Re: WARNING: fs/proc/generic.c:173 __xlate_proc_name

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Linus,

On Mon, Feb 12, 2024 at 2:35 PM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote:
> looping in Geert becaus I think he wants to look into this!

Oh no ;-)

> On Sat, Feb 10, 2024 at 11:06 AM Stefan Wahren <wahrenst@xxxxxxx> wrote:
> > we are using libgpiod-2.0.1 with Linux 6.1.49 on our Tarragon hardware
> > platform. Recently we implemented an application which waits for GPIO
> > interrupts and we were able to trigger a warning by naming the owner of
> > the GPIO as "R1/S1":
> >
> > WARNING: CPU: 0 PID: 429 at fs/proc/generic.c:173
> > __xlate_proc_name+0x78/0x98 name 'R1/S1'
> > CPU: 0 PID: 429 Comm: cb_tarragon_dri Not tainted
> > 6.1.49-00019-g9dbc76303a17 #147
> > Hardware name: Freescale i.MX6 Ultralite (Device Tree)
> > unwind_backtrace from show_stack+0x10/0x14
> > show_stack from dump_stack_lvl+0x24/0x2c
> > dump_stack_lvl from __warn+0x74/0xbc
> > __warn from warn_slowpath_fmt+0xc8/0x120
> > warn_slowpath_fmt from __xlate_proc_name+0x78/0x98
> > __xlate_proc_name from __proc_create+0x3c/0x284
> > __proc_create from _proc_mkdir+0x2c/0x70
> > _proc_mkdir from proc_mkdir_data+0x10/0x18
> > proc_mkdir_data from register_handler_proc+0xc8/0x118
> > register_handler_proc from __setup_irq+0x554/0x664
> > __setup_irq from request_threaded_irq+0xac/0x13c
> > request_threaded_irq from edge_detector_setup+0xc0/0x1f8
> > edge_detector_setup from linereq_create+0x30c/0x384
> > linereq_create from vfs_ioctl+0x20/0x38
> > vfs_ioctl from sys_ioctl+0xbc/0x8b0
> > sys_ioctl from ret_fast_syscall+0x0/0x54
> > Exception stack(0xe0b61fa8 to 0xe0b61ff0)
> > 1fa0:                   01b019b8 01a9f428 0000000d c250b407 beeae888
> > beeae880
> > 1fc0: 01b019b8 01a9f428 01af7e40 00000036 beeaeb88 beeaeb80 beeaeb58
> > beeaeb60
> > 1fe0: 00000036 beeae868 b6a88569 b6a01ae6
> > ---[ end trace 0000000000000000 ]---
> >
> > I'm not sure where this should be fixed.

Any names ending up in sysfs cannot contain a slash?

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds