x86, vdso: Zero-pad the VVAR page
x86, vdso: Zero-pad the VVAR page

By coincidence, the VVAR page is at the end of an ELF segment.  As a
result, if it ends up being a partial page, the kernel loader will
leave garbage behind at the end of the vvar page.  Zero-pad it to a
full page to fix this issue.

This has probably been broken since the VVAR page was introduced.
On QEMU, if you dump the run-time contents of the VVAR page, you can
find entertaining strings from seabios left behind.

It's remotely possible that this is a security bug -- conceivably
there's some BIOS out there that leaves something sensitive in the
few K of memory that is exposed to userspace.

Signed-off-by: Stefani Seibold <35951e2654371df7c68de546b20b3c3794b62aae@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-12-git-send-email-35951e2654371df7c68de546b20b3c3794b62aae@seibold.net
Signed-off-by: H. Peter Anvin <8a453bad9912ffe59bc0f0b8abe03df9be19379e@linux.intel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs