Sergey Senozhatsky 656d61ce96 lib/ratelimit.c: use deferred printk() version ... printk_ratelimit() invokes ___ratelimit() which may invoke a normal printk() (pr_warn() in this particular case) to warn about suppressed output. Given that printk_ratelimit() may be called from anywhere, that pr_warn() is dangerous - it may end up deadlocking the system. Fix ___ratelimit() by using deferred printk(). Sasha reported the following lockdep error: : Unregister pv shared memory for cpu 8 : select_fallback_rq: 3 callbacks suppressed : process 8583 (trinity-c78) no longer affine to cpu8 : : ====================================================== : WARNING: possible circular locking dependency detected : 4.14.0-rc2-next-20170927+ #252 Not tainted : ------------------------------------------------------ : migration/8/62 is trying to acquire lock: : (&port_lock_key){-.-.}, at: serial8250_console_write() : : but task is already holding lock: : (&rq->lock){-.-.}, at: sched_cpu_dying() : : which lock already depends on the new lock. : : : the existing dependency chain (in reverse order) is: : : -> #3 (&rq->lock){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock() : task_fork_fair() : sched_fork() : copy_process.part.31() : _do_fork() : kernel_thread() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #2 (&p->pi_lock){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : try_to_wake_up() : default_wake_function() : woken_wake_function() : __wake_up_common() : __wake_up_common_lock() : __wake_up() : tty_wakeup() : tty_port_default_wakeup() : tty_port_tty_wakeup() : uart_write_wakeup() : serial8250_tx_chars() : serial8250_handle_irq.part.25() : serial8250_default_handle_irq() : serial8250_interrupt() : __handle_irq_event_percpu() : handle_irq_event_percpu() : handle_irq_event() : handle_level_irq() : handle_irq() : do_IRQ() : ret_from_intr() : native_safe_halt() : default_idle() : arch_cpu_idle() : default_idle_call() : do_idle() : cpu_startup_entry() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #1 (&tty->write_wait){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : __wake_up_common_lock() : __wake_up() : tty_wakeup() : tty_port_default_wakeup() : tty_port_tty_wakeup() : uart_write_wakeup() : serial8250_tx_chars() : serial8250_handle_irq.part.25() : serial8250_default_handle_irq() : serial8250_interrupt() : __handle_irq_event_percpu() : handle_irq_event_percpu() : handle_irq_event() : handle_level_irq() : handle_irq() : do_IRQ() : ret_from_intr() : native_safe_halt() : default_idle() : arch_cpu_idle() : default_idle_call() : do_idle() : cpu_startup_entry() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #0 (&port_lock_key){-.-.}: : check_prev_add() : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : serial8250_console_write() : univ8250_console_write() : console_unlock() : vprintk_emit() : vprintk_default() : vprintk_func() : printk() : ___ratelimit() : __printk_ratelimit() : select_fallback_rq() : sched_cpu_dying() : cpuhp_invoke_callback() : take_cpu_down() : multi_cpu_stop() : cpu_stopper_thread() : smpboot_thread_fn() : kthread() : ret_from_fork() : : other info that might help us debug this: : : Chain exists of: : &port_lock_key --> &p->pi_lock --> &rq->lock : : Possible unsafe locking scenario: : : CPU0 CPU1 : ---- ---- : lock(&rq->lock); : lock(&p->pi_lock); : lock(&rq->lock); : lock(&port_lock_key); : : *** DEADLOCK *** : : 4 locks held by migration/8/62: : #0: (&p->pi_lock){-.-.}, at: sched_cpu_dying() : #1: (&rq->lock){-.-.}, at: sched_cpu_dying() : #2: (printk_ratelimit_state.lock){....}, at: ___ratelimit() : #3: (console_lock){+.+.