From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <5058BC96.8090601@siemens.com> Date: Tue, 18 Sep 2012 20:25:26 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <504F5F1B.4020806@siemens.com> <50550091.50002@xenomai.org> <505592B8.9000109@xenomai.org> <5056DBAD.1000903@xenomai.org> <5058AE95.2020103@siemens.com> <5058AF21.5000600@xenomai.org> In-Reply-To: <5058AF21.5000600@xenomai.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] ipipe/x86: kernel BUG due to missing IRQ_MOVE_CLEANUP_VECTOR entry in ipipe-core3.2 List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gilles Chanteperdrix Cc: "xenomai@xenomai.org" On 2012-09-18 19:28, Gilles Chanteperdrix wrote: > On 09/18/2012 07:25 PM, Jan Kiszka wrote: >> On 2012-09-17 10:13, Gilles Chanteperdrix wrote: >>> On 09/16/2012 10:50 AM, Philippe Gerum wrote: >>>> On 09/16/2012 12:26 AM, Gilles Chanteperdrix wrote: >>>>> On 09/11/2012 05:56 PM, Gernot Hillier wrote: >>>>> >>>>>> Hi there! >>>>>> >>>>>> While testing ipipe-core3.2 on an SMP x86 machine, I found a reproducible >>>>>> kernel BUG after some seconds after starting irqbalance: >>>>>> >>>>>> ------------[ cut here ]------------ >>>>>> kernel BUG at arch/x86/kernel/ipipe.c:592! >>>>>> invalid opcode: 0000 [#1] SMP >>>>>> CPU 0 >>>>>> Modules linked in: des_generic md4 i7core_edac psmouse nls_cp437 edac_core cifs serio_raw joydev raid10 raid456 async_pq async_xor xor async_memcpy async_raid6_recov usbhid hid mpt2sas scsi_transport_sas raid_class igb raid6_pq async_tx raid1 raid0 multipath linear >>>>>> >>>>>> Pid: 0, comm: swapper/0 Not tainted 3.2.21-9-xenomai #3 Siemens AG Healthcare Sector MARS 2.1/X8DTH >>>>>> RIP: 0010:[] [] __ipipe_handle_irq+0x1bc/0x1d0 >>>>>> RSP: 0018:ffffffff8177bbe0 EFLAGS: 00010086 >>>>>> RAX: 000000000000d880 RBX: 00000000ffffffff RCX: 0000000000000092 >>>>>> RDX: ffffffffffffffdf RSI: ffffffff8177bc18 RDI: ffffffff8177bbf8 >>>>>> RBP: ffffffff8177bc00 R08: 0000000000000001 R09: 0000000000000000 >>>>>> R10: ffff880624ebaef8 R11: 000000000029fbc4 R12: 000000000000d880 >>>>>> R13: ffffffff8177bbf8 R14: ffff880624e00000 R15: ffff880624e0d880 >>>>>> FS: 0000000000000000(0000) GS:ffff880624e00000(0000) knlGS:0000000000000000 >>>>>> CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b >>>>>> CR2: 00007f452a2efb80 CR3: 0000000c114d3000 CR4: 00000000000006f0 >>>>>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >>>>>> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 >>>>>> Process swapper/0 (pid: 0, threadinfo ffffffff81778000, task ffffffff81787020) >>>>>> Stack: >>>>>> 0000000000000000 ffffffff8177bfd8 0000000000000063 ffff880624e1f9a8 >>>>>> ffffffff8177bca8 ffffffff815a44dd ffffffff8177bc18 ffffffff8177bca8 >>>>>> 00000000815a373b 000000000029fbc4 ffff880624eba570 0000000000000000 >>>>>> Call Trace: >>>>>> [] irq_move_cleanup_interrupt+0x5d/0x90 >>>>>> [] ? call_softirq+0x19/0x30 >>>>>> [] do_softirq+0xc5/0x100 >>>>>> [] irq_exit+0xd5/0xf0 >>>>>> [] do_IRQ+0x6f/0x100 >>>>>> [] ? __entry_text_end+0x5/0x5 >>>>>> [] __ipipe_do_IRQ+0x83/0xa0 >>>>>> [] ? __ipipe_do_IRQ+0x89/0xa0 >>>>>> [] __ipipe_dispatch_irq_fast+0x16a/0x170 >>>>>> [] __ipipe_dispatch_irq+0xe9/0x210 >>>>>> [] __ipipe_handle_irq+0x71/0x1d0 >>>>>> [] common_interrupt+0x60/0x81 >>>>>> [] ? __ipipe_halt_root+0x34/0x50 >>>>>> [] ? __ipipe_halt_root+0x27/0x50 >>>>>> [] default_idle+0x66/0x1a0 >>>>>> [] cpu_idle+0xaf/0x100 >>>>>> [] rest_init+0x72/0x80 >>>>>> [] start_kernel+0x3b4/0x3bf >>>>>> [] x86_64_start_reservations+0x131/0x135 >>>>>> [] x86_64_start_kernel+0x131/0x138 >>>>>> Code: ff ff 0f 1f 44 00 00 48 83 a0 98 06 00 00 fe 4c 89 ee bf 20 00 00 00 e8 63 83 09 00 e9 f6 fe ff ff be 01 00 00 00 e9 ab fe ff ff <0f> 0b 66 90 eb fc 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 >>>>>> RIP [] __ipipe_handle_irq+0x1bc/0x1d0 >>>>>> RSP >>>>>> >>>>>> This seems to be caused by a missing entry for IRQ_MOVE_CLEANUP_VECTOR >>>>>> in the per_cpu array vector_irq[]. >>>>>> >>>>>> I found that ipipe_init_vector_irq() (which used to add the needed >>>>>> entry) was factored out from arch/x86/kernel/ipipe.c. This likely >>>>>> happened when porting from 2.6.38 to 3.1 - at least I can still see the >>>>>> code in ipipe-2.6.38-x86 and missed it in ipipe-core3.1 (and didn't find >>>>>> any x86-branch in-between). >>>>> >>>>> >>>>> If I understand correctly, ipipe_init_vector_irq is no longer needed >>>>> because the I-pipe core uses ipipe_apic_vector_irq for vectors above >>>>> FIRST_SYSTEM_VECTOR. All system vectors are above this limit... except >>>>> IRQ_MOVE_CLEANUP_VECTOR. So, your patch is correct. Another one which >>>>> should work is to handle the special case IRQ_MOVE_CLEANUP_IRQ in >>>>> __ipipe_handle_irq as well. >>>>> >>>>> >>>> >>>> This is correct, but unfortunately, upstream reshuffles the IRQ vector >>>> space every so often, and does not restrict the special vectors to the >>>> system range anymore. Therefore, we should re-introduce a post-setup >>>> routine for the vector->irq map, grouping all fixups we need in one place. >>>> >>> I propose the following change: >>> http://git.xenomai.org/?p=ipipe-gch.git;a=commitdiff;h=9d131dc33080cda3f7e40342210d9338dc0c3d02 >>> >>> Which avoids listing explicitely the vectors we want to intercept, and >>> so, should allow some changes to happen in the kernel without having to >>> care too much (except for vectors sur as IRQ_MOVE_CLEANUP_VECTOR which >>> do not go through alloc_intr_gate, but this vector is the only exception, >>> for now). >> >> Crashes on boot, SMP at least. Investigating. > > Well, I tested it in SMP, so, the crash is probably due to some option I > could not activate (such as IRQ_REMAP, the one triggering the use of > IRQ_MOVE_CLEANUP_VECTOR). One thing is sure however, some #ifdef is > missing, because it does not compile in UP mode without APIC/IO-APIC. Not sure what the precise option difference is, but the bug is that you write to vector_irq before __setup_vector_irq is finished. That's why the original patch had ipipe_init_vector_irq precisely at the end of this function. Also, ipipe_init_vector_irq looks nicer than #ifdefs IMHO. Should I forward-port my old patch? Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux