Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e16dad6b authored by Jake Oshins's avatar Jake Oshins Committed by Greg Kroah-Hartman
Browse files

drivers:hv: Lock access to hyperv_mmio resource tree 



In existing code, this tree of resources is created
in single-threaded code and never modified after it is
created, and thus needs no locking.  This patch introduces
a semaphore for tree access, as other patches in this
series introduce run-time modifications of this resource
tree which can happen on multiple threads.

Signed-off-by: default avatarJake Oshins <jakeo@microsoft.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ab028db4

drivers/hv/vmbus_drv.c

+12 −4
Original line number Diff line number Diff line
@@ -102,6 +102,7 @@ static struct notifier_block hyperv_panic_block = { 
};



struct resource *hyperv_mmio;

DEFINE_SEMAPHORE(hyperv_mmio_lock);



static int vmbus_exists(void)

{
@@ -1132,7 +1133,10 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj, 
	resource_size_t range_min, range_max, start, local_min, local_max;

	const char *dev_n = dev_name(&device_obj->device);

	u32 fb_end = screen_info.lfb_base + (screen_info.lfb_size << 1);

	int i;

	int i, retval;



	retval = -ENXIO;

	down(&hyperv_mmio_lock);



	for (iter = hyperv_mmio; iter; iter = iter->sibling) {

		if ((iter->start >= max) || (iter->end <= min))
@@ -1169,13 +1173,17 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj, 
			for (; start + size - 1 <= local_max; start += align) {

				*new = request_mem_region_exclusive(start, size,

								    dev_n);

				if (*new)

					return 0;

				if (*new) {

					retval = 0;

					goto exit;

				}

			}

		}

	}



	return -ENXIO;

exit:

	up(&hyperv_mmio_lock);

	return retval;

}

EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);