Re: [libgpiod][PATCH] tools: tests: replace egrep with grep -E

[Bartosz Golaszewski <brgl@xxxxxxxx>]

On Fri, Jun 2, 2023 at 3:26 PM Kent Gibson <warthog618@xxxxxxxxx> wrote:
>
> On Fri, Jun 02, 2023 at 03:10:18PM +0200, Bartosz Golaszewski wrote:
> > On Fri, Jun 2, 2023 at 12:34 PM Kent Gibson <warthog618@xxxxxxxxx> wrote:
> > >
> > > On Fri, Jun 02, 2023 at 10:13:35AM +0800, Kent Gibson wrote:
> > > >
> > > > On a related(??) note, I'm occasionally seeing Oopses when testing this
> > > > - when creating a basic sim with a shell script, not when deleting it.
> > > > In one case after a fresh reboot and on creating the first sim, so it
> > > > looks to be purely the construction.  Yay :-(.
> > > >
> > >
> > > I had thought it would be difficult to reproduce this and so difficult
> > > to bisect.  Fortunately(??) not.  If I run my setup and cleanup scripts[1]
> > > in a tight loop it occurs very readily.  Haven't bisected it yet, but did
> > > test it on 6.1-rc1 and it Oopsed there too, so I would need to go back
> > > further.  What was the initial release containing gpio-sim?
> > >
> > > The sim setp is pretty simple - a couple of banks each with a few lines
> > > and hogs.
> > >
> > > Could you confirm that you can repeat the problem?
> > > Otherwise I might start thinking there is something broken in my test
> > > environment.
> > >
> > > Btw, the loop script is:
> > >
> > > #!/bin/env bash
> > > for (( ; ; ))
> > > do
> > >         echo "create sim..."
> > >         ./basic_sim.sh
> > >         echo "destroy sim..."
> > >         ./clean_sims.sh
> > > done
> > >
> > > Cheers,
> > > Kent.
> > > [1] https://github.com/warthog618/gpiosim-rs
> > >
> >
> > With this script I've been able to trigger an issue but it looks
> > different from yours: https://pastebin.com/cbsgT2ae
> >
>
> Looks similar to me.
> I would assume that is the same issue - even if the  particulars of the
> crash differ.  If you can fix that and my problem remains then we can be
> sure they are distinct.
>
> I've been doing a coarse bisect to see how far back this goes -
> basically looking for a known good.
> 5.18 crashes, but it crashed hard, so no syslog.  It did run considerably
> longer before crashing, so that could be different issue masked by the
> other (later?) one.
>
> Moving on to subsequent releases...
>
> Cheers,
> Kent.

I managed to trigger a different crash: https://pastebin.com/6Gx29vHB

This one happened in gpio-sim:

$ ./scripts/faddr2line drivers/gpio/gpio-sim.o
gpio_sim_make_bank_swnode+0x12f/0x220
gpio_sim_make_bank_swnode+0x12f/0x220:
gpio_sim_make_line_names at
/home/brgl/workspace/yocto-gpio-sim-crash/build/linux/drivers/gpio/gpio-sim.c:725
(inlined by) gpio_sim_make_bank_swnode at
/home/brgl/workspace/yocto-gpio-sim-crash/build/linux/drivers/gpio/gpio-sim.c:837

But to me it looks like some memory corruption if the stack traces are
so random... Where is Rust when you need it? :)

Bart