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xen: switch gnttab_end_foreign_access() to take a struct page pointer

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Instead of a virtual kernel address use a pointer of the associated
struct page as second parameter of gnttab_end_foreign_access().

Most users have that pointer available already and are creating the
virtual address from it, risking problems in case the memory is
located in highmem.

gnttab_end_foreign_access() itself won't need to get the struct page
from the address again.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
This commit is contained in:
Juergen Gross 2022-05-24 13:46:30 +02:00
parent 5b3353949e
commit 49f8b459fc
11 changed files with 28 additions and 32 deletions
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6
drivers/block/xen-blkfront.c
View File

@ -1221,7 +1221,7 @@ static void blkif_free_ring(struct blkfront_ring_info *rinfo)
list_del(&persistent_gnt->node);
if (persistent_gnt->gref != INVALID_GRANT_REF) {
gnttab_end_foreign_access(persistent_gnt->gref,
0UL);
NULL);
rinfo->persistent_gnts_c--;
}
if (info->feature_persistent)
@ -1244,7 +1244,7 @@ static void blkif_free_ring(struct blkfront_ring_info *rinfo)
rinfo->shadow[i].req.u.rw.nr_segments;
for (j = 0; j < segs; j++) {
persistent_gnt = rinfo->shadow[i].grants_used[j];
gnttab_end_foreign_access(persistent_gnt->gref, 0UL);
gnttab_end_foreign_access(persistent_gnt->gref, NULL);
if (info->feature_persistent)
__free_page(persistent_gnt->page);
kfree(persistent_gnt);
@ -1259,7 +1259,7 @@ static void blkif_free_ring(struct blkfront_ring_info *rinfo)
for (j = 0; j < INDIRECT_GREFS(segs); j++) {
persistent_gnt = rinfo->shadow[i].indirect_grants[j];
gnttab_end_foreign_access(persistent_gnt->gref, 0UL);
gnttab_end_foreign_access(persistent_gnt->gref, NULL);
__free_page(persistent_gnt->page);
kfree(persistent_gnt);
}

4
drivers/input/misc/xen-kbdfront.c
View File

@ -481,7 +481,7 @@ static int xenkbd_connect_backend(struct xenbus_device *dev,
error_evtchan:
xenbus_free_evtchn(dev, evtchn);
error_grant:
gnttab_end_foreign_access(info->gref, 0UL);
gnttab_end_foreign_access(info->gref, NULL);
info->gref = -1;
return ret;
}
@ -492,7 +492,7 @@ static void xenkbd_disconnect_backend(struct xenkbd_info *info)
unbind_from_irqhandler(info->irq, info);
info->irq = -1;
if (info->gref >= 0)
gnttab_end_foreign_access(info->gref, 0UL);
gnttab_end_foreign_access(info->gref, NULL);
info->gref = -1;
}

7
drivers/net/xen-netfront.c
View File

@ -1386,7 +1386,7 @@ static void xennet_release_tx_bufs(struct netfront_queue *queue)
queue->tx_skbs[i] = NULL;
get_page(queue->grant_tx_page[i]);
gnttab_end_foreign_access(queue->grant_tx_ref[i],
(unsigned long)page_address(queue->grant_tx_page[i]));
queue->grant_tx_page[i]);
queue->grant_tx_page[i] = NULL;
queue->grant_tx_ref[i] = INVALID_GRANT_REF;
add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, i);
@ -1418,8 +1418,7 @@ static void xennet_release_rx_bufs(struct netfront_queue *queue)
* foreign access is ended (which may be deferred).
*/
get_page(page);
gnttab_end_foreign_access(ref,
(unsigned long)page_address(page));
gnttab_end_foreign_access(ref, page);
queue->grant_rx_ref[id] = INVALID_GRANT_REF;
kfree_skb(skb);
@ -1760,7 +1759,7 @@ static void xennet_end_access(int ref, void *page)
{
/* This frees the page as a side-effect */
if (ref != INVALID_GRANT_REF)
gnttab_end_foreign_access(ref, (unsigned long)page);
gnttab_end_foreign_access(ref, virt_to_page(page));
}
static void xennet_disconnect_backend(struct netfront_info *info)

9
drivers/xen/gntalloc.c
View File

@ -175,8 +175,6 @@ undo:
static void __del_gref(struct gntalloc_gref *gref)
{
unsigned long addr;
if (gref->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
uint8_t *tmp = kmap_local_page(gref->page);
tmp[gref->notify.pgoff] = 0;
@ -190,10 +188,9 @@ static void __del_gref(struct gntalloc_gref *gref)
gref->notify.flags = 0;
if (gref->gref_id) {
if (gref->page) {
addr = (unsigned long)page_to_virt(gref->page);
gnttab_end_foreign_access(gref->gref_id, addr);
} else
if (gref->page)
gnttab_end_foreign_access(gref->gref_id, gref->page);
else
gnttab_free_grant_reference(gref->gref_id);
}

2
drivers/xen/gntdev-dmabuf.c
View File

@ -524,7 +524,7 @@ static void dmabuf_imp_end_foreign_access(u32 *refs, int count)
for (i = 0; i < count; i++)
if (refs[i] != INVALID_GRANT_REF)
gnttab_end_foreign_access(refs[i], 0UL);
gnttab_end_foreign_access(refs[i], NULL);
}
static void dmabuf_imp_free_storage(struct gntdev_dmabuf *gntdev_dmabuf)

