SEGFAULT with MM HEAD when probing

[Aleksander Morgado]

> > Or give me a few days and I might be able to bisect the problem.
>
> A few meetings helps a lot with time for robotic work like bisecting :-)
>
> The winner is:
>
> commit ec375bd959f071ce01533d50a2775e8a6f69607b
> Author: Andrew Lassalle <andrewlassalle at chromium.org>
> Date:   Wed Nov 25 13:14:35 2020 -0800
>
>     port-qmi: add support for QRTR
>
>     Extend mm-port-qmi to accept a QRTR node to work with modems using the
>     QRTR protocol.
>
> :040000 040000 973a59e3f3652ccf07b9909820238279d9efbbc9 80418a9b0c5af26898d7a6b53e16cd4d720a93e9 M      src
>
> Log:
>
> git bisect start
> # bad: [e57c59bf88615129efc0241957749102ea8af90d] qmi: Increase qmi_device_open timeout
> git bisect bad e57c59bf88615129efc0241957749102ea8af90d
> # good: [7a5a49b75301b38c2bac6a94de5afb2f9930cf4e] release: bump version to 1.16.0
> git bisect good 7a5a49b75301b38c2bac6a94de5afb2f9930cf4e
> # good: [bb5bc9c8c560a24ef2951bdb9e1da18dedd7c5b0] shared-qmi: process all feature checks in SSP response together
> git bisect good bb5bc9c8c560a24ef2951bdb9e1da18dedd7c5b0
> # good: [7dfe6198e1015c3fcc875d7be17e6b1a925c8e00] iface-modem: publish helper to abort invocation if state not reached
> git bisect good 7dfe6198e1015c3fcc875d7be17e6b1a925c8e00
> # good: [bf519fcc1b591a1435b727e38ef4a108219bd28b] port-qmi: avoid using QmiDeviceExpectedDataFormat in the port setup
> git bisect good bf519fcc1b591a1435b727e38ef4a108219bd28b
> # bad: [f7ec13deb88e9bd292d69ec7442dc892e51f3c52] sim-mbim: increase the timeout for the MBIM_CID_HOME_PROVIDER query
> git bisect bad f7ec13deb88e9bd292d69ec7442dc892e51f3c52
> # bad: [f82f50fb13aa5d0dd85b0b06948cf1a3b1190c66] base-modem: create modem for QRTR subsystem
> git bisect bad f82f50fb13aa5d0dd85b0b06948cf1a3b1190c66
> # bad: [ec375bd959f071ce01533d50a2775e8a6f69607b] port-qmi: add support for QRTR
> git bisect bad ec375bd959f071ce01533d50a2775e8a6f69607b
> # good: [312f753046b4ceaddef7b45a676a8880bfc9d89d] port-qmi: initialize endpoint info for all backends
> git bisect good 312f753046b4ceaddef7b45a676a8880bfc9d89d
> # first bad commit: [ec375bd959f071ce01533d50a2775e8a6f69607b] port-qmi: add support for QRTR
>
>
> Note that 7dfe6198e1015c3fcc875d7be17e6b1a925c8e00 failed a bit later
> with
>
> [10227]: <debug> [1619071156.121734] [qmimux0] preloading contents and properties...
> [10227]: <warn>  [1619071156.122082] [qmimux0] invalid sysfs path read for net/qmimux0
> **
> ERROR:kerneldevice/mm-kernel-device-generic.c:235:ptr_array_add_sysfs_attribute_link_basename: assertion failed: (array && sysfs_path && attribute)
> Bail out! ERROR:kerneldevice/mm-kernel-device-generic.c:235:ptr_array_add_sysfs_attribute_link_basename: assertion failed: (array && sysfs_path && attribute)
> Aborted
>
>
> but that's another temporary problem, so it's therefore noted as
> "good".  Thanks for keeping this code bisectable, BTW.  Really great to
> be able to build and run arbitrary commits in the middle of a series
> like this.

It takes a ton of effort to do make it bisectable, but I'm extremely
happy this issue was quickly solved by bisecting. As if it was worth
the effort :)

>
>
> I was pessimistic about my ability to fix or revert what I found, but
> looking at the failing commit it turned out to be rather obvious and
> easy to fix:
>
> @@ -32,6 +33,16 @@
>
>  G_DEFINE_TYPE (MMPortQmi, mm_port_qmi, MM_TYPE_PORT)
>
> +enum {
> +    PROP_0,
> +#if WITH_QMI
> +    PROP_NODE,
> +#endif
> +    PROP_LAST
> +};
> +
> +static GParamSpec *properties[PROP_LAST];
> +
>  typedef struct {
>      QmiService     service;
>      QmiClient     *client;
> @@ -43,6 +54,10 @@ struct _MMPortQmiPrivate {
>      QmiDevice *qmi_device;
>      GList     *services;
>      gchar     *net_driver;
> +#if defined WITH_QRTR
> +    QrtrNode  *node;
> +#endif
> +
>
>
>
> There's a bit of inconsistency between WITH_QRTR and WITH_QMI there...
>

This issue is 100% my fault even if Andrew is the commit author :) I
reworked all those ifdefs when made libqrtr-glib a separate library,
and it looks like that one got mixed up.

Pushed it to git master now, thanks for the patch!

-- 
Aleksander
https://aleksander.es