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From:   Gerald Schaefer <gerald.schaefer@linux.ibm.com>
To:     Andrew Morton <akpm@linux-foundation.org>,
        Anshuman Khandual <anshuman.khandual@arm.com>
Cc:     linux-mm <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>,
        linux-arch <linux-arch@vger.kernel.org>,
        linux-sparc <sparclinux@vger.kernel.org>,
        linux-s390 <linux-s390@vger.kernel.org>,
        Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Subject: [PATCH 0/1] mm/debug_vm_pgtable: fix alignment for pmd/pud_advanced_tests()
Date:   Tue, 25 May 2021 15:00:42 +0200
Message-Id: <20210525130043.186290-1-gerald.schaefer@linux.ibm.com>
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We sometimes see a "BUG task_struct (Not tainted): Padding overwritten"
on s390, directly after running debug_vm_pgtable. This is because of
wrong vaddr alignment in pmd/pud_advanced_tests(), leading to memory
corruption at least on s390, see patch description.

At first glance, other architectures do not seem to care about vaddr in
their xxx_get_and_clear() implementations, so they should not be affected.
One exception is sparc, where the addr is passed over to some tlb_batch
code, but I'm not sure what implication the wrongly aligned vaddr would
have in this case.

Also adding linux-arch, just to make sure.

Gerald Schaefer (1):
  mm/debug_vm_pgtable: fix alignment for pmd/pud_advanced_tests()

 mm/debug_vm_pgtable.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.25.1