drivers/infiniband/sw/rxe/rxe_verbs.h | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-)
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.
Use the new TRAILING_OVERLAP() helper to fix the following warning:
21 drivers/infiniband/sw/rxe/rxe_verbs.h:271:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
This helper creates a union between a flexible-array member (FAM) and a
set of MEMBERS that would otherwise follow it.
This overlays the trailing MEMBER struct ib_sge sge[RXE_MAX_SGE]; onto
the FAM struct rxe_recv_wqe::dma.sge, while keeping the FAM and the
start of MEMBER aligned.
The static_assert() ensures this alignment remains, and it's
intentionally placed inmediately after the related structure --no
blank line in between.
Lastly, move the conflicting declaration struct rxe_resp_info resp;
to the end of the corresponding structure.
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
drivers/infiniband/sw/rxe/rxe_verbs.h | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
index fd48075810dd..6498d61e8956 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.h
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
@@ -219,12 +219,6 @@ struct rxe_resp_info {
u32 rkey;
u32 length;
- /* SRQ only */
- struct {
- struct rxe_recv_wqe wqe;
- struct ib_sge sge[RXE_MAX_SGE];
- } srq_wqe;
-
/* Responder resources. It's a circular list where the oldest
* resource is dropped first.
*/
@@ -232,7 +226,15 @@ struct rxe_resp_info {
unsigned int res_head;
unsigned int res_tail;
struct resp_res *res;
+
+ /* SRQ only */
+ /* Must be last as it ends in a flexible-array member. */
+ TRAILING_OVERLAP(struct rxe_recv_wqe, wqe, dma.sge,
+ struct ib_sge sge[RXE_MAX_SGE];
+ ) srq_wqe;
};
+static_assert(offsetof(struct rxe_resp_info, srq_wqe.wqe.dma.sge) ==
+ offsetof(struct rxe_resp_info, srq_wqe.sge));
struct rxe_qp {
struct ib_qp ibqp;
@@ -269,7 +271,6 @@ struct rxe_qp {
struct rxe_req_info req;
struct rxe_comp_info comp;
- struct rxe_resp_info resp;
atomic_t ssn;
atomic_t skb_out;
@@ -289,6 +290,9 @@ struct rxe_qp {
spinlock_t state_lock; /* guard requester and completer */
struct execute_work cleanup_work;
+
+ /* Must be last as it ends in a flexible-array member. */
+ struct rxe_resp_info resp;
};
enum {
--
2.43.0On Tue, Nov 11, 2025 at 12:35:02PM +0900, Gustavo A. R. Silva wrote:
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
> index fd48075810dd..6498d61e8956 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> @@ -219,12 +219,6 @@ struct rxe_resp_info {
> u32 rkey;
> u32 length;
>
> - /* SRQ only */
> - struct {
> - struct rxe_recv_wqe wqe;
> - struct ib_sge sge[RXE_MAX_SGE];
> - } srq_wqe;
I think this existing is just a mess, can we fix it properly?
What this code wants to do is to have rxe_resp_info allocate a
rxe_recv_wqe and have a maximum size of its flex array pre-allocated.
Probably like this, though maybe we need a FLEX version of the
INIT_RDMA_OBJ_SIZE macro to make it safer.
Zhu, this seems like a good thing for you to look at?
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index 38d8c408320f11..189eaa59a5fb14 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -1524,7 +1524,8 @@ static const struct ib_device_ops rxe_dev_ops = {
INIT_RDMA_OBJ_SIZE(ib_ah, rxe_ah, ibah),
INIT_RDMA_OBJ_SIZE(ib_cq, rxe_cq, ibcq),
INIT_RDMA_OBJ_SIZE(ib_pd, rxe_pd, ibpd),
- INIT_RDMA_OBJ_SIZE(ib_qp, rxe_qp, ibqp),
+ /* For resp.srq_wqe.dma.sge */
+ INIT_RDMA_OBJ_SIZE(ib_qp, rxe_qp, ibqp) + RXE_MAX_SGE*sizeof(struct ib_sge),
INIT_RDMA_OBJ_SIZE(ib_srq, rxe_srq, ibsrq),
INIT_RDMA_OBJ_SIZE(ib_ucontext, rxe_ucontext, ibuc),
INIT_RDMA_OBJ_SIZE(ib_mw, rxe_mw, ibmw),
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
index fd48075810dd10..dda741ec3ac701 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.h
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
@@ -219,12 +219,6 @@ struct rxe_resp_info {
u32 rkey;
u32 length;
- /* SRQ only */
- struct {
- struct rxe_recv_wqe wqe;
- struct ib_sge sge[RXE_MAX_SGE];
- } srq_wqe;
-
/* Responder resources. It's a circular list where the oldest
* resource is dropped first.
*/
@@ -232,6 +226,9 @@ struct rxe_resp_info {
unsigned int res_head;
unsigned int res_tail;
struct resp_res *res;
+
+ /* SRQ only. srq_wqe.dma.sge is a flex array */
+ struct rxe_recv_wqe srq_wqe;
};
struct rxe_qp {
@@ -269,7 +266,6 @@ struct rxe_qp {
struct rxe_req_info req;
struct rxe_comp_info comp;
- struct rxe_resp_info resp;
atomic_t ssn;
atomic_t skb_out;
@@ -289,6 +285,7 @@ struct rxe_qp {
spinlock_t state_lock; /* guard requester and completer */
struct execute_work cleanup_work;
+ struct rxe_resp_info resp;
};
enum {
在 2025/12/2 10:13, Jason Gunthorpe 写道:
> On Tue, Nov 11, 2025 at 12:35:02PM +0900, Gustavo A. R. Silva wrote:
>> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
>> index fd48075810dd..6498d61e8956 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
>> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
>> @@ -219,12 +219,6 @@ struct rxe_resp_info {
>> u32 rkey;
>> u32 length;
>>
>> - /* SRQ only */
>> - struct {
>> - struct rxe_recv_wqe wqe;
>> - struct ib_sge sge[RXE_MAX_SGE];
>> - } srq_wqe;
>
> I think this existing is just a mess, can we fix it properly?
>
> What this code wants to do is to have rxe_resp_info allocate a
> rxe_recv_wqe and have a maximum size of its flex array pre-allocated.
>
> Probably like this, though maybe we need a FLEX version of the
> INIT_RDMA_OBJ_SIZE macro to make it safer.
>
> Zhu, this seems like a good thing for you to look at?
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
> index 38d8c408320f11..189eaa59a5fb14 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.c
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
> @@ -1524,7 +1524,8 @@ static const struct ib_device_ops rxe_dev_ops = {
> INIT_RDMA_OBJ_SIZE(ib_ah, rxe_ah, ibah),
> INIT_RDMA_OBJ_SIZE(ib_cq, rxe_cq, ibcq),
> INIT_RDMA_OBJ_SIZE(ib_pd, rxe_pd, ibpd),
> - INIT_RDMA_OBJ_SIZE(ib_qp, rxe_qp, ibqp),
> + /* For resp.srq_wqe.dma.sge */
> + INIT_RDMA_OBJ_SIZE(ib_qp, rxe_qp, ibqp) + RXE_MAX_SGE*sizeof(struct ib_sge),
> INIT_RDMA_OBJ_SIZE(ib_srq, rxe_srq, ibsrq),
> INIT_RDMA_OBJ_SIZE(ib_ucontext, rxe_ucontext, ibuc),
> INIT_RDMA_OBJ_SIZE(ib_mw, rxe_mw, ibmw),
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
> index fd48075810dd10..dda741ec3ac701 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> @@ -219,12 +219,6 @@ struct rxe_resp_info {
> u32 rkey;
> u32 length;
>
> - /* SRQ only */
> - struct {
> - struct rxe_recv_wqe wqe;
> - struct ib_sge sge[RXE_MAX_SGE];
> - } srq_wqe;
> -
> /* Responder resources. It's a circular list where the oldest
> * resource is dropped first.
> */
> @@ -232,6 +226,9 @@ struct rxe_resp_info {
> unsigned int res_head;
> unsigned int res_tail;
> struct resp_res *res;
> +
> + /* SRQ only. srq_wqe.dma.sge is a flex array */
> + struct rxe_recv_wqe srq_wqe;
drivers/infiniband/sw/rxe/rxe_resp.c: In function get_srq_wqe:
drivers/infiniband/sw/rxe/rxe_resp.c:289:41: error: struct rxe_recv_wqe
has no member named wqe
289 | qp->resp.wqe = &qp->resp.srq_wqe.wqe;
| ^
struct {
struct rxe_recv_wqe wqe;
struct ib_sge sge[RXE_MAX_SGE];
} srq_wqe;
IMO, it is better to move this struct to the end of the struct
rxe_resp_info.
Yanjun.Zhu
> };
>
> struct rxe_qp {
> @@ -269,7 +266,6 @@ struct rxe_qp {
>
> struct rxe_req_info req;
> struct rxe_comp_info comp;
> - struct rxe_resp_info resp;
>
> atomic_t ssn;
> atomic_t skb_out;
> @@ -289,6 +285,7 @@ struct rxe_qp {
> spinlock_t state_lock; /* guard requester and completer */
>
> struct execute_work cleanup_work;
> + struct rxe_resp_info resp;
> };
>
> enum {
On Wed, Dec 03, 2025 at 09:08:45PM -0800, Zhu Yanjun wrote: > > unsigned int res_head; > > unsigned int res_tail; > > struct resp_res *res; > > + > > + /* SRQ only. srq_wqe.dma.sge is a flex array */ > > + struct rxe_recv_wqe srq_wqe; > > drivers/infiniband/sw/rxe/rxe_resp.c: In function get_srq_wqe: > drivers/infiniband/sw/rxe/rxe_resp.c:289:41: error: struct rxe_recv_wqe has > no member named wqe > 289 | qp->resp.wqe = &qp->resp.srq_wqe.wqe; > | ^ I didn't try to fix all the typos, you will need to do that. Jason
On 12/4/25 5:05 AM, Jason Gunthorpe wrote: > On Wed, Dec 03, 2025 at 09:08:45PM -0800, Zhu Yanjun wrote: >>> unsigned int res_head; >>> unsigned int res_tail; >>> struct resp_res *res; >>> + >>> + /* SRQ only. srq_wqe.dma.sge is a flex array */ >>> + struct rxe_recv_wqe srq_wqe; >> >> drivers/infiniband/sw/rxe/rxe_resp.c: In function get_srq_wqe: >> drivers/infiniband/sw/rxe/rxe_resp.c:289:41: error: struct rxe_recv_wqe has >> no member named wqe >> 289 | qp->resp.wqe = &qp->resp.srq_wqe.wqe; >> | ^ > > I didn't try to fix all the typos, you will need to do that. Exactly. I will fix this problem. This weekend, I will send out an official commit. Yanjun.Zhu > > Jason
在 2025/12/4 9:48, yanjun.zhu 写道:
> On 12/4/25 5:05 AM, Jason Gunthorpe wrote:
>> On Wed, Dec 03, 2025 at 09:08:45PM -0800, Zhu Yanjun wrote:
>>>> unsigned int res_head;
>>>> unsigned int res_tail;
>>>> struct resp_res *res;
>>>> +
>>>> + /* SRQ only. srq_wqe.dma.sge is a flex array */
>>>> + struct rxe_recv_wqe srq_wqe;
>>>
>>> drivers/infiniband/sw/rxe/rxe_resp.c: In function get_srq_wqe:
>>> drivers/infiniband/sw/rxe/rxe_resp.c:289:41: error: struct
>>> rxe_recv_wqe has
>>> no member named wqe
>>> 289 | qp->resp.wqe = &qp->resp.srq_wqe.wqe;
>>> | ^
>>
>> I didn't try to fix all the typos, you will need to do that.
>
> Exactly. I will fix this problem. This weekend, I will send out an
> official commit.
Hi, Jason
The followings are based on your commits and Leon's commits. And it can
pass the rdma-core tests.
I am not sure if this commit is good or not.
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c
b/drivers/infiniband/sw/rxe/rxe_verbs.c
index 38d8c408320f..189eaa59a5fb 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -1524,7 +1524,8 @@ static const struct ib_device_ops rxe_dev_ops = {
INIT_RDMA_OBJ_SIZE(ib_ah, rxe_ah, ibah),
INIT_RDMA_OBJ_SIZE(ib_cq, rxe_cq, ibcq),
INIT_RDMA_OBJ_SIZE(ib_pd, rxe_pd, ibpd),
- INIT_RDMA_OBJ_SIZE(ib_qp, rxe_qp, ibqp),
+ /* For resp.srq_wqe.dma.sge */
+ INIT_RDMA_OBJ_SIZE(ib_qp, rxe_qp, ibqp) +
RXE_MAX_SGE*sizeof(struct ib_sge),
INIT_RDMA_OBJ_SIZE(ib_srq, rxe_srq, ibsrq),
INIT_RDMA_OBJ_SIZE(ib_ucontext, rxe_ucontext, ibuc),
INIT_RDMA_OBJ_SIZE(ib_mw, rxe_mw, ibmw),
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h
b/drivers/infiniband/sw/rxe/rxe_verbs.h
index fd48075810dd..8c17f5f4e318 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.h
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
@@ -219,12 +219,6 @@ struct rxe_resp_info {
u32 rkey;
u32 length;
- /* SRQ only */
- struct {
- struct rxe_recv_wqe wqe;
- struct ib_sge sge[RXE_MAX_SGE];
- } srq_wqe;
-
/* Responder resources. It's a circular list where the oldest
* resource is dropped first.
*/
@@ -232,6 +226,12 @@ struct rxe_resp_info {
unsigned int res_head;
unsigned int res_tail;
struct resp_res *res;
+
+ /* SRQ only. srq_wqe.dma.sge is a flex array */
+ struct {
+ struct rxe_recv_wqe wqe;
+ struct ib_sge sge[RXE_MAX_SGE];
+ } srq_wqe;
};
struct rxe_qp {
@@ -269,7 +269,6 @@ struct rxe_qp {
struct rxe_req_info req;
struct rxe_comp_info comp;
- struct rxe_resp_info resp;
atomic_t ssn;
atomic_t skb_out;
@@ -289,6 +288,7 @@ struct rxe_qp {
spinlock_t state_lock; /* guard requester and
completer */
struct execute_work cleanup_work;
+ struct rxe_resp_info resp;
};
enum {
Yanjun.Zhu
>
> Yanjun.Zhu
>
>>
>> Jason
>
--
Best Regards,
Yanjun.Zhu
在 2025/12/5 20:41, Zhu Yanjun 写道:
>
>
> 在 2025/12/4 9:48, yanjun.zhu 写道:
>> On 12/4/25 5:05 AM, Jason Gunthorpe wrote:
>>> On Wed, Dec 03, 2025 at 09:08:45PM -0800, Zhu Yanjun wrote:
>>>>> unsigned int res_head;
>>>>> unsigned int res_tail;
>>>>> struct resp_res *res;
>>>>> +
>>>>> + /* SRQ only. srq_wqe.dma.sge is a flex array */
>>>>> + struct rxe_recv_wqe srq_wqe;
>>>>
>>>> drivers/infiniband/sw/rxe/rxe_resp.c: In function get_srq_wqe:
>>>> drivers/infiniband/sw/rxe/rxe_resp.c:289:41: error: struct
>>>> rxe_recv_wqe has
>>>> no member named wqe
>>>> 289 | qp->resp.wqe = &qp->resp.srq_wqe.wqe;
>>>> | ^
>>>
>>> I didn't try to fix all the typos, you will need to do that.
>>
>> Exactly. I will fix this problem. This weekend, I will send out an
>> official commit.
