From 3420c04b44d4568d2eba31feeba2242bf0e87e86 Mon Sep 17 00:00:00 2001 From: David Bright Date: Mon, 11 Feb 2019 22:09:26 +0000 Subject: [PATCH] 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. Reviewed by: cem MFC after: 1 week Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D19109 --- sys/cam/scsi/scsi_xpt.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/sys/cam/scsi/scsi_xpt.c b/sys/cam/scsi/scsi_xpt.c index 39eb5782215e..66ff056ff2e9 100644 --- a/sys/cam/scsi/scsi_xpt.c +++ b/sys/cam/scsi/scsi_xpt.c @@ -1385,6 +1385,12 @@ probedone(struct cam_periph *periph, union ccb *done_ccb) 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 || @@ -1398,9 +1404,6 @@ probedone(struct cam_periph *periph, union 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); break;