From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 48AEF4C6C; Fri, 2 May 2025 06:13:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746166410; cv=none; b=b1Uoe8FGT0lYScS0XX1hwDa9ju2ajQog9Ffd9tGiW5UIO9ViUfm7N3YyZwvXCzIwFKHHu8vJNSPYexGmZ2j/VLcFPkG36472SbILHXKqDU8/Y5MOK4Yxr/NTH04y/L1YPHsFQK+WhgY6mp860lOVdi3fUWTcVtN7DPz1qqpehT8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746166410; c=relaxed/simple; bh=iuRPynWNspiLCrv5o0TZawp9NxxaaX3vf1nNZ7+ykM0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GSRFIc6poIZ37UkbqtxkWk4Vw/fuL8pmSfMJc7vZTBipbVyb3NHkzLWaxZqMHHV1GzqTGTO9olrvXQScqegoneHDuRsWPA1f2Baj8JUWxMwP9KMMiHbWUHpAKnQ1HWn6IMUrx4hgUuIL5JN27PPeSFNl/v8xtN7zRzqXidfR5lY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=SzpDLkNg; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="SzpDLkNg" Received: from [192.168.7.202] ([71.202.166.45]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 5426CqxU1789768 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Thu, 1 May 2025 23:12:53 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 5426CqxU1789768 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025042001; t=1746166375; bh=+Zv9cQk+z9fAinewPJ/ZzGEn0L1B+MFr/2S7teyfsbU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=SzpDLkNgz/zeY6FwID+iYLUU+9gU7MCiwyCKWuiv4/Lnp/AtsoF6l+Y871ImKJ3iG VyedzKMuFs3O6d3GNJzCnDkSXilsB+MLwfv3bBH+Cx08hdlo0cdG7WPWlzHlRG/nsp Ensgq/BrNJpCPn7BKj6zCZPO4bBNTxlbmNuKZWMMN6zPa8zZj5T15HuYBo8xfADlf7 UhkAdoJwCsyiZ1DF9FHEMSvFzoJNiw6FQg0vipftdBqI8DFH0cRFfvJZMb2fzNXLUG XXEVmpm6/TjWmx/WMO4vqlWz6i48E03bzwHOy6plc4T8aEwYlZhAYjmBL3c2ir62L/ zB45qRNOb61Sg== Message-ID: Date: Thu, 1 May 2025 23:12:52 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 00/13] objtool: Detect and warn about indirect calls in __nocfi functions To: Sean Christopherson , "H. Peter Anvin" Cc: Peter Zijlstra , x86@kernel.org, kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, pbonzini@redhat.com, ardb@kernel.org, kees@kernel.org, Arnd Bergmann , gregkh@linuxfoundation.org, jpoimboe@kernel.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, samitolvanen@google.com, ojeda@kernel.org References: <20250430110734.392235199@infradead.org> <8B86A3AE-A296-438C-A7A7-F844C66D0198@zytor.com> <20250430190600.GQ4439@noisy.programming.kicks-ass.net> <20250501103038.GB4356@noisy.programming.kicks-ass.net> <20250501153844.GD4356@noisy.programming.kicks-ass.net> Content-Language: en-US From: Xin Li Autocrypt: addr=xin@zytor.com; keydata= xsDNBGUPz1cBDACS/9yOJGojBFPxFt0OfTWuMl0uSgpwk37uRrFPTTLw4BaxhlFL0bjs6q+0 2OfG34R+a0ZCuj5c9vggUMoOLdDyA7yPVAJU0OX6lqpg6z/kyQg3t4jvajG6aCgwSDx5Kzg5 Rj3AXl8k2wb0jdqRB4RvaOPFiHNGgXCs5Pkux/qr0laeFIpzMKMootGa4kfURgPhRzUaM1vy bsMsL8vpJtGUmitrSqe5dVNBH00whLtPFM7IbzKURPUOkRRiusFAsw0a1ztCgoFczq6VfAVu raTye0L/VXwZd+aGi401V2tLsAHxxckRi9p3mc0jExPc60joK+aZPy6amwSCy5kAJ/AboYtY