This commit regresses error message quality from
$ qemu-system-x86_64 -nodefaults -display none -object
secret,id=sec0,data=letmein,format=raw,foo=bar
qemu-system-x86_64: -object secret,id=sec0,data=letmein,format=raw,foo=bar:
Property '.foo' not found
to just
qemu-system-x86_64: Property '.foo' not found
Clue: cur_loc points to garbage.
(gdb) p cur_loc
$1 = (Location *) 0x7fffffffdc10
(gdb) p *cur_loc
$2 = {kind = (unknown: 4294958128), num = 32767,
ptr = 0x555555b804a2 <error_report_err+44>, prev = 0x5555565d2770
<std_loc>}
Looks like cur_loc is dangling. Happens when you forget to loc_pop() a
Location before it dies. This one is on the stack.
*Might* be release critical.
For comparison, this is how it looks before the patch:
(gdb) p cur_loc
$1 = (Location *) 0x7fffffffdc10
(gdb) p *cur_loc
$2 = {kind = LOC_CMDLINE, num = 2, ptr = 0x7fffffffe018, prev =
0x5555565d2770 <std_loc>}
Reported-by: Eric Blake <ebl...@redhat.com>
"Daniel P. Berrange" <berra...@redhat.com> writes:
> The QMP monitor code has two helper methods object_add
> and qmp_object_del that are called from several places
> in the code (QMP, HMP and main emulator startup).
>
> The HMP and main emulator startup code also share
> further logic that extracts the qom-type & id
> values from a qdict.
>
> We soon need to use this logic from qemu-img, qemu-io
> and qemu-nbd too, but don't want those to depend on
> the monitor, nor do we want to duplicate the code.
>
> To avoid this, move some code out of qmp.c and hmp.c
> adding new methods to qom/object_interfaces.c
>
> - user_creatable_add - takes a QDict holding a full
> object definition & instantiates it
> - user_creatable_add_type - takes an ID, type name,
> and QDict holding object properties & instantiates
> it
> - user_creatable_add_opts - takes a QemuOpts holding
> a full object definition & instantiates it
> - user_creatable_add_opts_foreach - variant on
> user_creatable_add_opts which can be directly used
> in conjunction with qemu_opts_foreach.
> - user_creatable_del - takes an ID and deletes the
> corresponding object
>
> The existing code is updated to use these new methods.
>
> Reviewed-by: Eric Blake <ebl...@redhat.com>
> Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
> ---
> hmp.c | 52 +++---------
> include/monitor/monitor.h | 3 -
> include/qom/object_interfaces.h | 92 +++++++++++++++++++++
> qmp.c | 76 ++----------------
> qom/object_interfaces.c | 174
> ++++++++++++++++++++++++++++++++++++++++
> vl.c | 68 ++--------------
> 6 files changed, 290 insertions(+), 175 deletions(-)
>
> diff --git a/hmp.c b/hmp.c
> index c6419da..41fb9ca 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -30,6 +30,7 @@
> #include "qapi/string-output-visitor.h"
> #include "qapi/util.h"
> #include "qapi-visit.h"
> +#include "qom/object_interfaces.h"
> #include "ui/console.h"
> #include "block/qapi.h"
> #include "qemu-io.h"
> @@ -1655,58 +1656,27 @@ void hmp_netdev_del(Monitor *mon, const QDict *qdict)
> void hmp_object_add(Monitor *mon, const QDict *qdict)
> {
> Error *err = NULL;
> - Error *err_end = NULL;
> QemuOpts *opts;
> - char *type = NULL;
> - char *id = NULL;
> OptsVisitor *ov;
> - QDict *pdict;
> - Visitor *v;
> + Object *obj = NULL;
>
> opts = qemu_opts_from_qdict(qemu_find_opts("object"), qdict, &err);
> if (err) {
> - goto out;
> + hmp_handle_error(mon, &err);
> + return;
> }
>
> ov = opts_visitor_new(opts);
> - pdict = qdict_clone_shallow(qdict);
> - v = opts_get_visitor(ov);
> -
> - visit_start_struct(v, NULL, NULL, 0, &err);
> - if (err) {
> - goto out_clean;
> - }
> -
> - qdict_del(pdict, "qom-type");
> - visit_type_str(v, "qom-type", &type, &err);
> - if (err) {
> - goto out_end;
> - }
> + obj = user_creatable_add(qdict, opts_get_visitor(ov), &err);
