Re: Drivers: hv: vmbus: One function call less in create_gpadl_header() after error detection

From: Markus Elfring
Date: Wed Jan 10 2024 - 12:09:02 EST


> It occurred to me overnight that the existing error handling
> in create_gpadl_header() is unnecessarily complicated. Here's
> an approach that I think would fix what you have flagged, and
> would reduce complexity instead of increasing it. Thoughts?

I find this development view interesting.


> diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
> index 56f7e06c673e..44b1d5c8dfed 100644
> --- a/drivers/hv/channel.c
> +++ b/drivers/hv/channel.c
> @@ -336,7 +336,7 @@ static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer,
> sizeof(struct gpa_range) + pfncount * sizeof(u64);
> msgheader = kzalloc(msgsize, GFP_KERNEL);
> if (!msgheader)
> - goto nomem;
> + return -ENOMEM;
>
> INIT_LIST_HEAD(&msgheader->submsglist);
> msgheader->msgsize = msgsize;
> @@ -386,8 +386,8 @@ static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer,
> list_del(&pos->msglistentry);
> kfree(pos);
> }
> -
> - goto nomem;
> + kfree(msgheader);
> + return -ENOMEM;
> }
>
> msgbody->msgsize = msgsize;
> @@ -416,8 +416,8 @@ static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer,
> sizeof(struct vmbus_channel_gpadl_header) +
> sizeof(struct gpa_range) + pagecount * sizeof(u64);
> msgheader = kzalloc(msgsize, GFP_KERNEL);
> - if (msgheader == NULL)
> - goto nomem;
> + if (!msgheader)
> + return -ENOMEM;
>
> INIT_LIST_HEAD(&msgheader->submsglist);
> msgheader->msgsize = msgsize;
> @@ -437,10 +437,6 @@ static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer,
> }
>
> return 0;
> -nomem:
> - kfree(msgheader);
> - kfree(msgbody);
> - return -ENOMEM;
> }
>
> /*
>

Should up to two memory areas still be released after a data processing failure?

Regards,
Markus