MFC r307684, r307747

  ------------------------------------------------------------------------
  r307684 | ken | 2016-10-20 13:42:26 -0600 (Thu, 20 Oct 2016) | 13 lines

  For CCBs allocated on the stack, we need to clear the entire CCB, not just
  the header.  Otherwise stack garbage can lead to random flags getting set.

  This showed up as 'camcontrol rescan all' failing with EINVAL because the
  address type wasn't CAM_DATA_VADDR.

  sbin/camcontrol/camcontrol.c:
  	In rescan_or_reset_bus(), bzero the stack-allocated CCBs before
  	use instead of clearing the body.

  Sponsored by:	Spectra Logic

  ------------------------------------------------------------------------
  r307747 | ken | 2016-10-21 12:54:56 -0600 (Fri, 21 Oct 2016) | 27 lines

  Fix a problem in camcontrol(8) that cropped up with r307684.

  In r307684, I changed rescan_or_reset_bus() to bzero stack-allocated CCBs
  before sending them to the kernel because there was stack garbage in there
  that wound up meaning that bogus CCB flags were set.

  While this fixed the 'camcontrol rescan all' case (XPT_DEV_MATCH CCBs were
  failing previously), it broke the 'camcontrol rescan 0' (or any other
  number) case when INVARIANTS are turned on.  Rescanning a single bus
  reliably produced an assert in cam_periph_runccb():

  panic: cam_periph_runccb: ccb=0xfffff80044ffe000, func_code=0x708, flags=0xffffdde0

  The flags values don't make sense from the code.  Changing the CCBs in
  rescan_or_reset_bus() from stack to heap allocated avoids the problem.

  It would be better to understand why userland stack allocated CCBs don't
  work properly, since there may be other code that breaks if stack allocated
  CCBs don't work.

  sbin/camcontrol/camcontrol.c:
  	In rescan_or_reset_bus(), allocate the CCBs using malloc(3) instead
  	of on the stack to avoid an assertion in cam_periph_runccb().

  Sponsored by:	Spectra Logic

  ------------------------------------------------------------------------

Sponsored by:	Spectra Logic

1 files changed, 67 insertions, 53 deletions

diff --git a/sbin/camcontrol/camcontrol.c b/sbin/camcontrol/camcontrol.c
index 901ab66..cae7ec2 100644
--- a/sbin/camcontrol/camcontrol.c
+++ b/sbin/camcontrol/camcontrol.c
@@ -3124,8 +3124,8 @@ dorescan_or_reset(int argc, char **argv, int rescan)
 static int
 rescan_or_reset_bus(path_id_t bus, int rescan)
 {
-	union ccb ccb, matchccb;
-	int fd, retval;
+	union ccb *ccb = NULL, *matchccb = NULL;
+	int fd = -1, retval;
 	int bufsize;
 
 	retval = 0;
@@ -3136,35 +3136,41 @@ rescan_or_reset_bus(path_id_t bus, int rescan)
 		return(1);
 	}
 
+	ccb = malloc(sizeof(*ccb));
+	if (ccb == NULL) {
+		warn("failed to allocate CCB");
+		retval = 1;
+		goto bailout;
+	}
+	bzero(ccb, sizeof(*ccb));
+
 	if (bus != CAM_BUS_WILDCARD) {
-		ccb.ccb_h.func_code = rescan ? XPT_SCAN_BUS : XPT_RESET_BUS;
-		ccb.ccb_h.path_id = bus;
-		ccb.ccb_h.target_id = CAM_TARGET_WILDCARD;
-		ccb.ccb_h.target_lun = CAM_LUN_WILDCARD;
-		ccb.crcn.flags = CAM_FLAG_NONE;
+		ccb->ccb_h.func_code = rescan ? XPT_SCAN_BUS : XPT_RESET_BUS;
+		ccb->ccb_h.path_id = bus;
+		ccb->ccb_h.target_id = CAM_TARGET_WILDCARD;
+		ccb->ccb_h.target_lun = CAM_LUN_WILDCARD;
+		ccb->crcn.flags = CAM_FLAG_NONE;
 
 		/* run this at a low priority */
-		ccb.ccb_h.pinfo.priority = 5;
+		ccb->ccb_h.pinfo.priority = 5;
 
