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Nicholas Piggin 4c6d2518e1 powerpc/64s: Fix lost pending interrupt due to race causing lost update to irq_happened
commit ff6781fd1b upstream.

force_external_irq_replay() can be called in the do_IRQ path with
interrupts hard enabled and soft disabled if may_hard_irq_enable() set
MSR[EE]=1. It updates local_paca->irq_happened with a load, modify,
store sequence. If a maskable interrupt hits during this sequence, it
will go to the masked handler to be marked pending in irq_happened.
This update will be lost when the interrupt returns and the store
instruction executes. This can result in unpredictable latencies,
timeouts, lockups, etc.

Fix this by ensuring hard interrupts are disabled before modifying
irq_happened.

This could cause any maskable asynchronous interrupt to get lost, but
it was noticed on P9 SMP system doing RDMA NVMe target over 100GbE,
so very high external interrupt rate and high IPI rate. The hang was
bisected down to enabling doorbell interrupts for IPIs. These provided
an interrupt type that could run at high rates in the do_IRQ path,
stressing the race.

Fixes: 1d607bb3bd ("powerpc/irq: Add mechanism to force a replay of interrupts")
Cc: stable@vger.kernel.org # v4.8+
Reported-by: Carol L. Soto <clsoto@us.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2018-04-08 14:26:27 +02:00
arch powerpc/64s: Fix lost pending interrupt due to race causing lost update to irq_happened 2018-04-08 14:26:27 +02:00
block blk-mq: don't call io sched's .requeue_request when requeueing rq to ->dispatch 2018-03-08 22:41:20 -08:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto crypto: ecc - Fix NULL pointer deref. on no default_rng 2018-03-19 08:42:49 +01:00
Documentation iio: ABI: Fix name of timestamp sysfs file 2018-03-28 18:24:49 +02:00
drivers i2c: i2c-stm32f7: fix no check on returned setup 2018-04-08 14:26:27 +02:00
firmware License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs ceph: only dirty ITER_IOVEC pages for direct read 2018-04-08 14:26:27 +02:00
include net: use skb_to_full_sk() in skb_update_prio() 2018-03-31 18:10:40 +02:00
init kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK 2018-02-22 15:42:23 +01:00
ipc ipc/shm.c: add split function to shm_vm_ops 2018-04-08 14:26:27 +02:00
kernel perf/hwbp: Simplify the perf-hwbp code, fix documentation 2018-04-08 14:26:27 +02:00
lib rhashtable: Fix rhlist duplicates insertion 2018-03-31 18:10:40 +02:00
mm mm/vmscan: wake up flushers for legacy cgroups too 2018-03-28 18:24:41 +02:00
net skbuff: Fix not waking applications when errors are enqueued 2018-03-31 18:10:42 +02:00
samples samples/bpf: adjust rlimit RLIMIT_MEMLOCK for xdp1 2017-12-20 10:10:31 +01:00
scripts kbuild: fix linker feature test macros when cross compiling with Clang 2018-03-24 11:01:29 +01:00
security /dev/mem: Add bounce buffer for copy-out 2018-03-24 11:01:24 +01:00
sound ALSA: pcm: potential uninitialized return values 2018-04-08 14:26:27 +02:00
tools x86/pkeys/selftests: Rename 'si_pkey' to 'siginfo_pkey' 2018-03-28 18:24:50 +02:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt KVM: arm/arm64: vgic: Don't populate multiple LRs with the same vintid 2018-03-21 12:06:43 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: rpm-pkg: keep spec file until make mrproper 2018-02-13 10:19:46 +01:00
.mailmap .mailmap: Add Maciej W. Rozycki's Imagination e-mail address 2017-11-10 12:16:15 -08:00
COPYING [PATCH] update FSF address in COPYING 2005-09-10 10:06:29 -07:00
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS dt-bindings: Document mti,mips-cpc binding 2018-03-15 10:54:35 +01:00
Makefile Linux 4.14.32 2018-03-31 18:10:43 +02:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.