}, at: vprintk_emit() : : stack backtrace: : CPU: 8 PID: 62 Comm: migration/8 Not tainted 4.14.0-rc2-next-20170927+ #252 : Call Trace: : dump_stack() : print_circular_bug() : check_prev_add() : ? add_lock_to_list.isra.26() : ? check_usage() : ? kvm_clock_read() : ? kvm_sched_clock_read() : ? sched_clock() : ? check_preemption_disabled() : __lock_acquire() : ? __lock_acquire() : ? add_lock_to_list.isra.26() : ? debug_check_no_locks_freed() : ? memcpy() : lock_acquire() : ? serial8250_console_write() : _raw_spin_lock_irqsave() : ? serial8250_console_write() : serial8250_console_write() : ? serial8250_start_tx() : ? lock_acquire() : ? memcpy() : univ8250_console_write() : console_unlock() : ? __down_trylock_console_sem() : vprintk_emit() : vprintk_default() : vprintk_func() : printk() : ? show_regs_print_info() : ? lock_acquire() : ___ratelimit() : __printk_ratelimit() : select_fallback_rq() : sched_cpu_dying() : ? sched_cpu_starting() : ? rcutree_dying_cpu() : ? sched_cpu_starting() : cpuhp_invoke_callback() : ? cpu_disable_common() : take_cpu_down() : ? trace_hardirqs_off_caller() : ? cpuhp_invoke_callback() : multi_cpu_stop() : ? __this_cpu_preempt_check() : ? cpu_stop_queue_work() : cpu_stopper_thread() : ? cpu_stop_create() : smpboot_thread_fn() : ? sort_range() : ? schedule() : ? __kthread_parkme() : kthread() : ? sort_range() : ? kthread_create_on_node() : ret_from_fork() : process 9121 (trinity-c78) no longer affine to cpu8 : smpboot: CPU 8 is now offline Link: http://lkml.kernel.org/r/20170928120405.18273-1-sergey.senozhatsky@gmail.com Fixes: 6b1d174b0c ("ratelimit: extend to print suppressed messages on release") Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: Sasha Levin <levinsasha928@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Borislav Petkov <bp@suse.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2017-10-03 17:54:26 -07:00
..
842	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2016-03-17 21:38:27 -07:00
fonts	lib/fonts/Kconfig: keep non-Sparc fonts listed together	2017-02-27 18:43:46 -08:00
lz4	lib/lz4: make arrays static const, reduces object code size	2017-10-03 17:54:25 -07:00
lzo
mpi	Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2017-08-22 14:53:32 +08:00
raid6	Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md	2017-09-07 12:41:48 -07:00
reed_solomon
xz
zlib_deflate
zlib_inflate	lib/zlib_inflate/inftrees.c: fix potential buffer overflow	2017-05-08 17:15:12 -07:00
zstd	lib: Add zstd modules	2017-08-15 09:02:08 -07:00
.gitignore
argv_split.c
asn1_decoder.c	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2016-05-17 09:33:39 -07:00
assoc_array.c	assoc_array: fix path to assoc_array documentation	2017-08-30 16:40:11 -06:00
atomic64_test.c	lib/atomic64_test.c: add a test that atomic64_inc_not_zero() returns an int	2017-07-14 15:05:13 -07:00
atomic64.c	locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()	2016-06-16 10:48:32 +02:00
audit.c
bcd.c
bch.c
bitmap.c	lib/bitmap.c: make bitmap_parselist() thread-safe and much faster	2017-09-08 18:26:49 -07:00
bitrev.c
bsearch.c	lib/bsearch.c: micro-optimize pivot position calculation	2017-07-10 16:32:35 -07:00
btree.c
bug.c	debug: Add _ONCE() logic to report_bug()	2017-03-30 09:37:20 +02:00
build_OID_registry
bust_spinlocks.c
chacha20.c	random: replace non-blocking pool with a Chacha20-based CRNG	2016-07-03 00:57:23 -04:00
check_signature.c
checksum.c	ipv4: Update parameters for csum_tcpudp_magic to their original types	2016-03-13 23:55:13 -04:00
clz_ctz.c
clz_tab.c
cmdline.c	lib/cmdline.c: remove meaningless comment	2017-09-08 18:26:49 -07:00
compat_audit.c
cordic.c
cpu_rmap.c
cpumask.c	cpumask: make cpumask_next() out-of-line	2017-09-08 18:26:51 -07:00
crc4.c	lib: Add crc4 module	2017-06-09 11:52:07 +02:00
