Juergen Gross a8fabb3852 xen/xenbus: fix self-deadlock after killing user process ... In case a user process using xenbus has open transactions and is killed e.g. via ctrl-C the following cleanup of the allocated resources might result in a deadlock due to trying to end a transaction in the xenbus worker thread: [ 2551.474706] INFO: task xenbus:37 blocked for more than 120 seconds. [ 2551.492215] Tainted: P OE 5.0.0-29-generic #5 [ 2551.510263] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 2551.528585] xenbus D 0 37 2 0x80000080 [ 2551.528590] Call Trace: [ 2551.528603] __schedule+0x2c0/0x870 [ 2551.528606] ? _cond_resched+0x19/0x40 [ 2551.528632] schedule+0x2c/0x70 [ 2551.528637] xs_talkv+0x1ec/0x2b0 [ 2551.528642] ? wait_woken+0x80/0x80 [ 2551.528645] xs_single+0x53/0x80 [ 2551.528648] xenbus_transaction_end+0x3b/0x70 [ 2551.528651] xenbus_file_free+0x5a/0x160 [ 2551.528654] xenbus_dev_queue_reply+0xc4/0x220 [ 2551.528657] xenbus_thread+0x7de/0x880 [ 2551.528660] ? wait_woken+0x80/0x80 [ 2551.528665] kthread+0x121/0x140 [ 2551.528667] ? xb_read+0x1d0/0x1d0 [ 2551.528670] ? kthread_park+0x90/0x90 [ 2551.528673] ret_from_fork+0x35/0x40 Fix this by doing the cleanup via a workqueue instead. Reported-by: James Dingwall <james@dingwall.me.uk> Fixes: fd8aa9095a ("xen: optimize xenbus driver for multiple concurrent xenstore accesses") Cc: <stable@vger.kernel.org> # 4.11 Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>		2019-10-02 16:40:11 -04:00
..
events	xen/events: fix binding user event channels to cpus	2019-07-17 08:09:57 +02:00
xen-pciback	xen/pciback: remove set but not used variable 'old_state'	2019-07-26 10:29:05 +02:00
xenbus	xen/xenbus: fix self-deadlock after killing user process	2019-10-02 16:40:11 -04:00
xenfs	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
acpi.c
arm-device.c
balloon.c	xen/balloon: Clear PG_offline in balloon_retrieve()	2019-10-01 15:52:53 -04:00
biomerge.c
cpu_hotplug.c
dbgp.c
efi.c	xen/efi: have a common runtime setup function	2019-10-02 10:31:07 -04:00
evtchn.c	xen/events: fix binding user event channels to cpus	2019-07-17 08:09:57 +02:00
features.c
gntalloc.c
gntdev-common.h
gntdev-dmabuf.c
gntdev-dmabuf.h
gntdev.c	xen/gntdev.c: Replace vm_map_pages() with vm_map_pages_zero()	2019-07-31 08:13:59 +02:00
grant-table.c
Kconfig	xen: remove tmem driver	2019-07-17 08:09:58 +02:00
Makefile	xen: remove tmem driver	2019-07-17 08:09:58 +02:00
manage.c
mcelog.c
mem-reservation.c
pci.c	xen/pci: reserve MCFG areas earlier	2019-09-12 15:02:55 -04:00
pcpu.c
platform-pci.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 320	2019-06-05 17:37:05 +02:00
preempt.c
privcmd-buf.c
privcmd.c	xen: avoid link error on ARM	2019-07-31 08:14:12 +02:00
privcmd.h
pvcalls-back.c
pvcalls-front.c	xen: fixes for 5.2-rc3	2019-05-31 10:53:34 -07:00
pvcalls-front.h
swiotlb-xen.c	swiotlb-xen: Convert to use macro	2019-09-06 09:20:50 -04:00
sys-hypervisor.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
time.c
xen-acpi-cpuhotplug.c
xen-acpi-memhotplug.c
xen-acpi-pad.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288	2019-06-05 17:36:37 +02:00
xen-acpi-processor.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288	2019-06-05 17:36:37 +02:00
xen-balloon.c	xen: remove tmem driver	2019-07-17 08:09:58 +02:00
xen-front-pgdir-shbuf.c
xen-scsiback.c
xen-stub.c
xlate_mmu.c	xen: avoid link error on ARM	2019-07-31 08:14:12 +02:00