linux_dsm_epyc7002/arch/s390/mm
Claudio Imbrenda 306d6c49ac s390/kvm: fix deadlock when killed by oom
When the oom killer kills a userspace process in the page fault handler
while in guest context, the fault handler fails to release the mm_sem
if the FAULT_FLAG_RETRY_NOWAIT option is set. This leads to a deadlock
when tearing down the mm when the process terminates. This bug can only
happen when pfault is enabled, so only KVM clients are affected.

The problem arises in the rare cases in which handle_mm_fault does not
release the mm_sem. This patch fixes the issue by manually releasing
the mm_sem when needed.

Fixes: 24eb3a824c ("KVM: s390: Add FAULT_FLAG_RETRY_NOWAIT for guest fault")
Cc: <stable@vger.kernel.org> # 3.15+
Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-07-16 15:45:46 +02:00
..
cmm.c s390/cmm: avoid add_timer on concurrently used timer 2018-07-16 15:45:41 +02:00
dump_pagetables.c s390: unify linker symbols usage 2018-02-27 08:05:23 +01:00
extmem.c s390/extmem: fix gcc 8 stringop-overflow warning 2018-07-02 11:24:50 +02:00
fault.c s390/kvm: fix deadlock when killed by oom 2018-07-16 15:45:46 +02:00
gmap.c KVM: s390: Add storage key facility interpretation control 2018-05-17 09:00:41 +02:00
gup.c mm/gup.c: document return value 2018-04-13 17:10:27 -07:00
hugetlbpage.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
init.c mm: pass the vmem_altmap to arch_remove_memory and __remove_pages 2018-01-08 11:46:23 -08:00
maccess.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mem_detect.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mmap.c exec: pass stack rlimit into mm layout functions 2018-04-11 10:28:37 -07:00
page-states.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pageattr.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pgalloc.c s390/mm: correct allocate_pgste proc_handler callback 2018-07-06 08:47:52 +02:00
pgtable.c KVM: s390: Add storage key facility interpretation control 2018-05-17 09:00:41 +02:00
vmem.c mm: pass the vmem_altmap to vmemmap_free 2018-01-08 11:46:23 -08:00