mm: replace get_user_pages() write/force parameters with gup_flags

This removes the 'write' and 'force' from get_user_pages() and replaces
them with 'gup_flags' to make the use of FOLL_FORCE explicit in callers
as use of this flag can result in surprising behaviour (and hence bugs)
within the mm subsystem.

Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 12 insertions, 4 deletions

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index c68746ce6624..224ad274ea0b 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -94,6 +94,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
         unsigned long dma_attrs = 0;
         struct scatterlist *sg, *sg_list_start;
         int need_release = 0;
+        unsigned int gup_flags = FOLL_WRITE;
 
         if (dmasync)
                 dma_attrs |= DMA_ATTR_WRITE_BARRIER;
@@ -183,6 +184,9 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
         if (ret)
                 goto out;
 
+        if (!umem->writable)
+                gup_flags |= FOLL_FORCE;
+
         need_release = 1;
         sg_list_start = umem->sg_head.sgl;
 
@@ -190,7 +194,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
                 ret = get_user_pages(cur_base,
                                      min_t(unsigned long, npages,
                                            PAGE_SIZE / sizeof (struct page *)),
-                                     1, !umem->writable, page_list, vma_list);
+                                     gup_flags, page_list, vma_list);
 
                 if (ret < 0)
                         goto out;
diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c
index 6c00d04b8b28..c6fe89d79248 100644
--- a/drivers/infiniband/hw/mthca/mthca_memfree.c
+++ b/drivers/infiniband/hw/mthca/mthca_memfree.c
@@ -472,7 +472,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
                 goto out;
         }
 
-        ret = get_user_pages(uaddr & PAGE_MASK, 1, 1, 0, pages, NULL);
+        ret = get_user_pages(uaddr & PAGE_MASK, 1, FOLL_WRITE, pages, NULL);
         if (ret < 0)
                 goto out;
 
diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c b/drivers/infiniband/hw/qib/qib_user_pages.c
index 2d2b94fd3633..75f08624ac05 100644
--- a/drivers/infiniband/hw/qib/qib_user_pages.c
+++ b/drivers/infiniband/hw/qib/qib_user_pages.c
@@ -67,7 +67,8 @@ static int __qib_get_user_pages(unsigned long start_page, size_t num_pages,
 
         for (got = 0; got < num_pages; got += ret) {
                 ret = get_user_pages(start_page + got * PAGE_SIZE,
-                                     num_pages - got, 1, 1,
+                                     num_pages - got,
+                                     FOLL_WRITE | FOLL_FORCE,
                                      p + got, NULL);
                 if (ret < 0)
                         goto bail_release;
diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c
index a0b6ebee4d8a..1ccee6ea5bc3 100644
--- a/drivers/infiniband/hw/usnic/usnic_uiom.c
+++ b/drivers/infiniband/hw/usnic/usnic_uiom.c
@@ -111,6 +111,7 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
         int i;
         int flags;
         dma_addr_t pa;
+        unsigned int gup_flags;
 
         if (!can_do_mlock())
                 return -EPERM;
@@ -135,6 +136,8 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
 
         flags = IOMMU_READ | IOMMU_CACHE;
         flags |= (writable) ? IOMMU_WRITE : 0;
+        gup_flags = FOLL_WRITE;
+        gup_flags |= (writable) ? 0 : FOLL_FORCE;
         cur_base = addr & PAGE_MASK;
         ret = 0;
 
@@ -142,7 +145,7 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
                 ret = get_user_pages(cur_base,
                                         min_t(unsigned long, npages,
                                         PAGE_SIZE / sizeof(struct page *)),
-                                        1, !writable, page_list, NULL);
+                                        gup_flags, page_list, NULL);
 
                 if (ret < 0)
                         goto out;