Re: [Xen-devel] [PATCH] Take a writer lock for mmap_sem.

To:	Hollis Blanchard <hollisb@xxxxxxxxxx>
Subject:	Re: [Xen-devel] [PATCH] Take a writer lock for mmap_sem.
From:	Keir Fraser <keir@xxxxxxxxxxxxx>
Date:	Mon, 09 Jul 2007 17:18:27 +0100
Cc:	xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, xen-ppc-devel <xen-ppc-devel@xxxxxxxxxxxxxxxxxxx>
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On 9/7/07 16:45, "Hollis Blanchard" <hollisb@xxxxxxxxxx> wrote:

> 
> My mistake, I meant to send this separately.
> 
> In 2.6.17, we did our own locking inside direct_remap_pfn_range(). In
> the current Linux tree though, the locking is done in privcmd_ioctl().
> 
> However, since direct_remap_pfn_range() is modifying the mm_struct,
> shouldn't that be a a write lock rather than a read lock?

Ah yes, agreed. All other callers seem to get this implicitly because they
are ->mmap handlers.

 -- Keir


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Re: [Xen-devel] [PATCH] Take a writer lock for mmap_sem.