diff options
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/balloon.c | 16 | ||||
| -rw-r--r-- | drivers/xen/evtchn.c | 20 |
2 files changed, 24 insertions, 12 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 9781e0dd59d6..d46839f51e73 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -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; } diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c index 38272ad24551..f4edd6df3df2 100644 --- a/drivers/xen/evtchn.c +++ b/drivers/xen/evtchn.c @@ -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; |