Re: [PATCH v3] cxl: Wrap iterations over afu slices inside 'afu_list_lock'

[christophe lombard <clombard@linux.vnet.ibm.com>]

On 29/01/2019 07:15, Vaibhav Jain wrote:
> Within cxl module, iteration over array 'adapter->slices' may be racy
> at few points as it might be simultaneously read during an EEH and its
> contents being set to NULL while driver is being unloaded or unbound
> from the adapter. This might result in a NULL pointer to 'struct afu'
> being de-referenced during an EEH thereby causing a kernel oops.
> 
> This patch fixes this by making sure that all access to the array
> 'adapter->slices' is wrapped within the context of spin-lock
> 'adapter->afu_list_lock'.
> 
> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
> ---
> Changelog:
> 
> v3:
> * Updated a slice loop in cxl_pci_error_detectected() to ignore NULL
>    slices [Fred]
> * Added a NULL AFU check in cxl_pci_slot_reset() [Fred]
> 
> v2:
> * Fixed a wrong comparison of non-null pointer [Fred]
> * Moved a call to cxl_vphb_error_detected() within a branch that
>    checks for not null AFU pointer in 'adapter->slices' [Fred]
> * Removed a misleading comment in code.
> ---

Thanks

Acked-by: Christophe Lombard<clombard@linux.vnet.ibm.com>