lkml.org 
[lkml]   [2021]   [Nov]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [syzbot] BUG: sleeping function called from invalid context in __might_resched
Date
On Friday, November 12, 2021 2:58:14 PM CET Marco Elver wrote:
> On Fri, 12 Nov 2021 at 13:22, Fabio M. De Francesco
> <fmdefrancesco@gmail.com> wrote:
> [...]
> > I think that this "BUG" is a false positive.
> >
> > In do_con_write(), Just before the call of console_lock() there is an
> > in_interrupt() check that, if it evaluates to true, makes this function
to
> > return "count" and prevents the SAC bug.
>
> It's not complaining about being in an interrupt, but rather
> interrupts disabled, i.e. still an atomic context.

Yes, still in an atomic context.

Actually, I've never talked about being "in an interrupt", but I've just said
that the in_interrupt() macro prevents to fall into the code that might
sleep.

Now I suppose that this is the place for in_atomic(). Isn't it?

I wrongly thought that in_interrupt() returns non-zero from any kind of
atomic context.

Thanks,

Fabio

> > > do_con_write+0x10f/0x1e40 drivers/tty/vt/vt.c:2908
> > > con_write+0x21/0x40 drivers/tty/vt/vt.c:3295
> > > n_hdlc_send_frames+0x24b/0x490 drivers/tty/n_hdlc.c:290
> > > tty_wakeup+0xe1/0x120 drivers/tty/tty_io.c:534
> > > __start_tty drivers/tty/tty_io.c:806 [inline]
> > > __start_tty+0xfb/0x130 drivers/tty/tty_io.c:799
> > > n_tty_ioctl_helper+0x299/0x2d0 drivers/tty/tty_ioctl.c:880
>
> ^^ n_tty_ioctl_helper() disabled interrupts via
> spin_lock_irq(&tty->flow.lock)
>




\
 
 \ /
  Last update: 2021-11-12 17:06    [W:0.067 / U:0.620 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site