This is a note to let you know that I've just added the patch titled
powerpc/mm/dax: Fix the condition when checking if altmap vmemap can cross-boundary
to the 5.15-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:
powerpc-mm-dax-fix-the-condition-when-checking-if-al.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c3ce08eea95b9cb1a7b9d31c50dff775617344bf
Author: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Date: Fri Jun 16 16:38:15 2023 +0530
powerpc/mm/dax: Fix the condition when checking if altmap vmemap can cross-boundary
[ Upstream commit c8eebc4a99f15280654f23e914e746c40a516e50 ]
Without this fix, the last subsection vmemmap can end up in memory even if
the namespace is created with -M mem and has sufficient space in the altmap
area.
Fixes: cf387d9644d8 ("libnvdimm/altmap: Track namespace boundaries in altmap")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Tested-by: Sachin Sant <sachinp@xxxxxxxxxxxxx <mailto:sachinp@xxxxxxxxxxxxx>>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://msgid.link/20230616110826.344417-6-aneesh.kumar@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index 386be136026e8..b76cd49d521b9 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -188,7 +188,7 @@ static bool altmap_cross_boundary(struct vmem_altmap *altmap, unsigned long star
unsigned long nr_pfn = page_size / sizeof(struct page);
unsigned long start_pfn = page_to_pfn((struct page *)start);
- if ((start_pfn + nr_pfn) > altmap->end_pfn)
+ if ((start_pfn + nr_pfn - 1) > altmap->end_pfn)
return true;
if (start_pfn < altmap->base_pfn)
