On Fri, Jul 5, 2024 at 1:33 PM Lorenzo Stoakes
<lorenzo.stoakes@xxxxxxxxxx> wrote:
>
> On Thu, Jul 04, 2024 at 02:27:14PM GMT, Liam R. Howlett wrote:
> > From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
> >
> > With the only caller to unmap_region() being the error path of
> > mmap_region(), the argument list can be significantly reduced.
> >
> > There is also no need to forward declare the static function any
> > longer.
> >
> > Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
> > ---
> > mm/mmap.c | 25 +++++++++----------------
> > 1 file changed, 9 insertions(+), 16 deletions(-)
> >
> > diff --git a/mm/mmap.c b/mm/mmap.c
> > index 45443a53be76..5d458c5f080e 100644
> > --- a/mm/mmap.c
> > +++ b/mm/mmap.c
> > @@ -76,11 +76,6 @@ int mmap_rnd_compat_bits __read_mostly = CONFIG_ARCH_MMAP_RND_COMPAT_BITS;
> > static bool ignore_rlimit_data;
> > core_param(ignore_rlimit_data, ignore_rlimit_data, bool, 0644);
> >
> > -static void unmap_region(struct mm_struct *mm, struct ma_state *mas,
> > - struct vm_area_struct *vma, struct vm_area_struct *prev,
> > - struct vm_area_struct *next, unsigned long start,
> > - unsigned long end, unsigned long tree_end, bool mm_wr_locked);
> > -
> > static pgprot_t vm_pgprot_modify(pgprot_t oldprot, unsigned long vm_flags)
> > {
> > return pgprot_modify(oldprot, vm_get_page_prot(vm_flags));
> > @@ -2398,22 +2393,21 @@ struct vm_area_struct *expand_stack(struct mm_struct *mm, unsigned long addr)
> > *
> > * Called with the mm semaphore held.
> > */
> > -static void unmap_region(struct mm_struct *mm, struct ma_state *mas,
> > - struct vm_area_struct *vma, struct vm_area_struct *prev,
> > - struct vm_area_struct *next, unsigned long start,
> > - unsigned long end, unsigned long tree_end, bool mm_wr_locked)
> > +static void unmap_region(struct ma_state *mas, struct vm_area_struct *vma,
> > + struct vm_area_struct *prev, struct vm_area_struct *next)
> > {
> > + struct mm_struct *mm = vma->vm_mm;
> > struct mmu_gather tlb;
> > - unsigned long mt_start = mas->index;
> >
> > lru_add_drain();
> > tlb_gather_mmu(&tlb, mm);
> > update_hiwater_rss(mm);
> > - unmap_vmas(&tlb, mas, vma, start, end, tree_end, mm_wr_locked);
> > - mas_set(mas, mt_start);
>
> OK so the 'raise something in one patch only for it to be removed in the
> next' pattern continues :) more aesthetically plasing.
>
> > + unmap_vmas(&tlb, mas, vma, vma->vm_start, vma->vm_end, vma->vm_end,
> > + /* mm_wr_locked = */ true);
> > + mas_set(mas, vma->vm_end);
> > free_pgtables(&tlb, mas, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS,
> > - next ? next->vm_start : USER_PGTABLES_CEILING,
> > - mm_wr_locked);
> > + next ? next->vm_start : USER_PGTABLES_CEILING,
> > + /* mm_wr_locked = */ true);
> > tlb_finish_mmu(&tlb);
> > }
> >
> > @@ -3186,8 +3180,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
> >
> > vma_iter_set(&vmi, vma->vm_end);
> > /* Undo any partial mapping done by a device driver. */
> > - unmap_region(mm, &vmi.mas, vma, prev, next, vma->vm_start,
> > - vma->vm_end, vma->vm_end, true);
> > + unmap_region(&vmi.mas, vma, prev, next);
> > }
> > if (writable_file_mapping)
> > mapping_unmap_writable(file->f_mapping);
> > --
> > 2.43.0
> >
>
> Lovely reduction in parameters.
>
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Reviewed-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
