From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755268AbaCYRWt (ORCPT ); Tue, 25 Mar 2014 13:22:49 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:55999 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755240AbaCYRW2 (ORCPT ); Tue, 25 Mar 2014 13:22:28 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Nicolas Pitre , Russell King , Florian Fainelli , Kamal Mostafa Subject: [PATCH 3.8 45/81] ARM: 7670/1: fix the memset fix Date: Tue, 25 Mar 2014 10:15:58 -0700 Message-Id: <1395767794-5012-46-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1395767794-5012-1-git-send-email-kamal@canonical.com> References: <1395767794-5012-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.20 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicolas Pitre commit 418df63adac56841ef6b0f1fcf435bc64d4ed177 upstream. Commit 455bd4c430b0 ("ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) optimizations") attempted to fix a compliance issue with the memset return value. However the memset itself became broken by that patch for misaligned pointers. This fixes the above by branching over the entry code from the misaligned fixup code to avoid reloading the original pointer. Also, because the function entry alignment is wrong in the Thumb mode compilation, that fixup code is moved to the end. While at it, the entry instructions are slightly reworked to help dual issue pipelines. Signed-off-by: Nicolas Pitre Tested-by: Alexander Holler Signed-off-by: Russell King Cc: Florian Fainelli Signed-off-by: Kamal Mostafa --- arch/arm/lib/memset.S | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-) diff --git a/arch/arm/lib/memset.S b/arch/arm/lib/memset.S index d912e73..94b0650 100644 --- a/arch/arm/lib/memset.S +++ b/arch/arm/lib/memset.S @@ -14,31 +14,15 @@ .text .align 5 - .word 0 - -1: subs r2, r2, #4 @ 1 do we have enough - blt 5f @ 1 bytes to align with? - cmp r3, #2 @ 1 - strltb r1, [ip], #1 @ 1 - strleb r1, [ip], #1 @ 1 - strb r1, [ip], #1 @ 1 - add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3)) -/* - * The pointer is now aligned and the length is adjusted. Try doing the - * memset again. - */ ENTRY(memset) -/* - * Preserve the contents of r0 for the return value. - */ - mov ip, r0 - ands r3, ip, #3 @ 1 unaligned? - bne 1b @ 1 + ands r3, r0, #3 @ 1 unaligned? + mov ip, r0 @ preserve r0 as return value + bne 6f @ 1 /* * we know that the pointer in ip is aligned to a word boundary. */ - orr r1, r1, r1, lsl #8 +1: orr r1, r1, r1, lsl #8 orr r1, r1, r1, lsl #16 mov r3, r1 cmp r2, #16 @@ -127,4 +111,13 @@ ENTRY(memset) tst r2, #1 strneb r1, [ip], #1 mov pc, lr + +6: subs r2, r2, #4 @ 1 do we have enough + blt 5b @ 1 bytes to align with? + cmp r3, #2 @ 1 + strltb r1, [ip], #1 @ 1 + strleb r1, [ip], #1 @ 1 + strb r1, [ip], #1 @ 1 + add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3)) + b 1b ENDPROC(memset) -- 1.8.3.2