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Revision e700898fa075c69b3ae02b702ab57fb75e1a82ec authored by Mike Kravetz on 12 December 2022, 23:50:41 UTC, committed by Andrew Morton on 21 December 2022, 22:31:52 UTC 
hugetlb: really allocate vma lock for all sharable vmas
 
Commit bbff39cc6cbc ("hugetlb: allocate vma lock for all sharable vmas")
removed the pmd sharable checks in the vma lock helper routines.  However,
it left the functional version of helper routines behind #ifdef
CONFIG_ARCH_WANT_HUGE_PMD_SHARE.  Therefore, the vma lock is not being
used for sharable vmas on architectures that do not support pmd sharing. 
On these architectures, a potential fault/truncation race is exposed that
could leave pages in a hugetlb file past i_size until the file is removed.

Move the functional vma lock helpers outside the ifdef, and remove the
non-functional stubs.  Since the vma lock is not just for pmd sharing,
rename the routine __vma_shareable_flags_pmd.

Link: https://lkml.kernel.org/r/20221212235042.178355-1-mike.kravetz@oracle.com
Fixes: bbff39cc6cbc ("hugetlb: allocate vma lock for all sharable vmas")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
1 parent 7ba594d
Raw File
shuffle.h 
// SPDX-License-Identifier: GPL-2.0
// Copyright(c) 2018 Intel Corporation. All rights reserved.
#ifndef _MM_SHUFFLE_H
#define _MM_SHUFFLE_H
#include <linux/jump_label.h>

#define SHUFFLE_ORDER (MAX_ORDER-1)

#ifdef CONFIG_SHUFFLE_PAGE_ALLOCATOR
DECLARE_STATIC_KEY_FALSE(page_alloc_shuffle_key);
extern void __shuffle_free_memory(pg_data_t *pgdat);
extern bool shuffle_pick_tail(void);
static inline void __meminit shuffle_free_memory(pg_data_t *pgdat)
{
	if (!static_branch_unlikely(&page_alloc_shuffle_key))
		return;
	__shuffle_free_memory(pgdat);
}

extern void __shuffle_zone(struct zone *z);
static inline void __meminit shuffle_zone(struct zone *z)
{
	if (!static_branch_unlikely(&page_alloc_shuffle_key))
		return;
	__shuffle_zone(z);
}

static inline bool is_shuffle_order(int order)
{
	if (!static_branch_unlikely(&page_alloc_shuffle_key))
		return false;
	return order >= SHUFFLE_ORDER;
}
#else
static inline bool shuffle_pick_tail(void)
{
	return false;
}

static inline void shuffle_free_memory(pg_data_t *pgdat)
{
}

static inline void shuffle_zone(struct zone *z)
{
}

static inline bool is_shuffle_order(int order)
{
	return false;
}
#endif
#endif /* _MM_SHUFFLE_H */
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