linux/arch/s390
Martin Schwidefsky 60f07c8ec5 s390/mm: fix race on mm->context.flush_mm
The order in __tlb_flush_mm_lazy is to flush TLB first and then clear
the mm->context.flush_mm bit. This can lead to missed flushes as the
bit can be set anytime, the order needs to be the other way aronud.

But this leads to a different race, __tlb_flush_mm_lazy may be called
on two CPUs concurrently. If mm->context.flush_mm is cleared first then
another CPU can bypass __tlb_flush_mm_lazy although the first CPU has
not done the flush yet. In a virtualized environment the time until the
flush is finally completed can be arbitrarily long.

Add a spinlock to serialize __tlb_flush_mm_lazy and use the function
in finish_arch_post_lock_switch as well.

Cc: <stable@vger.kernel.org>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-09-06 09:24:42 +02:00
..
appldata sched/headers: Move task statistics APIs from <linux/sched.h> to <linux/sched/stat.h> 2017-03-03 01:43:43 +01:00
boot s390/decompressor: fix initrd corruption caused by bss clear 2017-03-22 08:21:20 +01:00
configs s390: update defconfig 2017-06-08 15:53:48 +02:00
crypto s390/crypto: fix aes/paes Kconfig dependeny 2017-06-12 16:25:58 +02:00
hypfs s390: hypfs: make inode explicitly non-modular 2016-10-31 17:55:40 +01:00
include s390/mm: fix race on mm->context.flush_mm 2017-09-06 09:24:42 +02:00
kernel s390/dasd: Change unsigned long long to unsigned long 2017-08-23 13:31:51 +02:00
kvm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-09-05 09:45:46 -07:00
lib s390/uaccess: avoid mvcos jump label 2017-08-29 16:29:10 +02:00
mm s390/mm: use VM_BUG_ON in crst_table_[upgrade|downgrade] 2017-09-06 09:24:41 +02:00
net bpf, s390: fix jit branch offset related to ldimm64 2017-08-04 11:18:01 -07:00
numa s390/numa: pin all possible cpus to nodes early 2016-12-07 07:23:33 +01:00
oprofile s390/dumpstack: restore reliable indicator for call traces 2016-10-17 14:44:30 +02:00
pci s390/pci: log changes to uid checking 2017-08-09 09:09:41 -04:00
tools s390/facilities: fix typo 2017-08-29 16:29:04 +02:00
defconfig s390: update defconfig 2017-06-08 15:53:48 +02:00
Kbuild s390/crypto: Provide s390 specific arch random functionality. 2017-04-26 13:41:35 +02:00
Kconfig s390: add support for IBM z14 machines 2017-07-26 08:25:15 +02:00
Kconfig.debug Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-02-22 10:20:04 -08:00
Makefile s390: add support for IBM z14 machines 2017-07-26 08:25:15 +02:00