> Hi, Jason
>
> The followings are based on your commits and Leon's commits. And it can
> pass the rdma-core tests.
>
> I am not sure if this commit is good or not.
Hi, Jason && Leon
Any update? If this looks good to you, I will send out an official
commit based on the following commit.
Thanks,
Yanjun.Zhu
>
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/
> sw/rxe/rxe_verbs.c
> index 38d8c408320f..189eaa59a5fb 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.c
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
> @@ -1524,7 +1524,8 @@ static const struct ib_device_ops rxe_dev_ops = {
> INIT_RDMA_OBJ_SIZE(ib_ah, rxe_ah, ibah),
> INIT_RDMA_OBJ_SIZE(ib_cq, rxe_cq, ibcq),
> INIT_RDMA_OBJ_SIZE(ib_pd, rxe_pd, ibpd),
> - INIT_RDMA_OBJ_SIZE(ib_qp, rxe_qp, ibqp),
> + /* For resp.srq_wqe.dma.sge */
> + INIT_RDMA_OBJ_SIZE(ib_qp, rxe_qp, ibqp) +
> RXE_MAX_SGE*sizeof(struct ib_sge),
> INIT_RDMA_OBJ_SIZE(ib_srq, rxe_srq, ibsrq),
> INIT_RDMA_OBJ_SIZE(ib_ucontext, rxe_ucontext, ibuc),
> INIT_RDMA_OBJ_SIZE(ib_mw, rxe_mw, ibmw),
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/
> sw/rxe/rxe_verbs.h
> index fd48075810dd..8c17f5f4e318 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> @@ -219,12 +219,6 @@ struct rxe_resp_info {
> u32 rkey;
> u32 length;
>
> - /* SRQ only */
> - struct {
> - struct rxe_recv_wqe wqe;
> - struct ib_sge sge[RXE_MAX_SGE];
> - } srq_wqe;
> -
> /* Responder resources. It's a circular list where the oldest
> * resource is dropped first.
> */
> @@ -232,6 +226,12 @@ struct rxe_resp_info {
> unsigned int res_head;
> unsigned int res_tail;
> struct resp_res *res;
> +
> + /* SRQ only. srq_wqe.dma.sge is a flex array */
> + struct {
> + struct rxe_recv_wqe wqe;
> + struct ib_sge sge[RXE_MAX_SGE];
> + } srq_wqe;
> };
>
> struct rxe_qp {
> @@ -269,7 +269,6 @@ struct rxe_qp {
>
> struct rxe_req_info req;
> struct rxe_comp_info comp;
> - struct rxe_resp_info resp;
>
> atomic_t ssn;
> atomic_t skb_out;
> @@ -289,6 +288,7 @@ struct rxe_qp {
> spinlock_t state_lock; /* guard requester and
> completer */
>
> struct execute_work cleanup_work;
> + struct rxe_resp_info resp;
> };
>
> enum {
>
> Yanjun.Zhu
>
>>
>> Yanjun.Zhu
>>
>>>
>>> Jason
>>
>
--
Best Regards,
Yanjun.Zhu
On Sun, Dec 14, 2025 at 09:00:51PM -0800, Zhu Yanjun wrote: > > > 在 2025/12/5 20:41, Zhu Yanjun 写道: > > > > > > 在 2025/12/4 9:48, yanjun.zhu 写道: > > > On 12/4/25 5:05 AM, Jason Gunthorpe wrote: > > > > On Wed, Dec 03, 2025 at 09:08:45PM -0800, Zhu Yanjun wrote: > > > > > > unsigned int res_head; > > > > > > unsigned int res_tail; > > > > > > struct resp_res *res; > > > > > > + > > > > > > + /* SRQ only. srq_wqe.dma.sge is a flex array */ > > > > > > + struct rxe_recv_wqe srq_wqe; > > > > > > > > > > drivers/infiniband/sw/rxe/rxe_resp.c: In function get_srq_wqe: > > > > > drivers/infiniband/sw/rxe/rxe_resp.c:289:41: error: struct > > > > > rxe_recv_wqe has > > > > > no member named wqe > > > > > 289 | qp->resp.wqe = &qp->resp.srq_wqe.wqe; > > > > > | ^ > > > > > > > > I didn't try to fix all the typos, you will need to do that. > > > > > > Exactly. I will fix this problem. This weekend, I will send out an > > > official commit. > > Hi, Jason > > > > The followings are based on your commits and Leon's commits. And it can > > pass the rdma-core tests. > > > > I am not sure if this commit is good or not. > > Hi, Jason && Leon > > Any update? If this looks good to you, I will send out an official commit > based on the following commit. You are RXE maintainer, send the official patch. Thanks
On 12/18/25 7:56 AM, Leon Romanovsky wrote: > On Sun, Dec 14, 2025 at 09:00:51PM -0800, Zhu Yanjun wrote: >> >> 在 2025/12/5 20:41, Zhu Yanjun 写道: >>> >>> 在 2025/12/4 9:48, yanjun.zhu 写道: >>>> On 12/4/25 5:05 AM, Jason Gunthorpe wrote: >>>>> On Wed, Dec 03, 2025 at 09:08:45PM -0800, Zhu Yanjun wrote: >>>>>>> unsigned int res_head; >>>>>>> unsigned int res_tail; >>>>>>> struct resp_res *res; >>>>>>> + >>>>>>> + /* SRQ only. srq_wqe.dma.sge is a flex array */ >>>>>>> + struct rxe_recv_wqe srq_wqe; >>>>>> drivers/infiniband/sw/rxe/rxe_resp.c: In function get_srq_wqe: >>>>>> drivers/infiniband/sw/rxe/rxe_resp.c:289:41: error: struct >>>>>> rxe_recv_wqe has >>>>>> no member named wqe >>>>>> 289 | qp->resp.wqe = &qp->resp.srq_wqe.wqe; >>>>>> | ^ >>>>> I didn't try to fix all the typos, you will need to do that. >>>> Exactly. I will fix this problem. This weekend, I will send out an >>>> official commit. >>> Hi, Jason >>> >>> The followings are based on your commits and Leon's commits. And it can >>> pass the rdma-core tests. >>> >>> I am not sure if this commit is good or not. >> Hi, Jason && Leon >> >> Any update? If this looks good to you, I will send out an official commit >> based on the following commit. > You are RXE maintainer, send the official patch. Will do. I will send it out very soon. Yanjun.Zhu > > Thanks
On 12/19/25 04:22, Yanjun.Zhu wrote: > > On 12/18/25 7:56 AM, Leon Romanovsky wrote: >> On Sun, Dec 14, 2025 at 09:00:51PM -0800, Zhu Yanjun wrote: >>> >>> 在 2025/12/5 20:41, Zhu Yanjun 写道: >>>> >>>> 在 2025/12/4 9:48, yanjun.zhu 写道: >>>>> On 12/4/25 5:05 AM, Jason Gunthorpe wrote: >>>>>> On Wed, Dec 03, 2025 at 09:08:45PM -0800, Zhu Yanjun wrote: >>>>>>>> unsigned int res_head; >>>>>>>> unsigned int res_tail; >>>>>>>> struct resp_res *res; >>>>>>>> + >>>>>>>> + /* SRQ only. srq_wqe.dma.sge is a flex array */ >>>>>>>> + struct rxe_recv_wqe srq_wqe; >>>>>>> drivers/infiniband/sw/rxe/rxe_resp.c: In function get_srq_wqe: >>>>>>> drivers/infiniband/sw/rxe/rxe_resp.c:289:41: error: struct >>>>>>> rxe_recv_wqe has >>>>>>> no member named wqe >>>>>>> 289 | qp->resp.wqe = &qp->resp.srq_wqe.wqe; >>>>>>> | ^ >>>>>> I didn't try to fix all the typos, you will need to do that. >>>>> Exactly. I will fix this problem. This weekend, I will send out an >>>>> official commit. >>>> Hi, Jason >>>> >>>> The followings are based on your commits and Leon's commits. And it can >>>> pass the rdma-core tests. >>>> >>>> I am not sure if this commit is good or not. >>> Hi, Jason && Leon >>> >>> Any update? If this looks good to you, I will send out an official commit >>> based on the following commit. >> You are RXE maintainer, send the official patch. > > Will do. I will send it out very soon. I don't see how this addresses the flex-array in the middle issue that originated this discussion. -Gustavo
