svn commit: r344392 - stable/12/sys/cam/scsi

[David Bright]

Author: dab
Date: Wed Feb 20 22:48:38 2019
New Revision: 344392
URL: https://svnweb.freebsd.org/changeset/base/344392

Log:
  MFC r344024:
  
  CID 1009492: Logically dead code in sys/cam/scsi/scsi_xpt.c
  
  In `probedone()`, for the `PROBE_REPORT_LUNS` case, all paths that
  fall to the bottom of the case set `lp` to `NULL`, so the test for a
  non-NULL value of `lp` and call to `free()` if true is dead code as
  the test can never be true. Fix by eliminating the whole if
  statement. To guard against a possible future change that accidentally
  violates this assumption, use a `KASSERT()` to catch if `lp` is
  non-NULL.
  
  Sponsored by:	Dell EMC Isilon

Modified:
  stable/12/sys/cam/scsi/scsi_xpt.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/cam/scsi/scsi_xpt.c
==============================================================================
--- stable/12/sys/cam/scsi/scsi_xpt.c	Wed Feb 20 22:41:14 2019	(r344391)
+++ stable/12/sys/cam/scsi/scsi_xpt.c	Wed Feb 20 22:48:38 2019	(r344392)
@@ -1385,6 +1385,12 @@ out:
 			probe_purge_old(path, lp, softc->flags);
 			lp = NULL;
 		}
+		/* The processing above should either exit via a `goto
+		 * out` or leave the `lp` variable `NULL` and (if
+		 * applicable) `free()` the storage to which it had
+		 * pointed. Assert here that is the case.
+		 */
+		KASSERT(lp == NULL, ("%s: lp is not NULL", __func__));
 		inq_buf = &path->device->inq_data;
 		if (path->device->flags & CAM_DEV_INQUIRY_DATA_VALID &&
 		    (SID_QUAL(inq_buf) == SID_QUAL_LU_CONNECTED ||
@@ -1397,9 +1403,6 @@ out:
 			xpt_release_ccb(done_ccb);
 			xpt_schedule(periph, priority);
 			goto out;
-		}
-		if (lp) {
-			free(lp, M_CAMXPT);
 		}
 		PROBE_SET_ACTION(softc, PROBE_INVALID);
 		xpt_release_ccb(done_ccb);