From patchwork Thu Jun 6 09:31:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Thierry X-Patchwork-Id: 10978923 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2AFF992A for ; Thu, 6 Jun 2019 09:33:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 18B0928841 for ; Thu, 6 Jun 2019 09:33:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0D0B528843; Thu, 6 Jun 2019 09:33:53 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 90A1C28841 for ; Thu, 6 Jun 2019 09:33:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=05h/XW8cU5JHXnFmk4mPMswmuQr336cT6AgPsOIIMsg=; b=SKmH3Y/NXG/gma0ZnYILj+RSxS tGxWwbdObXKU5Plc+izQFT8hnAC+hj+6nsptuzplIUolsImVRtk+aFqUce1wHl0ENSWLovKl4Vxfx baTb25sDpijHpF9pdytRv7wNDUxsiejLyN2g5y15oFE4IY5WtDq7p/8ZIrqHBsD5hQpkIyB0RIwFz 7YrO/WJVhCrjS+x/NxF5Qro9C25pv7E9c1KR+wbpigaQQLBy5ob4SFhjK1QH3k4hsm0+RmRnIX2hj JuJwZYXqpIvxb2LtDLLXMViwRn+eR/HjBrCpMbkI8m7bOoHPbwKLONd3wsgnzTGURkqSZZU7fjylF U4fLWM9Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYomJ-0008Pq-HV; Thu, 06 Jun 2019 09:33:47 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYokv-0006jC-Tp for linux-arm-kernel@lists.infradead.org; Thu, 06 Jun 2019 09:32:29 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9AFBA169E; Thu, 6 Jun 2019 02:32:21 -0700 (PDT) Received: from e112298-lin.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 865543F690; Thu, 6 Jun 2019 02:32:19 -0700 (PDT) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 7/8] arm64: fix kernel stack overflow in kdump capture kernel Date: Thu, 6 Jun 2019 10:31:56 +0100 Message-Id: <1559813517-41540-8-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1559813517-41540-1-git-send-email-julien.thierry@arm.com> References: <1559813517-41540-1-git-send-email-julien.thierry@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190606_023222_881343_AB8DFF07 X-CRM114-Status: GOOD ( 16.43 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, Julien Thierry , marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, james.morse@arm.com, yuzenghui@huawei.com, wanghaibin.wang@huawei.com, liwei391@huawei.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Wei Li When enabling ARM64_PSEUDO_NMI feature in kdump capture kernel, it will report a kernel stack overflow exception: [ 0.000000] CPU features: detected: IRQ priority masking [ 0.000000] alternatives: patching kernel code [ 0.000000] Insufficient stack space to handle exception! [ 0.000000] ESR: 0x96000044 -- DABT (current EL) [ 0.000000] FAR: 0x0000000000000040 [ 0.000000] Task stack: [0xffff0000097f0000..0xffff0000097f4000] [ 0.000000] IRQ stack: [0x0000000000000000..0x0000000000004000] [ 0.000000] Overflow stack: [0xffff80002b7cf290..0xffff80002b7d0290] [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.34-lw+ #3 [ 0.000000] pstate: 400003c5 (nZcv DAIF -PAN -UAO) [ 0.000000] pc : el1_sync+0x0/0xb8 [ 0.000000] lr : el1_irq+0xb8/0x140 [ 0.000000] sp : 0000000000000040 [ 0.000000] pmr_save: 00000070 [ 0.000000] x29: ffff0000097f3f60 x28: ffff000009806240 [ 0.000000] x27: 0000000080000000 x26: 0000000000004000 [ 0.000000] x25: 0000000000000000 x24: ffff000009329028 [ 0.000000] x23: 0000000040000005 x22: ffff000008095c6c [ 0.000000] x21: ffff0000097f3f70 x20: 0000000000000070 [ 0.000000] x19: ffff0000097f3e30 x18: ffffffffffffffff [ 0.000000] x17: 0000000000000000 x16: 0000000000000000 [ 0.000000] x15: ffff0000097f9708 x14: ffff000089a382ef [ 0.000000] x13: ffff000009a382fd x12: ffff000009824000 [ 0.000000] x11: ffff0000097fb7b0 x10: ffff000008730028 [ 0.000000] x9 : ffff000009440018 x8 : 000000000000000d [ 0.000000] x7 : 6b20676e69686374 x6 : 000000000000003b [ 0.000000] x5 : 0000000000000000 x4 : ffff000008093600 [ 0.000000] x3 : 0000000400000008 x2 : 7db2e689fc2b8e00 [ 0.000000] x1 : 0000000000000000 x0 : ffff0000097f3e30 [ 0.000000] Kernel panic - not syncing: kernel stack overflow [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.34-lw+ #3 [ 0.000000] Call trace: [ 0.000000] dump_backtrace+0x0/0x1b8 [ 0.000000] show_stack+0x24/0x30 [ 0.000000] dump_stack+0xa8/0xcc [ 0.000000] panic+0x134/0x30c [ 0.000000] __stack_chk_fail+0x0/0x28 [ 0.000000] handle_bad_stack+0xfc/0x108 [ 0.000000] __bad_stack+0x90/0x94 [ 0.000000] el1_sync+0x0/0xb8 [ 0.000000] init_gic_priority_masking+0x4c/0x70 [ 0.000000] smp_prepare_boot_cpu+0x60/0x68 [ 0.000000] start_kernel+0x1e8/0x53c [ 0.000000] ---[ end Kernel panic - not syncing: kernel stack overflow ]--- The reason is init_gic_priority_masking() may unmask PSR.I while the irq stacks are not inited yet. Some "NMI" could be raised unfortunately and it will just go into this exception. In this patch, we just write the PMR in smp_prepare_boot_cpu(), and delay unmasking PSR.I after irq stacks inited in init_IRQ(). Fixes: e79321883842 ("arm64: Switch to PMR masking when starting CPUs") Signed-off-by: Wei Li [JT: make init_gic_priority_masking() not modify daif, rebase on other priority masking fixes] Signed-off-by: Julien Thierry --- arch/arm64/kernel/irq.c | 9 +++++++++ arch/arm64/kernel/smp.c | 8 +------- 2 files changed, 10 insertions(+), 7 deletions(-) diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c index fdd9cb2..e8daa7a 100644 --- a/arch/arm64/kernel/irq.c +++ b/arch/arm64/kernel/irq.c @@ -77,6 +77,15 @@ void __init init_IRQ(void) irqchip_init(); if (!handle_arch_irq) panic("No interrupt controller found."); + + if (system_uses_irq_prio_masking()) { + /* + * Now that we have a stack for our IRQ handler, set + * the PMR/PSR pair to a consistent state. + */ + WARN_ON(read_sysreg(daif) & PSR_A_BIT); + local_daif_restore(DAIF_PROCCTX_NOIRQ); + } } /* diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 4deaee3..83cdb0a 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -192,13 +192,7 @@ static void init_gic_priority_masking(void) WARN_ON(!(cpuflags & PSR_I_BIT)); - /* We can only unmask PSR.I if we can take aborts */ - if (!(cpuflags & PSR_A_BIT)) { - gic_write_pmr(GIC_PRIO_IRQOFF); - write_sysreg(cpuflags & ~PSR_I_BIT, daif); - } else { - gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET); - } + gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET); } /*