On Fri, Dec 19, 2025 at 11:51:54AM +0900, Gustavo A. R. Silva wrote: > > > > Any update? If this looks good to you, I will send out an official commit > > > > based on the following commit. > > > You are RXE maintainer, send the official patch. > > > > Will do. I will send it out very soon. > > I don't see how this addresses the flex-array in the middle issue that > originated this discussion. ?? It moved it to the end of every struct it is part of? Jason
在 2025/12/19 6:26, Jason Gunthorpe 写道: > On Fri, Dec 19, 2025 at 11:51:54AM +0900, Gustavo A. R. Silva wrote: > >>>>> Any update? If this looks good to you, I will send out an official commit >>>>> based on the following commit. >>>> You are RXE maintainer, send the official patch. >>> >>> Will do. I will send it out very soon. >> >> I don't see how this addresses the flex-array in the middle issue that >> originated this discussion. > > ?? > > It moved it to the end of every struct it is part of? Any update? Yanjun.Zhu > > Jason
在 2025/12/18 18:51, Gustavo A. R. Silva 写道: > > > On 12/19/25 04:22, Yanjun.Zhu wrote: >> >> On 12/18/25 7:56 AM, Leon Romanovsky wrote: >>> On Sun, Dec 14, 2025 at 09:00:51PM -0800, Zhu Yanjun wrote: >>>> >>>> 在 2025/12/5 20:41, Zhu Yanjun 写道: >>>>> >>>>> 在 2025/12/4 9:48, yanjun.zhu 写道: >>>>>> On 12/4/25 5:05 AM, Jason Gunthorpe wrote: >>>>>>> On Wed, Dec 03, 2025 at 09:08:45PM -0800, Zhu Yanjun wrote: >>>>>>>>> unsigned int res_head; >>>>>>>>> unsigned int res_tail; >>>>>>>>> struct resp_res *res; >>>>>>>>> + >>>>>>>>> + /* SRQ only. srq_wqe.dma.sge is a flex array */ >>>>>>>>> + struct rxe_recv_wqe srq_wqe; >>>>>>>> drivers/infiniband/sw/rxe/rxe_resp.c: In function get_srq_wqe: >>>>>>>> drivers/infiniband/sw/rxe/rxe_resp.c:289:41: error: struct >>>>>>>> rxe_recv_wqe has >>>>>>>> no member named wqe >>>>>>>> 289 | qp->resp.wqe = &qp->resp.srq_wqe.wqe; >>>>>>>> | ^ >>>>>>> I didn't try to fix all the typos, you will need to do that. >>>>>> Exactly. I will fix this problem. This weekend, I will send out an >>>>>> official commit. >>>>> Hi, Jason >>>>> >>>>> The followings are based on your commits and Leon's commits. And >>>>> it can >>>>> pass the rdma-core tests. >>>>> >>>>> I am not sure if this commit is good or not. >>>> Hi, Jason && Leon >>>> >>>> Any update? If this looks good to you, I will send out an official >>>> commit >>>> based on the following commit. >>> You are RXE maintainer, send the official patch. >> >> Will do. I will send it out very soon. > > I don't see how this addresses the flex-array in the middle issue that > originated this discussion. Could you please explain this in more detail? Also, if you have a better approach, would you mind sending a new commit for discussion? Thanks a lot. Yanjun.Zhu > > -Gustavo -- Best Regards, Yanjun.Zhu
On 12/19/25 13:29, Zhu Yanjun wrote: > > 在 2025/12/18 18:51, Gustavo A. R. Silva 写道: >> >> >> On 12/19/25 04:22, Yanjun.Zhu wrote: >>> >>> On 12/18/25 7:56 AM, Leon Romanovsky wrote: >>>> On Sun, Dec 14, 2025 at 09:00:51PM -0800, Zhu Yanjun wrote: >>>>> >>>>> 在 2025/12/5 20:41, Zhu Yanjun 写道: >>>>>> >>>>>> 在 2025/12/4 9:48, yanjun.zhu 写道: >>>>>>> On 12/4/25 5:05 AM, Jason Gunthorpe wrote: >>>>>>>> On Wed, Dec 03, 2025 at 09:08:45PM -0800, Zhu Yanjun wrote: >>>>>>>>>> unsigned int res_head; >>>>>>>>>> unsigned int res_tail; >>>>>>>>>> struct resp_res *res; >>>>>>>>>> + >>>>>>>>>> + /* SRQ only. srq_wqe.dma.sge is a flex array */ >>>>>>>>>> + struct rxe_recv_wqe srq_wqe; >>>>>>>>> drivers/infiniband/sw/rxe/rxe_resp.c: In function get_srq_wqe: >>>>>>>>> drivers/infiniband/sw/rxe/rxe_resp.c:289:41: error: struct >>>>>>>>> rxe_recv_wqe has >>>>>>>>> no member named wqe >>>>>>>>> 289 | qp->resp.wqe = &qp->resp.srq_wqe.wqe; >>>>>>>>> | ^ >>>>>>>> I didn't try to fix all the typos, you will need to do that. >>>>>>> Exactly. I will fix this problem. This weekend, I will send out an >>>>>>> official commit. >>>>>> Hi, Jason >>>>>> >>>>>> The followings are based on your commits and Leon's commits. And it can >>>>>> pass the rdma-core tests. >>>>>> >>>>>> I am not sure if this commit is good or not. >>>>> Hi, Jason && Leon >>>>> >>>>> Any update? If this looks good to you, I will send out an official commit >>>>> based on the following commit. >>>> You are RXE maintainer, send the official patch. >>> >>> Will do. I will send it out very soon. >> >> I don't see how this addresses the flex-array in the middle issue that >> originated this discussion. > > Could you please explain this in more detail? > Also, if you have a better approach, would you mind sending a new commit for discussion? This is exactly what my original patch is about. I've explained this a couple of times in this thread already. -Gustavo
在 2025/12/18 20:35, Gustavo A. R. Silva 写道:
>
>
> On 12/19/25 13:29, Zhu Yanjun wrote:
>>
>> 在 2025/12/18 18:51, Gustavo A. R. Silva 写道:
>>>
>>>
>>> On 12/19/25 04:22, Yanjun.Zhu wrote:
>>>>
>>>> On 12/18/25 7:56 AM, Leon Romanovsky wrote:
>>>>> On Sun, Dec 14, 2025 at 09:00:51PM -0800, Zhu Yanjun wrote:
>>>>>>
>>>>>> 在 2025/12/5 20:41, Zhu Yanjun 写道:
>>>>>>>
>>>>>>> 在 2025/12/4 9:48, yanjun.zhu 写道:
>>>>>>>> On 12/4/25 5:05 AM, Jason Gunthorpe wrote:
>>>>>>>>> On Wed, Dec 03, 2025 at 09:08:45PM -0800, Zhu Yanjun wrote:
>>>>>>>>>>> unsigned int res_head;
>>>>>>>>>>> unsigned int res_tail;
>>>>>>>>>>> struct resp_res *res;
>>>>>>>>>>> +
>>>>>>>>>>> + /* SRQ only. srq_wqe.dma.sge is a flex array */
>>>>>>>>>>> + struct rxe_recv_wqe srq_wqe;
>>>>>>>>>> drivers/infiniband/sw/rxe/rxe_resp.c: In function get_srq_wqe:
>>>>>>>>>> drivers/infiniband/sw/rxe/rxe_resp.c:289:41: error: struct
>>>>>>>>>> rxe_recv_wqe has
>>>>>>>>>> no member named wqe
>>>>>>>>>> 289 | qp->resp.wqe = &qp->resp.srq_wqe.wqe;
>>>>>>>>>> | ^
>>>>>>>>> I didn't try to fix all the typos, you will need to do that.
