svn commit: r346496 - in stable/12/stand/uboot: common lib

[Ian Lepore]

Author: ian
Date: Sun Apr 21 20:40:49 2019
New Revision: 346496
URL: https://svnweb.freebsd.org/changeset/base/346496

Log:
  MFC r344247:
  
  Make uboot_devdesc properly alias disk_devdesc, so that parsing the u-boot
  loaderdev variable works correctly.
  
  The uboot_devdesc struct is variously cast back and forth between
  uboot_devdesc and disk_devdesc as pointers are handed off through various
  opaque interfaces.  uboot_devdesc attempted to mimic the layout of
  disk_devdesc by having a devdesc struct, followed by a union of some
  device-specific stuff that included a struct that contains the same fields
  as a disk_devdesc.  However, one of those fields inside the struct is 64-bit
  which causes the entire union to be 64-bit aligned -- 32 bits of padding
  is added between the struct devdesc and the union, so the whole mess ends
  up NOT properly mimicking a disk_devdesc after all.  (In disk_devdesc there
  is also 32 bits of padding, but it shows up immediately before the d_offset
  field, rather than before the whole collection of d_* fields.)
  
  This fixes the problem by using an anonymous union to overlay the devdesc
  field uboot network devices need with the disk_devdesc that uboot storage
  devices need.  This is a different solution than the one contributed with
  the PR (so if anything goes wrong, the blame goes to me), but 95% of the
  credit for this fix goes to Pawel Worach and Manuel Stuhn who analyzed the
  problem and proposed a fix.
  
  PR:		233097

Modified:
  stable/12/stand/uboot/common/main.c
  stable/12/stand/uboot/lib/libuboot.h
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/stand/uboot/common/main.c
==============================================================================
--- stable/12/stand/uboot/common/main.c	Sun Apr 21 19:50:30 2019	(r346495)
+++ stable/12/stand/uboot/common/main.c	Sun Apr 21 20:40:49 2019	(r346496)
@@ -310,13 +310,13 @@ print_disk_probe_info()
 	char slice[32];
 	char partition[32];
 
-	if (currdev.d_disk.slice > 0)
-		sprintf(slice, "%d", currdev.d_disk.slice);
+	if (currdev.d_disk.d_slice > 0)
+		sprintf(slice, "%d", currdev.d_disk.d_slice);
 	else
 		strcpy(slice, "<auto>");
 
-	if (currdev.d_disk.partition >= 0)
-		sprintf(partition, "%d", currdev.d_disk.partition);
+	if (currdev.d_disk.d_partition >= 0)
+		sprintf(partition, "%d", currdev.d_disk.d_partition);
 	else
 		strcpy(partition, "<auto>");
 
@@ -332,8 +332,8 @@ probe_disks(int devidx, int load_type, int load_unit, 
 	int open_result, unit;
 	struct open_file f;
 
-	currdev.d_disk.slice = load_slice;
-	currdev.d_disk.partition = load_partition;
+	currdev.d_disk.d_slice = load_slice;
+	currdev.d_disk.d_partition = load_partition;
 
 	f.f_devdata = &currdev;
 	open_result = -1;

Modified: stable/12/stand/uboot/lib/libuboot.h
==============================================================================
--- stable/12/stand/uboot/lib/libuboot.h	Sun Apr 21 19:50:30 2019	(r346495)
+++ stable/12/stand/uboot/lib/libuboot.h	Sun Apr 21 20:40:49 2019	(r346496)
@@ -27,18 +27,14 @@
  * $FreeBSD$
  */
 
+#include <disk.h>
+
 struct uboot_devdesc {
-	struct devdesc		dd;	/* Must be first. */
 	union {
-		struct {
-			int	slice;
-			int	partition;
-			off_t	offset;
-		} disk;
-	} d_kind;
+		struct devdesc      dd;
+		struct disk_devdesc d_disk;
+	};
 };
-
-#define d_disk d_kind.disk
 
 /*
  * Default network packet alignment in memory.  On arm arches packets must be