libfdisk: (gpt) fix compiler warning [-Wmaybe-uninitialized]

Make sure that variables used in  gpt_calculate_* are always initialized.

Addresses: https://github.com/karelzak/util-linux/issues/1091
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libfdisk/src/gpt.c b/libfdisk/src/gpt.c
index 96221affe491f7cb441f43c7f8940adbf7d77c9d..99a178fa566102a911782c16a7a39ee157484dc0 100644 (file)
--- a/libfdisk/src/gpt.c
+++ b/libfdisk/src/gpt.c
@@ -399,7 +399,7 @@ static inline int gpt_calculate_sectorsof_entries(
                                uint32_t nents, uint64_t *sz,
                                struct fdisk_context *cxt)
 {
-       size_t esz;
+       size_t esz = 0;
        int rc = gpt_calculate_sizeof_entries(hdr, nents, &esz);        /* in bytes */
 
        if (rc == 0)
@@ -414,7 +414,7 @@ static inline int gpt_calculate_alternative_entries_lba(
                                uint64_t *sz,
                                struct fdisk_context *cxt)
 {
-       uint64_t esects;
+       uint64_t esects = 0;
        int rc = gpt_calculate_sectorsof_entries(hdr, nents, &esects, cxt);
 
        if (rc == 0)
@@ -428,7 +428,7 @@ static inline int gpt_calculate_last_lba(
                                uint64_t *sz,
                                struct fdisk_context *cxt)
 {
-       uint64_t esects;
+       uint64_t esects = 0;
        int rc = gpt_calculate_sectorsof_entries(hdr, nents, &esects, cxt);
 
        if (rc == 0)
@@ -442,7 +442,7 @@ static inline int gpt_calculate_first_lba(
                                uint64_t *sz,
                                struct fdisk_context *cxt)
 {
-       uint64_t esects;
+       uint64_t esects = 0;
        int rc = gpt_calculate_sectorsof_entries(hdr, nents, &esects, cxt);
 
        if (rc == 0)
@@ -503,14 +503,15 @@ static int gpt_mknew_pmbr(struct fdisk_context *cxt)
 
 
 /* Move backup header to the end of the device */
-static void gpt_fix_alternative_lba(struct fdisk_context *cxt, struct fdisk_gpt_label *gpt)
+static int gpt_fix_alternative_lba(struct fdisk_context *cxt, struct fdisk_gpt_label *gpt)
 {
        struct gpt_header *p, *b;
        uint64_t x = 0, orig;
        size_t nents;
+       int rc;
 
        if (!cxt)
-               return;
+               return -EINVAL;
 
        p = gpt->pheader;       /* primary */
        b = gpt->bheader;       /* backup */
@@ -526,16 +527,26 @@ static void gpt_fix_alternative_lba(struct fdisk_context *cxt, struct fdisk_gpt_
        b->my_lba = p->alternative_lba;
 
        /* fix backup partitions array address */
-       gpt_calculate_alternative_entries_lba(p, nents, &x, cxt);
+       rc = gpt_calculate_alternative_entries_lba(p, nents, &x, cxt);
+       if (rc)
+               goto failed;
+
        b->partition_entry_lba = cpu_to_le64(x);
 
        /* update last usable LBA */
-       gpt_calculate_last_lba(p, nents, &x, cxt);
+       rc = gpt_calculate_last_lba(p, nents, &x, cxt);
+       if (rc)
+               goto failed;
+
        p->last_usable_lba  = cpu_to_le64(x);
        b->last_usable_lba  = cpu_to_le64(x);
 
        DBG(GPT, ul_debug("Alternative-LBA updated from %"PRIu64" to %"PRIu64,
                                orig, le64_to_cpu(p->alternative_lba)));
+       return 0;
+failed:
+       DBG(GPT, ul_debug("failed to fix alternative-LBA [rc=%d]", rc));
+       return rc;
 }
 
 static uint64_t gpt_calculate_minimal_size(struct fdisk_context *cxt, struct fdisk_gpt_label *gpt)
@@ -582,16 +593,21 @@ static int gpt_possible_minimize(struct fdisk_context *cxt, struct fdisk_gpt_lab
 }
 