>>>>>>>> Exactly. I will fix this problem. This weekend, I will send out an
>>>>>>>> official commit.
>>>>>>> Hi, Jason
>>>>>>>
>>>>>>> The followings are based on your commits and Leon's commits. And
>>>>>>> it can
>>>>>>> pass the rdma-core tests.
>>>>>>>
>>>>>>> I am not sure if this commit is good or not.
>>>>>> Hi, Jason && Leon
>>>>>>
>>>>>> Any update? If this looks good to you, I will send out an official
>>>>>> commit
>>>>>> based on the following commit.
>>>>> You are RXE maintainer, send the official patch.
>>>>
>>>> Will do. I will send it out very soon.
>>>
>>> I don't see how this addresses the flex-array in the middle issue that
>>> originated this discussion.
>>
>> Could you please explain this in more detail?
>> Also, if you have a better approach, would you mind sending a new
>> commit for discussion?
>
> This is exactly what my original patch is about. I've explained this a
> couple of times
> in this thread already.
In your original patch, I have the following problem. I read all your
replies. But I can not find your answers to my problem.
My problem is as below:
1. The followings are the declaration of __TRAILING_OVERLAP
/**
* __TRAILING_OVERLAP() - Overlap a flexible-array member with trailing
* members.
*
* Creates a union between a flexible-array member (FAM) in a struct
and a set
* of additional members that would otherwise follow it.
*
* @TYPE: Flexible structure type name, including "struct" keyword.
* @NAME: Name for a variable to define.
* @FAM: The flexible-array member within @TYPE <----- Here
* @ATTRS: Any struct attributes (usually empty)
* @MEMBERS: Trailing overlapping members.
*/
#define __TRAILING_OVERLAP(TYPE, NAME, FAM, ATTRS, MEMBERS) \
union { \
TYPE NAME; \
struct { \
unsigned char __offset_to_FAM[offsetof(TYPE, FAM)]; \
MEMBERS \
} ATTRS; \
}
2. I expanded the above MACRO __TRAILING_OVERLAP into the following
following the definition in your commit.
union {
struct rxe_recv_wqe wqe;
struct {
unsigned char __offset_to_FAM[offsetof(struct rxe_recv_wqe,
dma.sge)]; \
struct ib_sge sge[RXE_MAX_SGE];
} ;
}srq_wqe;
3. In your original commit, dma.sge should be the member of struct
rxe_recv_wqe. The struct rxe_recv_wqe is as below.
"@FAM: The flexible-array member within @TYPE"
The struct rxe_recv_wqe is as below.
struct rxe_recv_wqe {
__aligned_u64 wr_id;
__u32 reserved;
__u32 padding;
struct rxe_dma_info dma;
};
But I can not find dma.sge in the above struct. Can you explain it?
To be honest, I read your original commit for several times, but I can
not get it. Can you explain the MACRO TRAILING_OVERLAP? And how can it
replace the following struct?
struct {
struct rxe_recv_wqe wqe;
struct ib_sge sge[RXE_MAX_SGE];
} srq_wqe;
Thanks a lot.
Yanjun.Zhu
>
> -Gustavo
> The struct rxe_recv_wqe is as below.
>
> struct rxe_recv_wqe {
> __aligned_u64 wr_id;
> __u32 reserved;
> __u32 padding;
> struct rxe_dma_info dma;
Expand struct rxe_dma_info here.
> };
>
> But I can not find dma.sge in the above struct. Can you explain it?
>
> To be honest, I read your original commit for several times, but I can not get it. Can you explain the MACRO TRAILING_OVERLAP? And how can it replace the
> following struct?
This is clearly explained in the changelog text. I think what you're
missing will be clear once you understand how nested structures
work. See my comment above.
-Gustavo
在 2025/12/18 21:48, Gustavo A. R. Silva 写道:
>
>> The struct rxe_recv_wqe is as below.
>>
>> struct rxe_recv_wqe {
>> __aligned_u64 wr_id;
>> __u32 reserved;
>> __u32 padding;
>> struct rxe_dma_info dma;
>
> Expand struct rxe_dma_info here.
Thanks. In struct rxe_dma_info, the struct is
struct rxe_sge {
__aligned_u64 addr;
__u32 length;
__u32 lkey;
};
But in your commit, struct ib_sge is used.
struct ib_sge {
u64 addr;
u32 length;
u32 lkey;
};
__aligned_u64 is a 64-bit integer with a guaranteed 8-byte alignment,
used to preserve ABI correctness across architectures and between
userspace and kernel, while u64 has architecture-dependent alignment.
I am not sure if we can treate "struct rxe_sge" as the same with "struct
ib_sge".
Leon and Jason, please comment on it.
Yanjun.Zhu
>
>> };
>>
>> But I can not find dma.sge in the above struct. Can you explain it?
>>
>> To be honest, I read your original commit for several times, but I
>> can not get it. Can you explain the MACRO TRAILING_OVERLAP? And how
>> can it replace the following struct?
>
> This is clearly explained in the changelog text. I think what you're
> missing will be clear once you understand how nested structures
> work. See my comment above.
>
> -Gustavo
On 12/19/25 15:59, Zhu Yanjun wrote:
>
> 在 2025/12/18 21:48, Gustavo A. R. Silva 写道:
>>
>>> The struct rxe_recv_wqe is as below.
>>>
>>> struct rxe_recv_wqe {
>>> __aligned_u64 wr_id;
>>> __u32 reserved;
>>> __u32 padding;
>>> struct rxe_dma_info dma;
>>
>> Expand struct rxe_dma_info here.
>
> Thanks. In struct rxe_dma_info, the struct is
>
> struct rxe_sge {
> __aligned_u64 addr;
> __u32 length;
> __u32 lkey;
> };
>
> But in your commit, struct ib_sge is used.
>
> struct ib_sge {
> u64 addr;
> u32 length;
> u32 lkey;
> };
> __aligned_u64 is a 64-bit integer with a guaranteed 8-byte alignment,
>
> used to preserve ABI correctness across architectures and between
>
> userspace and kernel, while u64 has architecture-dependent alignment.
>
> I am not sure if we can treate "struct rxe_sge" as the same with "struct ib_sge".
Just notice that the original code is the one actually doing that.
See my response in this same thread:
https://lore.kernel.org/linux-hardening/d3336e9d-2b84-4698-a799-b49e3845f38f@embeddedor.com/
So, if that code is fine, this is fine. If the original code is wrong,
then that code should be fixed first.
-Gustavo
>
>
> Leon and Jason, please comment on it.
>
>
> Yanjun.Zhu
>
>>
>>> };
>>>
>>> But I can not find dma.sge in the above struct. Can you explain it?
>>>
>>> To be honest, I read your original commit for several times, but I can not get it. Can you explain the MACRO TRAILING_OVERLAP? And how can it replace the
>>> following struct?
>>
>> This is clearly explained in the changelog text. I think what you're
>> missing will be clear once you understand how nested structures
>> work. See my comment above.
>>
>> -Gustavo
>
在 2025/12/19 1:55, Gustavo A. R. Silva 写道:
>
>
> On 12/19/25 15:59, Zhu Yanjun wrote:
>>
>> 在 2025/12/18 21:48, Gustavo A. R. Silva 写道:
>>>
>>>> The struct rxe_recv_wqe is as below.
>>>>
>>>> struct rxe_recv_wqe {
>>>> __aligned_u64 wr_id;
>>>> __u32 reserved;
>>>> __u32 padding;
>>>> struct rxe_dma_info dma;
>>>
>>> Expand struct rxe_dma_info here.
>>
>> Thanks. In struct rxe_dma_info, the struct is
>>
>> struct rxe_sge {
>> __aligned_u64 addr;
>> __u32 length;
>> __u32 lkey;
>> };
>>
>> But in your commit, struct ib_sge is used.
