On Fri, 2018-10-26 at 18:32 +0200, LEROY Christophe wrote:
> Russell Currey <rus...@russell.cc> a écrit :
>
> > Wrap the futex operations in GUAP locks and unlocks.
>
> Does it means futex doesn't work anymore once only patch 1 is
> applied
> ? If so, then you should split patch 1 in two parts and reorder
> patches so that guap can only be activated once all necessary
> changes
> are done. Otherwise the serie won't be bisectable
Yeah, I agree. I just wanted to remove some amount of breadth from
what already is one gigantic patch. Bisectability is more important
than that, however.
- Russell
>
> Christophe
>
> > Signed-off-by: Russell Currey <rus...@russell.cc>
> > ---
> > arch/powerpc/include/asm/futex.h | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/arch/powerpc/include/asm/futex.h
> > b/arch/powerpc/include/asm/futex.h
> > index 94542776a62d..3aed640ee9ef 100644
> > --- a/arch/powerpc/include/asm/futex.h
> > +++ b/arch/powerpc/include/asm/futex.h
> > @@ -35,6 +35,7 @@ static inline int
> > arch_futex_atomic_op_inuser(int
> > op, int oparg, int *oval,
> > {
> > int oldval = 0, ret;
> >
> > + unlock_user_access();
> > pagefault_disable();
> >
> > switch (op) {
> > @@ -62,6 +63,7 @@ static inline int
> > arch_futex_atomic_op_inuser(int
> > op, int oparg, int *oval,
> > if (!ret)
> > *oval = oldval;
> >
> > + lock_user_access();
> > return ret;
> > }
> >
> > @@ -75,6 +77,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32
> > __user *uaddr,
> > if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
> > return -EFAULT;
> >
> > + unlock_user_access();
> > __asm__ __volatile__ (
> > PPC_ATOMIC_ENTRY_BARRIER
> > "1: lwarx %1,0,%3 # futex_atomic_cmpxchg_inatomic\n\
> > @@ -95,6 +98,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32
> > __user *uaddr,
> > : "cc", "memory");
> >
> > *uval = prev;
> > + lock_user_access();
> > return ret;
> > }
> >
> > --
> > 2.19.1
>
>