crc7.c
crc8.c
crc16.c
crc32.c	lib: add module support to crc32 tests	2017-02-24 17:46:57 -08:00
crc32defs.h
crc32test.c	lib: add module support to crc32 tests	2017-02-24 17:46:57 -08:00
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
ctype.c
debug_info.c
debug_locks.c
debugobjects.c	debugobjects: Make kmemleak ignore debug objects	2017-08-14 16:51:01 +02:00
dec_and_lock.c
decompress_bunzip2.c
decompress_inflate.c
decompress_unlz4.c	lib/decompress_unlz4: change module to work with new LZ4 module version	2017-02-24 17:46:57 -08:00
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
decompress.c
devres.c	devres: fix devm_ioremap_*() offset parameter kerneldoc description	2017-04-24 13:53:13 -05:00
digsig.c	KEYS: Differentiate uses of rcu_dereference_key() and user_key_payload()	2017-03-02 10:09:00 +11:00
div64.c
dma-debug.c	dmaengine updates for 4.12-rc1	2017-05-09 15:40:28 -07:00
dma-noop.c	dma: Take into account dma_pfn_offset	2017-06-28 06:55:01 -07:00
dma-virt.c	dma-virt: remove dma_supported and mapping_error methods	2017-06-28 06:54:41 -07:00
dump_stack.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
dynamic_debug.c	dynamic_debug: add jump label support	2016-08-04 08:50:07 -04:00
dynamic_queue_limits.c
earlycpio.c	lib/cpio: Make find_cpio_data()'s offset arg optional	2016-06-08 11:04:19 +02:00
errseq.c	errseq: rename __errseq_set to errseq_set	2017-07-26 12:24:36 -04:00
extable.c	lib/extable.c: use bsearch() library function in search_extable()	2017-07-10 16:32:35 -07:00
fault-inject.c	fault-inject: fix wrong should_fail() decision in task context	2017-08-10 15:54:06 -07:00
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_bit.c	lib/find_bit.c: micro-optimise find_next_*_bit	2017-02-24 17:46:57 -08:00
flex_array.c
flex_proportions.c	percpu_counter: Rename __percpu_counter_add to percpu_counter_add_batch	2017-06-20 15:42:32 -04:00
gcd.c	lib/GCD.c: use binary GCD algorithm instead of Euclidean	2016-05-20 17:58:30 -07:00
gen_crc32table.c
genalloc.c	lib/genalloc.c: start search from start of chunk	2016-10-27 18:43:43 -07:00
glob.c	lib: add module support to glob tests	2017-02-24 17:46:57 -08:00
globtest.c	lib: add module support to glob tests	2017-02-24 17:46:57 -08:00
hexdump.c	lib/hexdump.c: return -EINVAL in case of error in hex2bin()	2017-09-08 18:26:49 -07:00
hweight.c	x86/hweight: Get rid of the special calling convention	2016-06-08 15:01:02 +02:00
idr.c	lib/idr.c: fix comment for idr_replace()	2017-10-03 17:54:25 -07:00
inflate.c
int_sqrt.c
interval_tree_test.c	lib/interval_tree: fast overlap detection	2017-09-08 18:26:49 -07:00
interval_tree.c
iomap_copy.c	lib/iomap_copy.c: add __ioread32_copy()	2016-01-20 17:09:18 -08:00
iomap.c
iommu-common.c
iommu-helper.c	lib/iommu-helper: skip to next segment	2016-08-02 19:35:07 -04:00
ioremap.c	mm: convert generic code to 5-level paging	2017-03-09 11:48:47 -08:00
iov_iter.c	iov_iter: fix page_copy_sane for compound pages	2017-09-20 23:27:48 -04:00
irq_poll.c	This adds a new gcc plugin named "latent_entropy". It is designed to	2016-10-15 10:03:15 -07:00
irq_regs.c
is_single_threaded.c	sched/headers: Prepare to move 'init_task' and 'init_thread_union' from <linux/sched.h> to <linux/sched/task.h>	2017-03-02 08:42:38 +01:00
jedec_ddr_data.c
kasprintf.c	lib/kasprintf.c: add sanity check to kvasprintf	2016-01-16 11:17:27 -08:00
Kconfig	Merge branch 'zstd-minimal' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs	2017-09-14 17:30:49 -07:00
Kconfig.debug	parisc: Fix too large frame size warnings	2017-09-22 19:46:07 +02:00
Kconfig.kasan	mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB	2016-07-28 16:07:41 -07:00
