Implement write protection for kernel modules text and read-only
data sections by implementing set_memory_[ro|rw] on s390.
Since s390 has no execute bit in the pte's NX is not supported.
set_memory_[ro|rw] will only work on normal pages and not on
large pages, so in case a large page should be modified bail
out with a warning.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The implementation of the cache flushing interfaces on the s390
is identical with the default implementation in asm-generic.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Mtdblock driver doesn't call flush_dcache_page for pages in request. So,
this causes problems on architectures where the icache doesn't fill from
the dcache or with dcache aliases. The patch fixes this.
The ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE symbol was introduced to avoid
pointless empty cache-thrashing loops on architectures for which
flush_dcache_page() is a no-op. Every architecture was provided with this
flush pages on architectires where ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE is
equal 1 or do nothing otherwise.
See "fix mtd_blkdevs problem with caches on some architectures" discussion
on LKML for more information.
Signed-off-by: Ilya Loginov <isloginov@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Peter Horton <phorton@bitbox.co.uk>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Jan Glauber