Heiko Carstens b03b467944 s390/uaccess: test if current->mm is set before walking page tables
If get_fs() == USER_DS we better test if current->mm is not zero before
walking page tables.
The page table walk code would try to lock mm->page_table_lock, however
if mm is zero this might crash.

Now it is arguably incorrect trying to access userspace if current->mm
is zero, however we have seen that and s390 would be the only architecture
which would crash in such a case.
So we better make the page table walk code a bit more robust and report
always a fault instead.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-01-22 14:02:16 +01:00
..
2014-01-22 14:02:15 +01:00
2013-10-24 17:17:15 +02:00
2012-11-30 15:40:45 +01:00
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