From: Gareth McMullin <gareth@blacksphere.co.nz>
To: Joel Brobecker <brobecker@adacore.com>
Cc: gdb@sourceware.org
Subject: Re: question about ARM watchpoints
Date: Thu, 04 Sep 2014 22:37:00 -0000 [thread overview]
Message-ID: <CAL8qUbqTyBAkrXnN=DxmL5d3h5nwnfv=dO-vDdqxB+kVrZNzSQ@mail.gmail.com> (raw)
In-Reply-To: <20140901085743.GG4981@adacore.com>
Hi
On Mon, Sep 1, 2014 at 8:57 PM, Joel Brobecker <brobecker@adacore.com> wrote:
> Everything works pretty well, except that we noticed that GDB stops
> 2 instructions after the variable update, rather than at the next
> instruction.
I get the same behaviour on the Black Magic Probe on ARMv7-M.
The DWT halts the core on the instruction after the address match.
> The question then becomes: Is QEMU behaving correctly, in which
> case we should be modifying GDB, or is QEMU signaling GDB too
> late, in which case we should be fixing QEMU?
What QEMU is doing is the same as the hardware DWT block, so I'd
say this is the correct behaviour. The fix should be in GDB. Working
around this in QEMU would leave all hardware based implementations
broken.
Regards,
Gareth
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Black Sphere Technologies Ltd.
Web: www.blacksphere.co.nz
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next prev parent reply other threads:[~2014-09-04 22:37 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-01 8:57 Joel Brobecker
2014-09-04 22:37 ` Gareth McMullin [this message]
2014-09-05 0:28 ` Pedro Alves
2014-09-05 3:51 ` Joel Brobecker
2014-09-05 8:17 ` Pedro Alves
2014-09-05 9:46 ` Pedro Alves
2014-09-16 11:18 ` Pedro Alves
2014-09-16 12:13 ` Joel Brobecker
2014-09-16 13:21 ` Pedro Alves
[not found] ` <87ioktav6i.fsf@codesourcery.com>
2014-09-15 13:02 ` Joel Brobecker
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