From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38193) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cqhW1-00012c-59 for qemu-devel@nongnu.org; Wed, 22 Mar 2017 10:45:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cqhW0-0000Ty-8g for qemu-devel@nongnu.org; Wed, 22 Mar 2017 10:45:33 -0400 From: Eric Blake Date: Wed, 22 Mar 2017 09:45:24 -0500 Message-Id: <20170322144525.18964-3-eblake@redhat.com> In-Reply-To: <20170322144525.18964-1-eblake@redhat.com> References: <20170322144525.18964-1-eblake@redhat.com> Subject: [Qemu-devel] [PATCH v3 2/3] qom: Avoid unvisited 'id'/'qom-type' in user_creatable_add_opts List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: armbru@redhat.com, lvivier@redhat.com, qemu-stable@nongnu.org, =?UTF-8?q?Andreas=20F=C3=A4rber?= A regression in commit 15c2f669e caused us to silently ignore excess input to the QemuOpts visitor. Later, commit ea4641 accidentally abused that situation, by removing "qom-type" and "id" from the corresponding QDict but leaving them defined in the QemuOpts, when using the pair of containers to create a user-defined object. Note that since we are already traversing two separate items (a QDict and a QemuOpts), we are already able to flag bogus arguments, as in: $ ./x86_64-softmmu/qemu-system-x86_64 -nodefaults -nographic -qmp stdio -object memory-backend-ram,id=mem1,size=4k,bogus=huh qemu-system-x86_64: -object memory-backend-ram,id=mem1,size=4k,bogus=huh: Property '.bogus' not found So the only real concern is that when we re-enable strict checking in the QemuOpts visitor, we do not want to start flagging the two leftover keys as unvisited. Rearrange the code to clean out the QemuOpts listing in advance, rather than removing items from the QDict. Since "qom-type" is usually an automatic implicit default, we don't have to restore it (this does mean that once instantiated, QemuOpts is not necessarily an accurate representation of the original command line - but this is not the first place to do that); however "id" has to be put back (requiring us to cast away a const). [As a side note, hmp_object_add() turns a QDict into a QemuOpts, then calls user_creatable_add_opts() which converts QemuOpts into a new QDict. There are probably a lot of wasteful conversions like this, but cleaning them up is a much bigger task than the immediate regression fix.] CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake --- v3: enhance commit message v2: new patch --- qom/object_interfaces.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c index 03a95c3..cc9a694 100644 --- a/qom/object_interfaces.c +++ b/qom/object_interfaces.c @@ -114,7 +114,7 @@ Object *user_creatable_add_opts(QemuOpts *opts, Error **errp) QDict *pdict; Object *obj; const char *id = qemu_opts_id(opts); - const char *type = qemu_opt_get(opts, "qom-type"); + char *type = qemu_opt_get_del(opts, "qom-type"); if (!type) { error_setg(errp, QERR_MISSING_PARAMETER, "qom-type"); @@ -125,14 +125,15 @@ Object *user_creatable_add_opts(QemuOpts *opts, Error **errp) return NULL; } + qemu_opts_set_id(opts, NULL); pdict = qemu_opts_to_qdict(opts, NULL); - qdict_del(pdict, "qom-type"); - qdict_del(pdict, "id"); v = opts_visitor_new(opts); obj = user_creatable_add_type(type, id, pdict, v, errp); visit_free(v); + qemu_opts_set_id(opts, (char *) id); + g_free(type); QDECREF(pdict); return obj; } -- 2.9.3