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,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 8D86EC433B4 for ; Mon, 19 Apr 2021 20:46:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5CAF1613B4 for ; Mon, 19 Apr 2021 20:46:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239747AbhDSUrX (ORCPT ); Mon, 19 Apr 2021 16:47:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:55020 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240352AbhDSUpS (ORCPT ); Mon, 19 Apr 2021 16:45:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 735CF613B8; Mon, 19 Apr 2021 20:44:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618865078; bh=6kyVlTTcQvm60muHEDHx+81IPWmlevGExB5GYk3nMuk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CaG85hAuYw6bdrY5vk7P1+SPuRiqNksH7qJRxioSYvKEangx86aZA/Wwyaeiq2d/3 88TcUDIBmCml1QIp+G5Ajn1RlC6nGHH+TBHsY/QsJkRiVKLHMtIWlgbprqM931g0vH 74/la0sFtXlXmUmIvrRdQrRtFkInUv39UuwX+CQyzMa1uGMqecn22EgWgC9K/bO53p kVpPhe1i6WMwk2VIczl1jGWwUIjVz+74wCJmH27PZb+fwLG1PxGnd+yNki8abCoijA CjbivXfd6zly6kNEUO0xwnIQ53l46Syzz+SXoic2mGyDNdZsrfg/mMGEj6ednpfr0w wDjGU3ObTGu9w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jisheng Zhang , Masami Hiramatsu , Will Deacon , Sasha Levin , linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org Subject: [PATCH AUTOSEL 5.10 12/21] arm64: kprobes: Restore local irqflag if kprobes is cancelled Date: Mon, 19 Apr 2021 16:44:10 -0400 Message-Id: <20210419204420.6375-12-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210419204420.6375-1-sashal@kernel.org> References: <20210419204420.6375-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 f11a1a1f7026..798c3e78b84b 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -286,10 +286,12 @@ 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