selftests/x86/sigreturn/32: Invalidate DS and ES when abusing the kernel
authorAndy Lutomirski <luto@kernel.org>
Wed, 20 Nov 2019 19:58:32 +0000 (11:58 -0800)
committerPeter Zijlstra <peterz@infradead.org>
Thu, 21 Nov 2019 20:55:59 +0000 (21:55 +0100)
commit4d2fa82d98d2d296043a04eb517d7dbade5b13b8
tree22cbeb0e35d67cd39a7b3d9bdb8550e3d535f322
parent8caa016bfc129f2c925d52da43022171d1d1de91
selftests/x86/sigreturn/32: Invalidate DS and ES when abusing the kernel

If the kernel accidentally uses DS or ES while the user values are
loaded, it will work fine for sane userspace.  In the interest of
simulating maximally insane userspace, make sigreturn_32 zero out DS
and ES for the nasty parts so that inadvertent use of these segments
will crash.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@kernel.org
tools/testing/selftests/x86/sigreturn.c