svn commit: r365445 - head/sys/cam/mmc

[Andriy Gapon]

Author: avg
Date: Tue Sep  8 05:46:10 2020
New Revision: 365445
URL: https://svnweb.freebsd.org/changeset/base/365445

Log:
  mmc_da: make sure that part_index is not used uninitialized in sddastart
  
  This is a fix to r334065.
  
  Without this change I once got stuck I/O with endless partition switching:
  
  (sdda0:aw_mmc_sim2:0:0:0): sddastart
  (sdda0:aw_mmc_sim2:0:0:0): Partition  0 -> -525703168
  (sdda0:aw_mmc_sim2:0:0:0): xpt_action: func 0x91d XPT_MMC_IO
  (sdda0:aw_mmc_sim2:0:0:0): xpt_done: func= 0x91d XPT_MMC_IO status 0x1
  (sdda0:aw_mmc_sim2:0:0:0): sddadone
  (sdda0:aw_mmc_sim2:0:0:0): Card status: 00000000
  (sdda0:aw_mmc_sim2:0:0:0): Current state: 4
  (sdda0:aw_mmc_sim2:0:0:0): Compteting partition switch to 0
  
  Note that -525703168 (an int) is 0xe0aa6800 in binary representation.
  The partition indexes are actually stored as uint8_t, so that value
  was converted / truncated to zero.
  
  MFC after:	1 week

Modified:
  head/sys/cam/mmc/mmc_da.c

Modified: head/sys/cam/mmc/mmc_da.c
==============================================================================
--- head/sys/cam/mmc/mmc_da.c	Tue Sep  8 04:44:37 2020	(r365444)
+++ head/sys/cam/mmc/mmc_da.c	Tue Sep  8 05:46:10 2020	(r365445)
@@ -1808,6 +1808,7 @@ sddastart(struct cam_periph *periph, union ccb *start_
 	}
 
 	/* Find partition that has outstanding commands.  Prefer current partition. */
+	part_index = softc->part_curr;
 	part = softc->part[softc->part_curr];
 	bp = bioq_first(&part->bio_queue);
 	if (bp == NULL) {