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=-19.4 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, 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 C6951C07E9C for ; Fri, 9 Jul 2021 13:18:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B0D84613BC for ; Fri, 9 Jul 2021 13:18:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231808AbhGINVO (ORCPT ); Fri, 9 Jul 2021 09:21:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:51300 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231839AbhGINVN (ORCPT ); Fri, 9 Jul 2021 09:21:13 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7F50E61377; Fri, 9 Jul 2021 13:18:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1625836710; bh=UA7kM1YSUvyFkHA+LB4CsP59vVgFeTQm0Av8wunOy4c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bVXqqB0aNxJ4vrqTnEhguwpM9eFYNJIK9xvyooUf5gbxbLeYFstfrYOvdMV2SpYMj AqmBT709JuCPeHvgDu/qQE1ERVbkG+SbyRfsAMk/INkagbM1OuBS4tnSk3ZQzyRlus +MRTy9E3I0FiAqNxJWJ/GI1WA6xejg66OA/J2UVM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Masami Hiramatsu , Jon Medhurst , huangshaobo Subject: [PATCH 4.4 4/4] arm: kprobes: Allow to handle reentered kprobe on single-stepping Date: Fri, 9 Jul 2021 15:18:16 +0200 Message-Id: <20210709131536.103724111@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210709131529.395072769@linuxfoundation.org> References: <20210709131529.395072769@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Masami Hiramatsu commit f3fbd7ec62dec1528fb8044034e2885f2b257941 upstream. This is arm port of commit 6a5022a56ac3 ("kprobes/x86: Allow to handle reentered kprobe on single-stepping") Since the FIQ handlers can interrupt in the single stepping (or preparing the single stepping, do_debug etc.), we should consider a kprobe is hit in the NMI handler. Even in that case, the kprobe is allowed to be reentered as same as the kprobes hit in kprobe handlers (KPROBE_HIT_ACTIVE or KPROBE_HIT_SSDONE). The real issue will happen when a kprobe hit while another reentered kprobe is processing (KPROBE_REENTER), because we already consumed a saved-area for the previous kprobe. Signed-off-by: Masami Hiramatsu Signed-off-by: Jon Medhurst Fixes: 24ba613c9d6c ("ARM kprobes: core code") Cc: stable@vger.kernel.org #v2.6.25~v4.11 Signed-off-by: huangshaobo Signed-off-by: Greg Kroah-Hartman --- arch/arm/probes/kprobes/core.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -270,6 +270,7 @@ void __kprobes kprobe_handler(struct pt_ switch (kcb->kprobe_status) { case KPROBE_HIT_ACTIVE: case KPROBE_HIT_SSDONE: + case KPROBE_HIT_SS: /* A pre- or post-handler probe got us here. */ kprobes_inc_nmissed_count(p); save_previous_kprobe(kcb); @@ -278,6 +279,11 @@ void __kprobes kprobe_handler(struct pt_ singlestep(p, regs, kcb); restore_previous_kprobe(kcb); break; + case KPROBE_REENTER: + /* A nested probe was hit in FIQ, it is a BUG */ + pr_warn("Unrecoverable kprobe detected at %p.\n", + p->addr); + /* fall through */ default: /* impossible cases */ BUG();