From patchwork Fri Jun 15 15:03:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Edgar E. Iglesias" X-Patchwork-Id: 10466799 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E9468600F4 for ; Fri, 15 Jun 2018 15:42:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D6BA928DF7 for ; Fri, 15 Jun 2018 15:42:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CB22028DFD; Fri, 15 Jun 2018 15:42:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, FSL_HELO_FAKE, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham version=3.3.1 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.wl.linuxfoundation.org (Postfix) with ESMTPS id 749BB28DF7 for ; Fri, 15 Jun 2018 15:42:30 +0000 (UTC) Received: from localhost ([::1]:47641 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fTqrt-0001EN-5g for patchwork-qemu-devel@patchwork.kernel.org; Fri, 15 Jun 2018 11:42:29 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45162) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fTqGX-0001oy-BJ for qemu-devel@nongnu.org; Fri, 15 Jun 2018 11:03:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fTqGW-0007Da-Bc for qemu-devel@nongnu.org; Fri, 15 Jun 2018 11:03:53 -0400 Received: from mail-lf0-x244.google.com ([2a00:1450:4010:c07::244]:35399) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fTqGW-0007D7-4q for qemu-devel@nongnu.org; Fri, 15 Jun 2018 11:03:52 -0400 Received: by mail-lf0-x244.google.com with SMTP id i15-v6so15120526lfc.2 for ; Fri, 15 Jun 2018 08:03:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=k/DL3yGeNj2rxkHmTFdHoFfjXKsNS/Ylj4+CW4YnHg4=; b=h9Rwj0n9z8Xwkhjf9xqfxYhT3KLEdyZ5tPd5040phCWzw4rm7OrnWz+hYm996BU7+G FzUERUIylKRsVQiR1f79ADv0xXlR6A+5AoX5Dp3Rp4YTOpbyHwAJsINp6V+8sravegbu KGzaZPU8pfhdFfNULdJeRiT3AKWkwyCfXSGZNxK0gjCEB4ovUuryBbz8L0XGBIjEl+UF 3zywxi934emJWY/c9QrpvUMDeAnORTGGSUO1s2ZaMp0RdxiUNa1iMBzuwxz8u+UgostT nGrsHQZabpR53QSm4nx44j4aIGuOwYCePAtWzog62b50Cxjbgmk5JgunRYP6vOzWz6nX 3PEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=k/DL3yGeNj2rxkHmTFdHoFfjXKsNS/Ylj4+CW4YnHg4=; b=pDEwUKGor0rIZkYy7yzaVTWKPsdeD3o6YcUvOIKbHMIUVvtII1YOF7+pILHWJChALW GmCfiI4Bi7AySLu4YZmdqMjIS37LOXkn6KoQogdofY379nn8yscn9hRTj2RZc8sOqKkc M3depeiyuff5nP84G/QOMIPmTGKlkwZqsyX8u2rbxXuzZAXBirY/sn/GGPF5/UQUWGJY 9c8PVAPKBJXKky+LuLQk2un7Xzo6Ep+8RryEL39v5udlLiEVKHtAMPsyblg9s7OxAaei mS4BHp0K70U8O+QYRJMwX9teISW1uahSoUDh2B3V4pIV3ndWZ5tS16rl6wQTqcwQQpM7 XHxg== X-Gm-Message-State: APt69E1wPSfWhZwTAG93Lb3SL5t9OPyrkhpJX4ZZ2USyyH4LNxiiDzz3 0+q9TDt3xTBYNEqoz8S9b7ehNw== X-Google-Smtp-Source: ADUXVKL1LnRaKGqUWMEgKt3QhArNK3ejgTRslFbJgzzDk8f46D2dYJsNDf9rkir1aNThTk3063oG2A== X-Received: by 2002:a2e:9c04:: with SMTP id s4-v6mr1572820lji.97.1529075029910; Fri, 15 Jun 2018 08:03:49 -0700 (PDT) Received: from gmail.com (81-231-232-130-no39.tbcn.telia.com. [81.231.232.130]) by smtp.gmail.com with ESMTPSA id g14-v6sm1510456lfb.36.2018.06.15.08.03.47 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 15 Jun 2018 08:03:48 -0700 (PDT) From: "Edgar E. Iglesias" To: qemu-devel@nongnu.org Date: Fri, 15 Jun 2018 17:03:43 +0200 Message-Id: <20180615150343.4937-3-edgar.iglesias@gmail.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180615150343.4937-1-edgar.iglesias@gmail.com> References: <20180615150343.4937-1-edgar.iglesias@gmail.com> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2a00:1450:4010:c07::244 Subject: [Qemu-devel] [PULL v1 2/2] target-microblaze: Rework NOP/zero instruction handling 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: edgar.iglesias@xilinx.com, peter.maydell@linaro.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: "Edgar E. Iglesias" Remove the abort on a sequence of NOP/zero instructions. Always return early and avoid decoding NOP/zero instructions. This fixes Coverity CID 1391443. Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Edgar E. Iglesias --- target/microblaze/translate.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/target/microblaze/translate.c b/target/microblaze/translate.c index 6c64946398..78ca265b04 100644 --- a/target/microblaze/translate.c +++ b/target/microblaze/translate.c @@ -90,7 +90,6 @@ typedef struct DisasContext { uint32_t jmp_pc; int abort_at_next_insn; - int nr_nops; struct TranslationBlock *tb; int singlestep_enabled; } DisasContext; @@ -1576,17 +1575,12 @@ static inline void decode(DisasContext *dc, uint32_t ir) dc->ir = ir; LOG_DIS("%8.8x\t", dc->ir); - if (dc->ir) - dc->nr_nops = 0; - else { + if (ir == 0) { trap_illegal(dc, dc->cpu->env.pvr.regs[2] & PVR2_OPCODE_0x0_ILL_MASK); - - LOG_DIS("nr_nops=%d\t", dc->nr_nops); - dc->nr_nops++; - if (dc->nr_nops > 4) { - cpu_abort(CPU(dc->cpu), "fetching nop sequence\n"); - } + /* Don't decode nop/zero instructions any further. */ + return; } + /* bit 2 seems to indicate insn type. */ dc->type_b = ir & (1 << 29); @@ -1633,7 +1627,6 @@ void gen_intermediate_code(CPUState *cs, struct TranslationBlock *tb) dc->singlestep_enabled = cs->singlestep_enabled; dc->cpustate_changed = 0; dc->abort_at_next_insn = 0; - dc->nr_nops = 0; if (pc_start & 3) { cpu_abort(cs, "Microblaze: unaligned PC=%x\n", pc_start);