On Mon, Jun 13, 2022 at 11:51:24AM +0200, Uladzislau Rezki wrote:
> On Sun, Jun 12, 2022 at 10:32:26PM +0100, Matthew Wilcox (Oracle) wrote:
> > Get rid of a lot of annoying casts by setting 'addr' once at the top
> > of the function.
> >
> > Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> > ---
> > mm/usercopy.c | 11 ++++++-----
> > 1 file changed, 6 insertions(+), 5 deletions(-)
> >
> > diff --git a/mm/usercopy.c b/mm/usercopy.c
> > index fdd1bed3b90a..31deee7dd2f5 100644
> > --- a/mm/usercopy.c
> > +++ b/mm/usercopy.c
> > @@ -161,19 +161,20 @@ static inline void check_bogus_address(const unsigned long ptr, unsigned long n,
> > static inline void check_heap_object(const void *ptr, unsigned long n,
> > bool to_user)
> > {
> > + uintptr_t addr = (uintptr_t)ptr;
> > struct folio *folio;
> >
> > if (is_kmap_addr(ptr)) {
> > - unsigned long page_end = (unsigned long)ptr | (PAGE_SIZE - 1);
> > + unsigned long page_end = addr | (PAGE_SIZE - 1);
> >
> > - if ((unsigned long)ptr + n - 1 > page_end)
> > + if (addr + n - 1 > page_end)
> > usercopy_abort("kmap", NULL, to_user,
> > offset_in_page(ptr), n);
> > return;
> > }
> >
> > if (is_vmalloc_addr(ptr)) {
> > - struct vmap_area *area = find_vmap_area((unsigned long)ptr);
> > + struct vmap_area *area = find_vmap_area(addr);
> > unsigned long offset;
> >
> > if (!area) {
> > @@ -183,8 +184,8 @@ static inline void check_heap_object(const void *ptr, unsigned long n,
> >
> > /* XXX: We should also abort for free vmap_areas */
> >
> > - offset = (unsigned long)ptr - area->va_start;
> > - if ((unsigned long)ptr + n > area->va_end)
> > + offset = addr - area->va_start;
> > + if (addr + n > area->va_end)
> > usercopy_abort("vmalloc", NULL, to_user, offset, n);
> > return;
> > }
> > --
> > 2.35.1
> >
> Looks good to me: Reviewed-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
For the future, please put your tags ("Reviewed-by") on a separate line
or the workflow tools (b4, patchwork, etc) won't see it. :)
--
Kees Cook
