[v4,4/9] cxl/mbox: Construct a users cxl_mbox_cmd in the validation path

Commit Message

Alison Schofield March 30, 2022, 1:30 a.m. UTC

From: Alison Schofield <[e-mail]>

This is a step in refactoring the handling of user space mailbox
commands. The intent is to have all the validation work originate
in cxl_validate_cmd_from_user().

Move the construction and validation of a mailbox command to the
validation path. Continue to pass both the out_cmd and the mbox_cmd
until handle_mbox_cmd_from_user() learns how to use a mbox_cmd param.

Signed-off-by: Alison Schofield <[e-mail]>
Reviewed-by: Jonathan Cameron <[e-mail]>
---
 drivers/cxl/core/mbox.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

Comments

Dan Williams March 30, 2022, 4:39 a.m. UTC | #1

On Tue, Mar 29, 2022 at 6:28 PM <[e-mail]> wrote:
>
> From: Alison Schofield <[e-mail]>
>
> This is a step in refactoring the handling of user space mailbox
> commands. The intent is to have all the validation work originate
> in cxl_validate_cmd_from_user().
>
> Move the construction and validation of a mailbox command to the
> validation path. Continue to pass both the out_cmd and the mbox_cmd
> until handle_mbox_cmd_from_user() learns how to use a mbox_cmd param.
>
> Signed-off-by: Alison Schofield <[e-mail]>
> Reviewed-by: Jonathan Cameron <[e-mail]>
> ---
>  drivers/cxl/core/mbox.c | 21 +++++++++++++++++----
>  1 file changed, 17 insertions(+), 4 deletions(-)

Looks good modulo destination parameter ordering.

Reviewed-by: Dan Williams <[e-mail]>

Patch

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index a19365075cae..95882ab9f87b 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -321,6 +321,7 @@  static int cxl_to_mem_cmd(struct cxl_dev_state *cxlds,
  * @cxlds: The device data for the operation
  * @send_cmd: &struct cxl_send_command copied in from userspace.
  * @out_cmd: Sanitized and populated &struct cxl_mem_command.
+ * @mbox_cmd: Sanitized and populated &struct cxl_mbox_cmd.
  *
  * Return:
  *  * %0	- @out_cmd is ready to send.
@@ -337,8 +338,11 @@  static int cxl_to_mem_cmd(struct cxl_dev_state *cxlds,
  */
 static int cxl_validate_cmd_from_user(struct cxl_dev_state *cxlds,
 				      const struct cxl_send_command *send_cmd,
-				      struct cxl_mem_command *out_cmd)
+				      struct cxl_mem_command *out_cmd,
+				      struct cxl_mbox_cmd *mbox_cmd)
 {
+	int rc;
+
 	if (send_cmd->id == 0 || send_cmd->id >= CXL_MEM_COMMAND_ID_MAX)
 		return -ENOTTY;
 
@@ -352,9 +356,17 @@  static int cxl_validate_cmd_from_user(struct cxl_dev_state *cxlds,
 
 	/* Sanitize and construct a cxl_mem_command */
 	if (send_cmd->id == CXL_MEM_COMMAND_ID_RAW)
-		return cxl_to_mem_cmd_raw(cxlds, send_cmd, out_cmd);
+		rc = cxl_to_mem_cmd_raw(cxlds, send_cmd, out_cmd);
 	else
-		return cxl_to_mem_cmd(cxlds, send_cmd, out_cmd);
+		rc = cxl_to_mem_cmd(cxlds, send_cmd, out_cmd);
+
+	if (rc)
+		return rc;
+
+	/* Sanitize and construct a cxl_mbox_cmd */
+	return cxl_to_mbox_cmd(cxlds, mbox_cmd, out_cmd->opcode,
+			       out_cmd->info.size_in, out_cmd->info.size_out,
+			       send_cmd->in.payload);
 }
 
 int cxl_query_cmd(struct cxl_memdev *cxlmd,
@@ -471,6 +483,7 @@  int cxl_send_cmd(struct cxl_memdev *cxlmd, struct cxl_send_command __user *s)
 	struct device *dev = &cxlmd->dev;
 	struct cxl_send_command send;
 	struct cxl_mem_command c;
+	struct cxl_mbox_cmd mbox_cmd;
 	int rc;
 
 	dev_dbg(dev, "Send IOCTL\n");
@@ -478,7 +491,7 @@  int cxl_send_cmd(struct cxl_memdev *cxlmd, struct cxl_send_command __user *s)
 	if (copy_from_user(&send, s, sizeof(send)))
 		return -EFAULT;
 
-	rc = cxl_validate_cmd_from_user(cxlmd->cxlds, &send, &c);
+	rc = cxl_validate_cmd_from_user(cxlmd->cxlds, &send, &c, &mbox_cmd);
 	if (rc)
 		return rc;