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From: will.deacon@arm•com (Will Deacon)
To: linux-arm-kernel@lists•infradead.org
Subject: Support for unaligned watchpoints in arm/arm64
Date: Tue, 31 May 2016 13:38:27 +0100	[thread overview]
Message-ID: <20160531123827.GF24936@arm.com> (raw)
In-Reply-To: <CAJt8pk8FBbTVMMM45SaEs86MZOp0o6xChAsMT1sO+_Xy-GENyw@mail.gmail.com>

On Thu, May 26, 2016 at 05:04:46PM +0100, Pavel Labath wrote:
> Hello all,

Hi Pavel,

> I've been wondering if there are any plans about adding support for
> unaligned watchpoints to the kernel. It seems quite a shame that
> applications are not able not use them, even though the hardware
> should support that feature.

I'm actually coming round to the idea of ditching the perf hw_breakpoint
mechanism entirely and simply writing a ptrace back-end that can expose
the hardware features directly to userspace. The two issues with this
are:

  (1) It's a fair amount of work
  (2) We might already have users of the perf interface (including compat)

I'm really not happy with the way hw_breakpoint worked out :(

Will

  reply	other threads:[~2016-05-31 12:38 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-26 16:04 Support for unaligned watchpoints in arm/arm64 Pavel Labath
2016-05-31 12:38 ` Will Deacon [this message]
2016-06-07  6:55   ` Pratyush Anand
2016-06-07 15:17     ` Pratyush Anand
2016-06-08  0:15       ` Pavel Labath
2016-06-08  8:13         ` Pratyush Anand

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