 /* move backup header behind the last partition */
-static void gpt_minimize_alternative_lba(struct fdisk_context *cxt, struct fdisk_gpt_label *gpt)
+static int gpt_minimize_alternative_lba(struct fdisk_context *cxt, struct fdisk_gpt_label *gpt)
 {
        uint64_t total = gpt_calculate_minimal_size(cxt, gpt);
        uint64_t orig = cxt->total_sectors;
+       int rc;
 
        /* Let's temporary change size of the device to recalculate backup header */
        cxt->total_sectors = total;
-       gpt_fix_alternative_lba(cxt, gpt);
+       rc = gpt_fix_alternative_lba(cxt, gpt);
+       if (rc)
+               return rc;
+
        cxt->total_sectors = orig;
        fdisk_label_set_changed(cxt->label, 1);
+       return 0;
 }
 
 /* some universal differences between the headers */
@@ -721,7 +737,7 @@ static int count_first_last_lba(struct fdisk_context *cxt,
                                 uint64_t *first, uint64_t *last)
 {
        int rc = 0;
-       uint64_t flba, llba;
+       uint64_t flba = 0, llba = 0;
 
        assert(cxt);
        assert(first);
@@ -730,8 +746,11 @@ static int count_first_last_lba(struct fdisk_context *cxt,
        *first = *last = 0;
 
        /* UEFI default */
-       gpt_calculate_last_lba(NULL, GPT_NPARTITIONS, &llba, cxt);
-       gpt_calculate_first_lba(NULL, GPT_NPARTITIONS, &flba, cxt);
+       rc = gpt_calculate_last_lba(NULL, GPT_NPARTITIONS, &llba, cxt);
+       if (rc == 0)
+               gpt_calculate_first_lba(NULL, GPT_NPARTITIONS, &flba, cxt);
+       if (rc)
+               return rc;
 
        /* script default */
        if (cxt->script) {
@@ -1629,7 +1648,8 @@ static int gpt_probe_label(struct fdisk_context *cxt)
                        fdisk_warnx(cxt, _("The backup GPT table is not on the end of the device. "
                                           "This problem will be corrected by write."));
 
-                       gpt_fix_alternative_lba(cxt, gpt);
+                       if (gpt_fix_alternative_lba(cxt, gpt) != 0)
+                               fdisk_warnx(cxt, _("Failed to recalculate backup GPT table location"));
                        gpt_recompute_crc(gpt->bheader, gpt->ents);
                        gpt_recompute_crc(gpt->pheader, gpt->ents);
                        fdisk_label_set_changed(cxt->label, 1);
@@ -2710,9 +2730,9 @@ static int gpt_check_table_overlap(struct fdisk_context *cxt,
 int fdisk_gpt_set_npartitions(struct fdisk_context *cxt, uint32_t nents)
 {
        struct fdisk_gpt_label *gpt;
-       size_t new_size;
+       size_t new_size = 0;
        uint32_t old_nents;
-       uint64_t first_usable, last_usable = 0ULL;
+       uint64_t first_usable = 0ULL, last_usable = 0ULL;
        int rc;
 
        assert(cxt);
@@ -2740,17 +2760,20 @@ int fdisk_gpt_set_npartitions(struct fdisk_context *cxt, uint32_t nents)
                return rc;
        }
 
-       gpt_calculate_first_lba(gpt->pheader, nents, &first_usable, cxt);
-       gpt_calculate_last_lba(gpt->pheader, nents, &last_usable, cxt);
+       rc = gpt_calculate_first_lba(gpt->pheader, nents, &first_usable, cxt);
+       if (rc == 0)
+               rc = gpt_calculate_last_lba(gpt->pheader, nents, &last_usable, cxt);
+       if (rc)
+               return rc;
 
        /* if expanding the table, first check that everything fits,
         * then allocate more memory and zero. */
        if (nents > old_nents) {
                unsigned char *ents;
-               size_t old_size;
+               size_t old_size = 0;
 
                rc = gpt_calculate_sizeof_entries(gpt->pheader, old_nents, &old_size);
-               if (!rc)
+               if (rc == 0)
                        rc = gpt_check_table_overlap(cxt, first_usable, last_usable);
                if (rc)
                        return rc;