All of lore.kernel.org
 help / color / mirror / Atom feed
From: Richard Weinberger <richard.weinberger@gmail.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: xenomai@xenomai.org
Subject: Re: Enable/Disable of ftrace events crashes kernel
Date: Thu, 11 Jul 2019 22:48:19 +0200	[thread overview]
Message-ID: <CAFLxGvwJx=JkQc-s6TkvmP=_JM+VYxTt9Qiyko9u8CguoeS0sw@mail.gmail.com> (raw)
In-Reply-To: <fb2a4587-5180-663b-1dee-e2b7b114fc63@siemens.com>

On Thu, Jul 11, 2019 at 8:30 PM Jan Kiszka <jan.kiszka@siemens.com> wrote:
>
> On 11.07.19 12:25, Richard Weinberger wrote:
> > On Thu, Jul 11, 2019 at 12:21 PM Jan Kiszka <jan.kiszka@siemens.com> wrote:
> >> Can't reproduce so far, even with a while-true loop. Can you share your .config?
> >
> > Sure, see attachment.
> >
>
> This seems to fix the issue here:
>
> diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
> index 119fd66d111e..8f647c208cf2 100644
> --- a/arch/x86/entry/entry_64.S
> +++ b/arch/x86/entry/entry_64.S
> @@ -997,8 +997,8 @@ apicinterrupt IRQ_WORK_VECTOR                       irq_work_interrupt              smp_irq_work_interrupt
>  \skip_label:
>         UNWIND_HINT_REGS
>         DISABLE_INTERRUPTS(CLBR_ANY)
> -       testl   %ebx, %ebx      /* %ebx: return to kernel mode */
> -       jnz     retint_kernel_early
> +       testb   $3, CS(%rsp)
> +       jz      retint_kernel_early
>         jmp     retint_user_early
>         .endif
>  1001:
>
> Tests welcome!

With that change I can no longer trigger the crash.
Can you please give more context? I'd like to understand the problem.

-- 
Thanks,
//richard


  parent reply	other threads:[~2019-07-11 20:48 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-10 22:29 Enable/Disable of ftrace events crashes kernel Richard Weinberger
2019-07-11 10:21 ` Jan Kiszka
2019-07-11 10:25   ` Richard Weinberger
2019-07-11 18:30     ` Jan Kiszka
2019-07-11 18:49       ` Jan Kiszka
2019-07-11 20:48       ` Richard Weinberger [this message]
2019-07-11 21:20         ` Jan Kiszka
2019-07-12  7:17           ` Richard Weinberger

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAFLxGvwJx=JkQc-s6TkvmP=_JM+VYxTt9Qiyko9u8CguoeS0sw@mail.gmail.com' \
    --to=richard.weinberger@gmail.com \
    --cc=jan.kiszka@siemens.com \
    --cc=xenomai@xenomai.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.