* [PATCH][next] IB/rdmavt: Use struct_size() helper
@ 2019-05-29 15:12 Gustavo A. R. Silva
2019-05-30 18:26 ` Dennis Dalessandro
2019-05-30 18:43 ` Jason Gunthorpe
0 siblings, 2 replies; 4+ messages in thread
From: Gustavo A. R. Silva @ 2019-05-29 15:12 UTC (permalink / raw)
To: Dennis Dalessandro, Mike Marciniszyn, Doug Ledford, Jason Gunthorpe
Cc: linux-rdma, linux-kernel, Gustavo A. R. Silva
Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.
So, replace the following form:
sizeof(struct rvt_sge) * init_attr->cap.max_send_sge + sizeof(struct rvt_swqe)
with:
struct_size(swq, sg_list, init_attr->cap.max_send_sge)
and so on...
Also, notice that variable size is unnecessary, hence it is removed.
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
drivers/infiniband/sw/rdmavt/qp.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c
index 31a2e65e4906..a60f5faea198 100644
--- a/drivers/infiniband/sw/rdmavt/qp.c
+++ b/drivers/infiniband/sw/rdmavt/qp.c
@@ -988,9 +988,7 @@ struct ib_qp *rvt_create_qp(struct ib_pd *ibpd,
case IB_QPT_UC:
case IB_QPT_RC:
case IB_QPT_UD:
- sz = sizeof(struct rvt_sge) *
- init_attr->cap.max_send_sge +
- sizeof(struct rvt_swqe);
+ sz = struct_size(swq, sg_list, init_attr->cap.max_send_sge);
swq = vzalloc_node(array_size(sz, sqsize), rdi->dparms.node);
if (!swq)
return ERR_PTR(-ENOMEM);
--
2.21.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH][next] IB/rdmavt: Use struct_size() helper
2019-05-29 15:12 [PATCH][next] IB/rdmavt: Use struct_size() helper Gustavo A. R. Silva
@ 2019-05-30 18:26 ` Dennis Dalessandro
2019-05-30 18:29 ` Jason Gunthorpe
2019-05-30 18:43 ` Jason Gunthorpe
1 sibling, 1 reply; 4+ messages in thread
From: Dennis Dalessandro @ 2019-05-30 18:26 UTC (permalink / raw)
To: Gustavo A. R. Silva, Mike Marciniszyn, Doug Ledford, Jason Gunthorpe
Cc: linux-rdma, linux-kernel
On 5/29/2019 11:12 AM, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes, in particular in the
> context in which this code is being used.
>
> So, replace the following form:
>
> sizeof(struct rvt_sge) * init_attr->cap.max_send_sge + sizeof(struct rvt_swqe)
>
> with:
>
> struct_size(swq, sg_list, init_attr->cap.max_send_sge)
>
> and so on...
>
> Also, notice that variable size is unnecessary, hence it is removed.
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
> drivers/infiniband/sw/rdmavt/qp.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c
> index 31a2e65e4906..a60f5faea198 100644
> --- a/drivers/infiniband/sw/rdmavt/qp.c
> +++ b/drivers/infiniband/sw/rdmavt/qp.c
> @@ -988,9 +988,7 @@ struct ib_qp *rvt_create_qp(struct ib_pd *ibpd,
> case IB_QPT_UC:
> case IB_QPT_RC:
> case IB_QPT_UD:
> - sz = sizeof(struct rvt_sge) *
> - init_attr->cap.max_send_sge +
> - sizeof(struct rvt_swqe);
> + sz = struct_size(swq, sg_list, init_attr->cap.max_send_sge);
> swq = vzalloc_node(array_size(sz, sqsize), rdi->dparms.node);
> if (!swq)
> return ERR_PTR(-ENOMEM);
>
Looks correct, I don't think this makes the code easier to read though.
The macro name "struct_size" is misleading to me. Maybe that's just me,
and in any case...
