Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754409AbZAIQWa (ORCPT ); Fri, 9 Jan 2009 11:22:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752754AbZAIQT7 (ORCPT ); Fri, 9 Jan 2009 11:19:59 -0500 Received: from outbound-dub.frontbridge.com ([213.199.154.16]:28858 "EHLO IE1EHSOBE003.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752174AbZAIQT4 (ORCPT ); Fri, 9 Jan 2009 11:19:56 -0500 X-BigFish: VPS-21(zz1528M1a09M936eQ4015Mzzzzz32i43j65h) X-Spam-TCS-SCL: 4:0 X-WSS-ID: 0KD7PCH-03-IWX-01 From: Joerg Roedel To: linux-kernel@vger.kernel.org CC: mingo@redhat.com, dwmw2@infradead.org, fujita.tomonori@lab.ntt.co.jp, netdev@vger.kernel.org, iommu@lists.linux-foundation.org Subject: [PATCH 0/16] DMA-API debugging facility v2 Date: Fri, 9 Jan 2009 17:19:14 +0100 Message-ID: <1231517970-20288-1-git-send-email-joerg.roedel@amd.com> X-Mailer: git-send-email 1.5.6.4 X-OriginalArrivalTime: 09 Jan 2009 16:19:30.0623 (UTC) FILETIME=[0CFAA4F0:01C97276] MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4374 Lines: 104 Hi, this is version 2 of the patchset which introduces code to debug drivers usage of the DMA-API. Many thanks to all the reviewers and the useful comments on the fist version of this patchset. Tests with hardware IOMMUs have shown several bugs in drivers regarding the usage of that API. Problems were found especially in network card drivers. These bugs often don't show up or have any negative impact if there is no hardware IOMMU in use in the system. But with an hardware IOMMU these bugs turn the hardware unusable or, in the worst case, cause data corruption on devices which are managed by other (good) drivers. With the code these patches introduce driver developers can find several bugs of misusing the DMA-API in their drivers. But be aware, it can not find all possible bugs. If it finds a problem it prints out messages like ------------[ cut here ]------------ WARNING: at /data2/repos/linux.trees.git/lib/dma-debug.c:231 check_unmap+0xab/0x3d9() Hardware name: Toonie bnx2 0000:01:00.0: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x00000000011] Modules linked in: Pid: 0, comm: swapper Not tainted 2.6.28 #174 Call Trace: [] warn_slowpath+0xd3/0xf2 [] ? find_usage_backwards+0xe2/0x116 [] ? find_usage_backwards+0xe2/0x116 [] ? usb_hcd_link_urb_to_ep+0x94/0xa0 [] ? mark_lock+0x1c/0x364 [] ? __lock_acquire+0xaec/0xb55 [] ? mark_lock+0x1c/0x364 [] ? get_hash_bucket+0x28/0x33 [] ? _spin_lock_irqsave+0x69/0x75 [] ? get_hash_bucket+0x28/0x33 [] check_unmap+0xab/0x3d9 [] ? trace_hardirqs_on_caller+0x108/0x14a [] ? trace_hardirqs_on+0xd/0xf [] debug_unmap_single+0x3e/0x40 [] dma_unmap_single+0x3d/0x60 [] pci_unmap_page+0x1c/0x1e [] bnx2_poll_work+0x626/0x8cb [] ? __lock_acquire+0xaec/0xb55 [] ? run_posix_cpu_timers+0x49c/0x603 [] ? run_posix_cpu_timers+0x39c/0x603 [] ? mark_lock+0x1c/0x364 [] ? __lock_acquire+0xaec/0xb55 [] bnx2_poll_msix+0x33/0x81 [] net_rx_action+0x8a/0x139 [] __do_softirq+0x8b/0x147 [] call_softirq+0x1c/0x34 [] do_softirq+0x39/0x90 [] irq_exit+0x4e/0x98 [] do_IRQ+0x11f/0x135 [] ret_from_intr+0x0/0xf <4>---[ end trace 4339d58302097423 ]--- This way driver developers get an idea where the problem is in their code. I hope I addressed most of the review comments and objections from the first version. Please give this version also a good review and send me your comments. Thanks, Joerg Changes from v1 -> v2: - moved code to lib/ and include/linux to make it usable for all architectures - more fine grained hash locking (locking is now per hash bucket, no global lock anymore) - dma_debug_entries are preallocated - per default the code will only print one warning and is silent then - added a debugfs interface to see some statistics and to enable more verbose error reporting in the kernel log - added command line parameter to disable debugging code - allocation errors are now handled correctly - added documentation about this facility for driver developers diffstat: Documentation/DMA-API.txt | 117 ++++++ Documentation/kernel-parameters.txt | 10 + arch/Kconfig | 2 + arch/x86/Kconfig | 1 + arch/x86/include/asm/dma-mapping.h | 30 ++- arch/x86/kernel/pci-dma.c | 5 + include/linux/dma-debug.h | 154 ++++++++ lib/Kconfig.debug | 11 + lib/Makefile | 2 + lib/dma-debug.c | 726 +++++++++++++++++++++++++++++++++++ 10 files changed, 1054 insertions(+), 4 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/