Re: ir-keytable segfault when writing keymap from file

[camden lindsay <camden.lindsay+kernel@gmail.com>]

Will do.

To do a quick test, i copied the sample config file out of the man
page and tried loading it:
[kodiuser@kodiarch ir-keytable]$ sudo ir-keytable -w /etc/ir-keytable/test.toml
Read iMON Station RSC table
/etc/ir-keytable/test.toml: keycode `KEY_MAX' not recognised, no
mapping for scancode 8392834
Wrote 42 keycode(s) to driver
Protocols changed to nec
Can't find imon_rsc bpf protocol in /etc/rc_keymaps/protocols or
/usr/lib/udev/rc_keymaps/protocols
[kodiuser@kodiarch ir-keytable]$


Looks like perhaps i should file a bug against arch for the missing
protocol file?

I have no idea what IR BPF decoding does.. but the pages i have
skimmed about it (including running across your ramblings and  bpf man
page description) seem to indicate it is more complex that what i'll
need, given i'll be using the kernel IR decoders.  I think? heh.

thank you
Camden

On Tue, Jan 21, 2020 at 11:29 AM Sean Young <sean@mess.org> wrote:
>
> Hi Camden,
>
> On Tue, Jan 21, 2020 at 11:18:30AM -0800, camden lindsay wrote:
> > Sean-
> >
> > Ah, it is possible that the keymap has multiple protocols.  I'm using
> > an A/V receiver remote that has had other remote information
> > programmed into it so it can control my sony tv as well as kodi, and
> > in controlling kodi i did some hackish stuff i'm sure (don't really
> > remember what).
> >
> > I don't have any idea how to identify what lines in the keymap are nec
> > and what are RC6-MCU.. let alone what variant the nec protocol is
> > using. Suggestions for finding this info?
>
> You can figure out what the remote is sending using the command:
> ir-keytable -p all -t
>
> Then test your remote. Look for "lirc protocol" in the output.
>
> > Thank you for finding the problem- indeed, once adding the following
> > to the top of the keyfile, no more segfault- and the keymap is written
> > (to ...kernel?) from file. :)
> > [kodiuser@kodiarch ir-keytable]$ head -1 /etc/ir-keytable/keymap.txt.wasworking
> > # table foobar, type: RC6-MCE
> > [kodiuser@kodiarch ir-keytable]$
> >
> > However, maybe something weird with my distribution-  it doesn't seem
> > to find the RC6-MCE bpf protocol (i've also tried lower case, since
> > the man page has rc6-mce in lower case)
> > [kodiuser@kodiarch ir-keytable]$ sudo ir-keytable -w
> > /etc/ir-keytable/keymap.txt.wasworking
> > Read foobar table
> > Wrote 64 keycode(s) to driver
> > Protocols changed to
> > Can't find RC6-MCE bpf protocol in /etc/rc_keymaps/protocols or
> > /usr/lib/udev/rc_keymaps/protocols
>
> Ah, my bad. That should be simply rc6, not rc6-mce.
>
> > [kodiuser@kodiarch ir-keytable]$
> >
> > the file 'protocols' doesn't seem to exist in either of those
> > locations on my distribution.
>
> That's odd. Looks like arch doesn't include them. Also, the kernel is built
> without IR BPF decoding (CONFIG_BPF_LIRC_MODE2).
>
> > Thank you for the pointer to the man page that includes the new format
> > of keymap.  Seems the best path forward is to identify the protocols
> > of scancodes i have, then  write a new keymap in a new format with
> > both protocols in it.
>
> Please let us know how you get on.
>
> Sean
>
> >
> > Your help is greatly appreciated-
> > Camden
> >
> > On Tue, Jan 21, 2020 at 8:49 AM Sean Young <sean@mess.org> wrote:
> > >
> > > Hi Camden,
> > >
> > > On Tue, Jan 21, 2020 at 07:57:35AM -0800, camden lindsay wrote:
> > > > On Tue, Jan 21, 2020 at 1:20 AM Sean Young <sean@mess.org> wrote:
> > > > > On Mon, Jan 20, 2020 at 06:47:17PM -0800, camden lindsay wrote:
> > > > > > And this shows that the segfault still occurs even if i don't clear
> > > > > > the keytable first (but of course the existing contents of the table
> > > > > > still exist)
> > > > > > [kodiuser@kodiarch ~]$ sudo ir-keytable -r | grep KEY_DOWN
> > > > > > Enabled kernel protocols: lirc nec
