Re: [PATCH] error path in setup_arg_pages() misses vm_unacct_memory()

From: Hugh Dickins
Date: Tue Sep 13 2005 - 06:21:16 EST


On Mon, 12 Sep 2005, Andrew Morton wrote:
> Kirill Korotaev <dev@xxxxx> wrote:
> >
> > This patch fixes error path in setup_arg_pages() functions, since it
> > misses vm_unacct_memory() after successful call of
> > security_vm_enough_memory(). Also it cleans up error path.
>
> Ugh. The identifier `security_vm_enough_memory()' sounds like some
> predicate which has no side-effects. Except it performs accounting. Hence
> bugs like this.
>
> It's a shame that you mixed a largeish cleanup along with a bugfix - please
> don't do that in future.
>
> Patch looks OK to me. Hugh, could you please double-check sometime?

It's a good find, and the patch looks correct to me, so far as it goes.
But I think it's the wrong patch, and incomplete: it can be done more
appropriately, more simply and more completely in insert_vm_struct itself.
I'll post a replacement patch (or admit I'm wrong) in a little while.

Hugh
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