Aleksander Morgado
246fe710b7
The GVariants that we obtain during the processing of the "previous" dictionary with g_variant_iter_next() are full references, while the GVariants that we obtain processing the input MMLocationXX objects are floating references. The code was working well with the floating references only, as it was assumed that g_variant_builder_add() would take ownership of them as full references; but when the GVariant came from the g_variant_iter_next() processing, g_variant_builder_add() would take a full new extra reference, triggering the memory leak. Fix this, by making sure that we always work with full GVariant references in all cases, converting the floating ones with g_variant_ref_sink() and making sure we explicitly unref them after g_variant_builder_add(). ==3146== 112 (48 direct, 64 indirect) bytes in 1 blocks are definitely lost in loss record 4,532 of 4,887 ==3146== at 0x483877F: malloc (vg_replace_malloc.c:309) ==3146== by 0x50D53DA: g_malloc (gmem.c:99) ==3146== by 0x50F19ED: g_slice_alloc (gslice.c:1024) ==3146== by 0x511D639: g_variant_alloc (gvariant-core.c:486) ==3146== by 0x511D6F9: g_variant_new_from_bytes (gvariant-core.c:529) ==3146== by 0x51146C3: g_variant_new_from_trusted (gvariant.c:326) ==3146== by 0x5115D28: g_variant_new_string (gvariant.c:1264) ==3146== by 0x48EC642: mm_location_3gpp_get_string_variant (mm-location-3gpp.c:294) ==3146== by 0x196350: build_location_dictionary (mm-iface-modem-location.c:162) ==3146== by 0x197E0C: handle_setup_auth_ready (mm-iface-modem-location.c:891) ==3146== by 0x4EC9160: g_task_return_now (gtask.c:1212) ==3146== by 0x4EC92AA: g_task_return (gtask.c:1281) ==3146== 41,658 (35,520 direct, 6,138 indirect) bytes in 740 blocks are definitely lost in loss record 4,887 of 4,887 ==3146== at 0x483877F: malloc (vg_replace_malloc.c:309) ==3146== by 0x50D53DA: g_malloc (gmem.c:99) ==3146== by 0x50F19ED: g_slice_alloc (gslice.c:1024) ==3146== by 0x511E02B: g_variant_get_child_value (gvariant-core.c:1093) ==3146== by 0x5114FA7: g_variant_get_variant (gvariant.c:748) ==3146== by 0x511B196: g_variant_valist_get_nnp (gvariant.c:4934) ==3146== by 0x511B87B: g_variant_valist_get_leaf (gvariant.c:5051) ==3146== by 0x511BFBF: g_variant_valist_get (gvariant.c:5232) ==3146== by 0x511C145: g_variant_valist_get (gvariant.c:5267) ==3146== by 0x511C953: g_variant_iter_next (gvariant.c:5667) ==3146== by 0x1962F5: build_location_dictionary (mm-iface-modem-location.c:128) ==3146== by 0x19659A: notify_gps_location_update (mm-iface-modem-location.c:231)
ModemManager. ModemManager provides a unified high level API for communicating with mobile broadband modems, regardless of the protocol used to communicate with the actual device (Generic AT, vendor-specific AT, QCDM, QMI, MBIM...). Using. ModemManager is a system daemon and is not meant to be used directly from the command line. However, since it provides a DBus API, it is possible to use 'dbus-send' commands or the new 'mmcli' command line interface to control it from the terminal. The devices are queried from udev and automatically updated based on hardware events, although a manual re-scan can also be requested to look for RS232 modems. Implementation. ModemManager is a DBus system bus activated service (meaning it's started automatically when a request arrives). It is written in C, using glib and gio. Several GInterfaces specify different features that the modems support, including the generic MMIfaceModem3gpp and MMIfaceModemCdma which provide basic operations for 3GPP (GSM, UMTS, LTE) or CDMA (CDMA1x, EV-DO) modems. If a given feature is not available in the modem, the specific interface will not be exported in DBus. Plugins. Plugins are loaded on startup, and must implement the MMPlugin interface. It consists of a couple of methods which tell the daemon whether the plugin supports a port and to create custom MMBroadbandModem implementations. It most likely makes sense to derive custom modem implementations from one of the generic classes and just add (or override) operations which are not standard. There are multiple fully working plugins in the plugins/ directory that can be used as an example for writing new plugins. Writing new plugins is highly encouraged! The plugin API is open for changes, so if you're writing a plugin and need to add or change some public method, feel free to suggest it! License. The ModemManager and mmcli binaries are both GPLv2+. The libmm-glib library is LGPLv2+.