From patchwork Fri Apr 15 14:23:41 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Alex_Benn=C3=A9e?= X-Patchwork-Id: 8851391 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 3C9F5BF29F for ; Fri, 15 Apr 2016 14:24:09 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 109952034A for ; Fri, 15 Apr 2016 14:24:08 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D745F202F0 for ; Fri, 15 Apr 2016 14:24:06 +0000 (UTC) Received: from localhost ([::1]:35120 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ar4fF-0000OM-Mh for patchwork-qemu-devel@patchwork.kernel.org; Fri, 15 Apr 2016 10:24:05 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49337) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ar4f5-0000LU-Rp for qemu-devel@nongnu.org; Fri, 15 Apr 2016 10:23:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ar4f4-0007cK-FU for qemu-devel@nongnu.org; Fri, 15 Apr 2016 10:23:55 -0400 Received: from mail-wm0-x231.google.com ([2a00:1450:400c:c09::231]:37161) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ar4f4-0007bi-87 for qemu-devel@nongnu.org; Fri, 15 Apr 2016 10:23:54 -0400 Received: by mail-wm0-x231.google.com with SMTP id n3so35017204wmn.0 for ; Fri, 15 Apr 2016 07:23:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=k1GOUEiMRsBX7QjDv/L6gy7uDkBguq2GGvbJdW95SKg=; b=id3SGVlzP2ngXAs1UqJ85SNarBqxnLWER6ba0UzFPq+yg5zPWP5L+B3a1cc/v/w9To DYFr/lm8YOOtsnA4PPJUUjY5UkzNCiBL5G14ndyyiaB5KTtysDFO2+pdAH3oKd3BfICO yAFKNab1n3U+3vnKJDXj+u3ZeOM1H+9tR5bLI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=k1GOUEiMRsBX7QjDv/L6gy7uDkBguq2GGvbJdW95SKg=; b=BqYYEhcDpZpmOYlC65xW4OBhF+DCRK2bo+Duf0w/O6jW6TP4Gv7ooyJino4+LbUPKl /e/3pmgiM/7FDDqY+zY0QRWSUvOdxCoepBtuMy464StTtkdnw46TXxmzkHCoI5LJs+k0 OUXEMjV2dQ3R13xWUObEYBoFxO96I+xn7mSuyuvZf6jnM/etwzzl4i4JWXvAk6EzW3Mu vkmuVo3LWj/inzkoJ//ZRQnPXw0NzSjuurrd/qKbUgzVailnzQ0FuE9nEXc+a0wTx7Ft /XOQ4Ndbq45uUuM8VwqEAHwivzx+Om92XeMuON57h7Iq0OgF+Tw6Ck81vQBXXJ5ZcbCw 9WgA== X-Gm-Message-State: AOPr4FWXuH4btnzSmJ9hwaDantyF3hRv+6oaeMTISnd08cAEAj+w2RA02u3ZkCbxXhIXJwOm X-Received: by 10.28.147.135 with SMTP id v129mr4522025wmd.65.1460730233626; Fri, 15 Apr 2016 07:23:53 -0700 (PDT) Received: from zen.linaro.local ([81.128.185.34]) by smtp.gmail.com with ESMTPSA id gg7sm49229195wjd.10.2016.04.15.07.23.49 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Apr 2016 07:23:50 -0700 (PDT) Received: from zen.linaroharston (localhost [127.0.0.1]) by zen.linaro.local (Postfix) with ESMTP id 813D33E0533; Fri, 15 Apr 2016 15:24:04 +0100 (BST) From: =?UTF-8?q?Alex=20Benn=C3=A9e?= To: mttcg@listserver.greensocs.com, fred.konrad@greensocs.com, a.rigo@virtualopensystems.com, serge.fdrv@gmail.com, cota@braap.org Date: Fri, 15 Apr 2016 15:23:41 +0100 Message-Id: <1460730231-1184-4-git-send-email-alex.bennee@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1460730231-1184-1-git-send-email-alex.bennee@linaro.org> References: <1460730231-1184-1-git-send-email-alex.bennee@linaro.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a00:1450:400c:c09::231 Subject: [Qemu-devel] [RFC v1 02/12] tcg/i386: Make direct jump patching thread-safe X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, claudio.fontana@huawei.com, Sergey Fedorov , Peter Crosthwaite , jan.kiszka@siemens.com, mark.burton@greensocs.com, qemu-devel@nongnu.org, pbonzini@redhat.com, rth@twiddle.net Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Sergey Fedorov Ensure direct jump patching in i386 is atomic by: * naturally aligning a location of direct jump address; * using atomic_read()/atomic_set() for code patching. Signed-off-by: Sergey Fedorov Signed-off-by: Sergey Fedorov --- include/exec/exec-all.h | 2 +- tcg/i386/tcg-target.inc.c | 17 +++++++++++++++++ 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index cde4b7a..9144ee0 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -324,7 +324,7 @@ void ppc_tb_set_jmp_target(uintptr_t jmp_addr, uintptr_t addr); static inline void tb_set_jmp_target1(uintptr_t jmp_addr, uintptr_t addr) { /* patch the branch destination */ - stl_le_p((void*)jmp_addr, addr - (jmp_addr + 4)); + atomic_set((int32_t *)jmp_addr, addr - (jmp_addr + 4)); /* no need to flush icache explicitly */ } #elif defined(__s390x__) diff --git a/tcg/i386/tcg-target.inc.c b/tcg/i386/tcg-target.inc.c index 2f98cae..8fd37f4 100644 --- a/tcg/i386/tcg-target.inc.c +++ b/tcg/i386/tcg-target.inc.c @@ -1123,6 +1123,19 @@ static void tcg_out_jmp(TCGContext *s, tcg_insn_unit *dest) tcg_out_branch(s, 0, dest); } +static void tcg_out_nopn(TCGContext *s, int n) +{ + static const uint8_t nop1[] = { 0x90 }; + static const uint8_t nop2[] = { 0x66, 0x90 }; + static const uint8_t nop3[] = { 0x8d, 0x76, 0x00 }; + static const uint8_t *const nopn[] = { nop1, nop2, nop3 }; + int i; + assert(n <= ARRAY_SIZE(nopn)); + for (i = 0; i < n; ++i) { + tcg_out8(s, nopn[n - 1][i]); + } +} + #if defined(CONFIG_SOFTMMU) /* helper signature: helper_ret_ld_mmu(CPUState *env, target_ulong addr, * int mmu_idx, uintptr_t ra) @@ -1777,6 +1790,10 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, case INDEX_op_goto_tb: if (s->tb_jmp_insn_offset) { /* direct jump method */ + /* align jump displacement for atomic pathing */ + if (((uintptr_t)s->code_ptr & 3) != 3) { + tcg_out_nopn(s, 3 - ((uintptr_t)s->code_ptr & 3)); + } tcg_out8(s, OPC_JMP_long); /* jmp im */ s->tb_jmp_insn_offset[args[0]] = tcg_current_code_size(s); tcg_out32(s, 0);