!(reg.flags & IOU_PBUF_RING_MMAP)) {
-		rd.user_addr = reg.ring_addr;
+	if (!(reg->flags & IOU_PBUF_RING_MMAP)) {
+		rd.user_addr = reg->ring_addr;
 		rd.flags |= IORING_MEM_REGION_TYPE_USER;
 	}
+
 	ret = io_create_region(ctx, &bl->region, &rd, mmap_offset);
 	if (ret)
-		goto fail;
-	br = io_region_get_ptr(&bl->region);
+		return ret;
+	bl->buf_ring = io_region_get_ptr(&bl->region);
 
 #ifdef SHM_COLOUR
 	/*
@@ -656,25 +672,50 @@ int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
 	 * should use IOU_PBUF_RING_MMAP instead, and liburing will handle
 	 * this transparently.
 	 */
-	if (!(reg.flags & IOU_PBUF_RING_MMAP) &&
-	    ((reg.ring_addr | (unsigned long)br) & (SHM_COLOUR - 1))) {
-		ret = -EINVAL;
-		goto fail;
+	if (!(reg->flags & IOU_PBUF_RING_MMAP) &&
+	    ((reg->ring_addr | (unsigned long)bl->buf_ring) &
+	     (SHM_COLOUR - 1))) {
+		io_free_region(ctx->user, &bl->region);
+		return -EINVAL;
 	}
 #endif
 
-	bl->nr_entries = reg.ring_entries;
-	bl->mask = reg.ring_entries - 1;
-	bl->flags |= IOBL_BUF_RING;
-	bl->buf_ring = br;
+	return 0;
+}
+
+int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
+{
+	unsigned int permitted_flags;
+	struct io_uring_buf_reg reg;
+	struct io_buffer_list *bl;
+	int ret;
+
+	lockdep_assert_held(&ctx->uring_lock);
+
+	if (copy_from_user(&reg, arg, sizeof(reg)))
+		return -EFAULT;
+
+	permitted_flags = IOU_PBUF_RING_MMAP | IOU_PBUF_RING_INC;
+	ret = io_validate_buf_reg(&reg, permitted_flags);
+	if (ret)
+		return ret;
+
+	ret = io_alloc_new_buffer_list(ctx, &reg, &bl);
+	if (ret)
+		return ret;
+
+	ret = io_setup_pbuf_ring(ctx, &reg, bl);
+	if (ret) {
+		kfree(bl);
+		return ret;
+	}
+
 	if (reg.flags & IOU_PBUF_RING_INC)
 		bl->flags |= IOBL_INC;
+
 	io_buffer_add_list(ctx, bl, reg.bgid);
+
 	return 0;
-fail:
-	io_free_region(ctx->user, &bl->region);
-	kfree(bl);
-	return ret;
 }
 
 int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
-- 
2.47.3[PATCH v3 01/25] io_uring/kbuf: refactor io_buf_pbuf_register() logic into generic helpersJoanne Koong <joannelkoong@gmail.com> undefinedmiklos@szeredi.hu, axboe@kernel.dk undefined undefined undefined undefined undefined undefined undefined undefinedÐF„ØC