On 22.04.22 09:15, Christophe JAILLET wrote:
> There is no point in doing put_device()/device_unregister() on a
> device that has just been registered a few lines above. This will lead to
> a double reference decrement.
>
> I guess that this put_device()/device_unregister() is a cut'n'paste from
> remove_memory_block() (i.e. unregister_memory() at the time being) which
> does need it.
>
> Fixes: 4fb6eabf1037 ("drivers/base/memory.c: cache memory blocks in xarray to accelerate lookup")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> drivers/base/memory.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index 7222ff9b5e05..084d67fd55cc 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -636,10 +636,9 @@ static int __add_memory_block(struct memory_block *memory)
> }
> ret = xa_err(xa_store(&memory_blocks, memory->dev.id, memory,
> GFP_KERNEL));
> - if (ret) {
> - put_device(&memory->dev);
> + if (ret)
> device_unregister(&memory->dev);
> - }
> +
> return ret;
> }
>
Looks correct to me. I assume this will only happen once the stars
align, but it's most certainly wrong I think.
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
--
Thanks,
David / dhildenb
