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=-9.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,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 54F2CC07E9B for ; Mon, 5 Jul 2021 07:03:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E1AE613DD for ; Mon, 5 Jul 2021 07:03:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229956AbhGEHGD (ORCPT ); Mon, 5 Jul 2021 03:06:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229823AbhGEHGB (ORCPT ); Mon, 5 Jul 2021 03:06:01 -0400 Received: from mail-wr1-x42f.google.com (mail-wr1-x42f.google.com [IPv6:2a00:1450:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A08BC061574; Mon, 5 Jul 2021 00:03:24 -0700 (PDT) Received: by mail-wr1-x42f.google.com with SMTP id a8so9023107wrp.5; Mon, 05 Jul 2021 00:03:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=mlwWEARxhvB9v498o+gz4FHu2tW7KE99FvhfhbdwvnQ=; b=gPWBWCjl/AEs1navJIBirtWyllhhvX6sQNVCaIZMeYwBEfs7GLC9+GM1Y2Yk/bNvr6 G+dsQWPYkcB0d1U7kqpDV8pCkUn2T4+oPCYD+f5BL8mUkb3BPu7YX+V15yw+sL1J/skw Rmwx16kpELiC5lmh8PZYAriC4OyK7al65qySoXrdztmzWBuuUk+2IBUX9unRqEdFt3Tx 18/u1MUe/hcHESv99soOmXhvNxTeJa40UVOO9lexlOg7/Wi8ss8oEgFOjGSIksj6R5Hi zcDpEr1fRMZ/29jtAhscbuIzRDflZ/lbAnm0vNdH71ZYVugPR3ZGq7UdaB5TjYYP91pj 7ccQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=mlwWEARxhvB9v498o+gz4FHu2tW7KE99FvhfhbdwvnQ=; b=rCwLcQV77Y8xU33/Osa8zzvGB8PFGgTsXo9rcVaWVVRVqrsOPgogsUJk5uZ3xiPDou /CNFfFkQNknzc8R1EJSonY3FcPZgp6AzWm7G3/G2uZhPJz1g0KqQSp5S11X1J65Zm3xF /Bpyde1f76OJdD53jE+u8ApBigaYjzhmIZfDd4VPzfkYFFxZdbPQqBEdXoJmjD9vO1lN u+eiRg6eSt9LkN6pIrBYUqnEQ65JXDlHqU61sCOjafx6xXZTWgqW0A0g7V0cKmfTmfdc UrO/kgynpakCfWHuoEtn5+tJvydgf0Q5DrobyLYcccmwCLs4OD97h4//cRyX0J3di+XI NpSg== X-Gm-Message-State: AOAM530Yvuhc3aVxUU+/BkLc4fM9lG1L6KdmwlJqW22wv+tA/7D6D3/7 /i+tcmeyk6cZNKQM2sCasFY= X-Google-Smtp-Source: ABdhPJwhWsUcQrxxaoQq5hi9fv0k0FmIYS9xrc4FMBnYq/L31XsG+Lqhd74lVl2YNvCjWhHIzXmfvg== X-Received: by 2002:adf:eb0c:: with SMTP id s12mr10826924wrn.383.1625468602269; Mon, 05 Jul 2021 00:03:22 -0700 (PDT) Received: from gmail.com (178-164-188-14.pool.digikabel.hu. [178.164.188.14]) by smtp.gmail.com with ESMTPSA id w4sm11861169wrp.15.2021.07.05.00.03.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Jul 2021 00:03:21 -0700 (PDT) Sender: Ingo Molnar Date: Mon, 5 Jul 2021 09:03:19 +0200 From: Ingo Molnar To: Masami Hiramatsu 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: References: <162399992186.506599.8457763707951687195.stgit@devnote2> <162399994996.506599.17672270294950096639.stgit@devnote2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <162399994996.506599.17672270294950096639.stgit@devnote2> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * 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. Thanks, Ingo