From patchwork Sat Sep 22 02:04:54 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Henderson X-Patchwork-Id: 186025 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 5F8DA2C0092 for ; Sat, 22 Sep 2012 12:05:45 +1000 (EST) Received: from localhost ([::1]:39785 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TFF6F-0005Mw-8X for incoming@patchwork.ozlabs.org; Fri, 21 Sep 2012 22:05:43 -0400 Received: from eggs.gnu.org ([208.118.235.92]:57456) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TFF5p-0005C9-HW for qemu-devel@nongnu.org; Fri, 21 Sep 2012 22:05:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TFF5o-0000dg-3k for qemu-devel@nongnu.org; Fri, 21 Sep 2012 22:05:17 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:64906) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TFF5n-0000d7-T8 for qemu-devel@nongnu.org; Fri, 21 Sep 2012 22:05:16 -0400 Received: by pbbrp12 with SMTP id rp12so8850169pbb.4 for ; Fri, 21 Sep 2012 19:05:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=NtCnuwlyvDkSePXWgdLd+mDTr9HYYnkFwNyYc86VpC4=; b=lVQ0iJR8zbgqYGXsak5Dxn6t5Z91WOk1QLxf/Ntb7ypLKM19WWVbo0bJhxx8BRodjj 1oeCzw1M0gwvtSV7rZZxS21LXiQ6vQEiTor2ZI+ZwK8Wnveu/J6hdXrTTWblqEcPFd3q TH4ZkLJ+o/fwhAMvVSb9ozwC2RbNfSBlmkps8epCB/yturwQz2uT/4t00dMhedEvbYY9 Rou1QhFnxa7iKB2pgBHkVu/OhOvKZh5R2OfCILsHcB5MI0VDE+LLq6BBT7QFV0Zowerf TfMsp/sSAlQX/oh8q5GRlYd1gdKx+uO7JqrD/qGqbDyxQ5nGZWYsoWGmYoQKdNKabpvn Sr4w== Received: by 10.66.83.33 with SMTP id n1mr17095127pay.66.1348279515016; Fri, 21 Sep 2012 19:05:15 -0700 (PDT) Received: from anchor.twiddle.home.com ([173.160.232.49]) by mx.google.com with ESMTPS id s4sm4956298paw.35.2012.09.21.19.05.14 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 21 Sep 2012 19:05:14 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Date: Fri, 21 Sep 2012 19:04:54 -0700 Message-Id: <1348279507-3617-2-git-send-email-rth@twiddle.net> X-Mailer: git-send-email 1.7.11.4 In-Reply-To: <1348279507-3617-1-git-send-email-rth@twiddle.net> References: <1348279507-3617-1-git-send-email-rth@twiddle.net> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.85.160.45 Cc: Blue Swirl Subject: [Qemu-devel] [PATCH 01/14] linux-user: Use memcpy in get_user/put_user. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org When host and target have differing alignment rules, using a cast and direct memory operation can result in SIGBUS. Use memcpy instead, which the compiler will happily optimize when alignment is satisfied. Signed-off-by: Richard Henderson Reviewed-by: Peter Maydell --- linux-user/qemu.h | 47 +++++++++++++++-------------------------------- 1 file changed, 15 insertions(+), 32 deletions(-) diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 69b27d7..fc4cc00 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -289,46 +289,29 @@ static inline int access_ok(int type, abi_ulong addr, abi_ulong size) * struct has been locked - usually with lock_user_struct(). */ #define __put_user(x, hptr)\ -({\ +({ __typeof(*hptr) pu_ = (x);\ switch(sizeof(*hptr)) {\ - case 1:\ - *(uint8_t *)(hptr) = (uint8_t)(typeof(*hptr))(x);\ - break;\ - case 2:\ - *(uint16_t *)(hptr) = tswap16((uint16_t)(typeof(*hptr))(x));\ - break;\ - case 4:\ - *(uint32_t *)(hptr) = tswap32((uint32_t)(typeof(*hptr))(x));\ - break;\ - case 8:\ - *(uint64_t *)(hptr) = tswap64((typeof(*hptr))(x));\ - break;\ - default:\ - abort();\ + case 1: break;\ + case 2: pu_ = tswap16(pu_); break; \ + case 4: pu_ = tswap32(pu_); break; \ + case 8: pu_ = tswap64(pu_); break; \ + default: abort();\ }\ + memcpy(hptr, &pu_, sizeof(pu_)); \ 0;\ }) #define __get_user(x, hptr) \ -({\ +({ __typeof(*hptr) gu_; \ + memcpy(&gu_, hptr, sizeof(gu_)); \ switch(sizeof(*hptr)) {\ - case 1:\ - x = (typeof(*hptr))*(uint8_t *)(hptr);\ - break;\ - case 2:\ - x = (typeof(*hptr))tswap16(*(uint16_t *)(hptr));\ - break;\ - case 4:\ - x = (typeof(*hptr))tswap32(*(uint32_t *)(hptr));\ - break;\ - case 8:\ - x = (typeof(*hptr))tswap64(*(uint64_t *)(hptr));\ - break;\ - default:\ - /* avoid warning */\ - x = 0;\ - abort();\ + case 1: break; \ + case 2: gu_ = tswap16(gu_); break; \ + case 4: gu_ = tswap32(gu_); break; \ + case 8: gu_ = tswap64(gu_); break; \ + default: abort();\ }\ + (x) = gu_; \ 0;\ })