From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] Make the 32-bit ARM get_user() and put_user() work for 16-bit quantities
Date: Tue, 29 Oct 2013 18:04:14 +0000 [thread overview]
Message-ID: <20131029180414.GS16735@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <1383065529-20001-1-git-send-email-wcohen@redhat.com>
On Tue, Oct 29, 2013 at 12:52:09PM -0400, William Cohen wrote:
> The 32-bit ARM does not have instructions to perform 16-bit loads or
> stores. The __get_user_asm_half and __put_user_asm_half macros
> sythesize those operations. However, in most cases the pointers
> passed into these macros are pointers to 16-bit types and the pointer
> arithmetic will end up pointing at the next 16-bit quantity rather
> than the second half (byte) of the 16-bit quantity. The macros need
> to explicitly typecast the pointers as pointers to 8-bit quantities to
> make the pointer arithmetic work out properly.
NAK.
Nothing should be making use of these macros other than the other
macros in that file; these are implementation specific helper macros.
There, the address passed as __gu_addr and __pu_addr is an 'unsigned
long' quantity, so there is no concern about pointer arithmetic; they
do not take pointers.
next prev parent reply other threads:[~2013-10-29 18:04 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-29 16:52 [PATCH] Make the 32-bit ARM get_user() and put_user() work for 16-bit quantities William Cohen
2013-10-29 17:49 ` Marc Zyngier
2013-10-29 18:04 ` Russell King - ARM Linux [this message]
2013-10-29 18:38 ` William Cohen
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=20131029180414.GS16735@n2100.arm.linux.org.uk \
--to=linux@arm.linux.org.uk \
--cc=linux-arm-kernel@lists.infradead.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;
as well as URLs for NNTP newsgroup(s).