Return-Path: From: Greg Kroah-Hartman Subject: [PATCH 4.4 169/342] drm/vmwgfx: Fix an incorrect lock check To: Cc: Greg Kroah-Hartman , , Thomas Hellstrom , Sinclair Yeh , Dave Airlie Message-Id: <20160301234533.423471476@linuxfoundation.org> In-Reply-To: <20160301234527.990448862@linuxfoundation.org> References: <20160301234527.990448862@linuxfoundation.org> Date: Tue, 01 Mar 2016 23:54:40 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Hellstrom commit fb89ac5102ae2875d685c847e6b5dbc141622d43 upstream. With CONFIG_SMP=n and CONFIG_DEBUG_SPINLOCK=y the vmwgfx kernel module would unconditionally throw a bug when checking for a held spinlock in the command buffer code. Fix this by using a lockdep check. Reported-and-tested-by: Tetsuo Handa Signed-off-by: Thomas Hellstrom Reviewed-by: Sinclair Yeh Signed-off-by: Dave Airlie Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c @@ -247,7 +247,7 @@ static void __vmw_cmdbuf_header_free(str { struct vmw_cmdbuf_man *man = header->man; - BUG_ON(!spin_is_locked(&man->lock)); + lockdep_assert_held_once(&man->lock); if (header->inline_space) { vmw_cmdbuf_header_inline_free(header);