All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: sxwjean@me.com
Cc: x86@kernel.org, linux-mm@kvack.org, Xiongwei Song <sxwjean@gmail.com>
Subject: Re: [PATCH 1/2] x86: Rename TIF_ADDR32 to TIF_32BIT
Date: Tue, 21 Sep 2021 13:50:11 +0200	[thread overview]
Message-ID: <YUnG8zy7U98wQ5b1@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20210921110252.2593542-2-sxwjean@me.com>

On Tue, Sep 21, 2021 at 07:02:51PM +0800, sxwjean@me.com wrote:
> From: Xiongwei Song <sxwjean@gmail.com>
> 
> In arm64 or powerpc or sparc, the 32 bits process in 64 bits kernel is set
> flag TIF_32BIT. However in x86, that flag name is TIF_ADDR32. This patch
> makes the flag name in x86 same as other archs.

x86 is fundamentally different here, the TIF flag does not say (nor can
it) anything about the bitness of the code running. On x86_64 a 64bit
process can run 32bit code without the kernel necessarily knowing
anything about it.

The only thing it does it limit the address range, and as such the name
is correct.



  reply	other threads:[~2021-09-21 11:51 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-21 11:02 [PATCH 0/2] Use generic code for virtual address of randomization of x86 sxwjean
2021-09-21 11:02 ` [PATCH 1/2] x86: Rename TIF_ADDR32 to TIF_32BIT sxwjean
2021-09-21 11:50   ` Peter Zijlstra [this message]
2021-09-21 14:13     ` Xiongwei Song
2021-09-21 11:02 ` [PATCH 2/2] x86/mm: Randomize va with generic arch_pick_mmap_layout() sxwjean
2021-09-21 12:02   ` Peter Zijlstra
2021-09-21 13:24 ` [PATCH 0/2] Use generic code for virtual address of randomization of x86 Kees Cook
2021-09-21 14:11   ` Xiongwei Song
2021-09-21 14:19   ` Peter Zijlstra

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=YUnG8zy7U98wQ5b1@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=linux-mm@kvack.org \
    --cc=sxwjean@gmail.com \
    --cc=sxwjean@me.com \
    --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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.