On Fri, Feb 27, 2015 at 4:34 PM, Robert White <rwhite@xxxxxxxxx> wrote: > Eh, wrong mailing list the first time...? Yep, I browse linux-kernel sometimes, but not enough to catch everything. Anyway, thanks a lot for the problem report. Would you mind opening a bug report at http://bugzilla.kernel.org, drivers/pci component, and attaching - a completely dmesg log from your most recent kernel (it probably doesn't boot, which it makes it hard to get an actual dmesg log; a complete console log with "ignore_loglevel" is fine, too). - complete "lspci -vv" output from a working system (v2.x is fine). Thanks, Bjorn > -------- Forwarded Message -------- > Subject: NULL Pointer in 3.x during PCI bus enumeration > Date: Mon, 23 Feb 2015 11:38:26 -0800 > From: Robert White <rwhite@xxxxxxxxx> > To: Linux Kernel <linux-kernel@xxxxxxxxxxxxxxx> > > The below BUG event happens during PCI bus enumeration on some of my > gear. In particular the Advanced Telecommunications Architecture (ATCA) > has carrier cards that contain Field Replaceable Units (FRUs). FRUs > are all attached by PCI-to-PCI bridges and some may be empty. > > So architecturally the main card is just an array of eight bridges > and the CPU/computer is just in one slot. > > carrier |--- adapter 1 > PCI |--- (empty) > bus |--- CPU (fru) > |--- adapter 4 > ... etc. > > The CPU module sees this as a PCI bus with all the normal things > on the local PCI bus within its FRU and then a bridge to a > tree of bridges, and some of those bridges go nowhere. > > CPU -|--- memory controller > |--- whatever > |--- PCI bridge(#) -|--- PCI bridge -|--- adapter 1 item 1 > | |--- adapter 1 item 2 > | > |--- PCI bridge -|--- adapter 4 item 1 > |--- adapter 4 item 2 > > (#)Actually I think there is another layer of bridges in there > but I am running out of ASCII art space. > > The longest link is something like > CPU to local bus > local bus to plug bus > plug bus to backplane > backplane to other plug bus > other plug bus to target local bus > target local bus to device. > > Anyway, I am taking a system that is working under 2.x where this > bridge to bridge (to bridge?) thing worked and it's bugging out > on 3.x (at least 3.18 and 3.19, I have no knowledge of 3.x for > x less than 18). > > I got as far as seeing that its a composite pointer deref thats > going bad in pci_aspm_init_link_state according to gdb > > parent = pdev->bus->parent->self->link_state; > > but the sequencing dependency (e.g. when "self", "parent" > and "bus" is really set for each item) is making my brain hurt. > > > > [ 1.590865] BUG: unable to handle kernel NULL pointer dereference at > 0000000000000088 > [ 1.606588] IP: [<ffffffff81550324>] > pcie_aspm_init_link_state+0x744/0x850 > [ 1.620375] PGD 0 > [ 1.624436] Oops: 0000 [#1] PREEMPT SMP > [ 1.632387] Modules linked in: > [ 1.638536] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.19.0-gentoo #9 > [ 1.651590] Hardware name: Kontron B3001/B3001, BIOS 4.6.3 08/07/2012 > [ 1.664472] task: ffff880116b20000 ti: ffff880116b28000 task.ti: > ffff880116b28000 > [ 1.679436] RIP: 0010:[<ffffffff81550324>] [<ffffffff81550324>] > pcie_aspm_init_link_state+0x744/0x850 > [ 1.698084] RSP: 0000:ffff880116b2b958 EFLAGS: 00010246 > [ 1.708707] RAX: 0000000000000000 RBX: 0000000000000000 RCX: > ffff8801165aae78 > [ 1.722978] RDX: ffff8801165aae58 RSI: 0000000000000000 RDI: > ffff8801165aaf00 > [ 1.737250] RBP: ffff880116b2b9c8 R08: 0000000000015b80 R09: > ffff8801165aae40 > [ 1.751520] R10: ffff8801165aae40 R11: 000000000000000f R12: > ffff8801165aae40 > [ 1.765791] R13: ffff8801165e8000 R14: 0000000000000000 R15: > ffff88011643fc00 > [ 1.780063] FS: 0000000000000000(0000) GS:ffff88011bc00000(0000) > knlGS:0000000000000000 > [ 1.796243] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 1.807738] CR2: 0000000000000088 CR3: 0000000002412000 CR4: > 00000000000007f0 > [ 1.822007] Stack: > [ 1.826036] ffff880116b2b988 ffffffff8153b682 ffff8801165e9000 > ffff8801165e9000 > [ 1.840966] ffff880117038400 0000000000000000 ffff880116b2b9c8 > ffffffff8153b761 > [ 1.855896] ffff880116b2b9b8 ffff880117038400 0000000000000001 > 0000000000000000 > [ 1.870828] Call Trace: > [ 1.875727] [<ffffffff8153b682>] ? pci_device_add+0x122/0x170 > [ 1.887392] [<ffffffff8153b761>] ? pci_scan_single_device+0x91/0xc0 > [ 1.900099] [<ffffffff8153b865>] pci_scan_slot+0xd5/0x120 > [ 1.911071] [<ffffffff8153ca1d>] pci_scan_child_bus+0x2d/0xd0 > [ 1.922738] [<ffffffff8153c733>] pci_scan_bridge+0x383/0x640 > [ 1.934233] [<ffffffff8153ca75>] pci_scan_child_bus+0x85/0xd0 > [ 1.945900] [<ffffffff8153c733>] pci_scan_bridge+0x383/0x640 > [ 1.957391] [<ffffffff8153b724>] ? pci_scan_single_device+0x54/0xc0 > [ 1.970101] [<ffffffff8153ca75>] pci_scan_child_bus+0x85/0xd0 > [ 1.981770] [<ffffffff81b26357>] pci_acpi_scan_root+0x317/0x520 > [ 1.993784] [<ffffffff8158c8a3>] acpi_pci_root_add+0x3c9/0x4db > [ 2.005623] [<ffffffff8158e44e>] ? acpi_pnp_match+0x2c/0xa4 > [ 2.016943] [<ffffffff825bb3c6>] ? acpi_sleep_proc_init+0x2a/0x2a > [ 2.029303] [<ffffffff81588f15>] acpi_bus_attach+0xcf/0x1bf > [ 2.040621] [<ffffffff825bb3c6>] ? acpi_sleep_proc_init+0x2a/0x2a > [ 2.052985] [<ffffffff817d1f85>] ? device_attach+0x45/0xb0 > [ 2.064128] [<ffffffff81588f8f>] acpi_bus_attach+0x149/0x1bf > [ 2.075622] [<ffffffff825bb3c6>] ? acpi_sleep_proc_init+0x2a/0x2a > [ 2.087984] [<ffffffff817d1f85>] ? device_attach+0x45/0xb0 > [ 2.099130] [<ffffffff81588f8f>] acpi_bus_attach+0x149/0x1bf > [ 2.110623] [<ffffffff825bb3c6>] ? acpi_sleep_proc_init+0x2a/0x2a > [ 2.122983] [<ffffffff815890f4>] acpi_bus_scan+0x5c/0x67 > [ 2.133782] [<ffffffff825bb7e6>] acpi_scan_init+0x6b/0x1a1 > [ 2.144929] [<ffffffff825bb617>] acpi_init+0x251/0x26e > [ 2.155379] [<ffffffff825bb3c6>] ? acpi_sleep_proc_init+0x2a/0x2a > [ 2.167741] [<ffffffff810002d8>] do_one_initcall+0x98/0x1e0 > [ 2.179063] [<ffffffff810e6900>] ? parse_args+0x150/0x430 > [ 2.190036] [<ffffffff8257907c>] kernel_init_freeable+0x17e/0x20b > [ 2.202394] [<ffffffff81d884f0>] ? rest_init+0x90/0x90 > [ 2.212846] [<ffffffff81d884f9>] kernel_init+0x9/0xf0 > [ 2.223125] [<ffffffff81d9b4ac>] ret_from_fork+0x7c/0xb0 > [ 2.233922] [<ffffffff81d884f0>] ? rest_init+0x90/0x90 > [ 2.244372] Code: 0f 85 e2 fa ff ff 41 80 4c 24 4a 03 b8 01 00 00 00 41 > 0f b6 54 24 49 e9 4b fb ff ff 0f 1f 00 49 8b 45 10 48 8b 40 10 48 8b 40 38 > <48> 8b 80 88 00 00 00 48 85 c0 0f > [ 2.284338] RIP [<ffffffff81550324>] > pcie_aspm_init_link_state+0x744/0x850 > [ 2.298296] RSP <ffff880116b2b958> > [ 2.305276] CR2: 0000000000000088 > [ 2.311913] ---[ end trace 153b3907ad1e19ba ]--- > > > (gdb) list *0xffffffff815502ba > 0xffffffff815502ba is in pcie_aspm_init_link_state > (drivers/pci/pcie/aspm.c:530). > 525 INIT_LIST_HEAD(&link->children); > 526 INIT_LIST_HEAD(&link->link); > 527 link->pdev = pdev; > 528 if (pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM) { > 529 struct pcie_link_state *parent; > 530 parent = pdev->bus->parent->self->link_state; > 531 if (!parent) { > 532 kfree(link); > 533 return NULL; > 534 } > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
