Re: [PATCH v4 0/5] Fixes for HiSilicon LPC driver and logical PIO code

[Wei Xu]

Hi John,

On 2019/7/30 21:29, John Garry wrote:
> As reported in [1], the hisi-lpc driver has certain issues in handling
> logical PIO regions, specifically unregistering regions.
>
> This series add a method to unregister a logical PIO region, and fixes up
> the driver to use them.
>
> RCU usage in logical PIO code looks to always have been broken, so that
> is fixed also. This is not a major fix as the list which RCU protects
> would be rarely modified.
>
> At this point, there are still separate ongoing discussions about how to
> stop the logical PIO and PCI host bridge code leaking ranges, as in [2],
> which I haven't had a chance to look at recently.
>
> Hopefully this series can go through the arm soc tree and the maintainers
> have no issue with that. I'm talking specifically about the logical PIO
> code, which went through PCI tree on only previous upstreaming.
>
>
> [1] https://lore.kernel.org/lkml/1560770148-57960-1-git-send-email-john.garry@xxxxxxxxxx/
> [2] https://lore.kernel.org/lkml/4b24fd36-e716-7c5e-31cc-13da727802e7@xxxxxxxxxx/

Thanks!
Series applied to the hisilicon fixes tree.

Best Regards,
Wei

> Changes since v3:
> https://lore.kernel.org/lkml/1561566418-22714-1-git-send-email-john.garry@xxxxxxxxxx/
> - drop optimisation patch (lib: logic_pio: Enforce LOGIC_PIO_INDIRECT
>    region ops are set at registration)
>    Not a fix
> - rebase to v5.3-rc2
> - cc stable
>
> Change since v2:
> - Add hisi_lpc_acpi_remove() stub to fix build for !CONFIG_ACPI
>
> Changes since v1:
> - Add more reasoning in RCU fix patch
> - Create separate patch to change LOGIC_PIO_CPU_MMIO registration to
>    accomodate unregistration
>
> John Garry (5):
>    lib: logic_pio: Fix RCU usage
>    lib: logic_pio: Avoid possible overlap for unregistering regions
>    lib: logic_pio: Add logic_pio_unregister_range()
>    bus: hisi_lpc: Unregister logical PIO range to avoid potential
>      use-after-free
>    bus: hisi_lpc: Add .remove method to avoid driver unbind crash
>
>   drivers/bus/hisi_lpc.c    | 47 +++++++++++++++++++++----
>   include/linux/logic_pio.h |  1 +
>   lib/logic_pio.c           | 73 +++++++++++++++++++++++++++++----------
>   3 files changed, 96 insertions(+), 25 deletions(-)