Merge branch 'for-4.18/mcsafe' into libnvdimm-for-next

4 files changed, 25 insertions, 4 deletions

diff --git a/include/linux/dax.h b/include/linux/dax.h
index 25bab6abb695..b51db4264c83 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -20,6 +20,9 @@ struct dax_operations {
         /* copy_from_iter: required operation for fs-dax direct-i/o */
         size_t (*copy_from_iter)(struct dax_device *, pgoff_t, void *, size_t,
                         struct iov_iter *);
+        /* copy_to_iter: required operation for fs-dax direct-i/o */
+        size_t (*copy_to_iter)(struct dax_device *, pgoff_t, void *, size_t,
+                        struct iov_iter *);
 };
 
 extern struct attribute_group dax_attribute_group;
@@ -125,6 +128,8 @@ long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
                 void **kaddr, pfn_t *pfn);
 size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
                 size_t bytes, struct iov_iter *i);
+size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
+                size_t bytes, struct iov_iter *i);
 void dax_flush(struct dax_device *dax_dev, void *addr, size_t size);
 
 ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 31fef7c34185..6fb0808e87c8 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -133,7 +133,7 @@ typedef int (*dm_busy_fn) (struct dm_target *ti);
  */
 typedef long (*dm_dax_direct_access_fn) (struct dm_target *ti, pgoff_t pgoff,
                 long nr_pages, void **kaddr, pfn_t *pfn);
-typedef size_t (*dm_dax_copy_from_iter_fn)(struct dm_target *ti, pgoff_t pgoff,
+typedef size_t (*dm_dax_copy_iter_fn)(struct dm_target *ti, pgoff_t pgoff,
                 void *addr, size_t bytes, struct iov_iter *i);
 #define PAGE_SECTORS (PAGE_SIZE / 512)
 
@@ -184,7 +184,8 @@ struct target_type {
         dm_iterate_devices_fn iterate_devices;
         dm_io_hints_fn io_hints;
         dm_dax_direct_access_fn direct_access;
-        dm_dax_copy_from_iter_fn dax_copy_from_iter;
+        dm_dax_copy_iter_fn dax_copy_from_iter;
+        dm_dax_copy_iter_fn dax_copy_to_iter;
 
         /* For internal device-mapper use. */
         struct list_head list;
diff --git a/include/linux/string.h b/include/linux/string.h
index dd39a690c841..4a5a0eb7df51 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -147,8 +147,8 @@ extern int memcmp(const void *,const void *,__kernel_size_t);
 extern void * memchr(const void *,int,__kernel_size_t);
 #endif
 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE
-static inline __must_check int memcpy_mcsafe(void *dst, const void *src,
-                size_t cnt)
+static inline __must_check unsigned long memcpy_mcsafe(void *dst,
+                const void *src, size_t cnt)
 {
         memcpy(dst, src, cnt);
         return 0;
diff --git a/include/linux/uio.h b/include/linux/uio.h
index e67e12adb136..409c845d4cd3 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -154,6 +154,12 @@ size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i);
 #define _copy_from_iter_flushcache _copy_from_iter_nocache
 #endif
 
+#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
+size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i);
+#else
+#define _copy_to_iter_mcsafe _copy_to_iter
+#endif
+
 static __always_inline __must_check
 size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
 {
@@ -163,6 +169,15 @@ size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
                 return _copy_from_iter_flushcache(addr, bytes, i);
 }
 
+static __always_inline __must_check
+size_t copy_to_iter_mcsafe(void *addr, size_t bytes, struct iov_iter *i)
+{
+        if (unlikely(!check_copy_size(addr, bytes, false)))
+                return 0;
+        else
+                return _copy_to_iter_mcsafe(addr, bytes, i);
+}
+
 size_t iov_iter_zero(size_t bytes, struct iov_iter *);
 unsigned long iov_iter_alignment(const struct iov_iter *i);
 unsigned long iov_iter_gap_alignment(const struct iov_iter *i);