From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-217.mta0.migadu.com [91.218.175.217]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3F29036A02F for ; Sun, 6 Sep 2026 20:41:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.217 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788727285; cv=none; b=BuKvOFpmzP3dwGv0WM3W7Vk2VWh00zorik9t8rTYGfXouHpKcJB10lwKaJ/hVH9bDaEycLXt66uS+oxKnjc722LI5O2fwW0i6mYs8uZOucHQhVX80YzYYiflyXJs+vZ/Cdg21t8a3G3PaEtv01TB5xZNNDQm4ZmKO61atOWq54o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788727285; c=relaxed/simple; bh=bSpNhh9FtdEJvuQK9j6aUZgksjI6iJ3Km92h4AkEbNc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KxjKsjK+vYrgoRh57HSYLaETXyQg9e/uxWMAkW5+s9tPVoHWD+pJcFEdKX9nOexMsFh21cVcPymQDz1Tdxy0MJDw/0rOy4ly0j0MogKCEecpLTuAsK5guJXeK/F6YZIbVNp+AqjwkiJK/2xbMiqPny5T+gNl6YniOLsrYvKDoR8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=omoRRI5D; arc=none smtp.client-ip=91.218.175.217 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="omoRRI5D" X-Envelope-To: linux-kbuild@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=bSpNhh9FtdEJvuQK9j6aUZgksjI6iJ3Km92h4AkEbNc=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1788727281; v=1; x=1789332081; b=omoRRI5Dzr5wBNhMy4mtHwZ7FEJVOMY0HPYFLcnT9CXo8cWkLFTDN8K0cZx9nQo2ltHsjl9q AWZ7l9tB8YKsXK5Or/obCEAp9GGGmdVumaoEQBglKAvpjjPMx67ilNL4afL+brMphlwppG1OQKb Ep9LAV0avim22jNsZ7WeX5Tg= X-Envelope-To: linux-kbuild@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id ce9db71ae2dcd178; Sun, 06 Sep 2026 20:41:11 +0000 X-Mizu-Trace-ID: ce9db71ae2dcd178 X-Migadu-Flow: FLOW_OUT Date: Sun, 6 Sep 2026 20:40:59 +0000 From: "Jose Fernandez (Anthropic)" To: Steven Rostedt Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Nathan Chancellor , Nicolas Schier , Nick Desaulniers , Bill Wendling , Justin Stitt , Catalin Marinas , Will Deacon , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Puranjay Mohan , Xu Kuohai , Ard Biesheuvel , Ilias Apalodimas , Miguel Ojeda , Boqun Feng , Gary Guo , =?utf-8?B?QmrDtnJu?= Roy Baron , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , Onur =?utf-8?B?w5Z6a2Fu?= , Sami Tolvanen , Kees Cook , Leon Hwang , Ihor Solodrai , Josh Poimboeuf , live-patching@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, llvm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, bpf@vger.kernel.org, linux-efi@vger.kernel.org, rust-for-linux@vger.kernel.org, Ben Cressey , "Florent Revest (Anthropic)" Subject: Re: [PATCH RFC 1/8] ftrace: Let ftrace_call_adjust() reject a patch site Message-ID: References: <20260904-b4-arm64-callops-kcfi-v1-0-ce6687739b0c@linux.dev> <20260904-b4-arm64-callops-kcfi-v1-1-ce6687739b0c@linux.dev> <20260904084728.6d2ebcc8@gandalf.local.home> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260904084728.6d2ebcc8@gandalf.local.home> On Fri, 4 Sep 2026 08:47:28 -0400, Steven Rostedt wrote: > The above could use a comment to why addr could be zero (I didn't even > realize some architectures do that). > > /* Some architectures may return zero for mis-aligned addresses */ Will add one in v2, thanks. Today arm64 returns 0 only for a mis-aligned patch site. But patch 4 of this series replaces that check with two: the two NOPs to patch must be there, and the ops pointer must fit in the prefix NOPs (which also catches a mis-aligned site). How about this to cover the series? /* The architecture may return 0 to reject a patch site */ Happy to name the mis-aligned case in patch 1 and extend the comment in patch 4 if you prefer that. Thanks, Jose