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=-19.0 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, 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 A5741C433ED for ; Mon, 26 Apr 2021 07:45:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 75BA760FEE for ; Mon, 26 Apr 2021 07:45:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233016AbhDZHp7 (ORCPT ); Mon, 26 Apr 2021 03:45:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:60148 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234124AbhDZHou (ORCPT ); Mon, 26 Apr 2021 03:44:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8BE7461009; Mon, 26 Apr 2021 07:41:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1619422897; bh=nAmp5UIFdq9tgAD5cLuft77KrM6yGyF0GIa2ORZdBR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d8Kp8fvrO+6Ou+CjBs4GBmnLxa2AVqwMvYKpMYUQXCCwxzT+TPKo00pQW6/1lGcES ljs8t37dIRTeD16Hmkv1WQxAR2i/u570HDTQr7rFb9e4Zb9/Ge2st5zlZGJbbfdLmo S4QzponrIHTWERVLxm7XIt5Ra+Xqn7Ri5SDSe10A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jisheng Zhang , Masami Hiramatsu , Will Deacon , Sasha Levin Subject: [PATCH 5.11 35/41] arm64: kprobes: Restore local irqflag if kprobes is cancelled Date: Mon, 26 Apr 2021 09:30:22 +0200 Message-Id: <20210426072820.882312452@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210426072819.666570770@linuxfoundation.org> References: <20210426072819.666570770@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: Jisheng Zhang [ Upstream commit 738fa58ee1328481d1d7889e7c430b3401c571b9 ] If instruction being single stepped caused a page fault, the kprobes is cancelled to let the page fault handler continue as a normal page fault. But the local irqflags are disabled so cpu will restore pstate with DAIF masked. After pagefault is serviced, the kprobes is triggerred again, we overwrite the saved_irqflag by calling kprobes_save_local_irqflag(). NOTE, DAIF is masked in this new saved irqflag. After kprobes is serviced, the cpu pstate is retored with DAIF masked. This patch is inspired by one patch for riscv from Liao Chang. Signed-off-by: Jisheng Zhang Acked-by: Masami Hiramatsu Link: https://lore.kernel.org/r/20210412174101.6bfb0594@xhacker.debian Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- arch/arm64/kernel/probes/kprobes.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index 66aac2881ba8..85645b2b0c7a 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -267,10 +267,12 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, unsigned int fsr) if (!instruction_pointer(regs)) BUG(); - if (kcb->kprobe_status == KPROBE_REENTER) + if (kcb->kprobe_status == KPROBE_REENTER) { restore_previous_kprobe(kcb); - else + } else { + kprobes_restore_local_irqflag(kcb, regs); reset_current_kprobe(); + } break; case KPROBE_HIT_ACTIVE: -- 2.30.2