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| author |   Heiko Carstens <hca@linux.ibm.com> | 2020-11-16 08:06:41 +0100 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2020-11-23 12:01:12 +0100 |
| commit | 0290c9e328e04052e317171953feb18177a34aed (patch) | |
| tree | 9ba70533fc8727ef2d664542b62f90180d44819c /arch/s390/include/asm/pgtable.h | |
| parent | s390/mm: remove set_fs / rework address space handling (diff) | |
| download | linux-dev-0290c9e328e04052e317171953feb18177a34aed.tar.xz linux-dev-0290c9e328e04052e317171953feb18177a34aed.zip | |
s390/mm: use invalid asce instead of kernel asce
Create a region 3 page table which contains only invalid entries, and
use that via "s390_invalid_asce" instead of the kernel ASCE whenever
there is either
- no user address space available, e.g. during early startup
- as an intermediate ASCE when address spaces are switched
This makes sure that user space accesses in such situations are
guaranteed to fail.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/pgtable.h')
| -rw-r--r-- | arch/s390/include/asm/pgtable.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index a8edd96b2103..794746a32806 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -23,6 +23,7 @@ extern pgd_t swapper_pg_dir[]; extern void paging_init(void); +extern unsigned long s390_invalid_asce; enum { PG_DIRECT_MAP_4K = 0, |