[PATCH 2/5] powerpc/futex: GUAP support for futex ops

[LEROY Christophe]

Russell Currey <ruscur at 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

Christophe

>
> Signed-off-by: Russell Currey <ruscur at 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