> + opts_visitor_cleanup(ov);
> + qemu_opts_del(opts);
>
> - qdict_del(pdict, "id");
> - visit_type_str(v, "id", &id, &err);
> if (err) {
> - goto out_end;
> + hmp_handle_error(mon, &err);
> }
> -
> - object_add(type, id, pdict, v, &err);
> -
> -out_end:
> - visit_end_struct(v, &err_end);
> - if (!err && err_end) {
> - qmp_object_del(id, NULL);
> + if (obj) {
> + object_unref(obj);
> }
> - error_propagate(&err, err_end);
> -out_clean:
> - opts_visitor_cleanup(ov);
> -
> - QDECREF(pdict);
> - qemu_opts_del(opts);
> - g_free(id);
> - g_free(type);
> -
> -out:
> - hmp_handle_error(mon, &err);
> }
>
> void hmp_getfd(Monitor *mon, const QDict *qdict)
> @@ -1934,7 +1904,7 @@ void hmp_object_del(Monitor *mon, const QDict *qdict)
> const char *id = qdict_get_str(qdict, "id");
> Error *err = NULL;
>
> - qmp_object_del(id, &err);
> + user_creatable_del(id, &err);
> hmp_handle_error(mon, &err);
> }
>
> diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h
> index 91b95ae..aa0f373 100644
> --- a/include/monitor/monitor.h
> +++ b/include/monitor/monitor.h
> @@ -43,9 +43,6 @@ void monitor_read_command(Monitor *mon, int show_prompt);
> int monitor_read_password(Monitor *mon, ReadLineFunc *readline_func,
> void *opaque);
>
> -void object_add(const char *type, const char *id, const QDict *qdict,
> - Visitor *v, Error **errp);
> -
> AddfdInfo *monitor_fdset_add_fd(int fd, bool has_fdset_id, int64_t fdset_id,
> bool has_opaque, const char *opaque,
> Error **errp);
> diff --git a/include/qom/object_interfaces.h b/include/qom/object_interfaces.h
> index 283ae0d..d579746 100644
> --- a/include/qom/object_interfaces.h
> +++ b/include/qom/object_interfaces.h
> @@ -2,6 +2,8 @@
> #define OBJECT_INTERFACES_H
>
> #include "qom/object.h"
> +#include "qapi/qmp/qdict.h"
> +#include "qapi/visitor.h"
>
> #define TYPE_USER_CREATABLE "user-creatable"
>
> @@ -72,4 +74,94 @@ void user_creatable_complete(Object *obj, Error **errp);
> * from implements USER_CREATABLE interface.
> */
> bool user_creatable_can_be_deleted(UserCreatable *uc, Error **errp);
> +
> +/**
> + * user_creatable_add:
> + * @qdict: the object definition
> + * @v: the visitor
> + * @errp: if an error occurs, a pointer to an area to store the error
> + *
> + * Create an instance of the user creatable object whose type
> + * is defined in @qdict by the 'qom-type' field, placing it
> + * in the object composition tree with name provided by the
> + * 'id' field. The remaining fields in @qdict are used to
> + * initialize the object properties.
> + *
> + * Returns: the newly created object or NULL on error
> + */
> +Object *user_creatable_add(const QDict *qdict,
> + Visitor *v, Error **errp);
> +
> +/**
> + * user_creatable_add_type:
> + * @type: the object type name
> + * @id: the unique ID for the object
> + * @qdict: the object properties
> + * @v: the visitor
> + * @errp: if an error occurs, a pointer to an area to store the error
> + *
> + * Create an instance of the user creatable object @type, placing
> + * it in the object composition tree with name @id, initializing
> + * it with properties from @qdict
> + *
> + * Returns: the newly created object or NULL on error
> + */
> +Object *user_creatable_add_type(const char *type, const char *id,
> + const QDict *qdict,
> + Visitor *v, Error **errp);
> +
> +/**
> + * user_creatable_add_opts:
> + * @opts: the object definition
> + * @errp: if an error occurs, a pointer to an area to store the error
> + *
> + * Create an instance of the user creatable object whose type
> + * is defined in @opts by the 'qom-type' option, placing it
> + * in the object composition tree with name provided by the
> + * 'id' field. The remaining options in @opts are used to
> + * initialize the object properties.
