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From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Michael Ellerman <mpe@ellerman.id.au>, linuxppc-dev@ozlabs.org
Subject: Re: [PATCH] powerpc: Add build-time check of ptrace PT_xx defines
Date: Thu,  7 Nov 2019 14:45:34 +1100 (AEDT)	[thread overview]
Message-ID: <477q725sMzz9sR4@ozlabs.org> (raw)
In-Reply-To: <20191030111231.22720-1-mpe@ellerman.id.au>

On Wed, 2019-10-30 at 11:12:31 UTC, Michael Ellerman wrote:
> As part of the uapi we export a lot of PT_xx defines for each register
> in struct pt_regs. These are expressed as an index from gpr[0], in
> units of unsigned long.
> 
> Currently there's nothing tying the values of those defines to the
> actual layout of the struct.
> 
> But we *don't* want to change the uapi defines to derive the PT_xx
> values based on the layout of the struct, those values are ABI and
> must never change.
> 
> Instead we want to do the reverse, make sure that the layout of the
> struct never changes vs the PT_xx defines. So add build time checks of
> that.
> 
> This probably seems paranoid, but at least once in the past someone
> has sent a patch that would have broken the ABI if it hadn't been
> spotted. Although it probably would have been detected via testing,
> it's preferable to just quash any issues at the source.
> 
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Applied to powerpc next.

https://git.kernel.org/powerpc/c/b9e0805abf2e92fc275ac5fbd8c1c9a92b00413d

cheers

      parent reply	other threads:[~2019-11-07  8:21 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-30 11:12 [PATCH] powerpc: Add build-time check of ptrace PT_xx defines Michael Ellerman
2019-10-30 11:17 ` Christophe Leroy
2019-11-07  3:45 ` Michael Ellerman [this message]

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