From: Carsten Otte <cotte@de.ibm.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>, Jared Hulbert <jaredeh@gmail.com>,
carsteno@de.ibm.com, Andrew Morton <akpm@linux-foundation.org>,
mschwid2@linux.vnet.ibm.com, heicars2@linux.vnet.ibm.com,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org
Subject: Re: [patch 4/6] xip: support non-struct page backed memory
Date: Tue, 04 Mar 2008 10:06:42 +0100 [thread overview]
Message-ID: <47CD1122.6090807@de.ibm.com> (raw)
In-Reply-To: <alpine.LFD.1.00.0803031420430.2979@woody.linux-foundation.org>
Linus Torvalds wrote:
> Implementing a kmap_pfn() sounds like a perfectly sane idea. But why does
> it need to even be mapped into kernel space? Is it for the ELF header
> reading or something (not having looked at the patch, just reacting to the
> wrongness of using virt_to_phys())?
It needs to be mapped into kernel space to do regular file operations
other than mmap. In mm/filemap_xip.c we do access the xip memory from
kernel to fulfill sys_read/sys_write and friends [copy_from/to_user to
user's buffer].
so long,
Carsten
prev parent reply other threads:[~2008-03-04 9:07 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20080118045649.334391000@suse.de>
2008-01-18 4:56 ` [patch 4/6] xip: support non-struct page backed memory npiggin
2008-03-01 8:14 ` Jared Hulbert
2008-03-03 5:29 ` Nick Piggin
2008-03-03 8:30 ` Carsten Otte
2008-03-03 15:59 ` Jared Hulbert
2008-03-03 8:18 ` Carsten Otte
2008-03-03 15:44 ` Jared Hulbert
2008-03-03 18:40 ` Linus Torvalds
2008-03-03 19:38 ` Jared Hulbert
2008-03-03 20:04 ` Linus Torvalds
2008-03-03 20:32 ` Nick Piggin
2008-03-03 22:21 ` Linus Torvalds
2008-03-03 23:25 ` Jared Hulbert
2008-03-04 9:06 ` Carsten Otte [this message]
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