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>
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Kconfig
config FUSE_FS
tristate "FUSE (Filesystem in Userspace) support"
help
With FUSE it is possible to implement a fully functional filesystem
in a userspace program.
There's also a companion library: libfuse2. This library is available
from the FUSE homepage:
<http://fuse.sourceforge.net/>
although chances are your distribution already has that library
installed if you've installed the "fuse" package itself.
See <file:Documentation/filesystems/fuse.txt> for more information.
See <file:Documentation/Changes> for needed library/utility version.
If you want to develop a userspace FS, or if you want to use
a filesystem based on FUSE, answer Y or M.
config CUSE
tristate "Character device in Userspace support"
depends on FUSE_FS
help
This FUSE extension allows character devices to be
implemented in userspace.
If you want to develop or use a userspace character device
based on CUSE, answer Y or M.
Computing file changes ...
