diff mbox series

[2/3] usercopy: Cast pointer to an integer once

Message ID 20220612213227.3881769-3-willy@infradead.org (mailing list archive)
State New, archived
Headers show
Series Fixes for usercopy | expand

Commit Message

Matthew Wilcox June 12, 2022, 9:32 p.m. UTC
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@infradead.org>
---
 mm/usercopy.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

Comments

Uladzislau Rezki June 13, 2022, 9:51 a.m. UTC | #1
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@infradead.org>
> ---
>  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@gmail.com>

--
Uladzislau Rezki
Kees Cook June 13, 2022, 4:20 p.m. UTC | #2
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@infradead.org>
> > ---
> >  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@gmail.com>

For the future, please put your tags ("Reviewed-by") on a separate line
or the workflow tools (b4, patchwork, etc) won't see it. :)
Uladzislau Rezki June 13, 2022, 4:27 p.m. UTC | #3
>
> For the future, please put your tags ("Reviewed-by") on a separate line
> or the workflow tools (b4, patchwork, etc) won't see it. :)
>
OK. Thanks :)
diff mbox series

Patch

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;
 	}