From: Michael Eager <eager@eagerm.com>
To: Daniel Jacobowitz <drow@false.org>
Cc: "gdb@sourceware.org" <gdb@sourceware.org>
Subject: Re: HW breakpoint on Linux x86 native
Date: Mon, 16 Jul 2012 18:17:00 -0000 [thread overview]
Message-ID: <50045AC7.1060006@eagerm.com> (raw)
In-Reply-To: <CAN9gPaENkC6J8QhL3emiqy4tvEKd4hTUhHFCUQO_bihNqq8-Sw@mail.gmail.com>
On 07/16/2012 10:32 AM, Daniel Jacobowitz wrote:
> On Mon, Jul 16, 2012 at 12:39 PM, Michael Eager <eager@eagerm.com> wrote:
>> Hi --
>>
>> I noticed that the FSF version of gdb builds without hw
>> break support for x86 native. The version of gdb distributed
>> by RedHat includes a patch to turn this feature on, with a
>> comment about gdb-6.6 compatibility.
>>
>> Can someone tell me why hw bp is not enabled by default
>> for native x86?
>
> Can you be a little more specific about what is not enabled by
> default? Hardware breakpoints are certainly supported.
In i386-linux-nat.c, _initialize_i386_linux_nat() calls
i386_use_watchpoints() which sets to_can_use_hw_breakpoint =
i386_can_use_hw_breakpoint in the target_ops returned by
linux_target(). Looks fine.
When running a local process, the target vector is different,
created by init_exec_ops() in exec.c. This defaults to
to_can_use_hw_breakpoint = reply_zero().
RH has a patch which forces the test in their gdb-7.3.1 release:
+/* Red Hat backward compatibility with gdb-6.8. */
+#define target_can_use_hardware_watchpoint(type, cnt, ot) 1
--
Michael Eager eager@eagercon.com
1960 Park Blvd., Palo Alto, CA 94306 650-325-8077
next prev parent reply other threads:[~2012-07-16 18:17 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-16 16:39 Michael Eager
2012-07-16 17:32 ` Daniel Jacobowitz
2012-07-16 18:17 ` Michael Eager [this message]
2012-07-16 18:43 ` Jan Kratochvil
2012-07-16 18:55 ` Michael Eager
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