diff options
| author | Peter Xu <peterx@redhat.com> | 2026-01-06 14:47:13 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-01-11 17:19:25 +0300 |
| commit | 238ff5056d392fcb1022b20966d6e1c58dade6a1 (patch) | |
| tree | 3fd0919bd233d193018cb49fa5b1dd2d9a84cd60 /include/linux | |
| parent | a6623712ba8449876f0b3de9462831523fb851e4 (diff) | |
| download | linux-238ff5056d392fcb1022b20966d6e1c58dade6a1.tar.xz | |
mm/mprotect: use long for page accountings and retval
commit a79390f5d6a78647fd70856bd42b22d994de0ba2 upstream.
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>
[ Adjust context ]
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/hugetlb.h | 4 | ||||
| -rw-r--r-- | include/linux/mm.h | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 26f2947c399d..1ddc2b1f96d5 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -233,7 +233,7 @@ 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); @@ -447,7 +447,7 @@ static inline void move_hugetlb_state(struct page *oldpage, { } -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) diff --git a/include/linux/mm.h b/include/linux/mm.h index c5720c0b7b77..97641304c455 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2148,7 +2148,7 @@ extern unsigned long move_page_tables(struct vm_area_struct *vma, #define MM_CP_UFFD_WP_ALL (MM_CP_UFFD_WP | \ MM_CP_UFFD_WP_RESOLVE) -extern unsigned long change_protection(struct mmu_gather *tlb, +extern long change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long start, unsigned long end, pgprot_t newprot, unsigned long cp_flags); |