Re: [PATCH 2.6.33-rc6] idr: revert misallocation bug fix

From: Tejun Heo
Date: Thu Feb 11 2010 - 03:45:38 EST


Hello,

On 02/05/2010 05:58 AM, Dave Hansen wrote:
> Bah. I just ran into and bisected the X startup problem. :)
>
> Let me know when you have a proper fix. I can test on my machine for
> you.

Can you please test the following against the current mainline?

Thanks.

diff --git a/lib/idr.c b/lib/idr.c
index 1cac726..0dc7822 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -156,10 +156,12 @@ static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa)
id = (id | ((1 << (IDR_BITS * l)) - 1)) + 1;

/* if already at the top layer, we need to grow */
- if (!(p = pa[l])) {
+ if (id >= 1 << (idp->layers * IDR_BITS)) {
*starting_id = id;
return IDR_NEED_TO_GROW;
}
+ p = pa[l];
+ BUG_ON(!p);

/* If we need to go up one layer, continue the
* loop; otherwise, restart from the top.


--
tejun
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