From: "H. Peter Anvin" <hpa@zytor.com>
To: Josh Poimboeuf <jpoimboe@redhat.com>, Arnd Bergmann <arnd@arndb.de>
Cc: x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Andy Lutomirski <luto@kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86: avoid warning for zero-filling .bss
Date: Thu, 17 Nov 2016 16:07:47 -0800 [thread overview]
Message-ID: <adb36672-58cb-e290-9587-99e3ec6d9f0a@zytor.com> (raw)
In-Reply-To: <20161117224445.n3nerymee5jnrq75@treble>
On 11/17/16 14:44, Josh Poimboeuf wrote:
> On Thu, Nov 17, 2016 at 11:32:30PM +0100, Arnd Bergmann wrote:
>> On Thursday, November 17, 2016 3:02:48 PM CET Josh Poimboeuf wrote:
>>> On Wed, Nov 16, 2016 at 03:17:09PM +0100, Arnd Bergmann wrote:
>>>> The latest binutils are warning about a .fill directive with an explicit
>>>> value in a .bss section:
>>>>
>>>> arch/x86/kernel/head_32.S: Assembler messages:
>>>> arch/x86/kernel/head_32.S:677: Warning: ignoring fill value in section `.bss..page_aligned'
>>>> arch/x86/kernel/head_32.S:679: Warning: ignoring fill value in section `.bss..page_aligned'
>>>>
>>>> This comes from the 'ENTRY()' macro padding the space between the symbols
>>>> with 'nop'. Open-coding the .globl directive without the padding
>>>> avoids that warning.
>>>
>>> How is there space between the symbols? Aren't they already aligned?
>>
>> My understanding is that they are aligned, it's just that gas complains
>> about the .align directive with a nonzero fill value.
>
> Ah, I see now. In that case your patch looks fine to me.
>
Yes, ENTRY() is for code.
-hpa
prev parent reply other threads:[~2016-11-18 0:08 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-16 14:17 Arnd Bergmann
2016-11-17 7:19 ` [tip:x86/urgent] x86/boot: Avoid " tip-bot for Arnd Bergmann
2016-11-17 21:02 ` [PATCH] x86: avoid " Josh Poimboeuf
2016-11-17 21:19 ` hpa
2016-11-17 22:32 ` Arnd Bergmann
2016-11-17 22:44 ` Josh Poimboeuf
2016-11-18 0:07 ` H. Peter Anvin [this message]
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