diff options
| author | Dominik Dingel <dingel@linux.vnet.ibm.com> | 2014-10-23 12:07:44 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-10-27 13:27:24 +0100 |
| commit | 593befa6ab74a805e4f503c8c737c3cffa8066b6 (patch) | |
| tree | cc8765c8ae5a8b26b0a618a93a6d13b4f73a1b56 /include/linux/mm.h | |
| parent | a13cff318cafbd493b8d5d679e5f3f761084c4fe (diff) | |
mm: introduce mm_forbids_zeropage function
Add a new function stub to allow architectures to disable for
an mm_structthe backing of non-present, anonymous pages with
read-only empty zero pages.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 27eb1bfbe704..ab7dadca4ea5 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -56,6 +56,17 @@ extern int sysctl_legacy_va_layout; #define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0)) #endif +/* + * To prevent common memory management code establishing + * a zero page mapping on a read fault. + * This macro should be defined within <asm/pgtable.h>. + * s390 does this to prevent multiplexing of hardware bits + * related to the physical page in case of virtualization. + */ +#ifndef mm_forbids_zeropage +#define mm_forbids_zeropage(X) (0) +#endif + extern unsigned long sysctl_user_reserve_kbytes; extern unsigned long sysctl_admin_reserve_kbytes; |