66b3367cf8
A few crashes have been observed in the field with the following signature: Thread 0 CRASHED [SIGSEGV @ 0x00000000 ] MAGIC SIGNATURE THREAD 0xf53ff5e8 (libglib-2.0.so.0.3600.4 -ghash.c:1732 ) g_str_hash 0xf53fe8c7 (libglib-2.0.so.0.3600.4 -ghash.c:365 ) g_hash_table_lookup 0xb953c3bd (ModemManager -mm-base-manager.c:130 ) device_removed 0xb953cc9f (ModemManager -mm-base-manager.c:408 ) handle_uevent 0xf54c535f (libgobject-2.0.so.0.3600.4 -gclosure.c:777 ) g_closure_invoke 0xf54d6fc7 (libgobject-2.0.so.0.3600.4 -gsignal.c:3584 ) signal_emit_unlocked_R 0xf54d7baf (libgobject-2.0.so.0.3600.4 -gsignal.c:3328 ) g_signal_emit_valist 0xf54d7fa5 (libgobject-2.0.so.0.3600.4 -gsignal.c:3384 ) g_signal_emit 0xf5623819 (libgudev-1.0.so.0.2.0 -gudevclient.c:104 ) monitor_event 0xf540cc51 (libglib-2.0.so.0.3600.4 -gmain.c:3054 ) g_main_context_dispatch 0xf540cfa5 (libglib-2.0.so.0.3600.4 -gmain.c:3701 ) g_main_context_iterate 0xf540d2c5 (libglib-2.0.so.0.3600.4 -gmain.c:3895 ) g_main_loop_run 0xb9539dad (ModemManager -main.c:180 ) main 0xf52d687d (libc-2.23.so -libc-start.c:289 ) __libc_start_main 0xb9539bf3 (ModemManager + 0x0001cbf3 ) _start 0xb95b0fbf (ModemManager -elf-init.c:87 ) __libc_csu_init 0xf56dbe43 (ld-2.23.so + 0x0000be43 ) _dl_sort_fini 0xb9539bbf (ModemManager + 0x0001cbbf ) _init The crash happens when mm-kernel-device-udev.c:find_physical_gudevdevice() fails to find the physical device, which eventually leads to a NULL `physdev_uid' being passed to g_hash_table_lookup() in mm-base-manager.cc:find_device_by_physdev_uid(). There isn't much information about the actual device that triggered the udev event, but it's suspected to be a tty or net device on a SDIO bus and thus associated with a physical device on the 'sdio' subsystem. This patch updates find_physical_gudevdevice() in mm-kernel-device-udev.c to handle this particular scenario.
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 provice 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+.