From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CEDB7E77171 for ; Fri, 6 Dec 2024 03:37:10 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tJP97-0002A9-Nd; Thu, 05 Dec 2024 22:36:49 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tJP96-00029s-Af for qemu-devel@nongnu.org; Thu, 05 Dec 2024 22:36:48 -0500 Received: from mail-oa1-x2f.google.com ([2001:4860:4864:20::2f]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1tJP94-00023j-Ng for qemu-devel@nongnu.org; Thu, 05 Dec 2024 22:36:48 -0500 Received: by mail-oa1-x2f.google.com with SMTP id 586e51a60fabf-29737adb604so991053fac.1 for ; Thu, 05 Dec 2024 19:36:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1733456205; x=1734061005; darn=nongnu.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=4Q4CjYM5W5+N42/CsSN7ICu6WDiRWRRGlurvgyo9R4M=; b=v3r2HXC4rPNIWkIwtN/VosUBGTAceNvEDw7Uw87G4VgMYdIpvTTwAh/2uxWjdhtMYa Zq9WntVKSvD2KZ+/P1nFGuybb9sADxXD6Otsuhk+vkA7K7j23LdeWdPtVdoSw8WYGTsG NYs9xZfxTNymzMTSvTu2Py42pCsBAlqEemnBVYo+o+R/NJrhJNsusE0bsTwcI+FSC/Wc djUP3wUlO/rqDLoZCsWRJ7/8T5n0GjdmGYbNFCBTjM4nePTgL8MtCGWWvASAe9NCp3ze 649GQVstj3pWRbSCwaYJqhWmHmbheI7vS255A8RP7z2eY2wI9UFTqlkdcExBUcKzlF8D OS7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733456205; x=1734061005; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=4Q4CjYM5W5+N42/CsSN7ICu6WDiRWRRGlurvgyo9R4M=; b=cWVUTw8VVNcNPB1fjgGiAYyHL2Z6NSH2S7xIfzBsSrQjYoHdOr/WJDqrtVNCZ70fQk qthcTzGG7PWxFNsRJd83FFEm1PDA3o6peNprjbdJgCaWE1WEAymoUfnVGg6fQd1osjrw J09bcLSeJqo+Y8a/vF9lbPT7JYZ8/Um9J+zsXngsIgxiE3y3bNBH0WeLojnZJVcchFgx xv64R1zqG8PiiI5+7vIwHkofMC2QpKapOAxwMUfv/ToLmV/iWYT1OKTYzpuPUZSCUsNx 5k+IZbyb1XuoiPjK7/B2qtHRLP2UG9uEJR/IkQq7kCuKDD6wdMoO4UyjFlbGIiU+HXFg gWZw== X-Forwarded-Encrypted: i=1; AJvYcCX16BNrlRiVbU1h/ASQ8DJzg88YfIiNSiMi+p/qBjVecUL4CPFdearit2CrBC/MjwQ9FdlExLozn48g@nongnu.org X-Gm-Message-State: AOJu0Yx6WDMUxcXvGYdsqu4ZVDhJqUtWq+ycnyejxXrmOK0OLFRgTdk1 JcujjUwUX8tXAce+tsAM9thnuBioL/eBlB079dbFAAWreVX6pY1u7mBo6q2s7DQ= X-Gm-Gg: ASbGncvrAMz3raECvlnjZmuq33PLzXcLJzEiy9RW7/J8MvYTeNLG/+CgRVroLkksXTf EC/2ridMebYlcK1mRUG/73k14utLyPuSsgAehU5WV797QgBmtaXuJ/VA1dDfVhdGtnQEtUkJzlc /OeMOMHAqhLC9Tgxi/8Mn+DOf45MvLx8k7J92cjbI4tuir0qq827LZletpb31fgGdH1tC68hKdj HrUw1AAdnjJHJWJhoIwP6OUsDC0s+9EfQcXs4dKNN1UPta0yhyPOvZ5fDj6jmqvzyDnvyXIbH+v uNkQ7M08mJ6z0SG+2dd6qYBnWSko X-Google-Smtp-Source: AGHT+IHY89GssUaXG9VuLmWOOYrOt+zfWaaqRgOAl3nMGzZ4WMdi7xm4CdBdww5B0IYCJAolvgVYbA== X-Received: by 2002:a05:6871:a68d:b0:29e:7a09:d92a with SMTP id 586e51a60fabf-29f731dd988mr1613787fac.5.1733456205144; Thu, 05 Dec 2024 19:36:45 -0800 (PST) Received: from [192.168.4.112] (fixed-187-189-51-143.totalplay.net. [187.189.51.143]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-29f80418861sm14013fac.50.2024.12.05.19.36.