VmKIGKx1yx8POy6m+1lZ8C0q9b8eJ8kWPAR78PgT37FQWKYS1uAroG2wLdK7FiIEpPhCD+zH wlslo2ETbdKjrLIPNehQCOWrT32k8vFNEMLP5G/mmjfNj5sEf3IOKgMTMVl9AFjsINLHcxEQ 6T8nGbX/n3msP6A36FDfdSEAEQEAAc0WWGluIExpIDx4aW5Aenl0b3IuY29tPsLBDQQTAQgA NxYhBIUq/WFSDTiOvUIqv2u9DlcdrjdRBQJlD89XBQkFo5qAAhsDBAsJCAcFFQgJCgsFFgID AQAACgkQa70OVx2uN1HUpgv/cM2fsFCQodLArMTX5nt9yqAWgA5t1srri6EgS8W3F+3Kitge tYTBKu6j5BXuXaX3vyfCm+zajDJN77JHuYnpcKKr13VcZi1Swv6Jx1u0II8DOmoDYLb1Q2ZW v83W55fOWJ2g72x/UjVJBQ0sVjAngazU3ckc0TeNQlkcpSVGa/qBIHLfZraWtdrNAQT4A1fa sWGuJrChBFhtKbYXbUCu9AoYmmbQnsx2EWoJy3h7OjtfFapJbPZql+no5AJ3Mk9eE5oWyLH+ QWqtOeJM7kKvn/dBudokFSNhDUw06e7EoVPSJyUIMbYtUO7g2+Atu44G/EPP0yV0J4lRO6EA wYRXff7+I1jIWEHpj5EFVYO6SmBg7zF2illHEW31JAPtdDLDHYcZDfS41caEKOQIPsdzQkaQ oW2hchcjcMPAfyhhRzUpVHLPxLCetP8vrVhTvnaZUo0xaVYb3+wjP+D5j/3+hwblu2agPsaE vgVbZ8Fx3TUxUPCAdr/p73DGg57oHjgezsDNBGUPz1gBDAD4Mg7hMFRQqlzotcNSxatlAQNL MadLfUTFz8wUUa21LPLrHBkUwm8RujehJrzcVbPYwPXIO0uyL/F///CogMNx7Iwo6by43KOy g89wVFhyy237EY76j1lVfLzcMYmjBoTH95fJC/lVb5Whxil6KjSN/R/y3jfG1dPXfwAuZ/4N cMoOslWkfZKJeEut5aZTRepKKF54T5r49H9F7OFLyxrC/uI9UDttWqMxcWyCkHh0v1Di8176 jjYRNTrGEfYfGxSp+3jYL3PoNceIMkqM9haXjjGl0W1B4BidK1LVYBNov0rTEzyr0a1riUrp Qk+6z/LHxCM9lFFXnqH7KWeToTOPQebD2B/Ah5CZlft41i8L6LOF/LCuDBuYlu/fI2nuCc8d m4wwtkou1Y/kIwbEsE/6RQwRXUZhzO6llfoN96Fczr/RwvPIK5SVMixqWq4QGFAyK0m/1ap4 bhIRrdCLVQcgU4glo17vqfEaRcTW5SgX+pGs4KIPPBE5J/ABD6pBnUUAEQEAAcLA/AQYAQgA JhYhBIUq/WFSDTiOvUIqv2u9DlcdrjdRBQJlD89ZBQkFo5qAAhsMAAoJEGu9DlcdrjdR4C0L /RcjolEjoZW8VsyxWtXazQPnaRvzZ4vhmGOsCPr2BPtMlSwDzTlri8BBG1/3t/DNK4JLuwEj OAIE3fkkm+UG4Kjud6aNeraDI52DRVCSx6xff3bjmJsJJMb12mWglN6LjdF6K+PE+OTJUh2F dOhslN5C2kgl0dvUuevwMgQF3IljLmi/6APKYJHjkJpu1E6luZec/lRbetHuNFtbh3xgFIJx 2RpgVDP4xB3f8r0I+y6ua+p7fgOjDLyoFjubRGed0Be45JJQEn7A3CSb6Xu7NYobnxfkwAGZ Q81a2XtvNS7Aj6NWVoOQB5KbM4yosO5+Me1V1SkX2jlnn26JPEvbV3KRFcwV5RnDxm4OQTSk PYbAkjBbm+tuJ/Sm+5Yp5T/BnKz21FoCS8uvTiziHj2H7Cuekn6F8EYhegONm+RVg3vikOpn gao85i4HwQTK9/D1wgJIQkdwWXVMZ6q/OALaBp82vQ2U9sjTyFXgDjglgh00VRAHP7u1Rcu4 l75w1xInsg== In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 5/1/2025 11:59 AM, Sean Christopherson wrote: >> Ok maybe I'm being dense, but what is left other than simply calling >> __fred_entry_from_kvm() as a normal C function? >> >> I'm on the go so there might be something in the code I'm missing, but on the >> surface...? > I'm sure it's doable, though I'd be more than a little nervous about diverging > from what FRED=y does, e.g. in case code somewhere expects the stack to look > exactly like a real FRED event. __fred_entry_from_kvm() accepts a pt_regs structure pointer, with event type and vector in FRED stack frame. They are set up in the assembly. > And since we'd still need the assembly to support FRED=y, I don't see any point > in adding more code when it's trivially easy to have asm_fred_entry_from_kvm() > skip ERETS. Yeah, your change seems minimized to me.