Messages in this thread | | | Subject | Re: [PATCH 1/2] xen/xenbus: avoid large structs and arrays on the stack | From | Jürgen Groß <> | Date | Tue, 12 May 2020 11:13:27 +0200 |
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On 11.05.20 20:01, Boris Ostrovsky wrote: > On 5/11/20 3:31 AM, Juergen Gross wrote: >> >> static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev, > > > I wonder whether we can drop valloc/vfree from xenbus_ring_ops' names.
I can do that.
> > >> + struct map_ring_valloc *info, >> grant_ref_t *gnt_ref, >> unsigned int nr_grefs, >> void **vaddr) >> { >> - struct xenbus_map_node *node; >> + struct xenbus_map_node *node = info->node; >> int err; >> void *addr; >> bool leaked = false; >> - struct map_ring_valloc_hvm info = { >> - .idx = 0, >> - }; >> unsigned int nr_pages = XENBUS_PAGES(nr_grefs); >> >> - if (nr_grefs > XENBUS_MAX_RING_GRANTS) >> - return -EINVAL; >> - >> - *vaddr = NULL; >> - >> - node = kzalloc(sizeof(*node), GFP_KERNEL); >> - if (!node) >> - return -ENOMEM; >> - >> err = alloc_xenballooned_pages(nr_pages, node->hvm.pages); >> if (err) >> goto out_err; >> >> gnttab_foreach_grant(node->hvm.pages, nr_grefs, >> xenbus_map_ring_setup_grant_hvm, >> - &info); >> + info); >> >> err = __xenbus_map_ring(dev, gnt_ref, nr_grefs, node->handles, >> - info.phys_addrs, GNTMAP_host_map, &leaked); >> + info, GNTMAP_host_map, &leaked); >> node->nr_handles = nr_grefs; >> >> if (err) >> @@ -641,11 +654,13 @@ static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev, >> spin_unlock(&xenbus_valloc_lock); >> >> *vaddr = addr; >> + info->node = NULL; > > > Is this so that xenbus_map_ring_valloc() doesn't free it accidentally?
Yes.
Juergen
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