linux-kernel - Re: [PATCH 1/4] x86: Save return value from kernel

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Message-ID: <CALCETrXbdXacNJBY8uo=cRsgAFwz7h46oyLNoF+rCNRQrpKTDg@mail.gmail.com>
Date:	Sat, 21 May 2016 18:44:02 -0700
From:	Andy Lutomirski <luto@...capital.net>
To:	Brian Gerst <brgerst@...il.com>
Cc:	X86 ML <x86@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...nel.org>,
	"H. Peter Anvin" <hpa@...or.com>,
	Denys Vlasenko <dvlasenk@...hat.com>,
	Borislav Petkov <bp@...e.de>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH 1/4] x86: Save return value from kernel_thread

On Sat, May 21, 2016 at 9:04 AM, Brian Gerst <brgerst@...il.com> wrote:
> Kernel threads should always return zero on success after calling do_execve().  The
> two existing cases in the kernel (kernel_init() and call_usermodehelper_exec_async())
> correctly do this.  Save a few bytes by storing EAX/RAX instead of an immediate zero.
> Also fix the 64-bit case which should save the full 64-bits.

Does this have any additional motivation beyond cleanup and fixing an
inconsequential bug?  I.e. does the rest of your series need this?

--Andy