>>
>> struct ib_sge {
>> u64 addr;
>> u32 length;
>> u32 lkey;
>> };
>> __aligned_u64 is a 64-bit integer with a guaranteed 8-byte alignment,
>>
>> used to preserve ABI correctness across architectures and between
>>
>> userspace and kernel, while u64 has architecture-dependent alignment.
>>
>> I am not sure if we can treate "struct rxe_sge" as the same with
>> "struct ib_sge".
>
> Just notice that the original code is the one actually doing that.
> See my response in this same thread:
>
> https://lore.kernel.org/linux-hardening/d3336e9d-2b84-4698-a799-
> b49e3845f38f@embeddedor.com/
>
> So, if that code is fine, this is fine. If the original code is wrong,
> then that code should be fixed first.
Thanks a lot. Because struct ib_sge and struct ib_sge is different,
struct ib_sge {
u64 addr; <--- u64 has architecture-dependent alignment
u32 length;
u32 lkey;
};
struct rxe_sge {
__aligned_u64 addr; <---guaranteed 8-byte alignment,
used to preserve ABI correctness across architectures and between
userspace and kernel
__u32 length;
__u32 lkey;
};
and struct rxe_sge is used in rxe_mr, it is working between userspace
and kernel, thus, I want to keep struct rxe_mr in rxe_mr.
But in other places, I want to replace struct rxe_sge with struct
ib_sge. The commit is as below.
In short, the commit "RDMA/rxe: Avoid -Wflex-array-member-not-at-end
warnings" && the following commit will work well. I have made tests in
my local host. It can work well.
Please Leon and Jason comment.
diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c
b/drivers/infiniband/sw/rxe/rxe_mr.c
index b1df05238848..390ae01f549d 100644
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -341,7 +341,7 @@ int copy_data(
enum rxe_mr_copy_dir dir)
{
int bytes;
- struct rxe_sge *sge = &dma->sge[dma->cur_sge];
+ struct ib_sge *sge = &dma->sge[dma->cur_sge];
int offset = dma->sge_offset;
int resid = dma->resid;
struct rxe_mr *mr = NULL;
@@ -580,7 +580,7 @@ enum resp_states rxe_mr_do_atomic_write(struct
rxe_mr *mr, u64 iova, u64 value)
int advance_dma_data(struct rxe_dma_info *dma, unsigned int length)
{
- struct rxe_sge *sge = &dma->sge[dma->cur_sge];
+ struct ib_sge *sge = &dma->sge[dma->cur_sge];
int offset = dma->sge_offset;
int resid = dma->resid;
diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c
b/drivers/infiniband/sw/rxe/rxe_resp.c
index 711f73e0bbb1..74f5b695da7a 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -283,7 +283,7 @@ static enum resp_states get_srq_wqe(struct rxe_qp *qp)
rxe_dbg_qp(qp, "invalid num_sge in SRQ entry\n");
return RESPST_ERR_MALFORMED_WQE;
}
- size = sizeof(*wqe) + wqe->dma.num_sge*sizeof(struct rxe_sge);
+ size = sizeof(*wqe) + wqe->dma.num_sge*sizeof(struct ib_sge);
memcpy(&qp->resp.srq_wqe, wqe, size);
qp->resp.wqe = &qp->resp.srq_wqe.wqe;
diff --git a/include/uapi/rdma/rdma_user_rxe.h
b/include/uapi/rdma/rdma_user_rxe.h
index bb092fccb813..360839498441 100644
--- a/include/uapi/rdma/rdma_user_rxe.h
+++ b/include/uapi/rdma/rdma_user_rxe.h
@@ -154,7 +154,7 @@ struct rxe_dma_info {
union {
__DECLARE_FLEX_ARRAY(__u8, inline_data);
__DECLARE_FLEX_ARRAY(__u8, atomic_wr);
- __DECLARE_FLEX_ARRAY(struct rxe_sge, sge);
+ __DECLARE_FLEX_ARRAY(struct ib_sge, sge);
};
};
To this commit, plus the above commit, it should work well.
Yanjun.Zhu
>
> -Gustavo
>
>>
>>
>> Leon and Jason, please comment on it.
>>
>>
>> Yanjun.Zhu
>>
>>>
>>>> };
>>>>
>>>> But I can not find dma.sge in the above struct. Can you explain it?
>>>>
>>>> To be honest, I read your original commit for several times, but I
>>>> can not get it. Can you explain the MACRO TRAILING_OVERLAP? And how
>>>> can it replace the following struct?
>>>
>>> This is clearly explained in the changelog text. I think what you're
>>> missing will be clear once you understand how nested structures
>>> work. See my comment above.
>>>
>>> -Gustavo
>>
>
在 2025/12/2 10:13, Jason Gunthorpe 写道:
> On Tue, Nov 11, 2025 at 12:35:02PM +0900, Gustavo A. R. Silva wrote:
>> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
>> index fd48075810dd..6498d61e8956 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
>> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
>> @@ -219,12 +219,6 @@ struct rxe_resp_info {
>> u32 rkey;
>> u32 length;
>>
>> - /* SRQ only */
>> - struct {
>> - struct rxe_recv_wqe wqe;
>> - struct ib_sge sge[RXE_MAX_SGE];
>> - } srq_wqe;
> I think this existing is just a mess, can we fix it properly?
>
> What this code wants to do is to have rxe_resp_info allocate a
> rxe_recv_wqe and have a maximum size of its flex array pre-allocated.
>
> Probably like this, though maybe we need a FLEX version of the
> INIT_RDMA_OBJ_SIZE macro to make it safer.
>
> Zhu, this seems like a good thing for you to look at?
Thanks. I’ll take a closer look at this.
I’ll provide my comments over the weekend.
Zhu Yanjun
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
> index 38d8c408320f11..189eaa59a5fb14 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.c
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
> @@ -1524,7 +1524,8 @@ static const struct ib_device_ops rxe_dev_ops = {
> INIT_RDMA_OBJ_SIZE(ib_ah, rxe_ah, ibah),
> INIT_RDMA_OBJ_SIZE(ib_cq, rxe_cq, ibcq),
> INIT_RDMA_OBJ_SIZE(ib_pd, rxe_pd, ibpd),
> - INIT_RDMA_OBJ_SIZE(ib_qp, rxe_qp, ibqp),
> + /* For resp.srq_wqe.dma.sge */
> + INIT_RDMA_OBJ_SIZE(ib_qp, rxe_qp, ibqp) + RXE_MAX_SGE*sizeof(struct ib_sge),
> INIT_RDMA_OBJ_SIZE(ib_srq, rxe_srq, ibsrq),
> INIT_RDMA_OBJ_SIZE(ib_ucontext, rxe_ucontext, ibuc),
> INIT_RDMA_OBJ_SIZE(ib_mw, rxe_mw, ibmw),
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
> index fd48075810dd10..dda741ec3ac701 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> @@ -219,12 +219,6 @@ struct rxe_resp_info {
> u32 rkey;
> u32 length;
>
> - /* SRQ only */
> - struct {
> - struct rxe_recv_wqe wqe;
> - struct ib_sge sge[RXE_MAX_SGE];
> - } srq_wqe;
> -
> /* Responder resources. It's a circular list where the oldest
> * resource is dropped first.
> */
> @@ -232,6 +226,9 @@ struct rxe_resp_info {
> unsigned int res_head;
> unsigned int res_tail;
> struct resp_res *res;
> +
> + /* SRQ only. srq_wqe.dma.sge is a flex array */
> + struct rxe_recv_wqe srq_wqe;
> };
>
> struct rxe_qp {
> @@ -269,7 +266,6 @@ struct rxe_qp {
>
> struct rxe_req_info req;
> struct rxe_comp_info comp;
> - struct rxe_resp_info resp;
>
> atomic_t ssn;
> atomic_t skb_out;
> @@ -289,6 +285,7 @@ struct rxe_qp {
> spinlock_t state_lock; /* guard requester and completer */
>
> struct execute_work cleanup_work;
> + struct rxe_resp_info resp;
> };
>
> enum {
On Tue, Nov 11, 2025 at 12:35:02PM +0900, Gustavo A. R. Silva wrote:
> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> getting ready to enable it, globally.
