Messages in this thread Patch in this message | | | Date | Mon, 3 Oct 2005 13:57:39 -0500 | Subject | [PATCH] ppc64: Crash in DLPAR code on PCI hotplug add | From | linas <> |
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08-hotplug-bugfix.patch
In the current 2.6.14-rc2-git6 kernel, performing a Dynamic LPAR Add of a hotplug slot will crash the system, with the following (abbreviated) stack trace:
cpu 0x3: Vector: 700 (Program Check) at [c000000053dff7f0] pc: c0000000004f5974: .__alloc_bootmem+0x0/0xb0 lr: c0000000000258a0: .update_dn_pci_info+0x108/0x118 c0000000000257c8 .update_dn_pci_info+0x30/0x118 (unreliable) c0000000000258fc .pci_dn_reconfig_notifier+0x4c/0x64 c000000000060754 .notifier_call_chain+0x68/0x9c
The root cause was that the phb was not marked "dynamic", and so instead of having kmalloc() being called, the __init __alloc_bootmem() was called, resulting in access of garage data. The patch below fixes this crash, and adds some docs to clarify the code.
Signed-off-by: Linas Vepstas <linas@linas.org>
Index: linux-2.6.14-rc2-git6/arch/ppc64/kernel/pci_dn.c =================================================================== --- linux-2.6.14-rc2-git6.orig/arch/ppc64/kernel/pci_dn.c 2005-10-03 13:45:58.011393833 -0500 +++ linux-2.6.14-rc2-git6/arch/ppc64/kernel/pci_dn.c 2005-10-03 13:52:26.421786761 -0500 @@ -121,6 +121,12 @@ return NULL; } +/** pci_devs_phb_init_dynamic -- setup pci devices under this PHB + * + * This routine is called both during boot, (before the memory + * subsystem is set up, before kmalloc is valid) and during the + * dynamic lpar operation of adding a PHB to a running system. + */ void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb) { struct device_node * dn = (struct device_node *) phb->arch_data; @@ -201,17 +207,19 @@ .notifier_call = pci_dn_reconfig_notifier, }; -/* - * Actually initialize the phbs. - * The buswalk on this phb has not happened yet. +/** pci_devs_phb_init -- Initialize phbs and pci devs under them. + * + * When this is called, the buswalk of PHB's has not happened yet. */ void __init pci_devs_phb_init(void) { struct pci_controller *phb, *tmp; /* This must be done first so the device nodes have valid pci info! */ - list_for_each_entry_safe(phb, tmp, &hose_list, list_node) + list_for_each_entry_safe(phb, tmp, &hose_list, list_node) { pci_devs_phb_init_dynamic(phb); + phb->is_dynamic = 1; + } pSeries_reconfig_notifier_register(&pci_dn_reconfig_nb); } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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