Juri Lelli 740797ce3a sched/core: Fix PI boosting between RT and DEADLINE tasks ... 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		2020-06-28 17:01:20 +02:00
..
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2020-06-13 16:27:13 -07:00
cgroup	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
configs	compiler: remove CONFIG_OPTIMIZE_INLINING entirely	2020-04-07 10:43:42 -07:00
debug	maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault	2020-06-17 10:57:41 -07:00
dma	dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL	2020-06-15 08:35:30 +02:00
events	Merge branch 'akpm' (patches from Andrew)	2020-06-09 09:54:46 -07:00
gcov	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
irq	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
kcsan	kcsan: Support distinguishing volatile accesses	2020-06-11 20:04:01 +02:00
livepatch	livepatch: Make klp_apply_object_relocs static	2020-05-11 00:31:38 +02:00
locking	The X86 entry, exception and interrupt code rework	2020-06-13 10:05:47 -07:00
power	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
printk	One more printk change for 5.8	2020-06-12 12:13:36 -07:00
rcu	TTY/Serial driver updates for 5.8-rc1	2020-06-07 09:52:36 -07:00
sched	sched/core: Fix PI boosting between RT and DEADLINE tasks	2020-06-28 17:01:20 +02:00
time	The X86 entry, exception and interrupt code rework	2020-06-13 10:05:47 -07:00
trace	A few fixes and small cleanups for tracing:	2020-06-20 13:17:47 -07:00
.gitignore	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
acct.c	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
async.c
audit_fsnotify.c	fsnotify: use helpers to access data by data_type	2020-03-23 18:19:06 +01:00
audit_tree.c
audit_watch.c	\n	2020-04-06 08:58:42 -07:00
audit.c	audit/stable-5.8 PR 20200601	2020-06-02 17:13:37 -07:00
audit.h	audit: fix a net reference leak in audit_list_rules_send()	2020-04-22 15:23:10 -04:00
auditfilter.c	audit: fix a net reference leak in audit_list_rules_send()	2020-04-22 15:23:10 -04:00
auditsc.c	audit: add subj creds to NETFILTER_CFG record to	2020-05-20 18:09:19 -04:00
backtracetest.c
bounds.c
capability.c
compat.c	uaccess: Selectively open read or write user access	2020-05-01 12:35:21 +10:00
configs.c	proc: convert everything to "struct proc_ops"	2020-02-04 03:05:26 +00:00
context_tracking.c	context_tracking: Ensure that the critical path cannot be instrumented	2020-06-11 15:14:36 +02:00
cpu_pm.c	kernel/cpu_pm: Fix uninitted local in cpu_pm	2020-05-15 11:44:34 -07:00
cpu.c	The changes in this cycle are:	2020-06-03 13:06:42 -07:00
crash_core.c
crash_dump.c	crash_dump: Remove no longer used saved_max_pfn	2020-04-15 11:21:54 +02:00
cred.c	exec: Teach prepare_exec_creds how exec treats uids & gids	2020-05-20 14:44:21 -05:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
extable.c	kernel/extable.c: use address-of operator on section symbols	2020-04-07 10:43:42 -07:00
fail_function.c
fork.c	mmap locking API: convert nested write lock sites	2020-06-09 09:39:14 -07:00
freezer.c
futex.c	mmap locking API: use coccinelle to convert mmap_sem rwsem call sites	2020-06-09 09:39:14 -07:00
gen_kheaders.sh	kbuild: add variables for compression tools	2020-06-06 23:42:01 +09:00
groups.c	mm: remove the pgprot argument to __vmalloc	2020-06-02 10:59:11 -07:00
hung_task.c	kernel/hung_task.c: introduce sysctl to print all traces when a hung task is detected	2020-06-08 11:05:56 -07:00
iomem.c
irq_work.c	irq_work, smp: Allow irq_work on call_single_queue	2020-05-28 10:54:15 +02:00
jump_label.c
kallsyms.c	kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol()	2020-04-07 10:43:44 -07:00
kcmp.c	kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve	2020-03-25 10:04:01 -05:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kcov: check kcov_softirq in kcov_remote_stop()	2020-06-10 19:14:17 -07:00
