• Rui Wang's avatar
    x86/ioapic: Fix incorrect pointers in ioapic_setup_resources() · 9d98bcec
    Rui Wang authored
    On a 4-socket Brickland system, hot-removing one ioapic is fine.
    Hot-removing the 2nd one causes panic in mp_unregister_ioapic()
    while calling release_resource().
    
    It is because the iomem_res pointer has already been released
    when removing the first ioapic.
    
    To explain the use of &res[num] here: res is assigned to ioapic_resources,
    and later in ioapic_insert_resources() we do:
    
    	struct resource *r = ioapic_resources;
    
            for_each_ioapic(i) {
                    insert_resource(&iomem_resource, r);
                    r++;
            }
    
    Here 'r' is treated as an arry of 'struct resource', and the r++ ensures
    that each element of the array is inserted separately. Thus we should call
    release_resouce() on each element at &res[num].
    
    Fix it by assigning the correct pointers to ioapics[i].iomem_res in
    ioapic_setup_resources().
    Signed-off-by: default avatarRui Wang <rui.y.wang@intel.com>
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Cc: tony.luck@intel.com
    Cc: linux-pci@vger.kernel.org
    Cc: rjw@rjwysocki.net
    Cc: linux-acpi@vger.kernel.org
    Cc: bhelgaas@google.com
    Link: http://lkml.kernel.org/r/1465369193-4816-3-git-send-email-rui.y.wang@intel.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    9d98bcec
io_apic.c 77.2 KB