The patch titled
Subject: iommu: fix MAX_ORDER usage in __iommu_dma_alloc_pages()
has been added to the -mm mm-unstable branch. Its filename is
iommu-fix-max_order-usage-in-__iommu_dma_alloc_pages.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/iommu-fix-max_order-usage-in-__iommu_dma_alloc_pages.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Subject: iommu: fix MAX_ORDER usage in __iommu_dma_alloc_pages()
Date: Wed, 15 Mar 2023 14:31:32 +0300
MAX_ORDER is not inclusive: the maximum allocation order buddy allocator
can deliver is MAX_ORDER-1.
Fix MAX_ORDER usage in __iommu_dma_alloc_pages().
Also use GENMASK() instead of hard to read "(2U << order) - 1" magic.
Link: https://lkml.kernel.org/r/20230315113133.11326-10-kirill.shutemov@xxxxxxxxxxxxxxx
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Acked-by: Robin Murphy <robin.murphy@xxxxxxx>
Reviewed-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/iommu/dma-iommu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/iommu/dma-iommu.c~iommu-fix-max_order-usage-in-__iommu_dma_alloc_pages
+++ a/drivers/iommu/dma-iommu.c
@@ -736,7 +736,7 @@ static struct page **__iommu_dma_alloc_p
struct page **pages;
unsigned int i = 0, nid = dev_to_node(dev);
- order_mask &= (2U << MAX_ORDER) - 1;
+ order_mask &= GENMASK(MAX_ORDER - 1, 0);
if (!order_mask)
return NULL;
@@ -756,7 +756,7 @@ static struct page **__iommu_dma_alloc_p
* than a necessity, hence using __GFP_NORETRY until
* falling back to minimum-order allocations.
*/
- for (order_mask &= (2U << __fls(count)) - 1;
+ for (order_mask &= GENMASK(__fls(count), 0);
order_mask; order_mask &= ~order_size) {
unsigned int order = __fls(order_mask);
gfp_t alloc_flags = gfp;
_
Patches currently in -mm which might be from kirill.shutemov@xxxxxxxxxxxxxxx are
sparc-mm-fix-max_order-usage-in-tsb_grow.patch
um-fix-max_order-usage-in-linux_main.patch
floppy-fix-max_order-usage.patch
drm-i915-fix-max_order-usage-in-i915_gem_object_get_pages_internal.patch
genwqe-fix-max_order-usage.patch
perf-core-fix-max_order-usage-in-rb_alloc_aux_page.patch
mm-page_reporting-fix-max_order-usage-in-page_reporting_register.patch
mm-slub-fix-max_order-usage-in-calculate_order.patch
iommu-fix-max_order-usage-in-__iommu_dma_alloc_pages.patch
mm-treewide-redefine-max_order-sanely.patch
