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 X-Spam-Level: X-Spam-Status: No, score=-12.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9ED55C07E9B for ; Mon, 5 Jul 2021 10:03:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 87353613D1 for ; Mon, 5 Jul 2021 10:03:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230488AbhGEKGM (ORCPT ); Mon, 5 Jul 2021 06:06:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:38060 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230476AbhGEKGK (ORCPT ); Mon, 5 Jul 2021 06:06:10 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CE968613C8; Mon, 5 Jul 2021 10:03:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625479414; bh=Q8/L2LRHglK2rXQ7PV40+1czQBiJ/w+Kx+K0KseNmao=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=XVf7rhMls18J9mYaKp4sO/vU7UNqO27Sea2F2RLPt6xM22kkJlLVMKD0NPBSdCzqw Ey/aI6wwkszdnn6rA/wC1ltyHxN0h+EY6dduRVFqDg9wqqo+CE7nb4doc/j3w6UQv4 HLDnq16sZ3HLpRqccxQ8XPHzPlTBhPDkYHv+q1/L1otOHzgye1yO7mNZjbo96iF0YH PdsJI0dunM2qwyyhZljvTfXZ+SmMDUhs0lkC2lw0V11llGuXcmZs5lzMKnVBrGkmAY I7Qxt5vwMRb0LAdEGEr0z7sHvzNa7iHUKy/PfUT4Y9dpuk2ISXFjetSouZ64vLASs0 XTG3BLYVVehbw== Date: Mon, 5 Jul 2021 19:03:28 +0900 From: Masami Hiramatsu To: Ingo Molnar Cc: Steven Rostedt , Josh Poimboeuf , X86 ML , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: Re: [PATCH -tip v8 03/13] kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler() Message-Id: <20210705190328.8cf3fb4397500f2dafb761f0@kernel.org> In-Reply-To: References: <162399992186.506599.8457763707951687195.stgit@devnote2> <162399994996.506599.17672270294950096639.stgit@devnote2> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ingo, On Mon, 5 Jul 2021 09:03:19 +0200 Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > > > --- a/include/linux/kprobes.h > > +++ b/include/linux/kprobes.h > > @@ -197,15 +197,23 @@ extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, > > struct pt_regs *regs); > > extern int arch_trampoline_kprobe(struct kprobe *p); > > > > +void kretprobe_trampoline(void); > > +/* > > + * Since some architecture uses structured function pointer, > > + * use dereference_function_descriptor() to get real function address. > > + */ > > +static nokprobe_inline void *kretprobe_trampoline_addr(void) > > +{ > > + return dereference_kernel_function_descriptor(kretprobe_trampoline); > > +} > > Could we please also make 'kretprobe_trampoline' harder to use > accidentally, such by naming it appropriately? > > __kretprobe_trampoline would be a good first step I guess. Good idea! Let me update it. Thank you, -- Masami Hiramatsu