Messages in this thread | | | Subject | Re: [PATCH 1/5] pagemap: Modify add_to_pagemap to use copy_to_user instead of put_user. | From | Matt Mackall <> | Date | Thu, 05 Jun 2008 10:57:57 -0500 |
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On Thu, 2008-06-05 at 11:04 -0400, Thomas Tuttle wrote: > While fiddling with pagemap, I discovered a bug in add_to_pagemap. > When it is copying an entry that is not at the end of the buffer, it > uses put_user to copy a u64 into a char* buffer. The problem is that > put_user determines how much to copy based on the size of the > *destination*, not the source, so it only copied one byte. To fix > this, I replaced the call to put_user with a call to copy_to_user, as > is used when copying the last (possibly partial) PFN into the buffer.
This looks fine to me, so:
Acked-by: Matt Mackall <mpm@selenic.com>
But your 3/5 undoes this, right? So we should just take one or the other route. While I like going the simplifying route, it's not very pretty from the user interface point of view. But it does have plenty of precedent in direct-I/O-like things.
-- Mathematics is the supreme nostalgia of our time.
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