> + *
> + * Returns: the newly created object or NULL on error
> + */
> +Object *user_creatable_add_opts(QemuOpts *opts, Error **errp);
> +
> +
> +/**
> + * user_creatable_add_opts_predicate:
> + * @type: the QOM type to be added
> + *
> + * A callback function to determine whether an object
> + * of type @type should be created. Instances of this
> + * callback should be passed to user_creatable_add_opts_foreach
> + */
> +typedef bool (*user_creatable_add_opts_predicate)(const char *type);
> +
> +/**
> + * user_creatable_add_opts_foreach:
> + * @opaque: a user_creatable_add_opts_predicate callback or NULL
> + * @opts: options to create
> + * @errp: if an error occurs, a pointer to an area to store the error
> + *
> + * An iterator callback to be used in conjunction with
> + * the qemu_opts_foreach() method for creating a list of
> + * objects from a set of QemuOpts
> + *
> + * The @opaque parameter can be passed a user_creatable_add_opts_predicate
> + * callback to filter which types of object are created during iteration.
> + *
> + * Returns: 0 on success, -1 on error
> + */
> +int user_creatable_add_opts_foreach(void *opaque,
> + QemuOpts *opts, Error **errp);
> +
> +/**
> + * user_creatable_del:
> + * @id: the unique ID for the object
> + * @errp: if an error occurs, a pointer to an area to store the error
> + *
> + * Delete an instance of the user creatable object identified
> + * by @id.
> + */
> +void user_creatable_del(const char *id, Error **errp);
> +
> #endif
> diff --git a/qmp.c b/qmp.c
> index 6ae7230..9a93d5e 100644
> --- a/qmp.c
> +++ b/qmp.c
> @@ -633,65 +633,13 @@ void qmp_add_client(const char *protocol, const char
> *fdname,
> close(fd);
> }
>
> -void object_add(const char *type, const char *id, const QDict *qdict,
> - Visitor *v, Error **errp)
> -{
> - Object *obj;
> - ObjectClass *klass;
> - const QDictEntry *e;
> - Error *local_err = NULL;
> -
> - klass = object_class_by_name(type);
> - if (!klass) {
> - error_setg(errp, "invalid object type: %s", type);
> - return;
> - }
> -
> - if (!object_class_dynamic_cast(klass, TYPE_USER_CREATABLE)) {
> - error_setg(errp, "object type '%s' isn't supported by object-add",
> - type);
> - return;
> - }
> -
> - if (object_class_is_abstract(klass)) {
> - error_setg(errp, "object type '%s' is abstract", type);
> - return;
> - }
> -
> - obj = object_new(type);
> - if (qdict) {
> - for (e = qdict_first(qdict); e; e = qdict_next(qdict, e)) {
> - object_property_set(obj, v, e->key, &local_err);
> - if (local_err) {
> - goto out;
> - }
> - }
> - }
> -
> - object_property_add_child(object_get_objects_root(),
> - id, obj, &local_err);
> - if (local_err) {
> - goto out;
> - }
> -
> - user_creatable_complete(obj, &local_err);
> - if (local_err) {
> - object_property_del(object_get_objects_root(),
> - id, &error_abort);
> - goto out;
> - }
> -out:
> - if (local_err) {
> - error_propagate(errp, local_err);
> - }
> - object_unref(obj);
> -}
>
> void qmp_object_add(const char *type, const char *id,
> bool has_props, QObject *props, Error **errp)
> {
> const QDict *pdict = NULL;
> QmpInputVisitor *qiv;
> + Object *obj;
>
> if (props) {
> pdict = qobject_to_qdict(props);
> @@ -702,27 +650,17 @@ void qmp_object_add(const char *type, const char *id,
> }
>
> qiv = qmp_input_visitor_new(props);
> - object_add(type, id, pdict, qmp_input_get_visitor(qiv), errp);
> + obj = user_creatable_add_type(type, id, pdict,
> + qmp_input_get_visitor(qiv), errp);
> qmp_input_visitor_cleanup(qiv);
> + if (obj) {
> + object_unref(obj);
