From: Richard Kuo <rkuo@codeaurora.org>
To: linasvepstas@gmail.com
Cc: linux-arch@vger.kernel.org, linux-hexagon@vger.kernel.org,
linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
Subject: Re: [PATCH 4/6] Hexagon: check to if we will overflow the signal stack
Date: Thu, 04 Apr 2013 11:58:58 -0500 [thread overview]
Message-ID: <515DB152.603@codeaurora.org> (raw)
In-Reply-To: <CAHrUA37oTkv-x5f4zZVwqjWAqvyMdwXAokw1EDBHiGv8ozWxVQ@mail.gmail.com>
On 04/04/2013 11:25 AM, Linas Vepstas wrote:
> On 3 April 2013 19:02, Richard Kuo <rkuo@codeaurora.org> wrote:
>
>> + /* check if we would overflow the alt stack */
>> + if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
>> + return (void __user __force *)-1UL;
> I found the !likely construction confusing, as its doing both a
> 'unlikely' (right?) and inverting the argument. It seems clearer,
> to idiots like me, to write this as:
>
> if (on_sig_stack(sp) && unlikely(!on_sig_stack(sp - frame_size)))
>
> since where checking for overflow, and its unlikely that the overflow happened.
>
> -- Linas
I'm not sure if putting a double negative in there will make it less not
easy to understand...
--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation
next prev parent reply other threads:[~2013-04-04 16:58 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-04 0:02 [PATCH 0/6] Hexagon: various signal and return path cleanups Richard Kuo
2013-04-04 0:02 ` [PATCH 1/6] Hexagon: Signal and return path fixes Richard Kuo
2013-04-04 0:02 ` [PATCH 2/6] Hexagon: fix up int enable/disable at ret_from_fork Richard Kuo
2013-04-04 0:02 ` [PATCH 3/6] Hexagon: use correct work mask when checking for more work Richard Kuo
2013-04-04 0:02 ` [PATCH 4/6] Hexagon: check to if we will overflow the signal stack Richard Kuo
2013-04-04 16:25 ` Linas Vepstas
2013-04-04 16:58 ` Richard Kuo [this message]
2013-04-04 0:02 ` [PATCH 5/6] Hexagon: break up user fn/arg register setting Richard Kuo
2013-04-04 0:02 ` [PATCH 6/6] Hexagon: fix psp/sp macro Richard Kuo
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