-		if (ioctl(fd, CAMIOCOMMAND, &ccb) == -1) {
+		if (ioctl(fd, CAMIOCOMMAND, ccb) == -1) {
 			warn("CAMIOCOMMAND ioctl failed");
-			close(fd);
-			return(1);
+			retval = 1;
+			goto bailout;
 		}
 
-		if ((ccb.ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP) {
+		if ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP) {
 			fprintf(stdout, "%s of bus %d was successful\n",
 			    rescan ? "Re-scan" : "Reset", bus);
 		} else {
 			fprintf(stdout, "%s of bus %d returned error %#x\n",
 				rescan ? "Re-scan" : "Reset", bus,
-				ccb.ccb_h.status & CAM_STATUS_MASK);
+				ccb->ccb_h.status & CAM_STATUS_MASK);
 			retval = 1;
 		}
 
-		close(fd);
-		return(retval);
-
+		goto bailout;
 	}
 
 
@@ -3178,58 +3184,64 @@ rescan_or_reset_bus(path_id_t bus, int rescan)
 	 * no-op, sending a rescan to the xpt bus would result in a status of
 	 * CAM_REQ_INVALID.
 	 */
-	CCB_CLEAR_ALL_EXCEPT_HDR(&matchccb.cdm);
-	matchccb.ccb_h.func_code = XPT_DEV_MATCH;
-	matchccb.ccb_h.path_id = CAM_BUS_WILDCARD;
+	matchccb = malloc(sizeof(*matchccb));
+	if (matchccb == NULL) {
+		warn("failed to allocate CCB");
+		retval = 1;
+		goto bailout;
+	}
+	bzero(matchccb, sizeof(*matchccb));
+	matchccb->ccb_h.func_code = XPT_DEV_MATCH;
+	matchccb->ccb_h.path_id = CAM_BUS_WILDCARD;
 	bufsize = sizeof(struct dev_match_result) * 20;
-	matchccb.cdm.match_buf_len = bufsize;
-	matchccb.cdm.matches=(struct dev_match_result *)malloc(bufsize);
-	if (matchccb.cdm.matches == NULL) {
+	matchccb->cdm.match_buf_len = bufsize;
+	matchccb->cdm.matches=(struct dev_match_result *)malloc(bufsize);
+	if (matchccb->cdm.matches == NULL) {
 		warnx("can't malloc memory for matches");
 		retval = 1;
 		goto bailout;
 	}
-	matchccb.cdm.num_matches = 0;
+	matchccb->cdm.num_matches = 0;
 
-	matchccb.cdm.num_patterns = 1;
-	matchccb.cdm.pattern_buf_len = sizeof(struct dev_match_pattern);
+	matchccb->cdm.num_patterns = 1;
+	matchccb->cdm.pattern_buf_len = sizeof(struct dev_match_pattern);
 
-	matchccb.cdm.patterns = (struct dev_match_pattern *)malloc(
-		matchccb.cdm.pattern_buf_len);
-	if (matchccb.cdm.patterns == NULL) {
+	matchccb->cdm.patterns = (struct dev_match_pattern *)malloc(
+		matchccb->cdm.pattern_buf_len);
+	if (matchccb->cdm.patterns == NULL) {
 		warnx("can't malloc memory for patterns");
 		retval = 1;
 		goto bailout;
 	}
-	matchccb.cdm.patterns[0].type = DEV_MATCH_BUS;
-	matchccb.cdm.patterns[0].pattern.bus_pattern.flags = BUS_MATCH_ANY;
+	matchccb->cdm.patterns[0].type = DEV_MATCH_BUS;
+	matchccb->cdm.patterns[0].pattern.bus_pattern.flags = BUS_MATCH_ANY;
 
 	do {
 		unsigned int i;
 
-		if (ioctl(fd, CAMIOCOMMAND, &matchccb) == -1) {
+		if (ioctl(fd, CAMIOCOMMAND, matchccb) == -1) {
 			warn("CAMIOCOMMAND ioctl failed");
 			retval = 1;
 			goto bailout;
 		}
 
