From 761434a318a64bf521f8abcc920e1d9837640fa2 Mon Sep 17 00:00:00 2001 From: Kenji Kaneshige Date: Fri, 6 Nov 2009 16:22:44 +0900 Subject: PCI ASPM: fix oops on root port removal Fix the following BUG_ON() problem reported by Alex Chiang. This problem happened when removing PCIe root port using PCI logical hotplug operation. The immediate cause of this problem is that the pointer to invalid data structure is passed to pcie_update_aspm_capable() by pcie_aspm_exit_link_state(). When pcie_aspm_exit_link_state() received a pointer to root port link, it unconfigures the root port link and frees its data structure at first. At this point, there are not links to configure under the root port and the data structure for root port link is already freed. So pcie_aspm_exit_link_state() must not call pcie_update_aspm_capable() and pcie_config_aspm_path(). This patch fixes the problem by changing pcie_aspm_exit_link_state() not to call pcie_update_aspm_capable() and pcie_config_aspm_path() if the specified link is root port link. ------------[ cut here ]------------ kernel BUG at drivers/pci/pcie/aspm.c:606! invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC last sysfs file: /sys/devices/pci0000:40/0000:40:13.0/remove CPU 1 Modules linked in: shpchp Pid: 9345, comm: sysfsd Not tainted 2.6.32-rc5 #98 ProLiant DL785 G6 RIP: 0010:[] [] pcie_update_aspm_capable+0x15/0xbe RSP: 0018:ffff88082a2f5ca0 EFLAGS: 00010202 RAX: 0000000000000e77 RBX: ffff88182cc3e000 RCX: ffff88082a33d006 RDX: 0000000000000001 RSI: ffffffff811dff4a RDI: ffff88182cc3e000 RBP: ffff88082a2f5cc0 R08: ffff88182cc3e000 R09: 0000000000000000 R10: ffff88182fc00180 R11: ffff88182fc00198 R12: ffff88182cc3e000 R13: 0000000000000000 R14: ffff88182cc3e000 R15: ffff88082a2f5e20 FS: 00007f259a64b6f0(0000) GS:ffff880864600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b CR2: 00007feb53f73da0 CR3: 000000102cc94000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process sysfsd (pid: 9345, threadinfo ffff88082a2f4000, task ffff88082a33cf00) Stack: ffff88182cc3e000 ffff88182cc3e000 0000000000000000 ffff88082a33cf00 <0> ffff88082a2f5cf0 ffffffff811dff52 ffff88082a2f5cf0 ffff88082c525168 <0> ffff88402c9fd2f8 ffff88402c9fd2f8 ffff88082a2f5d20 ffffffff811d7db2 Call Trace: [] pcie_aspm_exit_link_state+0xf5/0x11e [] pci_stop_bus_device+0x76/0x7e [] pci_stop_bus_device+0x2b/0x7e [] pci_remove_bus_device+0x15/0xb9 [] remove_callback+0x29/0x3a [] sysfs_schedule_callback_work+0x15/0x6d [] worker_thread+0x19d/0x298 [] ? worker_thread+0x148/0x298 [] ? sysfs_schedule_callback_work+0x0/0x6d [] ? autoremove_wake_function+0x0/0x38 [] ? worker_thread+0x0/0x298 [] kthread+0x7d/0x85 [] child_rip+0xa/0x20 [] ? restore_args+0x0/0x30 [] ? kthread+0x0/0x85 [] ? child_rip+0x0/0x20 Code: 89 e5 8a 50 48 31 c0 c0 ea 03 83 e2 07 e8 b2 de fe ff c9 48 98 c3 55 48 89 e5 41 56 49 89 fe 41 55 41 54 53 48 83 7f 10 00 74 04 <0f> 0b eb fe 48 8b 05 da 7d 63 00 4c 8d 60 e8 4c 89 e1 eb 24 4c RIP [] pcie_update_aspm_capable+0x15/0xbe RSP ---[ end trace 6ae0f65bdeab8555 ]--- Reported-by: Alex Chiang Signed-off-by: Kenji Kaneshige Tested-by: Alex Chiang Signed-off-by: Jesse Barnes --- drivers/pci/pcie/aspm.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 745402e..5b7056c 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -656,8 +656,10 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev) free_link_state(link); /* Recheck latencies and configure upstream links */ - pcie_update_aspm_capable(root); - pcie_config_aspm_path(parent_link); + if (parent_link) { + pcie_update_aspm_capable(root); + pcie_config_aspm_path(parent_link); + } out: mutex_unlock(&aspm_lock); up_read(&pci_bus_sem); -- cgit v1.1