On Thu, Nov 15, 2018 at 6:59 AM Palmer Dabbelt <pal...@sifive.com> wrote:
>
> On Wed, 14 Nov 2018 16:27:55 PST (-0800), Olof Johansson wrote:
> > Sparse highlighted it, and appears to be a pure bug (from vs to).
> >
> > ./arch/riscv/include/asm/uaccess.h:403:35: warning: incorrect type in
> > argument 1 (different address spaces)
> > ./arch/riscv/include/asm/uaccess.h:403:39: warning: incorrect type in
> > argument 2 (different address spaces)
> > ./arch/riscv/include/asm/uaccess.h:409:37: warning: incorrect type in
> > argument 1 (different address spaces)
> > ./arch/riscv/include/asm/uaccess.h:409:41: warning: incorrect type in
> > argument 2 (different address spaces)
> >
> > Signed-off-by: Olof Johansson <o...@lixom.net>
> > ---
> > arch/riscv/include/asm/uaccess.h | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/uaccess.h
> > b/arch/riscv/include/asm/uaccess.h
> > index 473cfc84e412f..8c3e3e3c8be12 100644
> > --- a/arch/riscv/include/asm/uaccess.h
> > +++ b/arch/riscv/include/asm/uaccess.h
> > @@ -400,13 +400,13 @@ extern unsigned long __must_check
> > __asm_copy_from_user(void *to,
> > static inline unsigned long
> > raw_copy_from_user(void *to, const void __user *from, unsigned long n)
> > {
> > - return __asm_copy_to_user(to, from, n);
> > + return __asm_copy_from_user(to, from, n);
> > }
> >
> > static inline unsigned long
> > raw_copy_to_user(void __user *to, const void *from, unsigned long n)
> > {
> > - return __asm_copy_from_user(to, from, n);
> > + return __asm_copy_to_user(to, from, n);
> > }
> >
> > extern long strncpy_from_user(char *dest, const char __user *src, long
> > count);
>
> Oh, no idea how I missed that one. This looks like it's been in for a long
> time, so I'm surprised anything works at all!
Actually, it boils down to a memcpy either way, it's just that
exceptions and access control isn't handled right. So as long as you
always do valid copying you'll luck out.
> I'm going to add a stable CC and PR this to Linus this week, assuming I get
> some time to at least give it a minimal test.
>
> Thanks for catching this!
Cool, sounds good.
-Olof
