Re: [PATCH 7/7] [v2] drivers/misc: introduce Freescale hypervisormanagement driver

From: Alan Cox
Date: Wed Jun 01 2011 - 15:45:00 EST


O> + /* One partition must be local, the other must be remote. In other
> + words, if source and target are both -1, or are both not -1, then
> + return an error. */
> + if ((param.source == -1) == (param.target == -1))
> + return -EINVAL;

Excess brackets (I just mention that one in passing)

> + /* pages is an array of struct page pointers that's initialized by
> + get_user_pages() */
> + pages = kzalloc(nr_pages * sizeof(struct page *), GFP_KERNEL);
> + if (!pages) {
> + pr_debug("fsl-hv: could not allocate page list\n");
> + return -ENOMEM;
> + }

pages allocated

> +
> + /* sg_list is the list of fh_sg_list objects that we pass to the
> + hypervisor */
> + sg_list_unaligned = kmalloc(nr_pages * sizeof(struct fh_sg_list) +
> + sizeof(struct fh_sg_list) - 1, GFP_KERNEL);
> + if (!sg_list_unaligned) {
> + pr_debug("fsl-hv: could not allocate S/G list\n");

but not freed on this path

Although the other paths look fine.

> +exit:
> + if (pages) {
> + for (i = 0; i < nr_pages; i++)
> + if (pages[i])
> + page_cache_release(pages[i]);
> + }
> +
> + kfree(sg_list_unaligned);
> + kfree(pages);

> +static char *strdup_from_user(const char __user *ustr, size_t max)
> +{
> + size_t len;
> + char *str;
> +
> + len = strnlen_user(ustr, max);
> + if (len > max)
> + return ERR_PTR(-ENAMETOOLONG);
> +
> + str = kmalloc(len, GFP_KERNEL);
> + if (!str)
> + return ERR_PTR(-ENOMEM);
> +
> + if (copy_from_user(str, ustr, len))
> + return ERR_PTR(-EFAULT);
> +
> + return str;
> +}

This belongs on lib/ if its of general use which I think it perhaps is
and if we don't have one already.


> + default:
> + pr_debug("fsl-hv: unknown ioctl %u\n", cmd);
> + ret = -ENOIOCTLCMD;

-ENOTTY

(-ENOIOCTLCMD is an internal indicator designed so driver layers can say
'dunno, try the next layer up')

> +/* Linked list of processes that have us open */
> +struct list_head db_list;

static ?


> + * We use the same interrupt handler for all doorbells. Whenever a doorbell
> + * is rung, and we receive an interrupt, we just put the handle for that
> + * doorbell (passed to us as *data) into all of the queues.

I wonder if these should be presented as IRQs or whether that makes no
sense ?


> +static irqreturn_t fsl_hv_state_change_isr(int irq, void *data)
> +{
> + unsigned int status;
> + struct doorbell_isr *dbisr = data;
> + int ret;
> +
> + /* Determine the new state, and if it's stopped, notify the clients. */
> + ret = fh_partition_get_status(dbisr->partition, &status);
> + if (!ret && (status == FH_PARTITION_STOPPED))
> + schedule_work(&dbisr->work);
> +
> + /* Call the normal handler */
> + return fsl_hv_isr(irq, (void *) (uintptr_t) dbisr->doorbell);
> +}

Would a threaded IRQ clean this up by avoiding the queue/work stuff ?


> +static irqreturn_t fsl_hv_shutdown_isr(int irq, void *data)
> +{
> + schedule_work(&power_off);
> +
> + /* We should never get here */

Probably worth printing something if you do (panic(...) ?)

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