2009/3/9 Alex Chiang <achiang@xxxxxx>: > * Alex Chiang <achiang@xxxxxx>: >> >> There is still one major bug somewhere that shows up only when using >> the PCIe portdriver (that is, any time PCIe support is built into >> the kernel). You get an oops during multiple remove/rescan cycles, >> especially on devices with an internal bridge. > > Got it, we had a double-free in the PCIe port driver which was > causing all sorts of problems. > > I fixed that and now this patch series is stable enough for > others to actually apply and test. As of now, there are no known > bugs. > > Of course, I'm going to keep testing and try to find some more > bugs. :) > > As a reminder, if you want to play with this series, you'll also > need these two patches: > >> http://thread.gmane.org/gmane.linux.kernel.pci/3437 >> http://lkml.org/lkml/2009/3/7/173 > > And now this third patch: > > http://thread.gmane.org/gmane.linux.kernel.pci/3524 > > Finally, patch 07/11 needs to be updated. I'll post a reply to > that mail with the updated patch. Hi, I got this crash: [ 279.029673] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 [ 279.030011] IP: [<ffffffff811fce96>] pci_remove_bus_device+0x56/0xe0 [ 279.030011] PGD 3e47e067 PUD 3e4d1067 PMD 0 [ 279.030011] Oops: 0002 [#1] SMP [ 279.030011] last sysfs file: /sys/devices/pci0000:00/0000:00:00.0/remove [ 279.030011] CPU 0 [ 279.030011] Pid: 6, comm: events/0 Not tainted 2.6.29-rc6 #361 945P-A [ 279.030011] RIP: 0010:[<ffffffff811fce96>] [<ffffffff811fce96>] pci_remove_bus_device+0x56/0xe0 [ 279.030011] RSP: 0018:ffff88003f8bde30 EFLAGS: 00010286 [ 279.030011] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817ab9b8 [ 279.030011] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff817ab9b0 [ 279.030011] RBP: ffff88003f8bde50 R08: 00000000002ec000 R09: 0000000000000000 [ 279.030011] R10: ffff88003d9fd7c0 R11: 0000000000000040 R12: ffff88003d929800 [ 279.030011] R13: ffff88003d929800 R14: ffff88003f80a908 R15: ffff88003f8adf00 [ 279.030011] FS: 0000000000000000(0000) GS:ffff8800019f1000(0000) knlGS:0000000000000000 [ 279.030011] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b [ 279.030011] CR2: ffff88003e4d1000 CR3: 000000003e452000 CR4: 00000000000006a0 [ 279.030011] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 279.030011] DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400 [ 279.030011] Process events/0 (pid: 6, threadinfo ffff88003f8bc000, task ffff88003f8a2350) [ 279.030011] Stack: [ 279.030011] ffffffffffffffff ffff88003d929800 ffff88003d9de800 ffff88003f80a908 [ 279.030011] ffff88003f8bde70 ffffffff81202f7d 0000000000000010 ffff88003d9de820 [ 279.030011] ffff88003f8bde90 ffffffff8112503f ffff88003f80a900 ffffffff81125020 [ 279.030011] Call Trace: [ 279.030011] [<ffffffff81202f7d>] remove_callback+0x3d/0x60 [ 279.030011] [<ffffffff8112503f>] sysfs_schedule_callback_work+0x1f/0x40 [ 279.030011] [<ffffffff81125020>] ? sysfs_schedule_callback_work+0x0/0x40 [ 279.030011] [<ffffffff81055510>] run_workqueue+0x70/0x130 [ 279.030011] [<ffffffff81055677>] worker_thread+0xa7/0x120 [ 279.030011] [<ffffffff810597f0>] ? autoremove_wake_function+0x0/0x40 [ 279.030011] [<ffffffff810555d0>] ? worker_thread+0x0/0x120 [ 279.030011] [<ffffffff810593d9>] kthread+0x49/0x90 [ 279.030011] [<ffffffff8100d45a>] child_rip+0xa/0x20 [ 279.030011] [<ffffffff81059390>] ? kthread+0x0/0x90 [ 279.030011] [<ffffffff8100d450>] ? child_rip+0x0/0x20 [ 279.030011] Code: 00 00 00 4c 89 ef 4d 89 ec 31 db e8 75 fe ff ff 48 c7 c7 b0 b9 7a 81 e8 f9 f8 3a 00 49 8b 55 00 49 8b 45 08 48 c7 c7 b0 b9 7a 81 <48> 89 42 08 48 89 10 49 c7 45 08 00 00 00 00 49 c7 45 00 00 00 [ 279.030011] RIP [<ffffffff811fce96>] pci_remove_bus_device+0x56/0xe0 [ 279.030011] RSP <ffff88003f8bde30> [ 279.030011] CR2: 0000000000000008 [ 279.291933] ---[ end trace 4ba18f2857f89768 ]--- It was with this patch queue on top of pci/linux-next (487e348b0ff23e061f60010477a664ea378c1b30): PCIe: portdrv: call pci_disable_device during remove PCIe: AER: during disable, check subordinate before walking PCIe portdrv: eliminate double kfree in remove path PCI Hotplug: schedule fakephp for feature removal PCI Hotplug: rename legacy_fakephp to fakephp PCI Hotplug: restore fakephp interface with complete reimplementation PCI: Introduce /sys/bus/pci/devices/.../rescan PCI: Introduce /sys/bus/pci/devices/.../remove (new version) PCI: Introduce /sys/bus/pci/rescan PCI: beef up pci_do_scan_bus() PCI: always scan child buses PCI: pci_scan_slot() returns newly found devices PCI: don't scan existing devices PCI: pci_is_root_bus helper It reproduces reliably if I do this: $ while true; do echo 1 > /sys/bus/pci/devices/0000\:00\:00.0/remove; done Line numbers: $ addr2line -e vmlinux -i ffffffff811fce96 include/linux/list.h:92 include/linux/list.h:105 drivers/pci/remove.c:40 drivers/pci/remove.c:106 And this is my drivers/pci/remove.c: 33 static void pci_destroy_dev(struct pci_dev *dev) 34 { 35 pci_stop_dev(dev); 36 37 /* Remove the device from the device lists, and prevent any further 38 * list accesses from this device */ 39 down_write(&pci_bus_sem); 40 list_del(&dev->bus_list); 41 dev->bus_list.next = dev->bus_list.prev = NULL; 42 up_write(&pci_bus_sem); 43 44 pci_free_resources(dev); 45 pci_dev_put(dev); 46 } Vegard -- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036 -- 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
