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=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 F1D06C43462 for ; Mon, 19 Apr 2021 20:44:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D9B63613C0 for ; Mon, 19 Apr 2021 20:44:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242412AbhDSUof (ORCPT ); Mon, 19 Apr 2021 16:44:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:54164 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242407AbhDSUoe (ORCPT ); Mon, 19 Apr 2021 16:44:34 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4F6C8613B0; Mon, 19 Apr 2021 20:44:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618865044; bh=nAmp5UIFdq9tgAD5cLuft77KrM6yGyF0GIa2ORZdBR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WkJzcDtLRxIiUmY9hnVWEo+0Ymu1f0trLmbVbn62ZoSQ7CJjM9yKCrP+DlvOnVOsv CchRoJeW2ZsbJ02mstiAJC9E6/HTOEnFp0Ny/O2uXiMrwwHpI0U40EM61czb4xXrkf Yg5xvBHV92s1LBtMJ2luQLP14G9SPQWmRZDpCsO4V6onU5P5movtlSmYo1Lo5b4rKy WeMTJX2BbkVHIIzrnjD78FD6FJEz/DydRTwCRSE+rvM64aiunI5+RBLmw09V1eeBUO HQ8ql2W9MV5EWLAI69+T59W9uJlZhCOfYdj/MXG/Jvy76huHQuvC6f03VZlGAwto9X QDUlbGKqMzZKw== 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 5.11 14/23] arm64: kprobes: Restore local irqflag if kprobes is cancelled Date: Mon, 19 Apr 2021 16:43:33 -0400 Message-Id: <20210419204343.6134-14-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210419204343.6134-1-sashal@kernel.org> References: <20210419204343.6134-1-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: 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