On 07/02/2024 08:24, Saeed Mahameed wrote:
+static int mlx5ctl_info_ioctl(struct file *file,
+ struct mlx5ctl_info __user *arg,
+ size_t usize)
+{
+ struct mlx5ctl_fd *mfd = file->private_data;
+ size_t ksize = sizeof(struct mlx5ctl_info);
+ struct mlx5ctl_dev *mcdev = mfd->mcdev;
+ struct mlx5_core_dev *mdev = mcdev->mdev;
+ struct mlx5ctl_info *info;
+ int err = 0;
+
+ if (usize < ksize)
+ return -EINVAL;
+
+ info = kzalloc(ksize, GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
struct mlx5ctl_info is small, why not put it on the stack or even copy
it directly from the original object, assuming it has no holes/padding?
+
+ info->dev_uctx_cap = MLX5_CAP_GEN(mdev, uctx_cap);
+ info->uctx_cap = mfd->uctx_cap;
+ info->uctx_uid = mfd->uctx_uid;
+ info->ucap = mfd->ucap;
+
+ if (copy_to_user(arg, info, ksize))
+ err = -EFAULT;
+
+ kfree(info);
+ return err;
+}
Is there even a remote possibility of extending this structure in the
future? If so the size check will not allow you to be backwards
compatible. Should there be a version field in there or would you
just add a new ioctl altogether? Adding linux-api@xxxxxxxxxxxxxxx to Cc.
diff --git a/include/uapi/misc/mlx5ctl.h b/include/uapi/misc/mlx5ctl.h
new file mode 100644
index 000000000000..9be944128025
--- /dev/null
+++ b/include/uapi/misc/mlx5ctl.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 WITH Linux-syscall-note */
+/* Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved. */
+
+#ifndef __MLX5CTL_IOCTL_H__
+#define __MLX5CTL_IOCTL_H__
+
+struct mlx5ctl_info {
+ __u16 uctx_uid; /* current process allocated UCTX UID */
+ __u16 reserved1; /* explicit padding must be zero */
+ __u32 uctx_cap; /* current process effective UCTX cap */
+ __u32 dev_uctx_cap; /* device's UCTX capabilities */
+ __u32 ucap; /* process user capability */
+};
+
+#define MLX5CTL_IOCTL_MAGIC 0x5c
+
+#define MLX5CTL_IOCTL_INFO \
+ _IOR(MLX5CTL_IOCTL_MAGIC, 0x0, struct mlx5ctl_info)
+
+#endif /* __MLX5CTL_IOCTL_H__ */
Should you add anything to Documentation/ABI/ ? (Or add other
documentation for this driver?)
Vegard
