From: Will Deacon <will.deacon@arm.com>
To: "Wang, Yalin" <Yalin.Wang@sonymobile.com>
Cc: "'linux-mmc@vger.kernel.org'" <linux-mmc@vger.kernel.org>,
"'linux-arch-owner@vger.kernel.org'"
<linux-arch-owner@vger.kernel.org>
Subject: Re: how to creat watchpoint in kernel for data access debug
Date: Mon, 16 Jun 2014 13:55:06 +0100 [thread overview]
Message-ID: <20140616125506.GD16758@arm.com> (raw)
In-Reply-To: <35FD53F367049845BC99AC72306C23D1029A27656A34@CNBJMBX05.corpusers.net>
On Thu, Jun 05, 2014 at 04:40:02AM +0100, Wang, Yalin wrote:
> Hi Will,
>
> Thanks for your point out very much ,
> I see your meaning ,
> And I do a try ,
> But Seems it can just work when you register a
> Perf event with a NULL callback function,
>
> https://git.kernel.org/cgit/linux/kernel/git/will/linux.git/tree/arch/arm/kernel/hw_breakpoint.c#n758
>
> i don't know why it design like this?
That's so that ptrace users can deal with the stepping themselves, which is
expected by programs such as GDB. Also, not all ARM CPUs have mismatch
breakpoints (e.g. ARMv6), so software emulation is required there.
Will
prev parent reply other threads:[~2014-06-16 12:55 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-23 2:50 (unknown), Wang, Yalin
2014-05-23 2:51 ` how to creat watchpoint in kernel for data access debug Wang, Yalin
2014-05-23 13:45 ` Will Deacon
2014-05-24 3:48 ` Wang, Yalin
2014-06-03 16:45 ` Will Deacon
2014-06-04 3:05 ` Wang, Yalin
2014-06-04 18:01 ` Will Deacon
2014-06-05 3:40 ` Wang, Yalin
2014-06-16 12:55 ` Will Deacon [this message]
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