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

[Dan Williams]

On Tue, 2017-02-28 at 18:49 -0800, Ben Chan wrote:
> A few crashes have been observed in the field with the following
> signature:

Pushed to git master, backported to mm-1-6 and mm-1-4.

Thanks!
Dan

>   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;
>              }
>          }
>