habanalabs: fix handling of wait CS for interrupting signals

The -ERESTARTSYS return value is not handled correctly when a signal is
received while waiting for CS completion.
This can lead to bad output values to user when waiting for a single CS
completion, and more severe, it can cause a non-stopping loop when
waiting to multi-CS completion and until a CS timeout.

Fix the handling and exit the waiting if this return value is received.

Signed-off-by: Tomer Tayar <ttayar@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

diff --git a/drivers/misc/habanalabs/common/command_submission.c b/drivers/misc/habanalabs/common/command_submission.c
index cf3b82e..0ec8cdc 100644 (file)
--- a/drivers/misc/habanalabs/common/command_submission.c
+++ b/drivers/misc/habanalabs/common/command_submission.c
@@ -2590,7 +2590,9 @@ report_results:
                *status = CS_WAIT_STATUS_BUSY;
        }
 
-       if (error == -ETIMEDOUT || error == -EIO)
+       if (completion_rc == -ERESTARTSYS)
+               rc = completion_rc;
+       else if (error == -ETIMEDOUT || error == -EIO)
                rc = error;
 
        return rc;
@@ -2849,6 +2851,9 @@ static int hl_wait_multi_cs_completion(struct multi_cs_data *mcs_data,
        if (completion_rc > 0)
                mcs_data->timestamp = mcs_compl->timestamp;
 
+       if (completion_rc == -ERESTARTSYS)
+               return completion_rc;
+
        mcs_data->wait_status = completion_rc;
 
        return 0;
@@ -2994,15 +2999,15 @@ put_ctx:
 free_seq_arr:
        kfree(cs_seq_arr);
 
-       if (rc)
-               return rc;
-
-       if (mcs_data.wait_status == -ERESTARTSYS) {
+       if (rc == -ERESTARTSYS) {
                dev_err_ratelimited(hdev->dev,
                                "user process got signal while waiting for Multi-CS\n");
-               return -EINTR;
+               rc = -EINTR;
        }
 
+       if (rc)
+               return rc;
+
        /* update output args */
        memset(args, 0, sizeof(*args));