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: 6b1d174b0c27b ("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>
idr_replace() returns the old value on success, not 0. Link: http://lkml.kernel.org/r/20170918162642.37511-1-ebiggers3@gmail.com Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't populate the read-only arrays dec32table and dec64table on the
stack, instead make them both static const. Makes the object code
smaller by over 10K bytes:
Before:
text data bss dec hex filename
31500 0 0 31500 7b0c lib/lz4/lz4_decompress.o
After:
text data bss dec hex filename
20237 176 0 20413 4fbd lib/lz4/lz4_decompress.o
(gcc version 7.2.0 x86_64)
Link: http://lkml.kernel.org/r/20170921221939.20820-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull driver core fixes from Greg KH: "Here are a few small fixes for 4.14-rc4. The removal of DRIVER_ATTR() was almost completed by 4.14-rc1, but one straggler made it in through some other tree (odds are, one of mine...) So there's a simple removal of the last user, and then finally the macro is removed from the tree. There's a fix for old crazy udev instances that insist on reloading a module when it is removed from the kernel due to the new uevents for bind/unbind. This fixes the reported regression, hopefully some year in the future we can drop the workaround, once users update to the latest version, but I'm not holding my breath. And then there's a build fix for a linker warning, and a buffer overflow fix to match the PCI fixes you took through the PCI tree in the same area. All of these have been in linux-next for a few weeks while I've been traveling, sorry for the delay" * tag 'driver-core-4.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: driver core: remove DRIVER_ATTR fpga: altera-cvp: remove DRIVER_ATTR() usage driver core: platform: Don't read past the end of "driver_override" buffer base: arch_topology: fix section mismatch build warnings driver core: suppress sending MODALIAS in UNBIND uevents
Pull parisc fixes from Helge Deller: - Unbreak parisc bootloader by avoiding a gcc-7 optimization to convert multiple byte-accesses into one word-access. - Add missing HWPOISON page fault handler code. I completely missed that when I added HWPOISON support during this merge window and it only showed up now with the madvise07 LTP test case. - Fix backtrace unwinding to stop when stack start has been reached. - Issue warning if initrd has been loaded into memory regions with broken RAM modules. - Fix HPMC handler (parisc hardware fault handler) to comply with architecture specification. - Avoid compiler warnings about too large frame sizes. - Minor init-section fixes. * 'parisc-4.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Unbreak bootloader due to gcc-7 optimizations parisc: Reintroduce option to gzip-compress the kernel parisc: Add HWPOISON page fault handler code parisc: Move init_per_cpu() into init section parisc: Check if initrd was loaded into broken RAM parisc: Add PDCE_CHECK instruction to HPMC handler parisc: Add wrapper for pdc_instr() firmware function parisc: Move start_parisc() into init section parisc: Stop unwinding at start of stack parisc: Fix too large frame size warnings
Pull networking fixes from David Miller:
1) Fix NAPI poll list corruption in enic driver, from Christian
Lamparter.
2) Fix route use after free, from Eric Dumazet.
3) Fix regression in reuseaddr handling, from Josef Bacik.
4) Assert the size of control messages in compat handling since we copy
it in from userspace twice. From Meng Xu.
5) SMC layer bug fixes (missing RCU locking, bad refcounting, etc.)
from Ursula Braun.
6) Fix races in AF_PACKET fanout handling, from Willem de Bruijn.
7) Don't use ARRAY_SIZE on spinlock array which might have zero
entries, from Geert Uytterhoeven.
8) Fix miscomputation of checksum in ipv6 udp code, from Subash Abhinov
Kasiviswanathan.
9) Push the ipv6 header properly in ipv6 GRE tunnel driver, from Xin
Long.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (75 commits)
inet: fix improper empty comparison
net: use inet6_rcv_saddr to compare sockets
net: set tb->fast_sk_family
net: orphan frags on stand-alone ptype in dev_queue_xmit_nit
MAINTAINERS: update git tree locations for ieee802154 subsystem
net: prevent dst uses after free
net: phy: Fix truncation of large IRQ numbers in phy_attached_print()
net/smc: no close wait in case of process shut down
net/smc: introduce a delay
net/smc: terminate link group if out-of-sync is received
net/smc: longer delay for client link group removal
net/smc: adapt send request completion notification
net/smc: adjust net_device refcount
net/smc: take RCU read lock for routing cache lookup
net/smc: add receive timeout check
net/smc: add missing dev_put
net: stmmac: Cocci spatch "of_table"
lan78xx: Use default values loaded from EEPROM/OTP after reset
lan78xx: Allow EEPROM write for less than MAX_EEPROM_SIZE
lan78xx: Fix for eeprom read/write when device auto suspend
...
The parisc architecture has larger stack frames than most other architectures on 32-bit kernels. Increase the maximum allowed stack frame to 1280 bytes for parisc to avoid warnings in the do_sys_poll() and pat_memconfig() functions. Signed-off-by: Helge Deller <deller@gmx.de>
Issue is that if the data crosses a page boundary inside a compound
page, this check will incorrectly trigger a WARN_ON.
To fix this, compute the order using the head of the compound page and
adjust the offset to be relative to that head.
Fixes: 72e809ed81ed ("iov_iter: sanity checks for copy to/from page
primitives")
Signed-off-by: Petar Penkov <ppenkov@google.com>
CC: Al Viro <viro@zeniv.linux.org.uk>
CC: Eric Dumazet <edumazet@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Clarify that rhashtable_walk_{stop,start} will not reset the iterator to
the beginning of the hash table. Confusion between rhashtable_walk_enter
and rhashtable_walk_start has already lead to a bug.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current udev rules cause modules to be loaded on all device events save
for "remove". With the introduction of KOBJ_BIND/KOBJ_UNBIND this causes
issues, as driver modules that have devices bound to their drivers get
immediately reloaded, and it appears to the user that module unloading doe
snot work.
The standard udev matching rule is foillowing:
ENV{MODALIAS}=="?*", RUN{builtin}+="kmod load $env{MODALIAS}"
Given that MODALIAS data is not terribly useful for UNBIND event, let's zap
it from the generated uevent environment until we get userspace updated
with the correct udev rule that only loads modules on "add" event.
Reported-by: Jakub Kicinski <kubakici@wp.pl>
Tested-by: Jakub Kicinski <kubakici@wp.pl>
Fixes: 1455cf8dbfd0 ("driver core: emit uevents when device is bound ...")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>