-		if ((matchccb.ccb_h.status != CAM_REQ_CMP)
-		 || ((matchccb.cdm.status != CAM_DEV_MATCH_LAST)
-		   && (matchccb.cdm.status != CAM_DEV_MATCH_MORE))) {
+		if ((matchccb->ccb_h.status != CAM_REQ_CMP)
+		 || ((matchccb->cdm.status != CAM_DEV_MATCH_LAST)
+		   && (matchccb->cdm.status != CAM_DEV_MATCH_MORE))) {
 			warnx("got CAM error %#x, CDM error %d\n",
-			      matchccb.ccb_h.status, matchccb.cdm.status);
+			      matchccb->ccb_h.status, matchccb->cdm.status);
 			retval = 1;
 			goto bailout;
 		}
 
-		for (i = 0; i < matchccb.cdm.num_matches; i++) {
+		for (i = 0; i < matchccb->cdm.num_matches; i++) {
 			struct bus_match_result *bus_result;
 
 			/* This shouldn't happen. */
-			if (matchccb.cdm.matches[i].type != DEV_MATCH_BUS)
+			if (matchccb->cdm.matches[i].type != DEV_MATCH_BUS)
 				continue;
 
-			bus_result = &matchccb.cdm.matches[i].result.bus_result;
+			bus_result =&matchccb->cdm.matches[i].result.bus_result;
 
 			/*
 			 * We don't want to rescan or reset the xpt bus.
@@ -3238,23 +3250,23 @@ rescan_or_reset_bus(path_id_t bus, int rescan)
 			if (bus_result->path_id == CAM_XPT_PATH_ID)
 				continue;
 
-			ccb.ccb_h.func_code = rescan ? XPT_SCAN_BUS :
+			ccb->ccb_h.func_code = rescan ? XPT_SCAN_BUS :
 						       XPT_RESET_BUS;
-			ccb.ccb_h.path_id = bus_result->path_id;
-			ccb.ccb_h.target_id = CAM_TARGET_WILDCARD;
-			ccb.ccb_h.target_lun = CAM_LUN_WILDCARD;
-			ccb.crcn.flags = CAM_FLAG_NONE;
+			ccb->ccb_h.path_id = bus_result->path_id;
+			ccb->ccb_h.target_id = CAM_TARGET_WILDCARD;
+			ccb->ccb_h.target_lun = CAM_LUN_WILDCARD;
+			ccb->crcn.flags = CAM_FLAG_NONE;
 
 			/* run this at a low priority */
-			ccb.ccb_h.pinfo.priority = 5;
+			ccb->ccb_h.pinfo.priority = 5;
 
-			if (ioctl(fd, CAMIOCOMMAND, &ccb) == -1) {
+			if (ioctl(fd, CAMIOCOMMAND, ccb) == -1) {
 				warn("CAMIOCOMMAND ioctl failed");
 				retval = 1;
 				goto bailout;
 			}
 
-			if ((ccb.ccb_h.status & CAM_STATUS_MASK) ==CAM_REQ_CMP){
+			if ((ccb->ccb_h.status & CAM_STATUS_MASK)==CAM_REQ_CMP){
 				fprintf(stdout, "%s of bus %d was successful\n",
 					rescan? "Re-scan" : "Reset",
 					bus_result->path_id);
@@ -3267,22 +3279,24 @@ rescan_or_reset_bus(path_id_t bus, int rescan)
 				fprintf(stderr, "%s of bus %d returned error "
 					"%#x\n", rescan? "Re-scan" : "Reset",
 					bus_result->path_id,
-					ccb.ccb_h.status & CAM_STATUS_MASK);
+					ccb->ccb_h.status & CAM_STATUS_MASK);
 				retval = 1;
 			}
 		}
-	} while ((matchccb.ccb_h.status == CAM_REQ_CMP)
-		 && (matchccb.cdm.status == CAM_DEV_MATCH_MORE));
+	} while ((matchccb->ccb_h.status == CAM_REQ_CMP)
+		 && (matchccb->cdm.status == CAM_DEV_MATCH_MORE));
 
 bailout:
 
 	if (fd != -1)
 		close(fd);
 
-	if (matchccb.cdm.patterns != NULL)
-		free(matchccb.cdm.patterns);
-	if (matchccb.cdm.matches != NULL)
-		free(matchccb.cdm.matches);
+	if (matchccb != NULL) {
+		free(matchccb->cdm.patterns);
+		free(matchccb->cdm.matches);
+		free(matchccb);
+	}
+	free(ccb);
 
 	return(retval);
 }