Re: [syzbot] [usb?] INFO: rcu detected stall in schedule_timeout (6)

From: Marcello Sylvester Bauer
Date: Tue Jun 04 2024 - 08:05:36 EST


Greetings,

I'm currently investigating this regression to properly fix it. My
patch only replaces the corresponding timer API calls without actually
changing the code. I'm trying to get it to work properly with the
hrtimer API.

Any hints on how to accomplish this are welcome.

Thanks
Marcello

On Thu, 2024-05-16 at 15:01 -0700, syzbot wrote:
> syzbot has bisected this issue to:
>
> commit a7f3813e589fd8e2834720829a47b5eb914a9afe
> Author: Marcello Sylvester Bauer <sylv@xxxxxxx>
> Date:   Thu Apr 11 14:51:28 2024 +0000
>
>     usb: gadget: dummy_hcd: Switch to hrtimer transfer scheduler
>
> bisection log: 
> https://syzkaller.appspot.com/x/bisect.txt?x=119318d0980000
> start commit:   75fa778d74b7 Add linux-next specific files for
> 20240510
> git tree:       linux-next
> final oops:    
> https://syzkaller.appspot.com/x/report.txt?x=139318d0980000
> console output:
> https://syzkaller.appspot.com/x/log.txt?x=159318d0980000
> kernel config: 
> https://syzkaller.appspot.com/x/.config?x=ccdd3ebd6715749a
> dashboard link:
> https://syzkaller.appspot.com/bug?extid=c793a7eca38803212c61
> syz repro:     
> https://syzkaller.appspot.com/x/repro.syz?x=16dcd598980000
> C reproducer:  
> https://syzkaller.appspot.com/x/repro.c?x=151d9c78980000
>
> Reported-by: syzbot+c793a7eca38803212c61@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: a7f3813e589f ("usb: gadget: dummy_hcd: Switch to hrtimer
> transfer scheduler")
>
> For information about bisection process see:
> https://goo.gl/tpsmEJ#bisection

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