public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Ingo Molnar <mingo@kernel.org>
To: Pingfan Liu <kernelfans@gmail.com>,
	"H. Peter Anvin" <hpa@zytor.com>, Borislav Petkov <bp@alien8.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Kees Cook <keescook@chromium.org>
Cc: x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Jordan Borgner <mail@jordan-borgner.de>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] x86/boot: move early_serial_base to .data section
Date: Tue, 7 May 2019 10:28:08 +0200	[thread overview]
Message-ID: <20190507082808.GB125993@gmail.com> (raw)
In-Reply-To: <1557208860-12846-1-git-send-email-kernelfans@gmail.com>


* Pingfan Liu <kernelfans@gmail.com> wrote:

> arch/x86/boot/compressed/head_64.S clears BSS after relocated. If early
> serial is set up before clearing BSS, the early_serial_base will be reset
> to 0.
> 
> Initializing early_serial_base as -1 to push it to .data section.

I'm wondering whether it's wise to clear the BSS after relocation to 
begin with. It already gets cleared once, and an implicit zeroing of all 
fields on kernel relocation sounds dubious to me.

Is there a strong reason for that? I.e. is there some uninitialized or 
otherwise important-to-clear data there?

Thanks,

	Ingo

  parent reply	other threads:[~2019-05-07  8:28 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-07  6:00 [PATCH 1/2] x86/boot: move early_serial_base to .data section Pingfan Liu
2019-05-07  6:01 ` [PATCH 2/2] x86/boot: push console_init forward Pingfan Liu
2019-05-07  8:28 ` Ingo Molnar [this message]
2019-05-08  4:42   ` [PATCH 1/2] x86/boot: move early_serial_base to .data section Pingfan Liu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190507082808.GB125993@gmail.com \
    --to=mingo@kernel.org \
    --cc=a.p.zijlstra@chello.nl \
    --cc=bp@alien8.de \
    --cc=hpa@zytor.com \
    --cc=keescook@chromium.org \
    --cc=kernelfans@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mail@jordan-borgner.de \
    --cc=mingo@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox