg	2020-01-09 10:19:00 +01:00
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	kernel/elfcore.c: include proper prototypes	2019-10-11 18:21:23 +02:00
exec_domain.c	proc: introduce proc_create_single{,_data}	2018-05-16 07:23:35 +02:00
exit.c	exit: Move preemption fixup up, move blocking operations down	2020-06-22 09:05:14 +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,memcg: alloc_thread_stack_node needs to set tsk->stack	2020-01-27 14:50:58 +01:00
freezer.c	PM / reboot: Eliminate race between reboot and suspend	2018-08-06 12:35:20 +02:00
futex.c	futex: Unbreak futex hashing	2020-03-25 08:06:14 +01:00
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	irq_work: Do not raise an IPI when queueing work on the local CPU	2019-05-31 06:46:19 -07:00
jump_label.c	jump_label: move 'asm goto' support test to Kconfig	2019-06-04 08:02:34 +02:00
kallsyms.c	kallsyms: Don't let kallsyms_lookup_size_offset() fail on retrieving the first symbol	2019-09-21 07:17:02 +02:00
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: Allocate decrypted control pages for kdump if SME is enabled	2019-11-24 08:20:29 +01:00
kexec_file.c	treewide: Use array_size() in vzalloc()	2018-06-12 16:19:22 -07:00
kexec_internal.h
kmod.c	kmod: make request_module() return an error when autoloading is disabled	2020-04-17 10:48:52 +02:00
kprobes.c	kretprobe: Prevent triggering kretprobe from within kprobe_flush_task	2020-06-25 15:33:10 +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	y2038: futex: Move compat implementation into futex.c	2019-12-01 09:17:38 +01:00
memremap.c	mm/memory_hotplug: shrink zones when offlining memory	2020-01-29 16:43:27 +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	module: avoid setting info->name early in case we can fall back to info->mod->name	2020-02-24 08:34:49 +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	x86/mm: split vmalloc_sync_all()	2020-03-25 08:06:13 +01:00
nsproxy.c
padata.c	padata: purge get_cpu and reorder_via_wq from padata_do_serial	2020-05-27 17:37:36 +02:00
panic.c	kernel/panic.c: do not append newline to the stack protector panic string	2019-12-01 09:17:10 +01:00
params.c
pid.c	Fix failure path in alloc_pid()	2019-01-13 09:51:06 +01:00
pid_namespace.c	signal/pid_namespace: Fix reboot_pid_ns to use send_sig not force_sig	2019-07-26 09:14:01 +02:00
profile.c
ptrace.c	ptrace: reintroduce usage of subjective credentials in ptrace_has_cap()	2020-01-23 08:21:29 +01:00
range.c
reboot.c	PM / reboot: Eliminate race between reboot and suspend	2018-08-06 12:35:20 +02:00
relay.c	kernel/relay.c: handle alloc_percpu returning NULL in relay_open	2020-06-07 13:17:54 +02:00
resource.c	resource: fix locking in find_next_iomem_res()	2019-09-16 08:22:20 +02:00
rseq.c	rseq: uapi: Declare rseq_cs field as union, update includes	2018-07-10 22:18:52 +02:00
seccomp.c	LSM: generalize flag passing to security_capable	2020-01-23 08:21:29 +01:00
signal.c	signal: Extend exec_id to 64bits	2020-04-17 10:48:47 +02:00
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: prctl: fix false positive in validate_prctl_map()	2019-06-15 11:54:01 +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: make drop_caches write-only	2020-01-04 19:13:17 +01:00
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	taskstats: fix data-race	2020-01-09 10:18:59 +01:00
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	coredump: fix crash when umh is disabled	2020-05-14 07:57:21 +02:00
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
utsname_sysctl.c	sys: don't hold uts_sem while accessing userspace memory	2018-08-11 02:05:53 -05:00
watchdog.c	watchdog/softlockup: Enforce that timestamp is valid on boot	2020-02-24 08:34:49 +01:00
watchdog_hld.c	watchdog: Mark watchdog touch functions as notrace	2018-08-30 12:56:40 +02:00
workqueue.c	workqueue: don't use wq_select_unbound_cpu() for bound works	2020-03-18 07:14:20 +01:00
workqueue_internal.h	workqueue: Set worker->desc to workqueue name by default	2018-05-18 08:47:13 -07:00