clang raise 'pointer-sign' warnings in __atomic_compare_exchange when passing 'uint64_t *' to parameter of type 'int64_t *' converts between pointers to integer types with different sign. Fixes: 7e6e609939a8 ("stack: add C11 atomic implementation") Signed-off-by: Phil Yang <phil.yang@arm.com> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> --- lib/librte_stack/rte_stack_lf_c11.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/librte_stack/rte_stack_lf_c11.h b/lib/librte_stack/rte_stack_lf_c11.h index a316e9a..e3b9eff 100644 --- a/lib/librte_stack/rte_stack_lf_c11.h +++ b/lib/librte_stack/rte_stack_lf_c11.h @@ -97,7 +97,7 @@ __rte_stack_lf_pop_elems(struct rte_stack_lf_list *list, return NULL; #else struct rte_stack_lf_head old_head; - uint64_t len; + int64_t len; int success; /* Reserve num elements, if available */ -- 2.7.4
> clang raise 'pointer-sign' warnings in __atomic_compare_exchange when
> passing 'uint64_t *' to parameter of type 'int64_t *' converts between
> pointers to integer types with different sign.
>
> Fixes: 7e6e609939a8 ("stack: add C11 atomic implementation")
>
> Signed-off-by: Phil Yang <phil.yang@arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
>
> ---
> lib/librte_stack/rte_stack_lf_c11.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/librte_stack/rte_stack_lf_c11.h
> b/lib/librte_stack/rte_stack_lf_c11.h
> index a316e9a..e3b9eff 100644
> --- a/lib/librte_stack/rte_stack_lf_c11.h
> +++ b/lib/librte_stack/rte_stack_lf_c11.h
> @@ -97,7 +97,7 @@ __rte_stack_lf_pop_elems(struct rte_stack_lf_list *list,
> return NULL;
> #else
> struct rte_stack_lf_head old_head;
> - uint64_t len;
> + int64_t len;
This works, but I'd prefer to keep 'len' unsigned. How about changing the definition of 'len' in struct rte_stack_lf_list to uint64_t, and in rte_stack_lf_generic.h casting it to rte_atomic64_t* when its address is passed to the rte_atomic64_...() functions?
clang raise 'pointer-sign' warnings in __atomic_compare_exchange when passing 'uint64_t *' to parameter of type 'int64_t *' converts between pointers to integer types with different sign. Fixes: 7e6e609939a8 ("stack: add C11 atomic implementation") Suggested-by: Gage Eads <gage.eads@intel.com> Signed-off-by: Phil Yang <phil.yang@arm.com> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> Reviewed-by: Gavin Hu <gavin.hu@arm.com> --- lib/librte_stack/rte_stack.h | 2 +- lib/librte_stack/rte_stack_lf_c11.h | 8 ++++---- lib/librte_stack/rte_stack_lf_generic.h | 7 ++++--- 3 files changed, 9 insertions(+), 8 deletions(-) diff --git a/lib/librte_stack/rte_stack.h b/lib/librte_stack/rte_stack.h index fe048f0..93c360c 100644 --- a/lib/librte_stack/rte_stack.h +++ b/lib/librte_stack/rte_stack.h @@ -47,7 +47,7 @@ struct rte_stack_lf_list { /** List head */ struct rte_stack_lf_head head __rte_aligned(16); /** List len */ - rte_atomic64_t len; + uint64_t len; }; /* Structure containing two lock-free LIFO lists: the stack itself and a list diff --git a/lib/librte_stack/rte_stack_lf_c11.h b/lib/librte_stack/rte_stack_lf_c11.h index a316e9a..3d677ae 100644 --- a/lib/librte_stack/rte_stack_lf_c11.h +++ b/lib/librte_stack/rte_stack_lf_c11.h @@ -26,7 +26,7 @@ __rte_stack_lf_count(struct rte_stack *s) * elements. If the mempool is near-empty to the point that this is a * concern, the user should consider increasing the mempool size. */ - return (unsigned int)__atomic_load_n(&s->stack_lf.used.len.cnt, + return (unsigned int)__atomic_load_n(&s->stack_lf.used.len, __ATOMIC_RELAXED); } @@ -78,7 +78,7 @@ __rte_stack_lf_push_elems(struct rte_stack_lf_list *list, /* Ensure the stack modifications are not reordered with respect * to the LIFO len update. */ - __atomic_add_fetch(&list->len.cnt, num, __ATOMIC_RELEASE); + __atomic_add_fetch(&list->len, num, __ATOMIC_RELEASE); #endif } @@ -101,7 +101,7 @@ __rte_stack_lf_pop_elems(struct rte_stack_lf_list *list, int success; /* Reserve num elements, if available */ - len = __atomic_load_n(&list->len.cnt, __ATOMIC_ACQUIRE); + len = __atomic_load_n(&list->len, __ATOMIC_ACQUIRE); while (1) { /* Does the list contain enough elements? */ @@ -109,7 +109,7 @@ __rte_stack_lf_pop_elems(struct rte_stack_lf_list *list, return NULL; /* len is updated on failure */ - if (__atomic_compare_exchange_n(&list->len.cnt, + if (__atomic_compare_exchange_n(&list->len, &len, len - num, 0, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE)) diff --git a/lib/librte_stack/rte_stack_lf_generic.h b/lib/librte_stack/rte_stack_lf_generic.h index 1191406..3182151 100644 --- a/lib/librte_stack/rte_stack_lf_generic.h +++ b/lib/librte_stack/rte_stack_lf_generic.h @@ -26,7 +26,8 @@ __rte_stack_lf_count(struct rte_stack *s) * elements. If the mempool is near-empty to the point that this is a * concern, the user should consider increasing the mempool size. */ - return (unsigned int)rte_atomic64_read(&s->stack_lf.used.len); + return (unsigned int)rte_atomic64_read((rte_atomic64_t *) + &s->stack_lf.used.len); } static __rte_always_inline void @@ -73,7 +74,7 @@ __rte_stack_lf_push_elems(struct rte_stack_lf_list *list, __ATOMIC_RELAXED); } while (success == 0); - rte_atomic64_add(&list->len, num); + rte_atomic64_add((rte_atomic64_t *)&list->len, num); #endif } @@ -96,7 +97,7 @@ __rte_stack_lf_pop_elems(struct rte_stack_lf_list *list, /* Reserve num elements, if available */ while (1) { - uint64_t len = rte_atomic64_read(&list->len); + uint64_t len = rte_atomic64_read((rte_atomic64_t *)&list->len); /* Does the list contain enough elements? */ if (unlikely(len < num)) -- 2.7.4
> -----Original Message-----
> From: Eads, Gage <gage.eads@intel.com>
> Sent: Saturday, June 15, 2019 3:50 AM
> To: Phil Yang (Arm Technology China) <Phil.Yang@arm.com>; dev@dpdk.org
> Cc: nd <nd@arm.com>; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>; Gavin Hu (Arm Technology China)
> <Gavin.Hu@arm.com>
> Subject: RE: [PATCH] eal/stack: fix 'pointer-sign' warning
>
> > clang raise 'pointer-sign' warnings in __atomic_compare_exchange when
> > passing 'uint64_t *' to parameter of type 'int64_t *' converts between
> > pointers to integer types with different sign.
> >
> > Fixes: 7e6e609939a8 ("stack: add C11 atomic implementation")
> >
> > Signed-off-by: Phil Yang <phil.yang@arm.com>
> > Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> >
> > ---
> > lib/librte_stack/rte_stack_lf_c11.h | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/lib/librte_stack/rte_stack_lf_c11.h
> > b/lib/librte_stack/rte_stack_lf_c11.h
> > index a316e9a..e3b9eff 100644
> > --- a/lib/librte_stack/rte_stack_lf_c11.h
> > +++ b/lib/librte_stack/rte_stack_lf_c11.h
> > @@ -97,7 +97,7 @@ __rte_stack_lf_pop_elems(struct rte_stack_lf_list
> *list,
> > return NULL;
> > #else
> > struct rte_stack_lf_head old_head;
> > - uint64_t len;
> > + int64_t len;
>
> This works, but I'd prefer to keep 'len' unsigned. How about changing the
> definition of 'len' in struct rte_stack_lf_list to uint64_t, and in
> rte_stack_lf_generic.h casting it to rte_atomic64_t* when its address is
> passed to the rte_atomic64_...() functions?
It is better I think. I have upstreamed the v2, please review it.
Thanks,
Phil
> clang raise 'pointer-sign' warnings in __atomic_compare_exchange when
> passing 'uint64_t *' to parameter of type 'int64_t *' converts between
> pointers to integer types with different sign.
>
> Fixes: 7e6e609939a8 ("stack: add C11 atomic implementation")
>
> Suggested-by: Gage Eads <gage.eads@intel.com>
> Signed-off-by: Phil Yang <phil.yang@arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Acked-By: Gage Eads <gage.eads@intel.com>
Thanks,
Gage
Title changed to "stack: fix sign of list length" (it does not belong to EAL) 18/06/2019 17:43, Eads, Gage: > > clang raise 'pointer-sign' warnings in __atomic_compare_exchange when > > passing 'uint64_t *' to parameter of type 'int64_t *' converts between > > pointers to integer types with different sign. > > > > Fixes: 7e6e609939a8 ("stack: add C11 atomic implementation") Cc: stable@dpdk.org > > Suggested-by: Gage Eads <gage.eads@intel.com> > > Signed-off-by: Phil Yang <phil.yang@arm.com> > > Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> > > Reviewed-by: Gavin Hu <gavin.hu@arm.com> > > Acked-By: Gage Eads <gage.eads@intel.com> Applied, thanks