Revision 6b7339f4c31ad69c8e9c0b2859276e22cf72176d authored by Kirill A. Shutemov on 06 July 2015, 20:18:37 UTC, committed by Linus Torvalds on 09 July 2015, 18:12:48 UTC
Reading page fault handler code I've noticed that under right
circumstances kernel would map anonymous pages into file mappings: if
the VMA doesn't have vm_ops->fault() and the VMA wasn't fully populated
on ->mmap(), kernel would handle page fault to not populated pte with
do_anonymous_page().

Let's change page fault handler to use do_anonymous_page() only on
anonymous VMA (->vm_ops == NULL) and make sure that the VMA is not
shared.

For file mappings without vm_ops->fault() or shred VMA without vm_ops,
page fault on pte_none() entry would lead to SIGBUS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Willy Tarreau <w@1wt.eu>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 883a2df
History
File Mode Size
Makefile -rw-r--r-- 377 bytes
compat.c -rw-r--r-- 19.1 KB
compat_mq.c -rw-r--r-- 3.9 KB
ipc_sysctl.c -rw-r--r-- 5.4 KB
mq_sysctl.c -rw-r--r-- 2.9 KB
mqueue.c -rw-r--r-- 35.9 KB
msg.c -rw-r--r-- 24.1 KB
msgutil.c -rw-r--r-- 3.6 KB
namespace.c -rw-r--r-- 4.0 KB
sem.c -rw-r--r-- 55.2 KB
shm.c -rw-r--r-- 32.5 KB
syscall.c -rw-r--r-- 2.3 KB
util.c -rw-r--r-- 21.2 KB
util.h -rw-r--r-- 6.4 KB

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