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| author | Peter Xu <peterx@redhat.com> | 2023-01-04 17:52:06 -0500 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-01-18 17:12:53 -0800 |
| commit | a79390f5d6a78647fd70856bd42b22d994de0ba2 (patch) | |
| tree | 4b6528a12bf5bcab1ca80b47029b286f80268f0d /include/linux/hugetlb.h | |
| parent | 6b7cea90c82e104c1151fec1f3ee216997fda652 (diff) | |
| download | linux-a79390f5d6a78647fd70856bd42b22d994de0ba2.tar.gz linux-a79390f5d6a78647fd70856bd42b22d994de0ba2.tar.bz2 linux-a79390f5d6a78647fd70856bd42b22d994de0ba2.zip | |
mm/mprotect: use long for page accountings and retval
Switch to use type "long" for page accountings and retval across the whole
procedure of change_protection().
The change should have shrinked the possible maximum page number to be
half comparing to previous (ULONG_MAX / 2), but it shouldn't overflow on
any system either because the maximum possible pages touched by change
protection should be ULONG_MAX / PAGE_SIZE.
Two reasons to switch from "unsigned long" to "long":
1. It suites better on count_vm_numa_events(), whose 2nd parameter takes
a long type.
2. It paves way for returning negative (error) values in the future.
Currently the only caller that consumes this retval is change_prot_numa(),
where the unsigned long was converted to an int. Since at it, touching up
the numa code to also take a long, so it'll avoid any possible overflow
too during the int-size convertion.
Link: https://lkml.kernel.org/r/20230104225207.1066932-3-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: James Houghton <jthoughton@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux/hugetlb.h')
| -rw-r--r-- | include/linux/hugetlb.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index b6b10101bea7..e3aa336df900 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -248,7 +248,7 @@ void hugetlb_vma_lock_release(struct kref *kref); int pmd_huge(pmd_t pmd); int pud_huge(pud_t pud); -unsigned long hugetlb_change_protection(struct vm_area_struct *vma, +long hugetlb_change_protection(struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot, unsigned long cp_flags); @@ -437,7 +437,7 @@ static inline void move_hugetlb_state(struct folio *old_folio, { } -static inline unsigned long hugetlb_change_protection( +static inline long hugetlb_change_protection( struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot, unsigned long cp_flags) |