• Vaibhav Jain's avatar
    cxl: Avoid double free_irq() for psl,slice interrupts · b3aa20ba
    Vaibhav Jain authored
    During an eeh call to cxl_remove can result in double free_irq of
    psl,slice interrupts. This can happen if perst_reloads_same_image == 1
    and call to cxl_configure_adapter() fails during slot_reset
    callback. In such a case we see a kernel oops with following back-trace:
    
    Oops: Kernel access of bad area, sig: 11 [#1]
    Call Trace:
      free_irq+0x88/0xd0 (unreliable)
      cxl_unmap_irq+0x20/0x40 [cxl]
      cxl_native_release_psl_irq+0x78/0xd8 [cxl]
      pci_deconfigure_afu+0xac/0x110 [cxl]
      cxl_remove+0x104/0x210 [cxl]
      pci_device_remove+0x6c/0x110
      device_release_driver_internal+0x204/0x2e0
      pci_stop_bus_device+0xa0/0xd0
      pci_stop_and_remove_bus_device+0x28/0x40
      pci_hp_remove_devices+0xb0/0x150
      pci_hp_remove_devices+0x68/0x150
      eeh_handle_normal_event+0x140/0x580
      eeh_handle_event+0x174/0x360
      eeh_event_handler+0x1e8/0x1f0
    
    This patch fixes the issue of double free_irq by checking that
    variables that hold the virqs (err_hwirq, serr_hwirq, psl_virq) are
    not '0' before un-mapping and resetting these variables to '0' when
    they are un-mapped.
    
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarVaibhav Jain <vaibhav@linux.vnet.ibm.com>
    Reviewed-by: default avatarAndrew Donnellan <andrew.donnellan@au1.ibm.com>
    Acked-by: default avatarFrederic Barrat <fbarrat@linux.vnet.ibm.com>
    Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    b3aa20ba
native.c 42.7 KB