Extract the slice from the zeroth swap device instead of assuming

it's the 'b' slice and (sanity) check against the partition count.
Also, make the "is union hibernate_info too large?" a compile time
check.

ok deraadt@

diff --git a/sys/kern/subr_hibernate.c b/sys/kern/subr_hibernate.c
index a9831be..22a79a2 100644 (file)
--- a/sys/kern/subr_hibernate.c
+++ b/sys/kern/subr_hibernate.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: subr_hibernate.c,v 1.130 2022/01/04 18:13:31 guenther Exp $   */
+/*     $OpenBSD: subr_hibernate.c,v 1.131 2022/01/07 02:26:53 guenther Exp $   */
 
 /*
  * Copyright (c) 2011 Ariane van der Steldt <ariane@stack.nl>
@@ -35,6 +35,9 @@
 
 #include <machine/hibernate.h>
 
+/* Make sure the signature can fit in one block */
+CTASSERT(sizeof(union hibernate_info) <= DEV_BSIZE);
+
 /*
  * Hibernate piglet layout information
  *
@@ -568,6 +571,7 @@ get_hibernate_info(union hibernate_info *hib, int suspend)
 {
        struct disklabel dl;
        char err_string[128], *dl_ret;
+       int part;
 
 #ifndef NO_PROPOLICE
        /* Save propolice guard */
@@ -591,19 +595,17 @@ get_hibernate_info(union hibernate_info *hib, int suspend)
        }
 
        /* Make sure we have a swap partition. */
-       if (dl.d_partitions[1].p_fstype != FS_SWAP ||
-           DL_GETPSIZE(&dl.d_partitions[1]) == 0)
-               return (1);
-
-       /* Make sure the signature can fit in one block */
-       if (sizeof(union hibernate_info) > DEV_BSIZE)
+       part = DISKPART(hib->dev);
+       if (dl.d_npartitions <= part ||
+           dl.d_partitions[part].p_fstype != FS_SWAP ||
+           DL_GETPSIZE(&dl.d_partitions[part]) == 0)
                return (1);
 
        /* Magic number */
        hib->magic = HIBERNATE_MAGIC;
 
        /* Calculate signature block location */
-       hib->sig_offset = DL_GETPSIZE(&dl.d_partitions[1]) -
+       hib->sig_offset = DL_GETPSIZE(&dl.d_partitions[part]) -
            sizeof(union hibernate_info)/DEV_BSIZE;
 
        /* Stash kernel version information */
@@ -626,8 +628,8 @@ get_hibernate_info(union hibernate_info *hib, int suspend)
                 * a matching HIB_DONE call performed after the write is
                 * completed.
                 */
-               if (hib->io_func(hib->dev, DL_GETPOFFSET(&dl.d_partitions[1]),
-                   (vaddr_t)NULL, DL_GETPSIZE(&dl.d_partitions[1]),
+               if (hib->io_func(hib->dev, DL_GETPOFFSET(&dl.d_partitions[part]),
+                   (vaddr_t)NULL, DL_GETPSIZE(&dl.d_partitions[part]),
                    HIB_INIT, hib->io_page))
                        goto fail;