From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from r-passerv.ralfj.de (r-passerv.ralfj.de [109.230.236.95]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 580DD2222AF for ; Wed, 26 Feb 2025 14:37:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=109.230.236.95 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740580656; cv=none; b=UQKehDZYfeaua55+gI+eUOdPFlTNDL36DV+lnW766D69ktN1BF7AQYvPiVhTaVHUB0ILhiaT5ipkLsQiowOMR0x1GHVnZh1sjo3f/ZYFEjwr8RDfrQlzNe0Eb/cyNUUpvkA99sIf4tVTI7y03qjsKKqnQmgZReuTKt0Xf41Wq5Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740580656; c=relaxed/simple; bh=0MLGL0Ho8ncjPovldYhbohlEnmj/Azb3Aqd9VsDSLcw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fzRe1Pd3Yjh1qOEAlke5WRyAAKEXI09WmBGBKuy/xM3172cwo4QrlGX0NKR4en0WOV2ySY9kLY5LAONPftPV56QotC/swQKwhBQ5Tsnm71zSPHWCrbaGPX6g4LjbUMpjEayDUO0J6OJkwH/JcpHPiiviIoE6fra00/s4QWS0X00= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ralfj.de; spf=pass smtp.mailfrom=ralfj.de; dkim=pass (1024-bit key) header.d=ralfj.de header.i=@ralfj.de header.b=GH5vf1BC; arc=none smtp.client-ip=109.230.236.95 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ralfj.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ralfj.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ralfj.de header.i=@ralfj.de header.b="GH5vf1BC" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=ralfj.de; s=mail; t=1740580653; bh=0MLGL0Ho8ncjPovldYhbohlEnmj/Azb3Aqd9VsDSLcw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=GH5vf1BC9HkGSX9L5LowKDsarbTfPCNKL6B1ekgpcPAIRkZ+frnF/14JW8v8IhH6y BR2Yz+qMjj4AZuo+7/CUrkUMhURvfbHtSyQD3ilpiowJrbKYN5e+pQZbzh6ctZfDRD 5XC0TJlNf7GSukKOYWmD4EGZlIBREiysvEE15+X8= Received: from [IPV6:2001:67c:10ec:5784:8000::87] (2001-67c-10ec-5784-8000--87.net6.ethz.ch [IPv6:2001:67c:10ec:5784:8000::87]) by r-passerv.ralfj.de (Postfix) with ESMTPSA id 8CF832052D08; Wed, 26 Feb 2025 15:37:33 +0100 (CET) Message-ID: <7bbe958c-0d25-4c68-b562-1c296b7311b7@ralfj.de> Date: Wed, 26 Feb 2025 15:37:33 +0100 Precedence: bulk X-Mailing-List: ksummit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: C aggregate passing (Rust kernel policy) To: James Bottomley , Miguel Ojeda , Ventura Jack Cc: Kent Overstreet , "H. Peter Anvin" , Alice Ryhl , Linus Torvalds , Gary Guo , airlied@gmail.com, boqun.feng@gmail.com, david.laight.linux@gmail.com, ej@inai.de, gregkh@linuxfoundation.org, hch@infradead.org, ksummit@lists.linux.dev, linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org References: <20250222141521.1fe24871@eugeo> <6pwjvkejyw2wjxobu6ffeyolkk2fppuuvyrzqpigchqzhclnhm@v5zhfpmirk2c> <5E3FEDC4-DBE3-45C7-A331-DAADD3E7EB42@zytor.com> <2rrp3fmznibxyg3ocvsfasfnpwfp2skhf4x7ihrnvm72lemykf@lwp2jkdbwqgm> Content-Language: en-US, de-DE From: Ralf Jung In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 26.02.25 15:26, James Bottomley wrote: > On Wed, 2025-02-26 at 14:53 +0100, Miguel Ojeda wrote: >> On Wed, Feb 26, 2025 at 2:03 PM Ventura Jack >> wrote: > [...] >>> Exception/unwind safety may be another subject that increases >>> the difficulty of writing unsafe Rust. >> >> Note that Rust panics in the kernel do not unwind. > > I presume someone is working on this, right? While rust isn't > pervasive enough yet for this to cause a problem, dumping a backtrace > is one of the key things we need to diagnose how something went wrong, > particularly for user bug reports where they can't seem to bisect. Rust panics typically print a backtrace even if they don't unwind. This works just fine in userland, but I don't know the state in the kernel. Kind regards, Ralf