[PATCH v2 1/2] kernel-device: handle SDIO device in find_physical_gudevdevice

[Ben Chan]

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.
---
 src/kerneldevice/mm-kernel-device-udev.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/kerneldevice/mm-kernel-device-udev.c b/src/kerneldevice/mm-kernel-device-udev.c
index 432832f4..763ccf86 100644
--- a/src/kerneldevice/mm-kernel-device-udev.c
+++ b/src/kerneldevice/mm-kernel-device-udev.c
@@ -178,7 +178,7 @@ find_physical_gudevdevice (GUdevDevice *child)
     const char *subsys, *type, *name;
     guint32 i = 0;
     gboolean is_usb = FALSE, is_pci = FALSE, is_pcmcia = FALSE, is_platform = FALSE;
-    gboolean is_pnp = FALSE;
+    gboolean is_pnp = FALSE, is_sdio = FALSE;
 
     g_return_val_if_fail (child != NULL, NULL);
 
@@ -233,6 +233,10 @@ find_physical_gudevdevice (GUdevDevice *child)
                 is_pnp = TRUE;
                 physdev = iter;
                 break;
+            } else if (is_sdio || !strcmp (subsys, "sdio")) {
+                is_sdio = TRUE;
+                physdev = iter;
+                break;
             }
         }
 
-- 
2.12.0.rc1.440.g5b76565f74-goog