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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32918C433EF for ; Tue, 22 Mar 2022 04:17:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236372AbiCVES2 (ORCPT ); Tue, 22 Mar 2022 00:18:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236363AbiCVES2 (ORCPT ); Tue, 22 Mar 2022 00:18:28 -0400 Received: from mail-pg1-x530.google.com (mail-pg1-x530.google.com [IPv6:2607:f8b0:4864:20::530]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A94011C0D for ; Mon, 21 Mar 2022 21:17:01 -0700 (PDT) Received: by mail-pg1-x530.google.com with SMTP id o13so11763891pgc.12 for ; Mon, 21 Mar 2022 21:17:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=1SX7VG7pcFZQTL6ghZ/zYF6sS4uvEZ0uS9Ptdb4LiaQ=; b=UYRR7DOJp+47629aFz0Vdy2LnsEHUTiyqbRnOeLHCm/tpXSA3Fl58WaYTxmuPMqD+M 9/TJ+vj1PSdG9oX0jFzKLOOJ+CPj1Nyx2iZ6KYzYleGNoAOegMo/WhQfwuNDeiwcsZ8g 2X8Fj+beFHqamZYWsKxa4waCD/QqE3MUFY36k= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=1SX7VG7pcFZQTL6ghZ/zYF6sS4uvEZ0uS9Ptdb4LiaQ=; b=zafEyl4kl4v0+Q8F2WBzZeeDBs95KrxZMIjotx/qA2bpltRZuboZcYdvIdY5GHrDFC kdM05Qb0H/FObIMlNS3wYCUmC89KMiiDxEQSD7WIG4uqn+im4lJ1oenxk56EKWK1+IY2 2iteWpv9tzRkR2VxgNzIeAei4NWMxDf2FfamH9p1iuOKmKgHDynVJtw2MH4TfzvkwF7E YxGWfG3+Pyn2n9VMqCteo3uNBJVpfiv4jswmX242hgDXC0nQwIknGa7dqjS9jd3DRuHm 8eC9n1k6wPZvB2aQ/DUc+3CYxJ+Maf5b4s913rnOY3SGehidkysfCQ+fx5sdZtuiuxdv 9Ttg== X-Gm-Message-State: AOAM530LhnFMn8324Mdas8Lx/za8yH+7TdMQCWcXwbQmxz+VpH1EtrC3 TNu+WE+XHp4EwCprhFjKJi0kQg== X-Google-Smtp-Source: ABdhPJxs0Y5O8LkJlXrrvhdEL8fgYGIzetMPjEFGIwlWa/F8vit8lWjvms4F/1c+Dv7cFyN0kigQGA== X-Received: by 2002:a63:5024:0:b0:380:83f7:1603 with SMTP id e36-20020a635024000000b0038083f71603mr20118067pgb.289.1647922621067; Mon, 21 Mar 2022 21:17:01 -0700 (PDT) Received: from google.com ([2401:fa00:8f:203:51af:6dff:4acd:7fa5]) by smtp.gmail.com with ESMTPSA id j14-20020a056a00174e00b004f776098715sm22006057pfc.68.2022.03.21.21.16.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 21 Mar 2022 21:17:00 -0700 (PDT) Date: Tue, 22 Mar 2022 13:16:54 +0900 From: Sergey Senozhatsky To: Petr Mladek Cc: Andy Shevchenko , Miguel Ojeda , Linus Torvalds , Greg Kroah-Hartman , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Gary Guo , Alex Gaynor , Wedson Almeida Filho , Steven Rostedt , Sergey Senozhatsky , Rasmus Villemoes Subject: Re: [PATCH v5 12/20] vsprintf: add new `%pA` format specifier Message-ID: References: <20220317181032.15436-1-ojeda@kernel.org> <20220317181032.15436-13-ojeda@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: rust-for-linux@vger.kernel.org On (22/03/18 17:04), Petr Mladek wrote: > On Fri 2022-03-18 16:07:31, Andy Shevchenko wrote: > > On Thu, Mar 17, 2022 at 07:10:00PM +0100, Miguel Ojeda wrote: > > > From: Gary Guo > > > + case 'A': > > > + if (!IS_ENABLED(CONFIG_RUST)) { > > > + WARN_ONCE(1, "Please remove %%pA from non-Rust code\n"); > > > + return error_string(buf, end, "(%pA?)", spec); > > > + } > > > > I'm wondering if the Big Scary Banner as trace_printk() does would be better > > (in case we can tell that %pA is used in the code when RUST=n). > > Good question! > > The advantage of WARN_ONCE() is that it shows the stack so that it is > easier to locate the caller. > > On the other hand, WARN_ONCE() is a bit misused here. It should be > used only in situations that might be potentially fatal. It might > even cause panic() with "panic_on_warn" kernel parameter. Stack trace is certainly helpful here. So maybe dump_stack() instead of WARN_ONCE()? I guess I don't mind WARN_ONCE().