From 49f8b459fc1de5e3712b57c8ccefae9ec45270f8 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Tue, 24 May 2022 13:46:30 +0200 Subject: [PATCH] xen: switch gnttab_end_foreign_access() to take a struct page pointer 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 Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich Signed-off-by: Juergen Gross --- drivers/block/xen-blkfront.c | 6 +++--- drivers/input/misc/xen-kbdfront.c | 4 ++-- drivers/net/xen-netfront.c | 7 +++---- drivers/xen/gntalloc.c | 9 +++------ drivers/xen/gntdev-dmabuf.c | 2 +- drivers/xen/grant-table.c | 8 ++++---- drivers/xen/pvcalls-front.c | 6 +++--- drivers/xen/xen-front-pgdir-shbuf.c | 2 +- drivers/xen/xenbus/xenbus_client.c | 2 +- include/xen/grant_table.h | 6 +++--- net/9p/trans_xen.c | 8 ++++---- 11 files changed, 28 insertions(+), 32 deletions(-) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index bd7b34f..a6123b6 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -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); } diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c index 1fc9b3e..8d8ebdc 100644 --- a/drivers/input/misc/xen-kbdfront.c +++ b/drivers/input/misc/xen-kbdfront.c @@ -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; } diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 65ab907..8c0b954 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -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) diff --git a/drivers/xen/gntalloc.c b/drivers/xen/gntalloc.c index 55acb32..a15729b 100644 --- a/drivers/xen/gntalloc.c +++ b/drivers/xen/gntalloc.c @@ -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); } diff --git a/drivers/xen/gntdev-dmabuf.c b/drivers/xen/gntdev-dmabuf.c index 91073b4..940e5e9 100644 --- a/drivers/xen/gntdev-dmabuf.c +++ b/drivers/xen/gntdev-dmabuf.c @@ -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) diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 1a1aec0..1b9b28b 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -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); diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c index e254ed1..1826e8e6 100644 --- a/drivers/xen/pvcalls-front.c +++ b/drivers/xen/pvcalls-front.c @@ -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); diff --git a/drivers/xen/xen-front-pgdir-shbuf.c b/drivers/xen/xen-front-pgdir-shbuf.c index b643376..bef8d72 100644 --- a/drivers/xen/xen-front-pgdir-shbuf.c +++ b/drivers/xen/xen-front-pgdir-shbuf.c @@ -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); diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c index d6fdd2d..d5f3f76 100644 --- a/drivers/xen/xenbus/xenbus_client.c +++ b/drivers/xen/xenbus/xenbus_client.c @@ -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; } } diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h index 7d0f2f0..527c990 100644 --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -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 diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c index 77883b6..833cd37 100644 --- a/net/9p/trans_xen.c +++ b/net/9p/trans_xen.c @@ -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; } -- 2.7.4