Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756325AbdLTTCs (ORCPT ); Wed, 20 Dec 2017 14:02:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36764 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755948AbdLTTCn (ORCPT ); Wed, 20 Dec 2017 14:02:43 -0500 Date: Wed, 20 Dec 2017 12:02:39 -0700 From: Alex Williamson To: Jerry Snitselaar Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Joerg Roedel , Ashok Raj Subject: Re: [PATCH] iommu/vt-d: clean up pr_irq if request_threaded_irq fails Message-ID: <20171220120239.77d62a1a@t450s.home> In-Reply-To: <20171206164959.23794-1-jsnitsel@redhat.com> References: <20171206164959.23794-1-jsnitsel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 20 Dec 2017 19:02:43 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5198 Lines: 97 On Wed, 6 Dec 2017 09:49:59 -0700 Jerry Snitselaar wrote: > It is unlikely request_threaded_irq will fail, but if it does for some > reason we should clear iommu->pr_irq in the error path. Also > intel_svm_finish_prq shouldn't try to clean up the page request > interrupt if pr_irq is 0. Without these, if request_threaded_irq were > to fail the following occurs: > > fail with no fixes: > > [ 0.683147] ------------[ cut here ]------------ > [ 0.683148] NULL pointer, cannot free irq > [ 0.683158] WARNING: CPU: 1 PID: 1 at kernel/irq/irqdomain.c:1632 irq_domain_free_irqs+0x126/0x140 > [ 0.683160] Modules linked in: > [ 0.683163] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2 #3 > [ 0.683165] Hardware name: /NUC7i3BNB, BIOS BNKBL357.86A.0036.2017.0105.1112 01/05/2017 > [ 0.683168] RIP: 0010:irq_domain_free_irqs+0x126/0x140 > [ 0.683169] RSP: 0000:ffffc90000037ce8 EFLAGS: 00010292 > [ 0.683171] RAX: 000000000000001d RBX: ffff880276283c00 RCX: ffffffff81c5e5e8 > [ 0.683172] RDX: 0000000000000001 RSI: 0000000000000096 RDI: 0000000000000246 > [ 0.683174] RBP: ffff880276283c00 R08: 0000000000000000 R09: 000000000000023c > [ 0.683175] R10: 0000000000000007 R11: 0000000000000000 R12: 000000000000007a > [ 0.683176] R13: 0000000000000001 R14: 0000000000000000 R15: 0000010010000000 > [ 0.683178] FS: 0000000000000000(0000) GS:ffff88027ec80000(0000) knlGS:0000000000000000 > [ 0.683180] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 0.683181] CR2: 0000000000000000 CR3: 0000000001c09001 CR4: 00000000003606e0 > [ 0.683182] Call Trace: > [ 0.683189] intel_svm_finish_prq+0x3c/0x60 > [ 0.683191] free_dmar_iommu+0x1ac/0x1b0 > [ 0.683195] init_dmars+0xaaa/0xaea > [ 0.683200] ? klist_next+0x19/0xc0 > [ 0.683203] ? pci_do_find_bus+0x50/0x50 > [ 0.683205] ? pci_get_dev_by_id+0x52/0x70 > [ 0.683208] intel_iommu_init+0x498/0x5c7 > [ 0.683211] pci_iommu_init+0x13/0x3c > [ 0.683214] ? e820__memblock_setup+0x61/0x61 > [ 0.683217] do_one_initcall+0x4d/0x1a0 > [ 0.683220] kernel_init_freeable+0x186/0x20e > [ 0.683222] ? set_debug_rodata+0x11/0x11 > [ 0.683225] ? rest_init+0xb0/0xb0 > [ 0.683226] kernel_init+0xa/0xff > [ 0.683229] ret_from_fork+0x1f/0x30 > [ 0.683259] Code: 89 ee 44 89 e7 e8 3b e8 ff ff 5b 5d 44 89 e7 44 89 ee 41 5c 41 5d 41 5e e9 a8 84 ff ff 48 c7 c7 a8 71 a7 81 31 c0 e8 6a d3 f9 ff <0f> ff 5b 5d 41 5c 41 5d 41 5 > e c3 0f 1f 44 00 00 66 2e 0f 1f 84 > [ 0.683285] ---[ end trace f7650e42792627ca ]--- > > with iommu->pr_irq = 0, but no check in intel_svm_finish_prq: > > [ 0.669561] ------------[ cut here ]------------ > [ 0.669563] Trying to free already-free IRQ 0 > [ 0.669573] WARNING: CPU: 3 PID: 1 at kernel/irq/manage.c:1546 __free_irq+0xa4/0x2c0 > [ 0.669574] Modules linked in: > [ 0.669577] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2 #4 > [ 0.669579] Hardware name: /NUC7i3BNB, BIOS BNKBL357.86A.0036.2017.0105.1112 01/05/2017 > [ 0.669581] RIP: 0010:__free_irq+0xa4/0x2c0 > [ 0.669582] RSP: 0000:ffffc90000037cc0 EFLAGS: 00010082 > [ 0.669584] RAX: 0000000000000021 RBX: 0000000000000000 RCX: ffffffff81c5e5e8 > [ 0.669585] RDX: 0000000000000001 RSI: 0000000000000086 RDI: 0000000000000046 > [ 0.669587] RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000023c > [ 0.669588] R10: 0000000000000007 R11: 0000000000000000 R12: ffff880276253960 > [ 0.669589] R13: ffff8802762538a4 R14: ffff880276253800 R15: ffff880276283600 > [ 0.669593] FS: 0000000000000000(0000) GS:ffff88027ed80000(0000) knlGS:0000000000000000 > [ 0.669594] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 0.669596] CR2: 0000000000000000 CR3: 0000000001c09001 CR4: 00000000003606e0 > [ 0.669602] Call Trace: > [ 0.669616] free_irq+0x30/0x60 > [ 0.669620] intel_svm_finish_prq+0x34/0x60 > [ 0.669623] free_dmar_iommu+0x1ac/0x1b0 > [ 0.669627] init_dmars+0xaaa/0xaea > [ 0.669631] ? klist_next+0x19/0xc0 > [ 0.669634] ? pci_do_find_bus+0x50/0x50 > [ 0.669637] ? pci_get_dev_by_id+0x52/0x70 > [ 0.669639] intel_iommu_init+0x498/0x5c7 > [ 0.669642] pci_iommu_init+0x13/0x3c > [ 0.669645] ? e820__memblock_setup+0x61/0x61 > [ 0.669648] do_one_initcall+0x4d/0x1a0 > [ 0.669651] kernel_init_freeable+0x186/0x20e > [ 0.669653] ? set_debug_rodata+0x11/0x11 > [ 0.669656] ? rest_init+0xb0/0xb0 > [ 0.669658] kernel_init+0xa/0xff > [ 0.669661] ret_from_fork+0x1f/0x30 > [ 0.669662] Code: 7a 08 75 0e e9 c3 01 00 00 4c 39 7b 08 74 57 48 89 da 48 8b 5a 18 48 85 db 75 ee 89 ee 48 c7 c7 78 67 a7 81 31 c0 e8 4c 37 fa ff <0f> ff 48 8b 34 24 4c 89 ef e > 8 0e 4c 68 00 49 8b 46 40 48 8b 80 > [ 0.669688] ---[ end trace 58a470248700f2fc ]--- > > Cc: Alex Williamson > Cc: Joerg Roedel > Cc: Ashok Raj > Signed-off-by: Jerry Snitselaar > --- > drivers/iommu/intel-svm.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) Applied to v4.16-iommu/vt-d. Thanks, Alex