Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933509AbdDETW1 (ORCPT ); Wed, 5 Apr 2017 15:22:27 -0400 Received: from lelnx194.ext.ti.com ([198.47.27.80]:16900 "EHLO lelnx194.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933440AbdDETWT (ORCPT ); Wed, 5 Apr 2017 15:22:19 -0400 From: Dave Gerlach To: Greg Kroah-Hartman , Arnd Bergmann , Tony Lindgren , Russell King CC: , , , Shawn Guo , Alexandre Belloni , Keerthy J , Dave Gerlach Subject: [PATCH] misc: sram-exec: Use aligned fncpy instead of memcpy Date: Wed, 5 Apr 2017 14:21:20 -0500 Message-ID: <20170405192120.1009-1-d-gerlach@ti.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1633 Lines: 46 Currently the sram-exec functionality, which allows allocation of executable memory and provides an API to move code to it, is only selected in configs for the ARM architecture. Based on commit 5756e9dd0de6 ("ARM: 6640/1: Thumb-2: Symbol manipulation macros for function body copying") simply copying a C function pointer address using memcpy without consideration of alignment and Thumb is unsafe on ARM platforms. The aforementioned patch introduces the fncpy macro which is a safe way to copy executable code on ARM platforms, so let's make use of that here rather than the unsafe plain memcpy that was previously used by sram_exec_copy. In the future, architectures hoping to make use of the sram-exec functionality must define an fncpy macro just as ARM has done to guarantee or check for safe copying to executable memory before allowing the arch to select CONFIG_SRAM_EXEC. Signed-off-by: Dave Gerlach --- drivers/misc/sram-exec.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/misc/sram-exec.c b/drivers/misc/sram-exec.c index ac522417c462..0057eabe5c03 100644 --- a/drivers/misc/sram-exec.c +++ b/drivers/misc/sram-exec.c @@ -19,6 +19,7 @@ #include #include +#include #include "sram.h" @@ -93,7 +94,7 @@ int sram_exec_copy(struct gen_pool *pool, void *dst, void *src, set_memory_nx((unsigned long)base, pages); set_memory_rw((unsigned long)base, pages); - memcpy(dst, src, size); + fncpy(dst, src, size); set_memory_ro((unsigned long)base, pages); set_memory_x((unsigned long)base, pages); -- 2.11.0