> > > > > > scancode 0x800f041f = KEY_DOWN (0x6c)
> > > > > > [kodiuser@kodiarch ~]$ cat /etc/ir-keytable/keymap.txt
> > > > > > scancode 0x800f041f = KEY_DOWN (0x6c)
> > > > > > [kodiuser@kodiarch ~]$ sudo ir-keytable -w /etc/ir-keytable/keymap.txt
> > > > > > Segmentation fault
> > > > > > [kodiuser@kodiarch ~]$ sudo ir-keytable -r | grep KEY_DOWN
> > > > > > Enabled kernel protocols: lirc nec
> > > > > > scancode 0x800f041f = KEY_DOWN (0x6c)
> > > > > > [kodiuser@kodiarch ~]$
> > > > >
> > > > > I suspect ir-keytable is segfaulting in the code that reads the file; would
> > > > > you be able to share the keymap.txt file please? That way I can see if I
> > > > > can reproduce the problem.
> > > > >
> > > > > Parsing of the keymap is done in C which can be prone to these sorts of
> > > > > problems.
> > > > >
> > > > > > Here is the example syslog output of the segfault:
> > > > > > Jan 20 18:15:33 kodiarch kernel: ir-keytable[817]: segfault at 0 ip
> > > > > > 00007f1a958436f5 sp 00007ffe039a5aa8 error 4 in
> > > > > > libc-2.30.so[7f1a95707000+14d000]
> > > > > > Jan 20 18:15:33 kodiarch kernel: Code: 00 00 0f 1f 00 31 c0 c5 f8 77
> > > > > > c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 89 f9 48 89 fa c5 f9 ef
> > > > > > c0 83 e1 3f 83 f9 20 77 2b <c5> fd 74 0f c5 fd d7 c1 85 c0 0f 85 eb 00
> > > > > > 00 00 48 83 c7 20 83 e1
> > > > > > Jan 20 18:15:33 kodiarch systemd[1]: Started Process Core Dump (PID 818/UID 0).
> > > > > > Jan 20 18:15:34 kodiarch systemd-coredump[819]: Process 817
> > > > > > (ir-keytable) of user 0 dumped core.
> > > > > >
> > > > > >                                                 Stack trace of thread 817:
> > > > > >                                                 #0  0x00007f1a958436f5
> > > > > > __strlen_avx2 (libc.so.6 + 0x1616f5)
> > > > > >                                                 #1  0x00007f1a95770be3
> > > > > > __strdup (libc.so.6 + 0x8ebe3)
> > > > > >                                                 #2  0x0000563150aa43b7
> > > > > > n/a (ir-keytable + 0x83b7)
> > > > > >                                                 #3  0x0000563150aa44c6
> > > > > > n/a (ir-keytable + 0x84c6)
> > > > > >                                                 #4  0x00007f1a957edfc0
> > > > > > argp_parse (libc.so.6 + 0x10bfc0)
> > > > > >                                                 #5  0x0000563150aa2099
> > > > > > n/a (ir-keytable + 0x6099)
> > > > > >                                                 #6  0x00007f1a95709153
> > > > > > __libc_start_main (libc.so.6 + 0x27153)
> > > > > >                                                 #7  0x0000563150aa325e
> > > > > > n/a (ir-keytable + 0x725e)
> > > > > > Jan 20 18:15:34 kodiarch systemd[1]: systemd-coredump@3-818-0.service:
> > > > > > Succeeded.
> > > > >
> > > > > This would have to be done a in debug build.
> > > > >
> > > > > Thanks
> > > > > Sean
> > > >
> > > >
> > > >
> > > > Hello, Sean-
> > > > I'd be happy to share the files, I greatly appreciate you looking into
> > > > this.  I'll try attaching them to this email.
> > > > There are two files- one was my original file, the other was my
> > > > attempt to make the most basic file based on a single line of
> > > > ir-keytable -r.
> > >
> > > Ok, ir-keytable segfaults because there is no protocol specified. You'll
> > > need something like "# table foobar, type: RC6-MCE" as a first line. Of
> > > course, ir-keytable should not segfault if this is missing. I'll write
> > > a fix for this.
> > >
> > > Secondly, there is a new format for rc keymaps written in toml. A new format
> > > was needed to support BPF keymaps and keymaps with multiple protocols
> > > are better supported. See man rc_keymap
> > >
> > > It looks like the keymap you are trying to load contains two different
> > > protocols, rc6-mce and something else (nec-x?). Please let me know what
> > > you are trying to do so I can help write a toml keymap.
> > >
> > >
> > > Sean
> > >