> + }
> }
>
> void qmp_object_del(const char *id, Error **errp)
> {
> - Object *container;
> - Object *obj;
> -
> - container = object_get_objects_root();
> - obj = object_resolve_path_component(container, id);
> - if (!obj) {
> - error_setg(errp, "object id not found");
> - return;
> - }
> -
> - if (!user_creatable_can_be_deleted(USER_CREATABLE(obj), errp)) {
> - error_setg(errp, "%s is in use, can not be deleted", id);
> - return;
> - }
> - object_unparent(obj);
> + user_creatable_del(id, errp);
> }
>
> MemoryDeviceInfoList *qmp_query_memory_devices(Error **errp)
> diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
> index f1218f0..c2f6e29 100644
> --- a/qom/object_interfaces.c
> +++ b/qom/object_interfaces.c
> @@ -1,6 +1,9 @@
> #include "qemu/osdep.h"
> #include "qom/object_interfaces.h"
> #include "qemu/module.h"
> +#include "qapi-visit.h"
> +#include "qapi/qmp-output-visitor.h"
> +#include "qapi/opts-visitor.h"
>
> void user_creatable_complete(Object *obj, Error **errp)
> {
> @@ -31,6 +34,177 @@ bool user_creatable_can_be_deleted(UserCreatable *uc,
> Error **errp)
> }
> }
>
> +
> +Object *user_creatable_add(const QDict *qdict,
> + Visitor *v, Error **errp)
> +{
> + char *type = NULL;
> + char *id = NULL;
> + Object *obj = NULL;
> + Error *local_err = NULL, *end_err = NULL;
> + QDict *pdict;
> +
> + pdict = qdict_clone_shallow(qdict);
> +
> + visit_start_struct(v, NULL, NULL, 0, &local_err);
> + if (local_err) {
> + goto out;
> + }
> +
> + qdict_del(pdict, "qom-type");
> + visit_type_str(v, "qom-type", &type, &local_err);
> + if (local_err) {
> + goto out_visit;
> + }
> +
> + qdict_del(pdict, "id");
> + visit_type_str(v, "id", &id, &local_err);
> + if (local_err) {
> + goto out_visit;
> + }
> +
> + obj = user_creatable_add_type(type, id, pdict, v, &local_err);
> + if (local_err) {
> + goto out_visit;
> + }
> +
> + out_visit:
> + visit_end_struct(v, &end_err);
> + if (end_err) {
> + error_propagate(&local_err, end_err);
> + if (obj) {
> + user_creatable_del(id, NULL);
> + }
> + goto out;
> + }
> +
> +out:
> + QDECREF(pdict);
> + g_free(id);
> + g_free(type);
> + if (local_err) {
> + error_propagate(errp, local_err);
> + object_unref(obj);
> + return NULL;
> + }
> + return obj;
> +}
> +
> +
> +Object *user_creatable_add_type(const char *type, const char *id,
> + const QDict *qdict,
> + Visitor *v, Error **errp)
> +{
> + Object *obj;
> + ObjectClass *klass;
> + const QDictEntry *e;
> + Error *local_err = NULL;
> +
> + klass = object_class_by_name(type);
> + if (!klass) {
> + error_setg(errp, "invalid object type: %s", type);
> + return NULL;
> + }
> +
> + if (!object_class_dynamic_cast(klass, TYPE_USER_CREATABLE)) {
> + error_setg(errp, "object type '%s' isn't supported by object-add",
> + type);
> + return NULL;
> + }
> +
> + if (object_class_is_abstract(klass)) {
> + error_setg(errp, "object type '%s' is abstract", type);
> + return NULL;
> + }
> +
> + obj = object_new(type);
> + if (qdict) {
> + for (e = qdict_first(qdict); e; e = qdict_next(qdict, e)) {
> + object_property_set(obj, v, e->key, &local_err);
> + if (local_err) {
> + goto out;
> + }
> + }
> + }
> +
> + object_property_add_child(object_get_objects_root(),
> + id, obj, &local_err);
> + if (local_err) {
> + goto out;
> + }
> +
> + user_creatable_complete(obj, &local_err);
> + if (local_err) {
> + object_property_del(object_get_objects_root(),
> + id, &error_abort);
> + goto out;
> + }
> +out:
> + if (local_err) {
> + error_propagate(errp, local_err);
> + object_unref(obj);
