Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1293415

Re: 4.4-rc5 Setting hardware breakpoint in int_ret_from_sys_call causes triple fault/reboot

Show all headers | View raw

On Dec 16, 2015 3:12 PM, "Jeff Merkey" <linux.mdb@gmail.com> wrote:
>
> Setting a hardware breakpoint at the
>
> rex64 sysret
>
> instruction at the end of int_ret_from_sys_call causes the system to
> triple fault
> and reboot when the breakpoint is triggered.  Appears to be related
> the same problem
> as the lockup.
>
> This function can be stepped over and traced through with the TRAP
> FLAG set so long as a hardware breakpoint is set somewhere in the
> function.  Otherwise upon exist the system hard hangs.  If you break
> exactly on that instruction -- reboot.   If you break a few
> instructions before it and single step through the call it works.  If
> you step through the call with no breakpoint the system hard hangs.
> Same behavior as when you try to step from inside an nmi handler.
> Looks related.

You're probably encountering the user mode RSP when SYSRET happens.

--Andy
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

4.4-rc5 Setting hardware breakpoint in int_ret_from_sys_call causes  triple fault/reboot Jeff Merkey <linux.mdb@gmail.com> - 2015-12-17 00:20 +0100
  Re: 4.4-rc5 Setting hardware breakpoint in int_ret_from_sys_call  causes triple fault/reboot Andy Lutomirski <luto@amacapital.net> - 2015-12-17 01:10 +0100
    Re: 4.4-rc5 Setting hardware breakpoint in int_ret_from_sys_call  causes triple fault/reboot Jeff Merkey <linux.mdb@gmail.com> - 2015-12-17 01:40 +0100
      Re: 4.4-rc5 Setting hardware breakpoint in int_ret_from_sys_call  causes triple fault/reboot Andy Lutomirski <luto@amacapital.net> - 2015-12-17 01:40 +0100
        Re: 4.4-rc5 Setting hardware breakpoint in int_ret_from_sys_call  causes triple fault/reboot Jeff Merkey <linux.mdb@gmail.com> - 2015-12-17 01:50 +0100
          Re: 4.4-rc5 Setting hardware breakpoint in int_ret_from_sys_call  causes triple fault/reboot Jeff Merkey <linux.mdb@gmail.com> - 2015-12-17 09:40 +0100
            Re: 4.4-rc5 Setting hardware breakpoint in int_ret_from_sys_call  causes triple fault/reboot Jeff Merkey <linux.mdb@gmail.com> - 2015-12-17 20:00 +0100
      Re: 4.4-rc5 Setting hardware breakpoint in int_ret_from_sys_call  causes triple fault/reboot Jeff Merkey <linux.mdb@gmail.com> - 2015-12-17 01:40 +0100

csiph-web