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][next] IB/rdmavt: Use struct_size() helper
2019-05-30 18:26 ` Dennis Dalessandro
@ 2019-05-30 18:29 ` Jason Gunthorpe
0 siblings, 0 replies; 4+ messages in thread
From: Jason Gunthorpe @ 2019-05-30 18:29 UTC (permalink / raw)
To: Dennis Dalessandro
Cc: Gustavo A. R. Silva, Mike Marciniszyn, Doug Ledford, linux-rdma,
linux-kernel
On Thu, May 30, 2019 at 02:26:22PM -0400, Dennis Dalessandro wrote:
> On 5/29/2019 11:12 AM, Gustavo A. R. Silva wrote:
> > Make use of the struct_size() helper instead of an open-coded version
> > in order to avoid any potential type mistakes, in particular in the
> > context in which this code is being used.
> >
> > So, replace the following form:
> >
> > sizeof(struct rvt_sge) * init_attr->cap.max_send_sge + sizeof(struct rvt_swqe)
> >
> > with:
> >
> > struct_size(swq, sg_list, init_attr->cap.max_send_sge)
> >
> > and so on...
> >
> > Also, notice that variable size is unnecessary, hence it is removed.
> >
> > This code was detected with the help of Coccinelle.
> >
> > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> > drivers/infiniband/sw/rdmavt/qp.c | 4 +---
> > 1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c
> > index 31a2e65e4906..a60f5faea198 100644
> > +++ b/drivers/infiniband/sw/rdmavt/qp.c
> > @@ -988,9 +988,7 @@ struct ib_qp *rvt_create_qp(struct ib_pd *ibpd,
> > case IB_QPT_UC:
> > case IB_QPT_RC:
> > case IB_QPT_UD:
> > - sz = sizeof(struct rvt_sge) *
> > - init_attr->cap.max_send_sge +
> > - sizeof(struct rvt_swqe);
> > + sz = struct_size(swq, sg_list, init_attr->cap.max_send_sge);
> > swq = vzalloc_node(array_size(sz, sqsize), rdi->dparms.node);
> > if (!swq)
> > return ERR_PTR(-ENOMEM);
> >
>
> Looks correct, I don't think this makes the code easier to read though. The
> macro name "struct_size" is misleading to me. Maybe that's just me, and in
> any case...
It is struct_size because it computes the full size of a struct ending in a
variable length array with N items.
The previous code was wonky because it assumes that struct rvt_swqe is
the underlying type of sg_list, while the new version gets the type
information automatically.
Jason
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][next] IB/rdmavt: Use struct_size() helper
2019-05-29 15:12 [PATCH][next] IB/rdmavt: Use struct_size() helper Gustavo A. R. Silva
2019-05-30 18:26 ` Dennis Dalessandro
@ 2019-05-30 18:43 ` Jason Gunthorpe
1 sibling, 0 replies; 4+ messages in thread
From: Jason Gunthorpe @ 2019-05-30 18:43 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Dennis Dalessandro, Mike Marciniszyn, Doug Ledford, linux-rdma,
linux-kernel
On Wed, May 29, 2019 at 10:12:48AM -0500, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes, in particular in the
> context in which this code is being used.
>
> So, replace the following form:
>
> sizeof(struct rvt_sge) * init_attr->cap.max_send_sge + sizeof(struct rvt_swqe)
>
> with:
>
> struct_size(swq, sg_list, init_attr->cap.max_send_sge)
>
> and so on...
>
> Also, notice that variable size is unnecessary, hence it is removed.
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
> ---
> drivers/infiniband/sw/rdmavt/qp.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
Applied to for-next, thanks
Jason
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-05-30 18:43 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2019-05-29 15:12 [PATCH][next] IB/rdmavt: Use struct_size() helper Gustavo A. R. Silva
2019-05-30 18:26 ` Dennis Dalessandro
2019-05-30 18:29 ` Jason Gunthorpe
2019-05-30 18:43 ` Jason Gunthorpe
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