xen-gntdev: Fix incorrect use of zero handle
The handle with numeric value 0 is a valid map handle, so it cannot be used to indicate that a page has not been mapped. Use -1 instead. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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1f169f66dd
Коммит
77c35acb7c
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@ -126,6 +126,8 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
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add->pages[i] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
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if (add->pages[i] == NULL)
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goto err;
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add->map_ops[i].handle = -1;
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add->unmap_ops[i].handle = -1;
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}
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add->index = 0;
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@ -248,7 +250,7 @@ static int find_grant_ptes(pte_t *pte, pgtable_t token,
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map->grants[pgnr].ref,
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map->grants[pgnr].domid);
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gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags,
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0 /* handle */);
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-1 /* handle */);
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return 0;
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}
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@ -259,7 +261,7 @@ static int map_grant_pages(struct grant_map *map)
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if (!use_ptemod) {
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/* Note: it could already be mapped */
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if (map->map_ops[0].handle)
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if (map->map_ops[0].handle != -1)
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return 0;
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for (i = 0; i < map->count; i++) {
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addr = (phys_addr_t)
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@ -268,7 +270,7 @@ static int map_grant_pages(struct grant_map *map)
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map->grants[i].ref,
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map->grants[i].domid);
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gnttab_set_unmap_op(&map->unmap_ops[i], addr,
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map->flags, 0 /* handle */);
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map->flags, -1 /* handle */);
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}
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}
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@ -280,7 +282,11 @@ static int map_grant_pages(struct grant_map *map)
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for (i = 0; i < map->count; i++) {
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if (map->map_ops[i].status)
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err = -EINVAL;
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map->unmap_ops[i].handle = map->map_ops[i].handle;
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else {
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BUG_ON(map->map_ops[i].handle == -1);
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map->unmap_ops[i].handle = map->map_ops[i].handle;
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pr_debug("map handle=%d\n", map->map_ops[i].handle);
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}
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}
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return err;
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}
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@ -313,7 +319,10 @@ static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
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for (i = 0; i < pages; i++) {
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if (map->unmap_ops[offset+i].status)
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err = -EINVAL;
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map->unmap_ops[offset+i].handle = 0;
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pr_debug("unmap handle=%d st=%d\n",
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map->unmap_ops[offset+i].handle,
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map->unmap_ops[offset+i].status);
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map->unmap_ops[offset+i].handle = -1;
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}
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return err;
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}
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@ -328,13 +337,13 @@ static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
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* already unmapped some of the grants. Only unmap valid ranges.
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*/
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while (pages && !err) {
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while (pages && !map->unmap_ops[offset].handle) {
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while (pages && map->unmap_ops[offset].handle == -1) {
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offset++;
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pages--;
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}
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range = 0;
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while (range < pages) {
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if (!map->unmap_ops[offset+range].handle) {
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if (map->unmap_ops[offset+range].handle == -1) {
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range--;
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break;
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}
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