8
drivers/xen/grant-table.c
View File

@ -430,13 +430,13 @@ int gnttab_try_end_foreign_access(grant_ref_t ref)
}
EXPORT_SYMBOL_GPL(gnttab_try_end_foreign_access);
void gnttab_end_foreign_access(grant_ref_t ref, unsigned long page)
void gnttab_end_foreign_access(grant_ref_t ref, struct page *page)
{
if (gnttab_try_end_foreign_access(ref)) {
if (page != 0)
put_page(virt_to_page(page));
if (page)
put_page(page);
} else
gnttab_add_deferred(ref, page ? virt_to_page(page) : NULL);
gnttab_add_deferred(ref, page);
}
EXPORT_SYMBOL_GPL(gnttab_end_foreign_access);

6
drivers/xen/pvcalls-front.c
View File

@ -238,8 +238,8 @@ static void pvcalls_front_free_map(struct pvcalls_bedata *bedata,
spin_unlock(&bedata->socket_lock);
for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++)
gnttab_end_foreign_access(map->active.ring->ref[i], 0);
gnttab_end_foreign_access(map->active.ref, 0);
gnttab_end_foreign_access(map->active.ring->ref[i], NULL);
gnttab_end_foreign_access(map->active.ref, NULL);
free_page((unsigned long)map->active.ring);
kfree(map);
@ -1117,7 +1117,7 @@ static int pvcalls_front_remove(struct xenbus_device *dev)
}
}
if (bedata->ref != -1)
gnttab_end_foreign_access(bedata->ref, 0);
gnttab_end_foreign_access(bedata->ref, NULL);
kfree(bedata->ring.sring);
kfree(bedata);
xenbus_switch_state(dev, XenbusStateClosed);

2
drivers/xen/xen-front-pgdir-shbuf.c
View File

@ -135,7 +135,7 @@ void xen_front_pgdir_shbuf_free(struct xen_front_pgdir_shbuf *buf)
for (i = 0; i < buf->num_grefs; i++)
if (buf->grefs[i] != INVALID_GRANT_REF)
gnttab_end_foreign_access(buf->grefs[i], 0UL);
gnttab_end_foreign_access(buf->grefs[i], NULL);
}
kfree(buf->grefs);
kfree(buf->directory);

2
drivers/xen/xenbus/xenbus_client.c
View File

@ -439,7 +439,7 @@ void xenbus_teardown_ring(void **vaddr, unsigned int nr_pages,
for (i = 0; i < nr_pages; i++) {
if (grefs[i] != INVALID_GRANT_REF) {
gnttab_end_foreign_access(grefs[i], 0);
gnttab_end_foreign_access(grefs[i], NULL);
grefs[i] = INVALID_GRANT_REF;
}
}

6
include/xen/grant_table.h
View File

@ -101,10 +101,10 @@ int gnttab_end_foreign_access_ref(grant_ref_t ref);
* Eventually end access through the given grant reference, and once that
* access has been ended, free the given page too. Access will be ended
* immediately iff the grant entry is not in use, otherwise it will happen
* some time later. page may be 0, in which case no freeing will occur.
* some time later. page may be NULL, in which case no freeing will occur.
* Note that the granted page might still be accessed (read or write) by the
* other side after gnttab_end_foreign_access() returns, so even if page was
* specified as 0 it is not allowed to just reuse the page for other
* specified as NULL it is not allowed to just reuse the page for other
* purposes immediately. gnttab_end_foreign_access() will take an additional
* reference to the granted page in this case, which is dropped only after
* the grant is no longer in use.
@ -112,7 +112,7 @@ int gnttab_end_foreign_access_ref(grant_ref_t ref);
* gnttab_end_foreign_access() are done via alloc_pages_exact() (and freeing
* via free_pages_exact()) in order to avoid high order pages.
*/
void gnttab_end_foreign_access(grant_ref_t ref, unsigned long page);
void gnttab_end_foreign_access(grant_ref_t ref, struct page *page);
/*
* End access through the given grant reference, iff the grant entry is

8
net/9p/trans_xen.c
View File

@ -279,13 +279,13 @@ static void xen_9pfs_front_free(struct xen_9pfs_front_priv *priv)
grant_ref_t ref;
ref = priv->rings[i].intf->ref[j];
gnttab_end_foreign_access(ref, 0);
gnttab_end_foreign_access(ref, NULL);
}
free_pages_exact(priv->rings[i].data.in,
1UL << (priv->rings[i].intf->ring_order +
XEN_PAGE_SHIFT));
}
gnttab_end_foreign_access(priv->rings[i].ref, 0);
gnttab_end_foreign_access(priv->rings[i].ref, NULL);
free_page((unsigned long)priv->rings[i].intf);
}
kfree(priv->rings);
@ -353,10 +353,10 @@ static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev,
out:
if (bytes) {
for (i--; i >= 0; i--)
gnttab_end_foreign_access(ring->intf->ref[i], 0);
gnttab_end_foreign_access(ring->intf->ref[i], NULL);
free_pages_exact(bytes, 1UL << (order + XEN_PAGE_SHIFT));
}
gnttab_end_foreign_access(ring->ref, 0);
gnttab_end_foreign_access(ring->ref, NULL);
free_page((unsigned long)ring->intf);
return ret;
}