Kconfig.kgdb	lib: update location of kgdb documentation	2017-05-16 08:44:22 -03:00
Kconfig.kmemcheck
Kconfig.ubsan	Kconfig: lib/Kconfig.ubsan fix reference to ubsan documentation	2016-12-14 16:04:08 -08:00
kfifo.c
klist.c	klist: fix starting point removed bug in klist iterators	2016-02-07 22:18:47 -08:00
kobject_uevent.c	driver core: suppress sending MODALIAS in UNBIND uevents	2017-09-18 16:48:33 +02:00
kobject.c	kobject: Export kobject_get_unless_zero()	2017-03-22 20:11:35 -06:00
kstrtox.c	lib/kstrtox.c: use "unsigned int" more	2017-07-10 16:32:34 -07:00
kstrtox.h
lcm.c
libcrc32c.c	crypto: Work around deallocated stack frame reference gcc bug on sparc.	2017-06-08 17:36:03 +08:00
list_debug.c	bug: switch data corruption check to __must_check	2017-02-24 17:46:56 -08:00
list_sort.c	lib: add module support to linked list sorting tests	2017-05-08 17:15:10 -07:00
llist.c
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-rtmutex.h	locking/selftest: Add RT-mutex support	2017-06-08 10:35:50 +02:00
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c	locking/lockdep/selftests: Fix mixed read-write ABBA tests	2017-08-29 15:15:17 +02:00
lockref.c	locking/core: Remove cpu_relax_lowlatency() users	2016-11-16 10:15:10 +01:00
lru_cache.c
Makefile	Merge branch 'zstd-minimal' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs	2017-09-14 17:30:49 -07:00
memory-notifier-error-inject.c
memweight.c
net_utils.c
netdev-notifier-error-inject.c	net: Add support for CHANGEUPPER notifier error injection	2015-12-03 11:49:23 -05:00
nlattr.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next	2017-09-03 17:08:42 -07:00
nmi_backtrace.c	printk: Use the main logbuf in NMI when logbuf_lock is available	2017-05-19 14:42:19 +02:00
nodemask.c	include/linux/nodemask.h: create next_node_in() helper	2016-05-19 19:12:14 -07:00
notifier-error-inject.c
notifier-error-inject.h
of-reconfig-notifier-error-inject.c
oid_registry.c	lib/oid_registry.c: X.509: fix the buffer overflow in the utility function for OID string	2017-09-08 18:26:49 -07:00
once.c
parman.c	lib: Introduce priority array area manager	2017-02-03 16:35:42 -05:00
parser.c	parser: add u64 number parser	2016-12-06 10:17:03 +02:00
pci_iomap.c
percpu_counter.c	writeback: rework wb_[dec|inc]_stat family of functions	2017-07-12 16:26:05 -07:00
percpu_ida.c	sched/headers: Prepare to remove the <linux/gfp.h> include from <linux/sched.h>	2017-03-02 08:42:34 +01:00
percpu_test.c
percpu-refcount.c	percpu-refcount: support synchronous switch to atomic mode.	2017-03-22 19:18:43 -07:00
plist.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h>	2017-03-02 08:42:27 +01:00
pm-notifier-error-inject.c
prime_numbers.c	lib/prime_numbers: Suppress warn on kmalloc failure	2017-01-23 09:17:12 +01:00
radix-tree.c	radix-tree: must check __radix_tree_preload() return value	2017-09-08 18:26:49 -07:00
random32.c	This adds a new gcc plugin named "latent_entropy". It is designed to	2016-10-15 10:03:15 -07:00
ratelimit.c	lib/ratelimit.c: use deferred printk() version	2017-10-03 17:54:26 -07:00
rational.c
rbtree_test.c	lib/rbtree_test.c: support rb_root_cached	2017-09-08 18:26:48 -07:00
rbtree.c	rbtree: add some additional comments for rebalancing cases	2017-09-08 18:26:48 -07:00
reciprocal_div.c
refcount.c	locking/refcount: Create unchecked atomic_t implementation	2017-06-28 18:54:46 +02:00
rhashtable.c	rhashtable: Documentation tweak	2017-09-19 15:18:33 -07:00
sbitmap.c	sbitmap: add sbitmap_get_shallow() operation	2017-04-14 14:06:52 -06:00
scatterlist.c	scatterlist: add sg_zero_buffer() helper	2017-06-15 14:30:14 +02:00
seq_buf.c	tracing: Use seq_buf_used() in seq_buf_to_user() instead of len	2015-12-23 14:27:20 -05:00
