block: Use g_new() & friends to avoid multiplying sizes

g_new(T, n) is safer than g_malloc(sizeof(*v) * n) for two reasons.
One, it catches multiplication overflowing size_t.  Two, it returns
T * rather than void *, which lets the compiler catch more type
errors.

Perhaps a conversion to g_malloc_n() would be neater in places, but
that's merely four years old, and we can't use such newfangled stuff.

This commit only touches allocations with size arguments of the form
sizeof(T), plus two that use 4 instead of sizeof(uint32_t).  We can
make the others safe by converting to g_malloc_n() when it becomes
available to us in a couple of years.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/bochs.c

@@ -131,7 +131,7 @@ static int bochs_open(BlockDriverState *bs, QDict *options, int flags,
         return -EFBIG;
     }
 
-    s->catalog_bitmap = g_try_malloc(s->catalog_size * 4);
+    s->catalog_bitmap = g_try_new(uint32_t, s->catalog_size);
     if (s->catalog_size && s->catalog_bitmap == NULL) {
         error_setg(errp, "Could not allocate memory for catalog");
         return -ENOMEM;

block/parallels.c

@@ -121,7 +121,7 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
         ret = -EFBIG;
         goto fail;
     }
-    s->catalog_bitmap = g_try_malloc(s->catalog_size * 4);
+    s->catalog_bitmap = g_try_new(uint32_t, s->catalog_size);
     if (s->catalog_size && s->catalog_bitmap == NULL) {
         ret = -ENOMEM;
         goto fail;

block/qcow2-cache.c

@@ -50,7 +50,7 @@ Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables)
 
     c = g_malloc0(sizeof(*c));
     c->size = num_tables;
-    c->entries = g_malloc0(sizeof(*c->entries) * num_tables);
+    c->entries = g_new0(Qcow2CachedTable, num_tables);
 
     for (i = 0; i < c->size; i++) {
         c->entries[i].table = qemu_try_blockalign(bs->file, s->cluster_size);

block/qed-check.c

@@ -227,8 +227,7 @@ int qed_check(BDRVQEDState *s, BdrvCheckResult *result, bool fix)
     };
     int ret;
 
-    check.used_clusters = g_try_malloc0(((check.nclusters + 31) / 32) *
-                                        sizeof(check.used_clusters[0]));
+    check.used_clusters = g_try_new0(uint32_t, (check.nclusters + 31) / 32);
     if (check.nclusters && check.used_clusters == NULL) {
         return -ENOMEM;
     }

block/rbd.c

@@ -862,7 +862,7 @@ static int qemu_rbd_snap_list(BlockDriverState *bs,
     int max_snaps = RBD_MAX_SNAPS;
 
     do {
-        snaps = g_malloc(sizeof(*snaps) * max_snaps);
+        snaps = g_new(rbd_snap_info_t, max_snaps);
         snap_count = rbd_snap_list(s->image, snaps, &max_snaps);
         if (snap_count <= 0) {
             g_free(snaps);

block/sheepdog.c

@@ -2357,7 +2357,7 @@ static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
         goto out;
     }
 
-    sn_tab = g_malloc0(nr * sizeof(*sn_tab));
+    sn_tab = g_new0(QEMUSnapshotInfo, nr);
 
     /* calculate a vdi id with hash function */
     hval = fnv_64a_buf(s->name, strlen(s->name), FNV1A_64_INIT);

hw/block/nvme.c

@@ -319,7 +319,7 @@ static void nvme_init_sq(NvmeSQueue *sq, NvmeCtrl *n, uint64_t dma_addr,
     sq->size = size;
     sq->cqid = cqid;
     sq->head = sq->tail = 0;
-    sq->io_req = g_malloc(sq->size * sizeof(*sq->io_req));
+    sq->io_req = g_new(NvmeRequest, sq->size);
 
     QTAILQ_INIT(&sq->req_list);
     QTAILQ_INIT(&sq->out_req_list);
@@ -773,9 +773,9 @@ static int nvme_init(PCIDevice *pci_dev)
     n->reg_size = 1 << qemu_fls(0x1004 + 2 * (n->num_queues + 1) * 4);
     n->ns_size = bs_size / (uint64_t)n->num_namespaces;
 
-    n->namespaces = g_malloc0(sizeof(*n->namespaces)*n->num_namespaces);
-    n->sq = g_malloc0(sizeof(*n->sq)*n->num_queues);
-    n->cq = g_malloc0(sizeof(*n->cq)*n->num_queues);
+    n->namespaces = g_new0(NvmeNamespace, n->num_namespaces);
+    n->sq = g_new0(NvmeSQueue *, n->num_queues);
+    n->cq = g_new0(NvmeCQueue *, n->num_queues);
 
     memory_region_init_io(&n->iomem, OBJECT(n), &nvme_mmio_ops, n,
                           "nvme", n->reg_size);

qemu-io-cmds.c

@@ -29,7 +29,7 @@ static int compare_cmdname(const void *a, const void *b)
 
 void qemuio_add_command(const cmdinfo_t *ci)
 {
-    cmdtab = g_realloc(cmdtab, ++ncmds * sizeof(*cmdtab));
+    cmdtab = g_renew(cmdinfo_t, cmdtab, ++ncmds);
     cmdtab[ncmds - 1] = *ci;
     qsort(cmdtab, ncmds, sizeof(*cmdtab), compare_cmdname);
 }
@@ -122,7 +122,7 @@ static char **breakline(char *input, int *count)
             continue;
         }
         c++;
-        tmp = g_realloc(rval, sizeof(*rval) * (c + 1));
+        tmp = g_renew(char *, rval, (c + 1));
         if (!tmp) {
             g_free(rval);
             rval = NULL;
@@ -1264,9 +1264,9 @@ static int multiwrite_f(BlockDriverState *bs, int argc, char **argv)
         }
     }
 
-    reqs = g_malloc0(nr_reqs * sizeof(*reqs));
-    buf = g_malloc0(nr_reqs * sizeof(*buf));
-    qiovs = g_malloc(nr_reqs * sizeof(*qiovs));
+    reqs = g_new0(BlockRequest, nr_reqs);
+    buf = g_new0(char *, nr_reqs);
+    qiovs = g_new(QEMUIOVector, nr_reqs);
 
     for (i = 0; i < nr_reqs && optind < argc; i++) {
         int j;