diff options
| 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/mm.h | |
| parent | 6b7cea90c82e104c1151fec1f3ee216997fda652 (diff) | |
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/mm.h')
| -rw-r--r-- | include/linux/mm.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 329ed67edd76..4ac5ea4b584c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2132,7 +2132,7 @@ static inline bool vma_wants_manual_pte_write_upgrade(struct vm_area_struct *vma } bool can_change_pte_writable(struct vm_area_struct *vma, unsigned long addr, pte_t pte); -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, unsigned long cp_flags); extern int mprotect_fixup(struct mmu_gather *tlb, struct vm_area_struct *vma, |