This is a note to let you know that I've just added the patch titled
mm/cma: fix cma bitmap aligned mask computing
to the 3.17-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:
mm-cma-fix-cma-bitmap-aligned-mask-computing.patch
and it can be found in the queue-3.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 68faed630fc151a7a1c4853df00fb3dcacf782b4 Mon Sep 17 00:00:00 2001
From: Weijie Yang <weijie.yang@xxxxxxxxxxx>
Date: Mon, 13 Oct 2014 15:51:03 -0700
Subject: mm/cma: fix cma bitmap aligned mask computing
From: Weijie Yang <weijie.yang@xxxxxxxxxxx>
commit 68faed630fc151a7a1c4853df00fb3dcacf782b4 upstream.
The current cma bitmap aligned mask computation is incorrect. It could
cause an unexpected alignment when using cma_alloc() if the wanted align
order is larger than cma->order_per_bit.
Take kvm for example (PAGE_SHIFT = 12), kvm_cma->order_per_bit is set to
6. When kvm_alloc_rma() tries to alloc kvm_rma_pages, it will use 15 as
the expected align value. After using the current implementation however,
we get 0 as cma bitmap aligned mask other than 511.
This patch fixes the cma bitmap aligned mask calculation.
[akpm@xxxxxxxxxxxxxxxxxxxx: coding-style fixes]
Signed-off-by: Weijie Yang <weijie.yang@xxxxxxxxxxx>
Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/cma.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -57,7 +57,9 @@ unsigned long cma_get_size(struct cma *c
static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order)
{
- return (1UL << (align_order >> cma->order_per_bit)) - 1;
+ if (align_order <= cma->order_per_bit)
+ return 0;
+ return (1UL << (align_order - cma->order_per_bit)) - 1;
}
static unsigned long cma_bitmap_maxno(struct cma *cma)
Patches currently in stable-queue which might be from weijie.yang@xxxxxxxxxxx are
queue-3.17/mm-cma-fix-cma-bitmap-aligned-mask-computing.patch
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