-Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
ready to enable it globally.
Use the `struct_group_tagged()` helper to separate the flexible array
from the rest of the members in flexible `struct cm_work`, and avoid
embedding the flexible-array member in `struct cm_timewait_info`.
Also, use `container_of()` to retrieve a pointer to the flexible
structure.
So, with these changes, fix the following warning:
drivers/infiniband/core/cm.c:196:24: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/infiniband/core/cm.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)
diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index bf0df6ee4f78..80c87085499c 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -182,18 +182,21 @@ struct cm_av {
};
struct cm_work {
- struct delayed_work work;
- struct list_head list;
- struct cm_port *port;
- struct ib_mad_recv_wc *mad_recv_wc; /* Received MADs */
- __be32 local_id; /* Established / timewait */
- __be32 remote_id;
- struct ib_cm_event cm_event;
+ /* New members must be added within the struct_group() macro below. */
+ struct_group_tagged(cm_work_hdr, hdr,
+ struct delayed_work work;
+ struct list_head list;
+ struct cm_port *port;
+ struct ib_mad_recv_wc *mad_recv_wc; /* Received MADs */
+ __be32 local_id; /* Established / timewait */
+ __be32 remote_id;
+ struct ib_cm_event cm_event;
+ );
struct sa_path_rec path[];
};
struct cm_timewait_info {
- struct cm_work work;
+ struct cm_work_hdr work;
struct list_head list;
struct rb_node remote_qp_node;
struct rb_node remote_id_node;
@@ -3440,7 +3443,7 @@ static int cm_timewait_handler(struct cm_work *work)
struct cm_timewait_info *timewait_info;
struct cm_id_private *cm_id_priv;
- timewait_info = container_of(work, struct cm_timewait_info, work);
+ timewait_info = container_of(&work->hdr, struct cm_timewait_info, work);
spin_lock_irq(&cm.lock);
list_del(&timewait_info->list);
spin_unlock_irq(&cm.lock);
--
2.34.1
On Mon, Mar 25, 2024 at 02:24:07PM -0600, Gustavo A. R. Silva wrote:
> -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
> ready to enable it globally.
>
> Use the `struct_group_tagged()` helper to separate the flexible array
> from the rest of the members in flexible `struct cm_work`, and avoid
> embedding the flexible-array member in `struct cm_timewait_info`.
>
> Also, use `container_of()` to retrieve a pointer to the flexible
> structure.
>
> So, with these changes, fix the following warning:
> drivers/infiniband/core/cm.c:196:24: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> drivers/infiniband/core/cm.c | 21 ++++++++++++---------
> 1 file changed, 12 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
> index bf0df6ee4f78..80c87085499c 100644
> --- a/drivers/infiniband/core/cm.c
> +++ b/drivers/infiniband/core/cm.c
> @@ -182,18 +182,21 @@ struct cm_av {
> };
>
> struct cm_work {
> - struct delayed_work work;
> - struct list_head list;
> - struct cm_port *port;
> - struct ib_mad_recv_wc *mad_recv_wc; /* Received MADs */
> - __be32 local_id; /* Established / timewait */
> - __be32 remote_id;
> - struct ib_cm_event cm_event;
> + /* New members must be added within the struct_group() macro below. */
> + struct_group_tagged(cm_work_hdr, hdr,
> + struct delayed_work work;
> + struct list_head list;
> + struct cm_port *port;
> + struct ib_mad_recv_wc *mad_recv_wc; /* Received MADs */
> + __be32 local_id; /* Established / timewait */
> + __be32 remote_id;
> + struct ib_cm_event cm_event;
> + );
> struct sa_path_rec path[];
> };
I didn't look, but does it make more sense to break out the path side
into its own type and avoid the struct_group_tagged? I seem to
remember only one thing used it.
Jason
On 3/25/24 16:47, Jason Gunthorpe wrote:
> On Mon, Mar 25, 2024 at 02:24:07PM -0600, Gustavo A. R. Silva wrote:
>> -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
>> ready to enable it globally.
>>
>> Use the `struct_group_tagged()` helper to separate the flexible array
>> from the rest of the members in flexible `struct cm_work`, and avoid
>> embedding the flexible-array member in `struct cm_timewait_info`.
>>
>> Also, use `container_of()` to retrieve a pointer to the flexible
>> structure.