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 05 Dec 2024 19:36:44 -0800 (PST) Message-ID: <79a76786-9ba7-4c04-8c11-52c92376e6df@linaro.org> Date: Thu, 5 Dec 2024 21:36:42 -0600 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/1] disas/riscv: Guard dec->cfg dereference for host disassemble To: LIU Zhiwei , qemu-devel@nongnu.org Cc: qemu-riscv@nongnu.org, palmer@dabbelt.com, alistair.francis@wdc.com, dbarboza@ventanamicro.com, liwei1518@gmail.com, bmeng.cn@gmail.com References: <20241206032411.52528-1-zhiwei_liu@linux.alibaba.com> Content-Language: en-US From: Richard Henderson In-Reply-To: <20241206032411.52528-1-zhiwei_liu@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2001:4860:4864:20::2f; envelope-from=richard.henderson@linaro.org; helo=mail-oa1-x2f.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 12/5/24 21:24, LIU Zhiwei wrote: > For riscv host, it will set dec->cfg to zero. Thus we shuld guard > the dec->cfg deference for riscv host disassemble. > > And in general, we should only use dec->cfg for target in three cases: > > 1) For not incompatible encodings, such as zcmp/zcmt/zfinx. > 2) For maybe-ops encodings, they are better to be disassembled to > the "real" extensions, such as zicfiss. The guard of dec->zimop > and dec->zcmop is for comment and avoid check for every extension > that encoded in maybe-ops area. > 3) For custom encodings, we have to use dec->cfg to disassemble > custom encodings using the same encoding area. > > Signed-off-by: LIU Zhiwei > Suggested-by: Richard Henderson ... > @@ -5112,28 +5112,28 @@ static GString *format_inst(size_t tab, rv_decode *dec) > g_string_append(buf, rv_ireg_name_sym[dec->rs2]); > break; > case '3': > - if (dec->cfg->ext_zfinx) { > + if (dec->cfg && dec->cfg->ext_zfinx) { > g_string_append(buf, rv_ireg_name_sym[dec->rd]); > } else { > g_string_append(buf, rv_freg_name_sym[dec->rd]); > } > break; > case '4': > - if (dec->cfg->ext_zfinx) { > + if (dec->cfg && dec->cfg->ext_zfinx) { > g_string_append(buf, rv_ireg_name_sym[dec->rs1]); > } else { > g_string_append(buf, rv_freg_name_sym[dec->rs1]); > } > break; > case '5': > - if (dec->cfg->ext_zfinx) { > + if (dec->cfg && dec->cfg->ext_zfinx) { > g_string_append(buf, rv_ireg_name_sym[dec->rs2]); > } else { > g_string_append(buf, rv_freg_name_sym[dec->rs2]); > } > break; > case '6': > - if (dec->cfg->ext_zfinx) { > + if (dec->cfg && dec->cfg->ext_zfinx) { > g_string_append(buf, rv_ireg_name_sym[dec->rs3]); > } else { > g_string_append(buf, rv_freg_name_sym[dec->rs3]); These are the only tests of cfg that are required. None of the other standard isa extensions overlap. > @@ -5439,7 +5439,8 @@ static GString *disasm_inst(rv_isa isa, uint64_t pc, rv_inst inst, > const rv_opcode_data *opcode_data = decoders[i].opcode_data; > void (*decode_func)(rv_decode *, rv_isa) = decoders[i].decode_func; > > - if (guard_func(cfg)) { > + /* always_true_p don't dereference cfg */ > + if (((i == 0) || cfg) && guard_func(cfg)) { This should be i == 0 || (cfg && guard_func(cfg)). r~