>
> Use the new TRAILING_OVERLAP() helper to fix the following warning:
>
> 21 drivers/infiniband/sw/rxe/rxe_verbs.h:271:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>
> This helper creates a union between a flexible-array member (FAM) and a
> set of MEMBERS that would otherwise follow it.
>
> This overlays the trailing MEMBER struct ib_sge sge[RXE_MAX_SGE]; onto
> the FAM struct rxe_recv_wqe::dma.sge, while keeping the FAM and the
> start of MEMBER aligned.
>
> The static_assert() ensures this alignment remains, and it's
> intentionally placed inmediately after the related structure --no
> blank line in between.
>
> Lastly, move the conflicting declaration struct rxe_resp_info resp;
> to the end of the corresponding structure.
>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> drivers/infiniband/sw/rxe/rxe_verbs.h | 18 +++++++++++-------
> 1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
> index fd48075810dd..6498d61e8956 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> @@ -219,12 +219,6 @@ struct rxe_resp_info {
> u32 rkey;
> u32 length;
>
> - /* SRQ only */
> - struct {
> - struct rxe_recv_wqe wqe;
> - struct ib_sge sge[RXE_MAX_SGE];
> - } srq_wqe;
> -
> /* Responder resources. It's a circular list where the oldest
> * resource is dropped first.
> */
> @@ -232,7 +226,15 @@ struct rxe_resp_info {
> unsigned int res_head;
> unsigned int res_tail;
> struct resp_res *res;
> +
> + /* SRQ only */
> + /* Must be last as it ends in a flexible-array member. */
> + TRAILING_OVERLAP(struct rxe_recv_wqe, wqe, dma.sge,
> + struct ib_sge sge[RXE_MAX_SGE];
> + ) srq_wqe;
Will this change be enough?
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
index fd48075810dd..9ab11421a585 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.h
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
@@ -219,12 +219,6 @@ struct rxe_resp_info {
u32 rkey;
u32 length;
- /* SRQ only */
- struct {
- struct rxe_recv_wqe wqe;
- struct ib_sge sge[RXE_MAX_SGE];
- } srq_wqe;
-
/* Responder resources. It's a circular list where the oldest
* resource is dropped first.
*/
@@ -232,6 +226,12 @@ struct rxe_resp_info {
unsigned int res_head;
unsigned int res_tail;
struct resp_res *res;
+
+ /* SRQ only */
+ struct {
+ struct ib_sge sge[RXE_MAX_SGE];
+ struct rxe_recv_wqe wqe;
+ } srq_wqe;
};
struct rxe_qp {
~
On 11/11/25 20:56, Leon Romanovsky wrote:
> On Tue, Nov 11, 2025 at 12:35:02PM +0900, Gustavo A. R. Silva wrote:
>> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
>> getting ready to enable it, globally.
>>
>> Use the new TRAILING_OVERLAP() helper to fix the following warning:
>>
>> 21 drivers/infiniband/sw/rxe/rxe_verbs.h:271:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>>
>> This helper creates a union between a flexible-array member (FAM) and a
>> set of MEMBERS that would otherwise follow it.
>>
>> This overlays the trailing MEMBER struct ib_sge sge[RXE_MAX_SGE]; onto
>> the FAM struct rxe_recv_wqe::dma.sge, while keeping the FAM and the
>> start of MEMBER aligned.
>>
>> The static_assert() ensures this alignment remains, and it's
>> intentionally placed inmediately after the related structure --no
>> blank line in between.
>>
>> Lastly, move the conflicting declaration struct rxe_resp_info resp;
>> to the end of the corresponding structure.
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
>> ---
>> drivers/infiniband/sw/rxe/rxe_verbs.h | 18 +++++++++++-------
>> 1 file changed, 11 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
>> index fd48075810dd..6498d61e8956 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
>> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
>> @@ -219,12 +219,6 @@ struct rxe_resp_info {
>> u32 rkey;
>> u32 length;
>>
>> - /* SRQ only */
>> - struct {
>> - struct rxe_recv_wqe wqe;
>> - struct ib_sge sge[RXE_MAX_SGE];
>> - } srq_wqe;
>> -
>> /* Responder resources. It's a circular list where the oldest
>> * resource is dropped first.
>> */
>> @@ -232,7 +226,15 @@ struct rxe_resp_info {
>> unsigned int res_head;
>> unsigned int res_tail;
>> struct resp_res *res;
>> +
>> + /* SRQ only */
>> + /* Must be last as it ends in a flexible-array member. */
>> + TRAILING_OVERLAP(struct rxe_recv_wqe, wqe, dma.sge,
>> + struct ib_sge sge[RXE_MAX_SGE];
>> + ) srq_wqe;
>
> Will this change be enough?
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
> index fd48075810dd..9ab11421a585 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> @@ -219,12 +219,6 @@ struct rxe_resp_info {
> u32 rkey;
> u32 length;
>
> - /* SRQ only */
> - struct {
> - struct rxe_recv_wqe wqe;
> - struct ib_sge sge[RXE_MAX_SGE];
> - } srq_wqe;
> -
> /* Responder resources. It's a circular list where the oldest
> * resource is dropped first.
> */
> @@ -232,6 +226,12 @@ struct rxe_resp_info {
> unsigned int res_head;
> unsigned int res_tail;
> struct resp_res *res;
> +
> + /* SRQ only */
> + struct {
> + struct ib_sge sge[RXE_MAX_SGE];
> + struct rxe_recv_wqe wqe;
> + } srq_wqe;
> };
The question is if this is really what you want?
sge[RXE_MAX_SGE] is of the following type:
struct ib_sge {
u64 addr;
u32 length;
u32 lkey;
};
and struct rxe_recv_wqe::dma.sge[] is of type:
struct rxe_sge {
__aligned_u64 addr;
__u32 length;
__u32 lkey;
};
Both types are basically the same, and the original code looks
pretty much like what people do when they want to pre-allocate
a number of elements (of the same element type as the flex array)
for a flexible-array member.
Based on the above, the change you suggest seems a bit suspicious,
and I'm not sure that's actually what you want?
Thanks
-Gustavo
On Tue, Nov 11, 2025 at 09:14:05PM +0900, Gustavo A. R. Silva wrote:
>
>
> On 11/11/25 20:56, Leon Romanovsky wrote:
> > On Tue, Nov 11, 2025 at 12:35:02PM +0900, Gustavo A. R. Silva wrote:
> > > -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> > > getting ready to enable it, globally.
> > >
> > > Use the new TRAILING_OVERLAP() helper to fix the following warning:
> > >
> > > 21 drivers/infiniband/sw/rxe/rxe_verbs.h:271:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> > >
> > > This helper creates a union between a flexible-array member (FAM) and a
> > > set of MEMBERS that would otherwise follow it.
> > >
> > > This overlays the trailing MEMBER struct ib_sge sge[RXE_MAX_SGE]; onto
> > > the FAM struct rxe_recv_wqe::dma.sge, while keeping the FAM and the
> > > start of MEMBER aligned.
> > >
> > > The static_assert() ensures this alignment remains, and it's
> > > intentionally placed inmediately after the related structure --no
> > > blank line in between.
> > >
> > > Lastly, move the conflicting declaration struct rxe_resp_info resp;
> > > to the end of the corresponding structure.
