linux-stable/arch/s390
Gerald Schaefer ac8372f3b4 s390/mm: fix set_huge_pte_at() for empty ptes
On s390, the layout of normal and large ptes (i.e. pmds/puds) differs.
Therefore, set_huge_pte_at() does a conversion from a normal pte to
the corresponding large pmd/pud. So, when converting an empty pte, this
should result in an empty pmd/pud, which would return true for
pmd/pud_none().

However, after conversion we also mark the pmd/pud as large, and
therefore present. For empty ptes, this will result in an empty pmd/pud
that is also marked as large, and pmd/pud_none() would not return true.

There is currently no issue with this behaviour, as set_huge_pte_at()
does not seem to be called for empty ptes. It would be valid though, so
let's fix this by not marking empty ptes as large in set_huge_pte_at().

This was found by testing a patch from from Anshuman Khandual, which is
currently discussed on LKML ("mm/debug: Add more arch page table helper
tests").

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-05-20 10:13:27 +02:00
..
appldata s390: Replace zero-length array with flexible-array member 2020-02-27 16:02:21 +01:00
boot s390/protvirt: fix compilation issue 2020-04-25 10:17:24 +02:00
configs s390 updates for the 5.7 merge window 2020-04-04 09:45:50 -07:00
crypto s390/crypto: explicitly memzero stack key material in aes_s390.c 2020-02-27 16:02:21 +01:00
hypfs
include s390/pci: Fix s390_mmio_read/write with MIO 2020-05-14 23:21:37 +02:00
kernel s390/kexec_file: fix initrd location for kdump kernel 2020-05-14 23:21:37 +02:00
kvm KVM: s390: Fix for running nested uner z/VM 2020-05-06 08:09:17 -04:00
lib s390/mm: fix page table upgrade vs 2ndary address mode accesses 2020-04-21 15:16:43 +02:00
mm s390/mm: fix set_huge_pte_at() for empty ptes 2020-05-20 10:13:27 +02:00
net
numa s390/mm: remove fake numa support 2020-02-27 16:02:21 +01:00
oprofile
pci s390/pci: Fix s390_mmio_read/write with MIO 2020-05-14 23:21:37 +02:00
purgatory .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
scripts
tools .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
Kbuild
Kconfig s390 updates for the 5.7 merge window 2020-04-04 09:45:50 -07:00
Kconfig.debug
Makefile s390: make 'install' not depend on vmlinux 2020-02-17 18:01:58 +01:00