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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50D18C433EF for ; Tue, 5 Oct 2021 14:02:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35A6461503 for ; Tue, 5 Oct 2021 14:02:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236536AbhJEOE0 (ORCPT ); Tue, 5 Oct 2021 10:04:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:41276 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235494AbhJEOCi (ORCPT ); Tue, 5 Oct 2021 10:02:38 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 BB37661A02; Tue, 5 Oct 2021 13:58:30 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94.2) (envelope-from ) id 1mXkxh-0055pL-PW; Tue, 05 Oct 2021 09:58:29 -0400 Message-ID: <20211005135829.626535781@goodmis.org> User-Agent: quilt/0.66 Date: Tue, 05 Oct 2021 09:57:55 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Masami Hiramatsu Subject: [for-linus][PATCH 22/27] arm: kprobes: Make space for instruction pointer on stack References: <20211005135733.485175654@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Masami Hiramatsu Since arm's __kretprobe_trampoline() saves partial 'pt_regs' on the stack, 'regs->ARM_pc' (instruction pointer) is not accessible from the kretprobe handler. This means if instruction_pointer_set() is used from kretprobe handler, it will break the data on the stack. Make space for instruction pointer (ARM_pc) on the stack in the __kretprobe_trampoline() for fixing this problem. Link: https://lkml.kernel.org/r/163163052262.489837.10327621053231461255.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- arch/arm/probes/kprobes/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index 67ce7eb8f285..95f23b47ba27 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -376,11 +376,13 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, void __naked __kprobes __kretprobe_trampoline(void) { __asm__ __volatile__ ( + "sub sp, sp, #16 \n\t" "stmdb sp!, {r0 - r11} \n\t" "mov r0, sp \n\t" "bl trampoline_handler \n\t" "mov lr, r0 \n\t" "ldmia sp!, {r0 - r11} \n\t" + "add sp, sp, #16 \n\t" #ifdef CONFIG_THUMB2_KERNEL "bx lr \n\t" #else -- 2.32.0