Patch "xtensa: fix threadptr reload on return to userspace" has been added to the 3.10-stable tree

Patch "xtensa: fix threadptr reload on return to userspace" has been added to the 3.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    xtensa: fix threadptr reload on return to userspace

to the 3.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xtensa-fix-threadptr-reload-on-return-to-userspace.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 4229fb12a03e5da5882b420b0aa4a02e77447b86 Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Sat, 4 Jul 2015 15:27:39 +0300
Subject: xtensa: fix threadptr reload on return to userspace

From: Max Filippov <jcmvbkbc@gmail.com>

commit 4229fb12a03e5da5882b420b0aa4a02e77447b86 upstream.

Userspace return code may skip restoring THREADPTR register if there are
no registers that need to be zeroed. This leads to spurious failures in
libc NPTL tests.

Always restore THREADPTR on return to userspace.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/xtensa/kernel/entry.S |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -549,12 +549,13 @@ user_exception_exit:
 	 *	 (if we have restored WSBITS-1 frames).
 	 */
 
+2:
 #if XCHAL_HAVE_THREADPTR
 	l32i	a3, a1, PT_THREADPTR
 	wur	a3, threadptr
 #endif
 
-2:	j	common_exception_exit
+	j	common_exception_exit
 
 	/* This is the kernel exception exit.
 	 * We avoided to do a MOVSP when we entered the exception, but we


Patches currently in stable-queue which might be from jcmvbkbc@gmail.com are

queue-3.10/xtensa-fix-kernel-register-spilling.patch
queue-3.10/xtensa-fix-threadptr-reload-on-return-to-userspace.patch