Messages in this thread |  | | From | Todd Kjos <> | Date | Sat, 23 Apr 2022 08:43:00 -0700 | Subject | Re: [PATCH 1/3] binder: Use memset_page() in binder_alloc_clear_buf() |
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On Sat, Apr 23, 2022 at 3:24 AM Fabio M. De Francesco <fmdefrancesco@gmail.com> wrote: > > The use of kmap() is being deprecated in favor of kmap_local_page() > where it is feasible. With kmap_local_page(), the mapping is per > thread, CPU local and not globally visible. > > binder_alloc_clear_buf() is a function where the use of kmap_local_page() > in place of kmap() is correctly suited because the mapping is local to the > thread. > > Therefore, use kmap_local_page() / kunmap_local() but, instead of open > coding these two functions and adding a memset() of the virtual address > of the mapping, prefer memset_page(). > > Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Acked-by: Todd Kjos <tkjos@google.com>
> --- > drivers/android/binder_alloc.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c > index 2ac1008a5f39..0b3f2f569053 100644 > --- a/drivers/android/binder_alloc.c > +++ b/drivers/android/binder_alloc.c > @@ -1175,14 +1175,11 @@ static void binder_alloc_clear_buf(struct binder_alloc *alloc, > unsigned long size; > struct page *page; > pgoff_t pgoff; > - void *kptr; > > page = binder_alloc_get_page(alloc, buffer, > buffer_offset, &pgoff); > size = min_t(size_t, bytes, PAGE_SIZE - pgoff); > - kptr = kmap(page) + pgoff; > - memset(kptr, 0, size); > - kunmap(page); > + memset_page(page, pgoff, 0, size); > bytes -= size; > buffer_offset += size; > } > -- > 2.34.1 >
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