From mboxrd@z Thu Jan  1 00:00:00 1970
From: will.deacon@arm.com (Will Deacon)
Date: Tue, 21 Feb 2012 10:52:50 +0000
Subject: [PATCH] ARM: ptrace: fix ptrace_read_user for !CONFIG_MMU
 platforms
In-Reply-To: <20120221101052.GH22562@n2100.arm.linux.org.uk>
References: <1329763029-18220-1-git-send-email-will.deacon@arm.com>
 <20120220194634.GK26840@n2100.arm.linux.org.uk>
 <201202210124.23028.paul@codesourcery.com>
 <20120221083612.GG22562@n2100.arm.linux.org.uk>
 <20120221100041.GA19696@mudshark.cambridge.arm.com>
 <20120221101052.GH22562@n2100.arm.linux.org.uk>
Message-ID: <20120221105250.GC19696@mudshark.cambridge.arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tue, Feb 21, 2012 at 10:10:52AM +0000, Russell King - ARM Linux wrote:
> On Tue, Feb 21, 2012 at 10:00:41AM +0000, Will Deacon wrote:
> > On Tue, Feb 21, 2012 at 08:36:12AM +0000, Russell King - ARM Linux wrote:
> > > Maybe no one uses a debugger for uclinux programs?
> > 
> > I confess to finding this by inspection rather than a debugging failure.
> 
> There is another explanation - that is no one in the uclinux world uses
> mainline kernels, and this bug has been fixed ages ago in some uclinux
> kernel tree.
> 
> That directly raises the question of the value of having the uclinux
> baggage in the mainline kernel if no one is using mainline kernels for
> uclinux work.  If the uclinux folk aren't willing to pass up bug fixes,
> then having it in mainline is, frankly, a waste of space.

I know the validation guys in ARM use mainline kernels for bringup on
MMU-less CPUs (ok, they have extra patches on top but these tend to be
platform-specific hacks since they're running on an RTL emulator. Plus they do
periodically rebase onto new release kernels.). Debugging tends to be at a
much lower level than GDB can provide though (i.e. waveforms), so this would
have gone un-noticed.

I think it's worth keeping the support, particularly in light of the recent
interest in M-class CPUs on the list.

Will