Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758502AbaKANL3 (ORCPT ); Sat, 1 Nov 2014 09:11:29 -0400 Received: from mail-pa0-f49.google.com ([209.85.220.49]:57271 "EHLO mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753513AbaKANL2 (ORCPT ); Sat, 1 Nov 2014 09:11:28 -0400 Message-ID: <5454DD70.6060004@gmail.com> Date: Sat, 01 Nov 2014 21:17:36 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: metcalf@tilera.com CC: "linux-kernel@vger.kernel.org" Subject: [PATCH] arch: tile: kernel: kgdb.c: Use memcpy() instead of pointer copy one by one Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Not only memcpy() is faster than pointer copy, but also let code more clearer and simple, which can avoid compiling warning (the original implementation copy registers by exceeding member array border). The related warning (with allmodconfig under tile): CC arch/tile/kernel/kgdb.o arch/tile/kernel/kgdb.c: In function 'sleeping_thread_to_gdb_regs': arch/tile/kernel/kgdb.c:140:31: warning: iteration 53u invokes undefined behavior [-Waggressive-loop-optimizations] *(ptr++) = thread_regs->regs[reg]; ^ arch/tile/kernel/kgdb.c:139:2: note: containing loop for (reg = 0; reg <= TREG_LAST_GPR; reg++) ^ Signed-off-by: Chen Gang --- arch/tile/kernel/kgdb.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/arch/tile/kernel/kgdb.c b/arch/tile/kernel/kgdb.c index 4cd8838..ff5335a 100644 --- a/arch/tile/kernel/kgdb.c +++ b/arch/tile/kernel/kgdb.c @@ -125,9 +125,7 @@ int dbg_set_reg(int regno, void *mem, struct pt_regs *regs) void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task) { - int reg; struct pt_regs *thread_regs; - unsigned long *ptr = gdb_regs; if (task == NULL) return; @@ -136,9 +134,7 @@ sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task) memset(gdb_regs, 0, NUMREGBYTES); thread_regs = task_pt_regs(task); - for (reg = 0; reg <= TREG_LAST_GPR; reg++) - *(ptr++) = thread_regs->regs[reg]; - + memcpy(gdb_regs, thread_regs, TREG_LAST_GPR * sizeof(unsigned long)); gdb_regs[TILEGX_PC_REGNUM] = thread_regs->pc; gdb_regs[TILEGX_FAULTNUM_REGNUM] = thread_regs->faultnum; } -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/