sg_pool.c	lib: scatterlist: move SG pool code from SCSI driver to lib/sg_pool.c	2016-04-15 16:53:14 -04:00
sg_split.c
sha1.c
show_mem.c	lib/show_mem.c: teach show_mem to work with the given nodemask	2017-02-22 16:41:30 -08:00
siphash.c	siphash: implement HalfSipHash1-3 for hash tables	2017-01-09 13:58:57 -05:00
smp_processor_id.c	sched/core: Enable might_sleep() and smp_processor_id() checks early	2017-05-23 10:01:38 +02:00
sort.c	lib: add CONFIG_TEST_SORT to enable self-test of sort()	2017-02-24 17:46:57 -08:00
stackdepot.c	lib/stackdepot: export save/fetch stack for drivers	2016-11-11 08:12:37 -08:00
stmp_device.c
string_helpers.c	mm: treewide: remove GFP_TEMPORARY allocation flag	2017-09-13 18:53:16 -07:00
string.c	lib/string.c: check for kmalloc() failure	2017-09-08 18:26:49 -07:00
strncpy_from_user.c	lib: harden strncpy_from_user	2016-10-11 15:06:30 -07:00
strnlen_user.c	kill strlen_user()	2017-05-15 23:40:22 -04:00
swiotlb.c	swiotlb: Add warnings for use of bounce buffers with SME	2017-07-18 11:38:03 +02:00
syscall.c	lib/syscall: Clear return values when no stack	2017-03-24 07:43:35 +01:00
test_bitmap.c	lib/test_bitmap.c: use ULL suffix for 64-bit constants	2017-09-13 18:53:15 -07:00
test_bpf.c	bpf: add BPF_J{LT,LE,SLT,SLE} instructions	2017-08-09 16:53:56 -07:00
test_debug_virtual.c	lib: add test module for CONFIG_DEBUG_VIRTUAL	2017-09-08 18:26:49 -07:00
test_firmware.c	test_firmware: add batched firmware tests	2017-08-10 13:58:41 -07:00
test_hash.c	lib/test_hash.c: fix warning in preprocessor symbol evaluation	2016-09-01 17:52:01 -07:00
test_hexdump.c	test_hexdump: print statistics at the end	2016-01-20 17:09:18 -08:00
test_kasan.c	kasan: report only the first error by default	2017-03-31 17:13:30 -07:00
test_kmod.c	test_kmod: flip INT checks to be consistent	2017-09-08 18:26:50 -07:00
test_list_sort.c	lib: add module support to linked list sorting tests	2017-05-08 17:15:10 -07:00
test_module.c
test_parman.c	lib: fix spelling mistake: "actualy" -> "actually"	2017-02-26 11:03:38 -05:00
test_printf.c	mm, printk: introduce new format string for flags	2016-03-15 16:55:16 -07:00
test_rhashtable.c	lib: test_rhashtable: Fix KASAN warning	2017-07-25 12:35:23 -07:00
test_siphash.c	siphash: implement HalfSipHash1-3 for hash tables	2017-01-09 13:58:57 -05:00
test_sort.c	Revert "lib/test_sort.c: make it explicitly non-modular"	2017-05-08 17:15:10 -07:00
test_static_key_base.c
test_static_keys.c	locking/static_keys: Avoid nested functions	2016-02-09 10:27:29 +01:00
test_sysctl.c	test_sysctl: test against int proc_dointvec() array support	2017-07-12 16:26:00 -07:00
test_user_copy.c	lib: remove check for AVR32 arch in test_user_copy	2017-05-01 09:36:30 +02:00
test_uuid.c	uuid: fix incorrect uuid_equal conversion in test_uuid_test	2017-07-21 09:38:30 +02:00
test-kstrtox.c
test-string_helpers.c	lib/test-string_helpers.c: fix and improve string_get_size() tests	2016-02-03 08:28:43 -08:00
textsearch.c
timerqueue.c	timerqueue: Use rb_entry_safe() instead of open-coding it	2017-01-20 08:03:42 +01:00
ts_bm.c
ts_fsm.c
ts_kmp.c
ubsan.c	UBSAN: fix typo in format string	2016-08-02 17:31:41 -04:00
ubsan.h	UBSAN: run-time undefined behavior sanity checker	2016-01-20 17:09:18 -08:00
ucs2_string.c	lib/ucs2_string: Speed up ucs2_utf8size()	2016-09-09 16:08:46 +01:00
usercopy.c	copy_{from,to}_user(): move kasan checks and might_fault() out-of-line	2017-06-29 22:21:20 -04:00
uuid.c	uuid: hoist uuid_is_null() helper from libnvdimm	2017-06-05 16:59:05 +02:00
vsprintf.c	DeviceTree for 4.13:	2017-07-07 10:37:54 -07:00
win_minmax.c	lib/win_minmax: windowed min or max estimator	2016-09-21 00:22:59 -04:00
xxhash.c	lib: Add xxhash module	2017-08-15 09:02:07 -07:00