From patchwork Mon Apr 26 07:29:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 427882 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_RED, USER_AGENT_GIT 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 84710C43460 for ; Mon, 26 Apr 2021 07:36:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 54FEC613B0 for ; Mon, 26 Apr 2021 07:36:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233050AbhDZHhb (ORCPT ); Mon, 26 Apr 2021 03:37:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:49798 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232965AbhDZHgq (ORCPT ); Mon, 26 Apr 2021 03:36:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 48BFD613C1; Mon, 26 Apr 2021 07:34:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1619422492; bh=mVyWi9XG90EchzaJQHS0kyf10Ks7lxWF4bcLEboImsE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bHnd2N7GuvmvHhSTlyn2GHvYc5BCc/oMENQ/sMnVYIVBmlAu1WrTysnOw3OFEseTv YPZng2T20jzpf0QYEzt5SZ6pCtcJrcBsLPffZ09F4M5/Z0DWiX3rUoYPG3DC4alHo2 RYqdUl6xSNWsJJpOIfdo+BeRmp39vHUDNUNHRsAY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Fredrik Strupe , Russell King Subject: [PATCH 4.14 35/49] ARM: 9071/1: uprobes: Dont hook on thumb instructions Date: Mon, 26 Apr 2021 09:29:31 +0200 Message-Id: <20210426072820.920816921@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210426072819.721586742@linuxfoundation.org> References: <20210426072819.721586742@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Fredrik Strupe commit d2f7eca60b29006285d57c7035539e33300e89e5 upstream. 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 Cc: stable@vger.kernel.org Fixes: c7edc9e326d5 ("ARM: add uprobes support") Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- arch/arm/probes/uprobes/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/arm/probes/uprobes/core.c +++ b/arch/arm/probes/uprobes/core.c @@ -207,7 +207,7 @@ unsigned long uprobe_get_swbp_addr(struc static struct undef_hook uprobes_arm_break_hook = { .instr_mask = 0x0fffffff, .instr_val = (UPROBE_SWBP_ARM_INSN & 0x0fffffff), - .cpsr_mask = MODE_MASK, + .cpsr_mask = (PSR_T_BIT | MODE_MASK), .cpsr_val = USR_MODE, .fn = uprobe_trap_handler, }; @@ -215,7 +215,7 @@ static struct undef_hook uprobes_arm_bre static struct undef_hook uprobes_arm_ss_hook = { .instr_mask = 0x0fffffff, .instr_val = (UPROBE_SS_ARM_INSN & 0x0fffffff), - .cpsr_mask = MODE_MASK, + .cpsr_mask = (PSR_T_BIT | MODE_MASK), .cpsr_val = USR_MODE, .fn = uprobe_trap_handler, };