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=-16.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 0D7E1C433B4 for ; Fri, 16 Apr 2021 06:25:50 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 70F6661153 for ; Fri, 16 Apr 2021 06:25:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 70F6661153 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC:To:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=I0IApayPmYmL6JJi0q95lan2gE6+PN8/TcfdInT2mpI=; b=LqMoxiQTG/6Mz9hwVKmaFHfXGl 7JCqHuPH/RgCk0NH78LN+UOu4gBXVxAj9F6sSza28ZWMMLYgrRWo97woBQyc861PN2XdRsntKvDzG ML81P5D4xw072CAyqu64xsNsW2Veb08HCSoAKQGq+MA779XtyGKrzeCtsZXAj4XiBWlYrwuPc2v2g jZ+sRthJcn/7nYB3vAdR+8DEywSL1rsj5XO+2FWE4h7KExpPyFjAz7qlLxcqpgfSQ2HWHnoe8qSxZ VD5pF8d0LA6KRYT+zpUPCfOGlxkMRBe0c+r0KiEOBogYjfYM31x5f2fSPObFAf0RFeZOyl7efvuc9 0g8fG8ZQ==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lXHtT-0011Ws-A9; Fri, 16 Apr 2021 06:23:55 +0000 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lXHsB-0011Gr-Vg for linux-arm-kernel@desiato.infradead.org; Fri, 16 Apr 2021 06:22:46 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Type:MIME-Version:Message-ID: Date:Subject:CC:To:From:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:In-Reply-To:References; bh=NvxaZgl6lplZLIR2jvSJSfNR2l7fvt166486E7nZxuY=; b=k16h9I7yXOodKzg5b45IYBbqdg 1UX8UcIZsinUV3sCp3L+kAEVPgTuBnh0y0Sb0NapjDd/JCGi6V4bxnhYtgkNe/GUwjgRnH5uZMhgb tCvmmirgVGizmME3mMJ0TGPIK7/XKqcg2P97cFYSJYmMvnZnDL3n+SdmMkGidBwqaNjpRkdYksAIs TLMM2ElZujlTee3D27CmvuTN4kNVvjbcCnkXUaPojLgv8/+0pqUXfDmYGNY0biRh/+MqaFCtPrCIz qsTX+kD1csbTjJfUSisuSwOKewaL8XL1ep5zatvtYWhrcx3SLHA+tkhQ9NS/W9SN/271VHTbCgoU2 ZyNJXJhQ==; Received: from szxga07-in.huawei.com ([45.249.212.35]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lXHs7-0097AL-L7 for linux-arm-kernel@lists.infradead.org; Fri, 16 Apr 2021 06:22:33 +0000 Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4FM5fV55S3z7vDh; Fri, 16 Apr 2021 14:20:02 +0800 (CST) Received: from huawei.com (10.67.174.47) by DGGEMS401-HUB.china.huawei.com (10.3.19.201) with Microsoft SMTP Server id 14.3.498.0; Fri, 16 Apr 2021 14:22:11 +0800 From: He Ying To: , , , CC: , , Subject: [RFC PATCH] irqchip/gic-v3: Do not enable irqs when handling spurious interrups Date: Fri, 16 Apr 2021 02:22:17 -0400 Message-ID: <20210416062217.25157-1-heying24@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.67.174.47] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210415_232232_046386_6A15E638 X-CRM114-Status: GOOD ( 18.18 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org We found this problem in our kernel src tree: [ 14.816231] ------------[ cut here ]------------ [ 14.816231] kernel BUG at irq.c:99! [ 14.816232] Internal error: Oops - BUG: 0 [#1] SMP [ 14.816232] Process swapper/0 (pid: 0, stack limit = 0x(____ptrval____)) [ 14.816233] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 4.19.95-1.h1.AOS2.0.aarch64 #14 [ 14.816233] Hardware name: evb (DT) [ 14.816234] pstate: 80400085 (Nzcv daIf +PAN -UAO) [ 14.816234] pc : asm_nmi_enter+0x94/0x98 [ 14.816235] lr : asm_nmi_enter+0x18/0x98 [ 14.816235] sp : ffff000008003c50 [ 14.816235] pmr_save: 00000070 [ 14.816237] x29: ffff000008003c50 x28: ffff0000095f56c0 [ 14.816238] x27: 0000000000000000 x26: ffff000008004000 [ 14.816239] x25: 00000000015e0000 x24: ffff8008fb916000 [ 14.816240] x23: 0000000020400005 x22: ffff0000080817cc [ 14.816241] x21: ffff000008003da0 x20: 0000000000000060 [ 14.816242] x19: 00000000000003ff x18: ffffffffffffffff [ 