diff options
| -rw-r--r-- | arch/s390/kernel/uv.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c index 35ed2aea8891..9646f773208a 100644 --- a/arch/s390/kernel/uv.c +++ b/arch/s390/kernel/uv.c @@ -14,6 +14,7 @@ #include <linux/memblock.h> #include <linux/pagemap.h> #include <linux/swap.h> +#include <linux/pagewalk.h> #include <asm/facility.h> #include <asm/sections.h> #include <asm/uv.h> @@ -462,9 +463,9 @@ EXPORT_SYMBOL_GPL(gmap_convert_to_secure); int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr) { struct vm_area_struct *vma; + struct folio_walk fw; unsigned long uaddr; struct folio *folio; - struct page *page; int rc; rc = -EFAULT; @@ -483,11 +484,15 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr) goto out; rc = 0; - /* we take an extra reference here */ - page = follow_page(vma, uaddr, FOLL_WRITE | FOLL_GET); - if (IS_ERR_OR_NULL(page)) + folio = folio_walk_start(&fw, vma, uaddr, 0); + if (!folio) goto out; - folio = page_folio(page); + /* + * See gmap_make_secure(): large folios cannot be secure. Small + * folio implies FW_LEVEL_PTE. + */ + if (folio_test_large(folio) || !pte_write(fw.pte)) + goto out_walk_end; rc = uv_destroy_folio(folio); /* * Fault handlers can race; it is possible that two CPUs will fault @@ -500,7 +505,8 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr) */ if (rc) rc = uv_convert_from_secure_folio(folio); - folio_put(folio); +out_walk_end: + folio_walk_end(&fw, vma); out: mmap_read_unlock(gmap->mm); return rc; |