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Commit 41143b77 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-linus-4.6-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip 

Pull xen regression fixes from David Vrabel:

 - Fix two regressions causing crashes in 32-bit PV guests

 - Fix a regression in the evtchn driver

* tag 'for-linus-4.6-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/evtchn: fix ring resize when binding new events
  xen/balloon: Fix crash when ballooning on x86 32 bit PAE
  xen: Fix page <-> pfn conversion on 32 bit systems
parents 83858a70 27e0e638

drivers/xen/balloon.c

+16 −0
Original line number Diff line number Diff line
@@ -151,6 +151,8 @@ static DECLARE_WAIT_QUEUE_HEAD(balloon_wq); 
static void balloon_process(struct work_struct *work);

static DECLARE_DELAYED_WORK(balloon_worker, balloon_process);



static void release_memory_resource(struct resource *resource);



/* When ballooning out (allocating memory to return to Xen) we don't really

   want the kernel to try too hard since that can trigger the oom killer. */

#define GFP_BALLOON \
@@ -267,6 +269,20 @@ static struct resource *additional_memory_resource(phys_addr_t size) 
		return NULL;

	}



#ifdef CONFIG_SPARSEMEM

	{

		unsigned long limit = 1UL << (MAX_PHYSMEM_BITS - PAGE_SHIFT);

		unsigned long pfn = res->start >> PAGE_SHIFT;



		if (pfn > limit) {

			pr_err("New System RAM resource outside addressable RAM (%lu > %lu)\n",

			       pfn, limit);

			release_memory_resource(res);

			return NULL;

		}

	}

#endif



	return res;

}

drivers/xen/evtchn.c

+8 −12
Original line number Diff line number Diff line
@@ -316,7 +316,6 @@ static int evtchn_resize_ring(struct per_user_data *u) 
{

	unsigned int new_size;

	evtchn_port_t *new_ring, *old_ring;

	unsigned int p, c;



	/*

	 * Ensure the ring is large enough to capture all possible
@@ -346,20 +345,17 @@ static int evtchn_resize_ring(struct per_user_data *u) 
	/*

	 * Copy the old ring contents to the new ring.

	 *

	 * If the ring contents crosses the end of the current ring,

	 * it needs to be copied in two chunks.

	 * To take care of wrapping, a full ring, and the new index

	 * pointing into the second half, simply copy the old contents

	 * twice.

	 *

	 * +---------+    +------------------+

	 * |34567  12| -> |       1234567    |

	 * +-----p-c-+    +------------------+

	 * |34567  12| -> |34567  1234567  12|

	 * +-----p-c-+    +-------c------p---+

	 */

	p = evtchn_ring_offset(u, u->ring_prod);

	c = evtchn_ring_offset(u, u->ring_cons);

	if (p < c) {

		memcpy(new_ring + c, u->ring + c, (u->ring_size - c) * sizeof(*u->ring));

		memcpy(new_ring + u->ring_size, u->ring, p * sizeof(*u->ring));

	} else

		memcpy(new_ring + c, u->ring + c, (p - c) * sizeof(*u->ring));

	memcpy(new_ring, old_ring, u->ring_size * sizeof(*u->ring));

	memcpy(new_ring + u->ring_size, old_ring,

	       u->ring_size * sizeof(*u->ring));



	u->ring = new_ring;

	u->ring_size = new_size;

include/xen/page.h

+2 −2
Original line number Diff line number Diff line
@@ -15,9 +15,9 @@ 
 */



#define xen_pfn_to_page(xen_pfn)	\

	((pfn_to_page(((unsigned long)(xen_pfn) << XEN_PAGE_SHIFT) >> PAGE_SHIFT)))

	(pfn_to_page((unsigned long)(xen_pfn) >> (PAGE_SHIFT - XEN_PAGE_SHIFT)))

#define page_to_xen_pfn(page)		\

	(((page_to_pfn(page)) << PAGE_SHIFT) >> XEN_PAGE_SHIFT)

	((page_to_pfn(page)) << (PAGE_SHIFT - XEN_PAGE_SHIFT))



#define XEN_PFN_PER_PAGE	(PAGE_SIZE / XEN_PAGE_SIZE)