All of lore.kernel.org
 help / color / mirror / Atom feed
From: Anton Blanchard <anton@samba.org>
To: benh@kernel.crashing.org, paulus@samba.org, paulmck@linux.vnet.ibm.com
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] powerpc: Make 64-bit non-VMX __copy_tofrom_user bi-endian
Date: Wed, 18 Dec 2013 21:15:02 +1100	[thread overview]
Message-ID: <20131218211502.034c3eb0@kryten> (raw)
In-Reply-To: <20131218092957.4a12cbcf@kryten>


Hi,

> [ This is a rare but nasty LE issue. Most of the time we use the
> POWER7 optimised __copy_tofrom_user_power7 loop, but when it hits an
> exception we fall back to the base __copy_tofrom_user loop. - Anton ]

To try and catch any screw ups in our ppc64 memcpy and copy_tofrom_user
loops, I wrote a quick test:

http://ozlabs.org/~anton/junkcode/validate_kernel_copyloops.tar.gz

"make check" runs through all source and destination alignments for a
range of sizes. It verifies the data was copied correctly and the
redzone before and after were untouched.

It tests:

copyuser_64
copyuser_power7
memcpy_64
memcpy_power7

memcpy_64 is currently unused on LE, but I added Paul McKenney's LE
fixes regardless. copyuser_64 has the same LE fix (posted yesterday).
All loops pass the test on both LE and BE.

Anton

  reply	other threads:[~2013-12-18 10:15 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-17 22:29 [PATCH] powerpc: Make 64-bit non-VMX __copy_tofrom_user bi-endian Anton Blanchard
2013-12-18 10:15 ` Anton Blanchard [this message]
2013-12-19 13:17   ` Michael Ellerman
2013-12-24  1:02     ` Anton Blanchard
2013-12-24  3:34       ` Michael Ellerman

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=20131218211502.034c3eb0@kryten \
    --to=anton@samba.org \
    --cc=benh@kernel.crashing.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=paulus@samba.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.