9pfs: Use g_new() & friends where that makes obvious sense

g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
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.

This commit only touches allocations with size arguments of the form
sizeof(T).

Initial patch created mechanically with:

    $ spatch --in-place --sp-file scripts/coccinelle/use-g_new-etc.cocci \
	     --macro-file scripts/cocci-macro-file.h FILES...

This uncovers a typing error:

    ../hw/9pfs/9p.c: In function ‘qid_path_fullmap’:
    ../hw/9pfs/9p.c:855:13: error: assignment to ‘QpfEntry *’ from incompatible pointer type ‘QppEntry *’ [-Werror=incompatible-pointer-types]
      855 |         val = g_new0(QppEntry, 1);
	  |             ^

Harmless, because QppEntry is larger than QpfEntry.  Manually fixed to
allocate a QpfEntry instead.

Cc: Greg Kurz <groug@kaod.org>
Cc: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20220315144156.1595462-3-armbru@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/hw/9pfs/codir.c b/hw/9pfs/codir.c
index 75148bc985..93ba44fb75 100644
--- a/hw/9pfs/codir.c
+++ b/hw/9pfs/codir.c
@@ -141,9 +141,9 @@ static int do_readdir_many(V9fsPDU *pdu, V9fsFidState *fidp,
 
         /* append next node to result chain */
         if (!e) {
-            *entries = e = g_malloc0(sizeof(V9fsDirEnt));
+            *entries = e = g_new0(V9fsDirEnt, 1);
         } else {
-            e = e->next = g_malloc0(sizeof(V9fsDirEnt));
+            e = e->next = g_new0(V9fsDirEnt, 1);
         }
         e->dent = qemu_dirent_dup(dent);
 
@@ -163,7 +163,7 @@ static int do_readdir_many(V9fsPDU *pdu, V9fsFidState *fidp,
                 break;
             }
 
-            e->st = g_malloc0(sizeof(struct stat));
+            e->st = g_new0(struct stat, 1);
             memcpy(e->st, &stbuf, sizeof(struct stat));
         }