libfdisk: cleanup sun label checksum usuage

We are using now the formerly unused function sun_pt_checksum(). This
cleanup was motivated by clang compiler warning, see below. Also nice
that we are now always using uint16_t instead of short.

Warning was:

../libfdisk/src/sun.c:177:35: warning: taking address of packed member 'csum' of class or structure 'sun_disklabel' may result in an unaligned pointer value
      [-Waddress-of-packed-member]
                while(ush < (unsigned short *)(&sunlabel->csum))

Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>

diff --git a/include/pt-sun.h b/include/pt-sun.h
index b085268ca020f05858c02e6c3509ae6c4bd97394..e6a4ed13ff1849ef7f9eb8bb9e53a680fcd1115f 100644 (file)
--- a/include/pt-sun.h
+++ b/include/pt-sun.h
@@ -76,7 +76,7 @@ struct sun_disklabel {
 #define SUN_FLAG_UNMNT         0x01    /* Unmountable partition*/
 #define SUN_FLAG_RONLY         0x10    /* Read only            */
 
-static inline uint16_t sun_pt_checksum(struct sun_disklabel *label)
+static inline uint16_t sun_pt_checksum(const struct sun_disklabel *label)
 {
        uint16_t *ptr = ((uint16_t *) (label + 1)) - 1;
        uint16_t sum;

diff --git a/libfdisk/src/sun.c b/libfdisk/src/sun.c
index a3a5b401e5d19916d5a4b793e64b91144cc009c4..0526227ce58d2a8246dd86f663ca5455706492c7 100644 (file)
--- a/libfdisk/src/sun.c
+++ b/libfdisk/src/sun.c
@@ -110,8 +110,6 @@ static int sun_probe_label(struct fdisk_context *cxt)
 {
        struct fdisk_sun_label *sun;
        struct sun_disklabel *sunlabel;
-       unsigned short *ush;
-       int csum;
        int need_fixing = 0;
 
        assert(cxt);
@@ -128,11 +126,7 @@ static int sun_probe_label(struct fdisk_context *cxt)
                return 0;               /* failed */
        }
 
-       ush = ((unsigned short *) (sunlabel + 1)) - 1;
-       for (csum = 0; ush >= (unsigned short *)sunlabel;)
-               csum ^= *ush--;
-
-       if (csum) {
+       if (sun_pt_checksum(sunlabel)) {
                fdisk_warnx(cxt, _("Detected sun disklabel with wrong checksum. "
                              "Probably you'll have to set all the values, "
                              "e.g. heads, sectors, cylinders and partitions "
@@ -171,12 +165,8 @@ static int sun_probe_label(struct fdisk_context *cxt)
                sunlabel->vtoc.version = cpu_to_be32(SUN_VTOC_VERSION);
                sunlabel->vtoc.sanity = cpu_to_be32(SUN_VTOC_SANITY);
                sunlabel->vtoc.nparts = cpu_to_be16(SUN_MAXPARTITIONS);
-
-               ush = (unsigned short *)sunlabel;
-               csum = 0;
-               while(ush < (unsigned short *)(&sunlabel->csum))
-                       csum ^= *ush++;
-               sunlabel->csum = csum;
+               sunlabel->csum = 0;
+               sunlabel->csum = sun_pt_checksum(sunlabel);
 
                fdisk_label_set_changed(cxt->label, 1);
        }
@@ -286,13 +276,8 @@ static int sun_create_disklabel(struct fdisk_context *cxt)
                          SUN_TAG_WHOLEDISK);
        }
 
-       {
-               unsigned short *ush = (unsigned short *)sunlabel;
-               unsigned short csum = 0;
-               while(ush < (unsigned short *)(&sunlabel->csum))
-                       csum ^= *ush++;
-               sunlabel->csum = csum;
-       }
+       sunlabel->csum = 0;
+       sunlabel->csum = sun_pt_checksum(sunlabel);
 
        fdisk_label_set_changed(cxt->label, 1);
        cxt->label->nparts_cur = count_used_partitions(cxt);
@@ -979,8 +964,6 @@ int fdisk_sun_set_pcylcount(struct fdisk_context *cxt)
 static int sun_write_disklabel(struct fdisk_context *cxt)
 {
        struct sun_disklabel *sunlabel;
-       unsigned short *ush;
-       unsigned short csum = 0;
        const size_t sz = sizeof(struct sun_disklabel);
 
        assert(cxt);
@@ -999,11 +982,9 @@ static int sun_write_disklabel(struct fdisk_context *cxt)
                sunlabel->ncyl = a - b;
        }
 
-       ush = (unsigned short *) sunlabel;
+       sunlabel->csum = 0;
+       sunlabel->csum = sun_pt_checksum(sunlabel);
 
-       while(ush < (unsigned short *)(&sunlabel->csum))
-               csum ^= *ush++;
-       sunlabel->csum = csum;
        if (lseek(cxt->dev_fd, 0, SEEK_SET) < 0)
                return -errno;
        if (write_all(cxt->dev_fd, sunlabel, sz) != 0)