kexec_core.c
kexec_elf.c
kexec_file.c	kexec_file: don't place kexec images on IORESOURCE_MEM_DRIVER_MANAGED	2020-06-04 19:06:23 -07:00
kexec_internal.h
kexec.c
kheaders.c
kmod.c	kmod: make request_module() return an error when autoloading is disabled	2020-04-10 15:36:22 -07:00
kprobes.c	kretprobe: Prevent triggering kretprobe from within kprobe_flush_task	2020-06-16 21:21:01 -04:00
ksysfs.c
kthread.c	maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault	2020-06-17 10:57:41 -07:00
latencytop.c	sysctl: pass kernel pointers to ->proc_handler	2020-04-27 02:07:40 -04:00
Makefile	Notifications over pipes + Keyring notifications	2020-06-13 09:56:21 -07:00
module_signature.c
module_signing.c
module-internal.h
module.c	module: move the set_fs hack for flush_icache_range to m68k	2020-06-08 11:05:58 -07:00
notifier.c	mm: remove vmalloc_sync_(un)mappings()	2020-06-02 10:59:12 -07:00
nsproxy.c	nsproxy: attach to namespaces via pidfds	2020-05-13 11:41:22 +02:00
padata.c	padata: add basic support for multithreaded jobs	2020-06-03 20:09:45 -07:00
panic.c	bug: Annotate WARN/BUG/stackfail as noinstr safe	2020-06-11 15:14:36 +02:00
params.c
pid_namespace.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next	2020-06-03 16:27:18 -07:00
pid.c	remove the no longer needed pid_alive() check in __task_pid_nr_ns()	2020-04-30 06:40:14 -05:00
profile.c	proc: convert everything to "struct proc_ops"	2020-02-04 03:05:26 +00:00
ptrace.c	ptrace: reintroduce usage of subjective credentials in ptrace_has_cap()	2020-01-18 13:51:39 +01:00
range.c
reboot.c	printk: Collapse shutdown types into a single dump reason	2020-05-30 10:34:03 -07:00
relay.c	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
resource.c	/dev/mem: Revoke mappings when a driver claims the region	2020-05-27 11:10:05 +02:00
rseq.c
scs.c	scs: Report SCS usage in bytes rather than number of entries	2020-06-04 16:14:56 +01:00
seccomp.c	sysctl: pass kernel pointers to ->proc_handler	2020-04-27 02:07:40 -04:00
signal.c	Merge branch 'work.set_fs-exec' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2020-06-01 16:21:46 -07:00
smp.c	The changes in this cycle are:	2020-06-03 13:06:42 -07:00
smpboot.c
smpboot.h
softirq.c	x86/entry: Clarify irq_{enter,exit}_rcu()	2020-06-11 15:15:24 +02:00
stackleak.c
stacktrace.c
stop_machine.c	stop_machine: Make stop_cpus() static	2020-01-17 10:19:21 +01:00
sys_ni.c
sys.c	Add additional LSM hooks for SafeSetID	2020-06-14 11:39:31 -07:00
sysctl_binary.c
sysctl-test.c	kunit: allow kunit tests to be loaded as a module	2020-01-09 16:42:29 -07:00
sysctl.c	kernel/sysctl.c: ignore out-of-range taint bits introduced via kernel.tainted	2020-06-08 11:05:56 -07:00
task_work.c	task_work_run: don't take ->pi_lock unconditionally	2020-03-02 14:06:33 -07:00
taskstats.c
test_kprobes.c
torture.c	CPU (hotplug) updates:	2020-03-30 18:06:39 -07:00
tracepoint.c
tsacct.c
ucount.c	ucount: Make sure ucounts in /proc/sys/user don't regress again	2020-04-07 21:51:27 +02:00
uid16.c
uid16.h
umh.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2020-05-15 13:48:59 -07:00
up.c	smp/up: Make smp_call_function_single() match SMP semantics	2020-02-07 15:34:12 +01:00
user_namespace.c	nsproxy: add struct nsset	2020-05-09 13:57:12 +02:00
user-return-notifier.c
user.c	user.c: make uidhash_table static	2020-06-04 19:06:24 -07:00
utsname_sysctl.c	sysctl: pass kernel pointers to ->proc_handler	2020-04-27 02:07:40 -04:00
utsname.c	nsproxy: add struct nsset	2020-05-09 13:57:12 +02:00
watch_queue.c	Notifications over pipes + Keyring notifications	2020-06-13 09:56:21 -07:00
watchdog_hld.c
watchdog.c	kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases	2020-06-08 11:05:56 -07:00
workqueue_internal.h
workqueue.c	maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault	2020-06-17 10:57:41 -07:00