Fix multiple addition error recently introduced for when extended partitions

are just before an OpenBSD partition in a MBR; done with kettenis & otto
ok reyk

diff --git a/sys/arch/amd64/stand/libsa/biosdev.c b/sys/arch/amd64/stand/libsa/biosdev.c
index ad5075e..ef679b5 100644 (file)
--- a/sys/arch/amd64/stand/libsa/biosdev.c
+++ b/sys/arch/amd64/stand/libsa/biosdev.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: biosdev.c,v 1.7 2008/08/04 15:58:13 reyk Exp $        */
+/*     $OpenBSD: biosdev.c,v 1.8 2008/08/12 22:48:32 deraadt Exp $     */
 
 /*
  * Copyright (c) 1996 Michael Shalayeff
@@ -342,34 +342,37 @@ biosd_io(int rw, bios_diskinfo_t *bd, daddr_t off, int nsect, void *buf)
  * Try to read the bsd label on the given BIOS device
  */
 static daddr_t
-findopenbsd(bios_diskinfo_t *bd, daddr_t off, const char **err, int *n)
+findopenbsd(bios_diskinfo_t *bd, daddr_t mbroff, const char **err, int *n)
 {
        int error, i;
        struct dos_mbr mbr;
        struct dos_partition *dp;
+       daddr_t off;
 
        /* Limit the number of recursions */
        if (!(*n)--) {
                *err = "too many extended partitions";
-               return (0);
+               return (-1);
        }
 
        /* Read MBR */
-       error = biosd_io(F_READ, bd, off, 1, &mbr);
+       error = biosd_io(F_READ, bd, mbroff, 1, &mbr);
        if (error) {
                *err = biosdisk_err(error);
-               return (0);
+               return (-1);
        }
 
        /* check mbr signature */
        if (mbr.dmbr_sign != DOSMBR_SIGNATURE) {
                *err = "bad MBR signature\n";
-               return (0);
+               return (-1);
        }
 
        /* Search for OpenBSD partition */
        for (i = 0; i < NDOSPART; i++) {
                dp = &mbr.dmbr_parts[i];
+               if (!dp->dp_size)
+                       continue;
 #ifdef BIOS_DEBUG
                if (debug)
                        printf("found partition %u: "
@@ -379,28 +382,16 @@ findopenbsd(bios_diskinfo_t *bd, daddr_t off, const char **err, int *n)
                            dp->dp_start, dp->dp_start);
 #endif
                if (dp->dp_typ == DOSPTYP_OPENBSD) {
-                       off = dp->dp_start + off;
-                       break;
+                       return (dp->dp_start + mbroff);
                } else if (dp->dp_typ == DOSPTYP_EXTEND ||
                    dp->dp_typ == DOSPTYP_EXTENDL) {
-                       off = findopenbsd(bd, dp->dp_start + off, err, n);
-                       if (off != 0)
-                               break;
+                       off = findopenbsd(bd, dp->dp_start + mbroff, err, n);
+                       if (off != -1)
+                               return (off);
                }
        }
 
-#ifdef BIOS_DEBUG
-       if (debug)
-               printf("using offset %u\n", off);
-#endif
-
-       if (off == 0) {
-               if (*err == NULL)
-                       *err = "no OpenBSD partition\n";
-               return (0);
-       }
-
-       return (off);
+       return (-1);
 }
 
 const char *
@@ -420,7 +411,7 @@ bios_getdisklabel(bios_diskinfo_t *bd, struct disklabel *label)
        /* MBR is a harddisk thing */
        if (bd->bios_number & 0x80) {
                off = findopenbsd(bd, DOSBBSECTOR, &err, &n);
-               if (off == 0) {
+               if (off == -1) {
                        if (err != NULL)
                                return (err);
                        return "no OpenBSD partition\n";

diff --git a/sys/arch/i386/stand/libsa/biosdev.c b/sys/arch/i386/stand/libsa/biosdev.c
index 3ccc012..01a0ca7 100644 (file)
--- a/sys/arch/i386/stand/libsa/biosdev.c
+++ b/sys/arch/i386/stand/libsa/biosdev.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: biosdev.c,v 1.75 2008/08/04 15:58:13 reyk Exp $       */
+/*     $OpenBSD: biosdev.c,v 1.76 2008/08/12 22:48:31 deraadt Exp $    */
 
 /*
  * Copyright (c) 1996 Michael Shalayeff
@@ -345,34 +345,37 @@ biosd_io(int rw, bios_diskinfo_t *bd, daddr_t off, int nsect, void *buf)
  * Try to read the bsd label on the given BIOS device
  */
 static daddr_t
-findopenbsd(bios_diskinfo_t *bd, daddr_t off, const char **err, int *n)
+findopenbsd(bios_diskinfo_t *bd, daddr_t mbroff, const char **err, int *n)
 {
        int error, i;
        struct dos_mbr mbr;
        struct dos_partition *dp;
+       daddr_t off;
 
        /* Limit the number of recursions */
        if (!(*n)--) {
                *err = "too many extended partitions";
-               return (0);
+               return (-1);
        }
 
        /* Read MBR */
-       error = biosd_io(F_READ, bd, off, 1, &mbr);
+       error = biosd_io(F_READ, bd, mbroff, 1, &mbr);
        if (error) {
                *err = biosdisk_err(error);
-               return (0);
+               return (-1);
        }
 
        /* check mbr signature */
        if (mbr.dmbr_sign != DOSMBR_SIGNATURE) {
                *err = "bad MBR signature\n";
-               return (0);
+               return (-1);
        }
 
        /* Search for OpenBSD partition */
        for (i = 0; i < NDOSPART; i++) {
                dp = &mbr.dmbr_parts[i];
+               if (!dp->dp_size)
+                       continue;
 #ifdef BIOS_DEBUG
                if (debug)
                        printf("found partition %u: "
@@ -382,28 +385,16 @@ findopenbsd(bios_diskinfo_t *bd, daddr_t off, const char **err, int *n)
                            dp->dp_start, dp->dp_start);
 #endif
                if (dp->dp_typ == DOSPTYP_OPENBSD) {
-                       off = dp->dp_start + off;
-                       break;
+                       return (dp->dp_start + mbroff);
                } else if (dp->dp_typ == DOSPTYP_EXTEND ||
                    dp->dp_typ == DOSPTYP_EXTENDL) {
-                       off = findopenbsd(bd, dp->dp_start + off, err, n);
-                       if (off != 0)
-                               break;
+                       off = findopenbsd(bd, dp->dp_start + mbroff, err, n);
+                       if (off != -1)
+                               return (off);
                }
        }
 
-#ifdef BIOS_DEBUG
-       if (debug)
-               printf("using offset %u\n", off);
-#endif
-
-       if (off == 0) {
-               if (*err == NULL)
-                       *err = "no OpenBSD partition\n";
-               return (0);
-       }
-
-       return (off);
+       return (-1);
 }
 
 const char *
@@ -423,7 +414,7 @@ bios_getdisklabel(bios_diskinfo_t *bd, struct disklabel *label)
        /* MBR is a harddisk thing */
        if (bd->bios_number & 0x80) {
                off = findopenbsd(bd, DOSBBSECTOR, &err, &n);
-               if (off == 0) {
+               if (off == -1) {
                        if (err != NULL)
                                return (err);
                        return "no OpenBSD partition\n";