This is a note to let you know that I've just added the patch titled
Resource: fix wrong resource window calculation
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
resource-fix-wrong-resource-window-calculation.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 47ea91b4052d9e94b9dca5d7a3d947fbebd07ba9 Mon Sep 17 00:00:00 2001
From: Ram Pai <[email protected]>
Date: Thu, 22 Sep 2011 15:48:58 +0800
Subject: Resource: fix wrong resource window calculation
From: Ram Pai <[email protected]>
commit 47ea91b4052d9e94b9dca5d7a3d947fbebd07ba9 upstream.
__find_resource() incorrectly returns a resource window which overlaps
an existing allocated window. This happens when the parent's
resource-window spans 0x00000000 to 0xffffffff and is entirely allocated
to all its children resource-windows.
__find_resource() looks for gaps in resource allocation among the
children resource windows. When it encounters the last child window it
blindly tries the range next to one allocated to the last child. Since
the last child's window ends at 0xffffffff the calculation overflows,
leading the algorithm to believe that any window in the range 0x0000000
to 0xfffffff is available for allocation. This leads to a conflicting
window allocation.
Michal Ludvig reported this issue seen on his platform. The following
patch fixes the problem and has been verified by Michal. I believe this
bug has been there for ages. It got exposed by git commit 2bbc6942273b
("PCI : ability to relocate assigned pci-resources")
Signed-off-by: Ram Pai <[email protected]>
Tested-by: Michal Ludvig <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Cc: Herton Ronaldo Krzesinski <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
kernel/resource.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -419,6 +419,9 @@ static int __find_resource(struct resour
else
tmp.end = root->end;
+ if (tmp.end < tmp.start)
+ goto next;
+
resource_clip(&tmp, constraint->min, constraint->max);
arch_remove_reservations(&tmp);
@@ -436,8 +439,10 @@ static int __find_resource(struct resour
return 0;
}
}
- if (!this)
+
+next: if (!this || this->end == root->end)
break;
+
if (this != old)
tmp.start = this->end + 1;
this = this->sibling;
Patches currently in stable-queue which might be from [email protected] are
queue-3.0/pci-ability-to-relocate-assigned-pci-resources.patch
queue-3.0/resource-fix-wrong-resource-window-calculation.patch
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