> + return NULL;
> + }
> + return obj;
> +}
> +
> +
> +Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
> +{
> + OptsVisitor *ov;
> + QDict *pdict;
> + Object *obj = NULL;
> +
> + ov = opts_visitor_new(opts);
> + pdict = qemu_opts_to_qdict(opts, NULL);
> +
> + obj = user_creatable_add(pdict, opts_get_visitor(ov), errp);
> + opts_visitor_cleanup(ov);
> + QDECREF(pdict);
> + return obj;
> +}
> +
> +
> +int user_creatable_add_opts_foreach(void *opaque, QemuOpts *opts, Error
> **errp)
> +{
> + bool (*type_predicate)(const char *) = opaque;
> + Object *obj = NULL;
> + const char *type;
> +
> + type = qemu_opt_get(opts, "qom-type");
> + if (type && type_predicate &&
> + !type_predicate(type)) {
> + return 0;
> + }
> +
> + obj = user_creatable_add_opts(opts, errp);
> + if (!obj) {
> + return -1;
> + }
> + object_unref(obj);
> + return 0;
> +}
> +
> +
> +void user_creatable_del(const char *id, Error **errp)
> +{
> + Object *container;
> + Object *obj;
> +
> + container = object_get_objects_root();
> + obj = object_resolve_path_component(container, id);
> + if (!obj) {
> + error_setg(errp, "object '%s' not found", id);
> + return;
> + }
> +
> + if (!user_creatable_can_be_deleted(USER_CREATABLE(obj), errp)) {
> + error_setg(errp, "object '%s' is in use, can not be deleted", id);
> + return;
> + }
> + object_unparent(obj);
> +}
> +
> static void register_types(void)
> {
> static const TypeInfo uc_interface_info = {
> diff --git a/vl.c b/vl.c
> index 175ebcc..9bd881e 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -2816,64 +2816,6 @@ static bool object_create_delayed(const char *type)
> }
>
>
> -static int object_create(void *opaque, QemuOpts *opts, Error **errp)
> -{
> - Error *err = NULL;
> - Error *err_end = NULL;
> - char *type = NULL;
> - char *id = NULL;
> - OptsVisitor *ov;
> - QDict *pdict;
> - bool (*type_predicate)(const char *) = opaque;
> - Visitor *v;
> -
> - ov = opts_visitor_new(opts);
> - pdict = qemu_opts_to_qdict(opts, NULL);
> - v = opts_get_visitor(ov);
> -
> - visit_start_struct(v, NULL, NULL, 0, &err);
> - if (err) {
> - goto out;
> - }
> -
> - qdict_del(pdict, "qom-type");
> - visit_type_str(v, "qom-type", &type, &err);
> - if (err) {
> - goto out;
> - }
> - if (!type_predicate(type)) {
> - visit_end_struct(v, NULL);
> - goto out;
> - }
> -
> - qdict_del(pdict, "id");
> - visit_type_str(v, "id", &id, &err);
> - if (err) {
> - goto out_end;
> - }
> -
> - object_add(type, id, pdict, v, &err);
> -
> -out_end:
> - visit_end_struct(v, &err_end);
> - if (!err && err_end) {
> - qmp_object_del(id, NULL);
> - }
> - error_propagate(&err, err_end);
> -
> -out:
> - opts_visitor_cleanup(ov);
> -
> - QDECREF(pdict);
> - g_free(id);
> - g_free(type);
> - if (err) {
> - error_report_err(err);
> - return -1;
> - }
> - return 0;
> -}
> -
> static void set_memory_options(uint64_t *ram_slots, ram_addr_t *maxram_size,
> MachineClass *mc)
> {
> @@ -4299,8 +4241,9 @@ int main(int argc, char **argv, char **envp)
> socket_init();
>
> if (qemu_opts_foreach(qemu_find_opts("object"),
> - object_create,
> - object_create_initial, NULL)) {
> + user_creatable_add_opts_foreach,
> + object_create_initial, &err)) {
> + error_report_err(err);
> exit(1);
> }
>
> @@ -4417,8 +4360,9 @@ int main(int argc, char **argv, char **envp)
> }
>
> if (qemu_opts_foreach(qemu_find_opts("object"),
> - object_create,
> - object_create_delayed, NULL)) {
> + user_creatable_add_opts_foreach,
> + object_create_delayed, &err)) {
> + error_report_err(err);
> exit(1);
> }
