Commit-ID: 303fc0870f8fbfabe260c5c32b18e53458d597ea Gitweb: http://git.kernel.org/tip/303fc0870f8fbfabe260c5c32b18e53458d597ea Author: Prarit Bhargava <prarit@xxxxxxxxxx> AuthorDate: Thu, 12 Nov 2009 13:09:31 -0500 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Mon, 16 Nov 2009 15:43:05 +0100 x86: AMD Northbridge: Verify NB's node is online Fix panic seen on some IBM and HP systems on 2.6.32-rc6: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8120bf3f>] find_next_bit+0x77/0x9c [...] [<ffffffff8120bbde>] cpumask_next_and+0x2e/0x3b [<ffffffff81225c62>] pci_device_probe+0x8e/0xf5 [<ffffffff812b9be6>] ? driver_sysfs_add+0x47/0x6c [<ffffffff812b9da5>] driver_probe_device+0xd9/0x1f9 [<ffffffff812b9f1d>] __driver_attach+0x58/0x7c [<ffffffff812b9ec5>] ? __driver_attach+0x0/0x7c [<ffffffff812b9298>] bus_for_each_dev+0x54/0x89 [<ffffffff812b9b4f>] driver_attach+0x19/0x1b [<ffffffff812b97ae>] bus_add_driver+0xd3/0x23d [<ffffffff812ba1e7>] driver_register+0x98/0x109 [<ffffffff81225ed0>] __pci_register_driver+0x63/0xd3 [<ffffffff81072776>] ? up_read+0x26/0x2a [<ffffffffa0081000>] ? k8temp_init+0x0/0x20 [k8temp] [<ffffffffa008101e>] k8temp_init+0x1e/0x20 [k8temp] [<ffffffff8100a073>] do_one_initcall+0x6d/0x185 [<ffffffff8108d765>] sys_init_module+0xd3/0x236 [<ffffffff81011ac2>] system_call_fastpath+0x16/0x1b I put in a printk and commented out the set_dev_node() call when and got this output: quirk_amd_nb_node: current numa_node = 0x0, would set to val & 7 = 0x0 quirk_amd_nb_node: current numa_node = 0x0, would set to val & 7 = 0x1 quirk_amd_nb_node: current numa_node = 0x0, would set to val & 7 = 0x2 quirk_amd_nb_node: current numa_node = 0x0, would set to val & 7 = 0x3 I.e. the issue appears to be that the HW has set val to a valid value, however, the system is only configured for a single node -- 0, the others are offline. Check to see if the node is actually online before setting the numa node for an AMD northbridge in quirk_amd_nb_node(). Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx> Cc: bhavna.sarathy@xxxxxxx Cc: jbarnes@xxxxxxxxxxxxxxxx Cc: andreas.herrmann3@xxxxxxx LKML-Reference: <20091112180933.12532.98685.sendpatchset@xxxxxxxxxxxxxxxxxxxxx> [ v2: clean up the code and add comments ] Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- arch/x86/kernel/quirks.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c index 6c3b2c6..18093d7 100644 --- a/arch/x86/kernel/quirks.c +++ b/arch/x86/kernel/quirks.c @@ -499,6 +499,7 @@ static void __init quirk_amd_nb_node(struct pci_dev *dev) { struct pci_dev *nb_ht; unsigned int devfn; + u32 node; u32 val; devfn = PCI_DEVFN(PCI_SLOT(dev->devfn), 0); @@ -507,7 +508,13 @@ static void __init quirk_amd_nb_node(struct pci_dev *dev) return; pci_read_config_dword(nb_ht, 0x60, &val); - set_dev_node(&dev->dev, val & 7); + node = val & 7; + /* + * Some hardware may return an invalid node ID, + * so check it first: + */ + if (node_online(node)) + set_dev_node(&dev->dev, node); pci_dev_put(nb_ht); } -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html