Date: Wed, 12 Feb 2014 15:14:37 -0800 (PST)
From: David Rientjes <rientjes@google.com>
To: Paul Gortmaker <paul.gortmaker@windriver.com>
cc: linux-kernel@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        x86@kernel.org
Subject: Re: [PATCH] x86: fix two sparse warnings in early boot string
 handling
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On Wed, 12 Feb 2014, Paul Gortmaker wrote:

> > This means there is a strstr() prototype that is visible to 
> > drivers/firmware/efi/efi-stub-helper.c but fails at linkage because you've 
> > removed the definition. 
> 
> Yes, because you suggested removal when you said, in what is
> now deleted context text:
> 
>  "I don't see why you can't remove strstr() in 
>  arch/x86/boot/string.c entirely.  What breaks?"
> 
> The above answers your question. The eboot.c breaks.  So
> we can't remove strstr.
> 

Thanks.

> > So, again, why would you add a duplicate 
> > prototype with your patch?
> 
> I'm sure there is an implicit path to <linux/string.h>
> which allows eboot.c to see a prototype and hence compile.
> 

Nope, linux/string.h only declares the prototype when 
#ifndef __HAVE_ARCH_STRSTR and the 32-bit x86 declaration in 
include/asm/string_32.h properly does #define __HAVE_ARCH_STRSTR.

There's also no #include ordering issue here since linux/string.h does 
#include <asm/string.h> first.

If you had a real problem here, the build would break.  So I'll renew my 
original objection: I don't think it's acceptable to add unneeded 
prototypes because sparse doesn't understand this.
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