From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6726221506E; Thu, 6 Feb 2025 11:54:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738842895; cv=none; b=iwqcPFrJr1FZYPuSd9NViVjmD2a0tKDASsmC5O9XEru5sZuQ6Z5NYQtJHUzFuv+LJFKTvPkv/hmYyT7vLgQGaGw9gEJzeSrhrr/10puSwkxiXubIHonC4m6uUhGc6VYtquvCOQFE9TXuslV0XZu+sVy0O2M7nozrs+vWqFRz2fI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738842895; c=relaxed/simple; bh=j3wbsZhH071Dq/51XFPsy9CDyT3KcXjm37OtjCYNNTY=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=FLQQ8y4t895kGOHtfz+2OBGJRscI6cM2nF5XQ1Y6xHM64cLQV8JC/t5bHrv67QAYYvtT9aJJurThsRvs/DwkyBAePK/uLn8NtCYtfJ4+thpQXOsyClN+QjWe1CttGzEcQNPKBsJ7oWLwr4n/ypPHdyKOhY2eOVkFYjZA24xSYk8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HZHpoX1N; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HZHpoX1N" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8F8DC4CEE2; Thu, 6 Feb 2025 11:54:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738842894; bh=j3wbsZhH071Dq/51XFPsy9CDyT3KcXjm37OtjCYNNTY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=HZHpoX1NfDM8PGJOMCl+ug6J7wmzjFdzrggV3GhPrdoFM6jgzX35/T4+SS6etxquQ Gv0UsMjcW4hcHCMFXzaidCAvKXtVWgOwphTjlPC6BvmV6rRBmQFrudFdDhFo12qBxN Wvm7mm9EQfFEAN8lzFMsr0z53PSfDlDnTRmAm5zR46b5KHT17yuyfq6G2Hnnc++GMQ ZnuKSAgmEMfCq8Z9o9/gJ2GKbWyAvVAv7c3OsxUtV5cIJX0V9QjK4X7TOgw8Gm0ZxQ tc+6A9yXWu1K2CvsUegoLkwltC2P7l186B7pYoLopFMA73bWmR9iOADJ1+quTTYO1+ /KmuErlxI7j2Q== Date: Thu, 6 Feb 2025 20:54:49 +0900 From: Masami Hiramatsu (Google) To: Peter Zijlstra Cc: Steven Rostedt , Gabriel de Perthuis , Haiyue Wang , Sami Tolvanen , Mark Rutland , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H . Peter Anvin" , x86@kernel.org, linux-trace-kernel@vger.kernel.org, LKML Subject: Re: [PATCH] ftrace: x86: Fix a compile error about get_kernel_nofault() Message-Id: <20250206205449.5f83a585945ae6eb0cc15483@kernel.org> In-Reply-To: <20250206081225.GI7145@noisy.programming.kicks-ass.net> References: <173881156244.211648.1242168038709680511.stgit@devnote2> <20250206081225.GI7145@noisy.programming.kicks-ass.net> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 6 Feb 2025 09:12:25 +0100 Peter Zijlstra wrote: > > > +#ifdef CONFIG_HAVE_FENTRY > > +/* Convert fentry address to the symbol address. */ > > +unsigned long arch_ftrace_get_symaddr(unsigned long fentry_ip) > > +{ > > +#ifdef CONFIG_X86_KERNEL_IBT > > + u32 instr; > > + > > + /* We want to be extra safe in case entry ip is on the page edge, > > + * but otherwise we need to avoid get_kernel_nofault()'s overhead. > > + */ > > + if ((fentry_ip & ~PAGE_MASK) < ENDBR_INSN_SIZE) { > > + if (get_kernel_nofault(instr, (u32 *)(fentry_ip - ENDBR_INSN_SIZE))) > > + return fentry_ip; > > + } else { > > + instr = *(u32 *)(fentry_ip - ENDBR_INSN_SIZE); > > + } > > + if (is_endbr(instr)) > > + fentry_ip -= ENDBR_INSN_SIZE; > > +#endif > > + return fentry_ip; > > +} > > +#endif > > Urgh, that reminds, me. I have a pile of patches cleaning up this mess. > Let me go find them. Thanks for cleaning up! So would it change the location of ENDBR and symbol address? Thanks, -- Masami Hiramatsu (Google)