xtensa: fix threadptr reload on return to userspace

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>

diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 6e53174f85565ccad7899d4315f5de1f76248d80..d29bac601be5bd9b16e75de34abe49447dab8625 100644 (file)
--- 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