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From: Xavier Roirand <roirand@adacore.com>
To: Pedro Alves <palves@redhat.com>, gdb-patches@sourceware.org
Cc: brobecker@adacore.com
Subject: Re: [RFA v2] (x86) Fix watchpoint using hardware breakpoint for some distro
Date: Wed, 21 Mar 2018 16:17:00 -0000	[thread overview]
Message-ID: <736c9dbb-4583-c425-f20f-fd3bc5cf84e8@adacore.com> (raw)
In-Reply-To: <c0d80d21-9f0e-c6b0-caaf-7b6246e83807@redhat.com>

Hello Pedro,

Le 3/20/18 à 4:11 PM, Pedro Alves a écrit :
> On 03/20/2018 02:28 PM, Xavier Roirand wrote:
> Hmm, that's TRAP_BRKPT nowadays.  What was '1' supposed to mean in
> kernels of such vintage?  What was it's symbolic name back then?

As far as I can see in header file (/usr/include/bits/siginfo.h),
this is the same value, it's:

TRAP_BRKPT = 1,		/* Process breakpoint.  */

> In the table in linux-ptrace.h, we see that modern kernels report
> TRAP_BRKPT/1 for the "single-stepping a syscall" case.  What do
> those older kernels report in that case then?

When "single-stepping" syscall, the same value (TRAP_BRKPT) is
reported.

> What do those kernels report for hardware _breakpoints_?  Is it 1 too?

Yes, I've checked this and it's 1 also.

> Wondering whether we should make GDB_ARCH_IS_TRAP_HWBKPT return
> true for 1 too...
> 
> Please provide a more complete picture.
> 

Is it enough or do you think I need to provide more info ?

> Thanks,
> Pedro Alves
> 

Regards.

  reply	other threads:[~2018-03-21 16:17 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-16 14:07 [RFA] " Xavier Roirand
2018-03-19 14:29 ` Pedro Alves
2018-03-20 14:28   ` [RFA v2] " Xavier Roirand
2018-03-20 15:11     ` Pedro Alves
2018-03-21 16:17       ` Xavier Roirand [this message]
2018-03-26 11:38         ` Pedro Alves
2018-03-27 13:19           ` Xavier Roirand

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