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>

1 files changed, 5 insertions, 5 deletions

diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index 3a1e11e1ea..afd8867591 100644
--- a/qemu-io-cmds.c
+++ b/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;