14.816243] x17: 0000000000000008 x16: 003d090000000000 [ 14.816244] x15: ffff0000095ea6c8 x14: ffff8008fff5ab40 [ 14.816244] x13: ffff8008fff58b9d x12: 0000000000000000 [ 14.816245] x11: ffff000008c8a200 x10: 000000008e31fca5 [ 14.816246] x9 : ffff000008c8a208 x8 : 000000000000000f [ 14.816247] x7 : 0000000000000004 x6 : ffff8008fff58b9e [ 14.816248] x5 : 0000000000000000 x4 : 0000000080000000 [ 14.816249] x3 : 0000000000000000 x2 : 0000000080000000 [ 14.816250] x1 : 0000000000120000 x0 : ffff0000095f56c0 [ 14.816251] Call trace: [ 14.816251] asm_nmi_enter+0x94/0x98 [ 14.816251] el1_irq+0x8c/0x180 [ 14.816252] gic_handle_irq+0xbc/0x2e4 [ 14.816252] el1_irq+0xcc/0x180 [ 14.816253] arch_timer_handler_virt+0x38/0x58 [ 14.816253] handle_percpu_devid_irq+0x90/0x240 [ 14.816253] generic_handle_irq+0x34/0x50 [ 14.816254] __handle_domain_irq+0x68/0xc0 [ 14.816254] gic_handle_irq+0xf8/0x2e4 [ 14.816255] el1_irq+0xcc/0x180 [ 14.816255] arch_cpu_idle+0x34/0x1c8 [ 14.816255] default_idle_call+0x24/0x44 [ 14.816256] do_idle+0x1d0/0x2c8 [ 14.816256] cpu_startup_entry+0x28/0x30 [ 14.816256] rest_init+0xb8/0xc8 [ 14.816257] start_kernel+0x4c8/0x4f4 [ 14.816257] Code: 940587f1 d5384100 b9401001 36a7fd01 (d4210000) [ 14.816258] Modules linked in: start_dp(O) smeth(O) [ 15.103092] ---[ end trace 701753956cb14aa8 ]--- [ 15.103093] Kernel panic - not syncing: Fatal exception in interrupt [ 15.103099] SMP: stopping secondary CPUs [ 15.103100] Kernel Offset: disabled [ 15.103100] CPU features: 0x36,a2400218 [ 15.103100] Memory Limit: none Our kernel src tree is based on 4.19.95 and backports arm64 pseudo-NMI patches but doesn't support nested NMI. Its top relative commit is commit 17ce302f3117 ("arm64: Fix interrupt tracing in the presence of NMIs"). I look into this issue and find that it's caused by 'BUG_ON(in_nmi())' in nmi_enter(). From the call trace, we find two 'el1_irqs' which means an interrupt preempts the other one and the new one is an NMI. Furthermore, by adding some prints, we find the first irq also calls nmi_enter(), but its priority is not GICD_INT_NMI_PRI and its irq number is 1023. It enables irq by calling gic_arch_enable_irqs() in gic_handle_irq(). At this moment, the second irq preempts the first irq and it's an NMI but current context is already in nmi. So that may be the problem. In my opinion, when handling spurious interrupts, we shouldn't enable irqs. My reason is that for spurious interrupts we may enter nmi context in el1_irq() because current PMR may be GIC_PRIO_IRQOFF. If we enable irqs at this time, another NMI may happen and preempt this spurious interrupt but the context is already in nmi. That causes a bug on if nested NMI is not supported. Even for nested nmi, I think it's not a normal scenario. Fixes: 17ce302f3117 ("arm64: Fix interrupt tracing in the presence of NMIs") Signed-off-by: He Ying --- drivers/irqchip/irq-gic-v3.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 94b89258d045..d3b52734a2c5 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -654,15 +654,15 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs return; } + /* Check for special IDs first */ + if ((irqnr >= 1020 && irqnr <= 1023)) + return; + if (gic_prio_masking_enabled()) { gic_pmr_mask_irqs(); gic_arch_enable_irqs(); } - /* Check for special IDs first */ - if ((irqnr >= 1020 && irqnr <= 1023)) - return; - if (static_branch_likely(&supports_deactivate_key)) gic_write_eoir(irqnr); else -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel