* Pedro Falcato <pedro.falcato@xxxxxxxxx> [240816 20:19]:
> Avoid taking an extra trip down the mmap tree by checking the vmas
> directly. mprotect (per POSIX) tolerates partial failure.
>
> Signed-off-by: Pedro Falcato <pedro.falcato@xxxxxxxxx>
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
> ---
> mm/mprotect.c | 12 +++---------
> 1 file changed, 3 insertions(+), 9 deletions(-)
>
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index 446f8e5f10d9..0c5d6d06107d 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -611,6 +611,9 @@ mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb,
> unsigned long charged = 0;
> int error;
>
> + if (!can_modify_vma(vma))
> + return -EPERM;
> +
> if (newflags == oldflags) {
> *pprev = vma;
> return 0;
> @@ -769,15 +772,6 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
> }
> }
>
> - /*
> - * checking if memory is sealed.
> - * can_modify_mm assumes we have acquired the lock on MM.
> - */
> - if (unlikely(!can_modify_mm(current->mm, start, end))) {
> - error = -EPERM;
> - goto out;
> - }
> -
> prev = vma_prev(&vmi);
> if (start > vma->vm_start)
> prev = vma;
>
> --
> 2.46.0
>
