From b03b467944b3e88a36a33b5429425c42dbd5b8a0 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Fri, 17 Jan 2014 13:12:34 +0100 Subject: [PATCH] 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 Signed-off-by: Martin Schwidefsky --- Reading git-format-patch failed