>>
>> So, with these changes, fix the following warning:
>> drivers/infiniband/core/cm.c:196:24: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>>
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>> ---
>> drivers/infiniband/core/cm.c | 21 ++++++++++++---------
>> 1 file changed, 12 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
>> index bf0df6ee4f78..80c87085499c 100644
>> --- a/drivers/infiniband/core/cm.c
>> +++ b/drivers/infiniband/core/cm.c
>> @@ -182,18 +182,21 @@ struct cm_av {
>> };
>>
>> struct cm_work {
>> - struct delayed_work work;
>> - struct list_head list;
>> - struct cm_port *port;
>> - struct ib_mad_recv_wc *mad_recv_wc; /* Received MADs */
>> - __be32 local_id; /* Established / timewait */
>> - __be32 remote_id;
>> - struct ib_cm_event cm_event;
>> + /* New members must be added within the struct_group() macro below. */
>> + struct_group_tagged(cm_work_hdr, hdr,
>> + struct delayed_work work;
>> + struct list_head list;
>> + struct cm_port *port;
>> + struct ib_mad_recv_wc *mad_recv_wc; /* Received MADs */
>> + __be32 local_id; /* Established / timewait */
>> + __be32 remote_id;
>> + struct ib_cm_event cm_event;
>> + );
>> struct sa_path_rec path[];
>> };
>
> I didn't look, but does it make more sense to break out the path side
> into its own type and avoid the struct_group_tagged? I seem to
> remember only one thing used it.
>
I thought about that, but I'd have to change the parameter type of
`static int cm_timewait_handler(struct cm_work *work)`, and that would
imply also modifying the internals of function `cm_work_handler()` (and
then I didn't look much into it). So, the `struct_group_tagged()`
strategy is in general more cleaner and straightforward.
--
Gustavo
On Mon, Mar 25, 2024 at 08:57:08PM -0600, Gustavo A. R. Silva wrote:
>
>
> On 3/25/24 16:47, Jason Gunthorpe wrote:
> > On Mon, Mar 25, 2024 at 02:24:07PM -0600, Gustavo A. R. Silva wrote:
> > > -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
> > > ready to enable it globally.
> > >
> > > Use the `struct_group_tagged()` helper to separate the flexible array
> > > from the rest of the members in flexible `struct cm_work`, and avoid
> > > embedding the flexible-array member in `struct cm_timewait_info`.
> > >
> > > Also, use `container_of()` to retrieve a pointer to the flexible
> > > structure.
> > >
> > > So, with these changes, fix the following warning:
> > > drivers/infiniband/core/cm.c:196:24: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> > >
> > > Signed-off-by: Gustavo A. R. Silva <[email protected]>
> > > ---
> > > drivers/infiniband/core/cm.c | 21 ++++++++++++---------
> > > 1 file changed, 12 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
> > > index bf0df6ee4f78..80c87085499c 100644
> > > --- a/drivers/infiniband/core/cm.c
> > > +++ b/drivers/infiniband/core/cm.c
> > > @@ -182,18 +182,21 @@ struct cm_av {
> > > };
> > > struct cm_work {
> > > - struct delayed_work work;
> > > - struct list_head list;
> > > - struct cm_port *port;
> > > - struct ib_mad_recv_wc *mad_recv_wc; /* Received MADs */
> > > - __be32 local_id; /* Established / timewait */
> > > - __be32 remote_id;
> > > - struct ib_cm_event cm_event;
> > > + /* New members must be added within the struct_group() macro below. */
> > > + struct_group_tagged(cm_work_hdr, hdr,
> > > + struct delayed_work work;
> > > + struct list_head list;
> > > + struct cm_port *port;
> > > + struct ib_mad_recv_wc *mad_recv_wc; /* Received MADs */
> > > + __be32 local_id; /* Established / timewait */
> > > + __be32 remote_id;
> > > + struct ib_cm_event cm_event;
> > > + );
> > > struct sa_path_rec path[];
> > > };
> >
> > I didn't look, but does it make more sense to break out the path side
> > into its own type and avoid the struct_group_tagged? I seem to
> > remember only one thing used it.
> >
>
> I thought about that, but I'd have to change the parameter type of
> `static int cm_timewait_handler(struct cm_work *work)`, and that would
> imply also modifying the internals of function `cm_work_handler()` (and
> then I didn't look much into it).
So let's try to invest in this direction first before we add obfuscation
with magic words to the code.
Thanks
> So, the `struct_group_tagged()` strategy is in general more cleaner and straightforward.
>
> --
> Gustavo
>
>