IB/uverbs: Add PTR_IN attributes that are allocated/copied automatically

Adding UVERBS_ATTR_SPEC_F_ALLOC_AND_COPY flag to PTR_IN attributes.
By using this flag, the parse automatically allocates and copies the
user-space data. This data is accessible by using uverbs_attr_get_len
and uverbs_attr_get_alloced_ptr inline accessor functions from the
handler.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/core/uverbs_ioctl.c b/drivers/infiniband/core/uverbs_ioctl.c
index 6759d59..5ac2950 100644 (file)
--- a/drivers/infiniband/core/uverbs_ioctl.c
+++ b/drivers/infiniband/core/uverbs_ioctl.c
@@ -114,9 +114,27 @@ static int uverbs_process_attr(struct ib_device *ibdev,
                    uattr->attr_data.reserved)
                        return -EINVAL;
 
-               e->ptr_attr.data = uattr->data;
                e->ptr_attr.len = uattr->len;
                e->ptr_attr.flags = uattr->flags;
+
+               if (val_spec->flags & UVERBS_ATTR_SPEC_F_ALLOC_AND_COPY &&
+                   !uverbs_attr_ptr_is_inline(e)) {
+                       void *p;
+
+                       p = kvmalloc(uattr->len, GFP_KERNEL);
+                       if (!p)
+                               return -ENOMEM;
+
+                       e->ptr_attr.ptr = p;
+
+                       if (copy_from_user(p, u64_to_user_ptr(uattr->data),
+                                          uattr->len)) {
+                               kvfree(p);
+                               return -EFAULT;
+                       }
+               } else {
+                       e->ptr_attr.data = uattr->data;
+               }
                break;
 
        case UVERBS_ATTR_TYPE_IDR:
@@ -200,6 +218,11 @@ static int uverbs_finalize_attrs(struct uverbs_attr_bundle *attrs_bundle,
                                        spec->obj.access, commit);
                                if (!ret)
                                        ret = current_ret;
+                       } else if (spec->type == UVERBS_ATTR_TYPE_PTR_IN &&
+                                  spec->flags &
+                                          UVERBS_ATTR_SPEC_F_ALLOC_AND_COPY &&
+                                  !uverbs_attr_ptr_is_inline(attr)) {
+                               kvfree(attr->ptr_attr.ptr);
                        }
                }
        }

diff --git a/include/rdma/uverbs_ioctl.h b/include/rdma/uverbs_ioctl.h
index bd6bba3..11cc40e 100644 (file)
--- a/include/rdma/uverbs_ioctl.h
+++ b/include/rdma/uverbs_ioctl.h
@@ -65,6 +65,10 @@ enum {
        UVERBS_ATTR_SPEC_F_MANDATORY    = 1U << 0,
        /* Support extending attributes by length, validate all unknown size == zero  */
        UVERBS_ATTR_SPEC_F_MIN_SZ_OR_ZERO = 1U << 1,
+       /*
+        * Valid only for PTR_IN. Allocate and copy the data inside the parser
+        */
+       UVERBS_ATTR_SPEC_F_ALLOC_AND_COPY = 1U << 2,
 };
 
 /* Specification of a single attribute inside the ioctl message */
@@ -323,7 +327,14 @@ struct uverbs_object_tree_def {
  */
 
 struct uverbs_ptr_attr {
-       u64             data;
+       /*
+        * If UVERBS_ATTR_SPEC_F_ALLOC_AND_COPY is set then the 'ptr' is
+        * used.
+        */
+       union {
+               void *ptr;
+               u64 data;
+       };
        u16             len;
        /* Combination of bits from enum UVERBS_ATTR_F_XXXX */
        u16             flags;
@@ -431,6 +442,17 @@ static inline struct ib_uobject *uverbs_attr_get_uobject(const struct uverbs_att
        return attr->obj_attr.uobject;
 }
 
+static inline int
+uverbs_attr_get_len(const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
+{
+       const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
+
+       if (IS_ERR(attr))
+               return PTR_ERR(attr);
+
+       return attr->ptr_attr.len;
+}
+
 static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
                                 size_t idx, const void *from, size_t size)
 {
@@ -457,6 +479,18 @@ static inline bool uverbs_attr_ptr_is_inline(const struct uverbs_attr *attr)
        return attr->ptr_attr.len <= sizeof(attr->ptr_attr.data);
 }
 
+static inline void *uverbs_attr_get_alloced_ptr(
+       const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
+{
+       const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
+
+       if (IS_ERR(attr))
+               return (void *)attr;
+
+       return uverbs_attr_ptr_is_inline(attr) ? (void *)&attr->ptr_attr.data :
+                                                attr->ptr_attr.ptr;
+}
+
 static inline int _uverbs_copy_from(void *to,
                                    const struct uverbs_attr_bundle *attrs_bundle,
                                    size_t idx,