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,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 0C41AC433B4 for ; Wed, 31 Mar 2021 13:43:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D89016199A for ; Wed, 31 Mar 2021 13:43:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235808AbhCaNnN (ORCPT ); Wed, 31 Mar 2021 09:43:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:59840 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235879AbhCaNmz (ORCPT ); Wed, 31 Mar 2021 09:42:55 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E025361994; Wed, 31 Mar 2021 13:42:54 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lRb7U-004uXd-TC; Wed, 31 Mar 2021 14:42:53 +0100 Date: Wed, 31 Mar 2021 14:42:52 +0100 Message-ID: <875z17qw0z.wl-maz@kernel.org> From: Marc Zyngier To: Fredrik Strupe Cc: Russell King , Rabin Vincent , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm: uprobes: Don't hook on thumb instructions In-reply-to: <20200518125948.25315-1-fredrik@strupe.net> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: fredrik@strupe.net, linux@armlinux.org.uk, rabin@rab.in, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Fredrik, On Mon, 18 May 2020, Fredrik Strupe wrote: > Since uprobes is not supported for thumb, check that the thumb bit is > not set when matching the uprobes instruction hooks. > > The Arm UDF instructions used for uprobes triggering > (UPROBE_SWBP_ARM_INSN and UPROBE_SS_ARM_INSN) coincidentally share the > same encoding as a pair of unallocated 32-bit thumb instructions (not > UDF) when the condition code is 0b1111 (0xf). This in effect makes it > possible to trigger the uprobes functionality from thumb, and at that > using two unallocated instructions which are not permanently > undefined. > > Signed-off-by: Fredrik Strupe Fixes: c7edc9e326d5 ("ARM: add uprobes support") It looks like we dropped the ball on this patch. Could you please add it to Russell's patch system, together with a Cc: stable? Otherwise, just say the word and I'll do it for you. Thanks, M. -- Without deviation from the norm, progress is not possible.