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 240E5C433FE for ; Tue, 22 Mar 2022 15:57:59 +0000 (UTC) Received: from localhost ([::1]:57922 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nWgtS-00083Z-6S for qemu-devel@archiver.kernel.org; Tue, 22 Mar 2022 11:57:58 -0400 Received: from eggs.gnu.org ([209.51.188.92]:43640) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nWgs0-0006S3-K7 for qemu-devel@nongnu.org; Tue, 22 Mar 2022 11:56:28 -0400 Received: from [2607:f8b0:4864:20::b2e] (port=46632 helo=mail-yb1-xb2e.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nWgry-000363-Tw for qemu-devel@nongnu.org; Tue, 22 Mar 2022 11:56:28 -0400 Received: by mail-yb1-xb2e.google.com with SMTP id v130so34387356ybe.13 for ; Tue, 22 Mar 2022 08:56:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ScJMrFlzrL75xvqe+jXTJooANOeB/UChAvvQsLs3ty0=; b=lQjw3yIUShb2Z4y422cfMwJQNleIJQ/3NI5VKA6qJZT8llrdydsCHkL4ufwRAT46VD sjWfpJxnNCciS0dl6BEvKGBULWfEPjNOhTWG2zILnX3nrBpMKwPcfVc6WcRiVnPPoF3u AKYLVJrNIS6qJeWmQk2c5dYMAwlfhvahDDrSz9FK3nHWd2uBqlA2sOgVcfz1/VyUTvoc myWj0NN1o4Sgn1tn5/if+m3gHkwEkVEdhuH/wumPAGGpmvHboaj1e6ftraK9WnHUDg3k LMdhIsziudTao/6D0IoUVlX82ilSAp1N3MVLiEpd4jAJseAxk/WNWIv3aBxUOW1yOrDQ MIWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ScJMrFlzrL75xvqe+jXTJooANOeB/UChAvvQsLs3ty0=; b=Lhr6pmHbXWw06bp0uWrZXfIvSB/CqTr/t9Vh8JK+Ktrd6YGf0a8Ym2T3gHl5GyH4s8 wWhagvfOC4ug3JPMjZ2g2ievByg/fzqmI88DOyGQAjJubSlb4JEXqZbW2UUpYwsSTN1V 3Cdp0T9d7M4F2eQnpnS0EuM2m0V6KM7Bz2El3WfKHTUmuLxwF1574+Xr+LnXiIOts17/ kVpqzImcpo3RmkI6coOT+QezJWwZi7NTTqSytp0cKp0fQ5Bk9FzPHCcXlOPxzvh5Dj99 zd1tT7pb3tantm3Qvl2OJ7eIyRZOzhOVcl5ZZF7cQ2YLFXIXLMhzfkXAWVJFLyFxWWrn VACQ== X-Gm-Message-State: AOAM533se4Nj1EE5G2u4L4ckbObNoJCdDtTSQhONSgU3JdM0yDG4wo/D GaGqREQueYOp/p2M0n1fSoMv6ADqXDC8Z+mdEvping== X-Google-Smtp-Source: ABdhPJz6k8liq8xZwx1/Nzdg6apoq4IXABh8HomThEXpW5N+a0yO9bhiIvVBM4zq8jH7ZRfyLxd29nwW1lJTGLi3P3w= X-Received: by 2002:a5b:350:0:b0:628:86b8:6e09 with SMTP id q16-20020a5b0350000000b0062886b86e09mr27132023ybp.39.1647964585847; Tue, 22 Mar 2022 08:56:25 -0700 (PDT) MIME-Version: 1.0 References: <20220322154213.86475-1-bmeng.cn@gmail.com> In-Reply-To: <20220322154213.86475-1-bmeng.cn@gmail.com> From: Peter Maydell Date: Tue, 22 Mar 2022 15:56:13 +0000 Message-ID: Subject: Re: [PATCH 1/2] gdbstub: Set current_cpu for memory read write To: Bin Meng Content-Type: text/plain; charset="UTF-8" X-Host-Lookup-Failed: Reverse DNS lookup failed for 2607:f8b0:4864:20::b2e (failed) Received-SPF: pass client-ip=2607:f8b0:4864:20::b2e; envelope-from=peter.maydell@linaro.org; helo=mail-yb1-xb2e.google.com X-Spam_score_int: -6 X-Spam_score: -0.7 X-Spam_bar: / X-Spam_report: (-0.7 / 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, PDS_HP_HELO_NORDNS=0.659, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no 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: , Cc: =?UTF-8?B?QWxleCBCZW5uw6ll?= , =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, 22 Mar 2022 at 15:43, Bin Meng wrote: > > When accessing the per-CPU register bank of some devices (e.g.: GIC) > from the GDB stub context, a segfault occurs. This is due to current_cpu > is not set, as the contect is not a guest CPU. > > Let's set current_cpu before doing the acutal memory read write. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/124 > Signed-off-by: Bin Meng > --- This works, but I worry a bit that it might have unexpected side effects, and setting globals (even if thread-local) to cause side-effects elsewhere isn't ideal... -- PMM