> > >
> > > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> > > ---
> > > drivers/infiniband/sw/rxe/rxe_verbs.h | 18 +++++++++++-------
> > > 1 file changed, 11 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > index fd48075810dd..6498d61e8956 100644
> > > --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > @@ -219,12 +219,6 @@ struct rxe_resp_info {
> > > u32 rkey;
> > > u32 length;
> > > - /* SRQ only */
> > > - struct {
> > > - struct rxe_recv_wqe wqe;
> > > - struct ib_sge sge[RXE_MAX_SGE];
> > > - } srq_wqe;
> > > -
> > > /* Responder resources. It's a circular list where the oldest
> > > * resource is dropped first.
> > > */
> > > @@ -232,7 +226,15 @@ struct rxe_resp_info {
> > > unsigned int res_head;
> > > unsigned int res_tail;
> > > struct resp_res *res;
> > > +
> > > + /* SRQ only */
> > > + /* Must be last as it ends in a flexible-array member. */
> > > + TRAILING_OVERLAP(struct rxe_recv_wqe, wqe, dma.sge,
> > > + struct ib_sge sge[RXE_MAX_SGE];
> > > + ) srq_wqe;
> >
> > Will this change be enough?
> >
> > diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
> > index fd48075810dd..9ab11421a585 100644
> > --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> > +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> > @@ -219,12 +219,6 @@ struct rxe_resp_info {
> > u32 rkey;
> > u32 length;
> > - /* SRQ only */
> > - struct {
> > - struct rxe_recv_wqe wqe;
> > - struct ib_sge sge[RXE_MAX_SGE];
> > - } srq_wqe;
> > -
> > /* Responder resources. It's a circular list where the oldest
> > * resource is dropped first.
> > */
> > @@ -232,6 +226,12 @@ struct rxe_resp_info {
> > unsigned int res_head;
> > unsigned int res_tail;
> > struct resp_res *res;
> > +
> > + /* SRQ only */
> > + struct {
> > + struct ib_sge sge[RXE_MAX_SGE];
> > + struct rxe_recv_wqe wqe;
> > + } srq_wqe;
> > };
>
> The question is if this is really what you want?
>
> sge[RXE_MAX_SGE] is of the following type:
>
> struct ib_sge {
> u64 addr;
> u32 length;
> u32 lkey;
> };
>
> and struct rxe_recv_wqe::dma.sge[] is of type:
>
> struct rxe_sge {
> __aligned_u64 addr;
> __u32 length;
> __u32 lkey;
> };
>
> Both types are basically the same, and the original code looks
> pretty much like what people do when they want to pre-allocate
> a number of elements (of the same element type as the flex array)
> for a flexible-array member.
>
> Based on the above, the change you suggest seems a bit suspicious,
> and I'm not sure that's actually what you want?
You wrote about this error: "warning: structure containing a flexible array
member is not at the end of another structure".
My suggestion was simply to move that flex array to be the last element
and save us from the need to have some complex, magic macro in RXE.
Thanks
>
> Thanks
> -Gustavo
>
>
>
>
>
On 11/11/25 23:19, Leon Romanovsky wrote:
> On Tue, Nov 11, 2025 at 09:14:05PM +0900, Gustavo A. R. Silva wrote:
>>
>>
>> On 11/11/25 20:56, Leon Romanovsky wrote:
>>> On Tue, Nov 11, 2025 at 12:35:02PM +0900, Gustavo A. R. Silva wrote:
>>>> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
>>>> getting ready to enable it, globally.
>>>>
>>>> Use the new TRAILING_OVERLAP() helper to fix the following warning:
>>>>
>>>> 21 drivers/infiniband/sw/rxe/rxe_verbs.h:271:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>>>>
>>>> This helper creates a union between a flexible-array member (FAM) and a
>>>> set of MEMBERS that would otherwise follow it.
>>>>
>>>> This overlays the trailing MEMBER struct ib_sge sge[RXE_MAX_SGE]; onto
>>>> the FAM struct rxe_recv_wqe::dma.sge, while keeping the FAM and the
>>>> start of MEMBER aligned.
>>>>
>>>> The static_assert() ensures this alignment remains, and it's
>>>> intentionally placed inmediately after the related structure --no
>>>> blank line in between.
>>>>
>>>> Lastly, move the conflicting declaration struct rxe_resp_info resp;
>>>> to the end of the corresponding structure.
>>>>
>>>> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
>>>> ---
>>>> drivers/infiniband/sw/rxe/rxe_verbs.h | 18 +++++++++++-------
>>>> 1 file changed, 11 insertions(+), 7 deletions(-)
>>>>
>>>> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
>>>> index fd48075810dd..6498d61e8956 100644
>>>> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
>>>> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
>>>> @@ -219,12 +219,6 @@ struct rxe_resp_info {
>>>> u32 rkey;
>>>> u32 length;
>>>> - /* SRQ only */
>>>> - struct {
>>>> - struct rxe_recv_wqe wqe;
>>>> - struct ib_sge sge[RXE_MAX_SGE];
>>>> - } srq_wqe;
>>>> -
>>>> /* Responder resources. It's a circular list where the oldest
>>>> * resource is dropped first.
>>>> */
>>>> @@ -232,7 +226,15 @@ struct rxe_resp_info {
>>>> unsigned int res_head;
>>>> unsigned int res_tail;
>>>> struct resp_res *res;
>>>> +
>>>> + /* SRQ only */
>>>> + /* Must be last as it ends in a flexible-array member. */
>>>> + TRAILING_OVERLAP(struct rxe_recv_wqe, wqe, dma.sge,
>>>> + struct ib_sge sge[RXE_MAX_SGE];
>>>> + ) srq_wqe;
>>>
>>> Will this change be enough?
>>>
>>> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
>>> index fd48075810dd..9ab11421a585 100644
>>> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
>>> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
>>> @@ -219,12 +219,6 @@ struct rxe_resp_info {
>>> u32 rkey;
>>> u32 length;
>>> - /* SRQ only */
>>> - struct {
>>> - struct rxe_recv_wqe wqe;
>>> - struct ib_sge sge[RXE_MAX_SGE];
>>> - } srq_wqe;
>>> -
>>> /* Responder resources. It's a circular list where the oldest
>>> * resource is dropped first.
>>> */
>>> @@ -232,6 +226,12 @@ struct rxe_resp_info {
>>> unsigned int res_head;
>>> unsigned int res_tail;
>>> struct resp_res *res;
>>> +
>>> + /* SRQ only */
>>> + struct {
>>> + struct ib_sge sge[RXE_MAX_SGE];
>>> + struct rxe_recv_wqe wqe;
>>> + } srq_wqe;
>>> };
>>
>> The question is if this is really what you want?
>>
>> sge[RXE_MAX_SGE] is of the following type:
>>
>> struct ib_sge {
>> u64 addr;
>> u32 length;
>> u32 lkey;
>> };
>>
>> and struct rxe_recv_wqe::dma.sge[] is of type:
>>
>> struct rxe_sge {
>> __aligned_u64 addr;
>> __u32 length;
>> __u32 lkey;
>> };
>>
>> Both types are basically the same, and the original code looks
>> pretty much like what people do when they want to pre-allocate
>> a number of elements (of the same element type as the flex array)
>> for a flexible-array member.
>>
>> Based on the above, the change you suggest seems a bit suspicious,
>> and I'm not sure that's actually what you want?
>
> You wrote about this error: "warning: structure containing a flexible array
> member is not at the end of another structure".
>
> My suggestion was simply to move that flex array to be the last element
> and save us from the need to have some complex, magic macro in RXE.
Yep, but as I commented above, that doesn't seem to be the right change.
Look at the following couple of lines:
drivers/infiniband/sw/rxe/rxe_resp.c-286- size = sizeof(*wqe) + wqe->dma.num_sge*sizeof(struct rxe_sge);
drivers/infiniband/sw/rxe/rxe_resp.c-287- memcpy(&qp->resp.srq_wqe, wqe, size);
Notice that line 286 is the open-coded arithmetic (struct_size(wqe,
dma.sge, wqe->dma.num_sge) is preferred) to get the number of bytes
to allocate for a flexible structure, in this case struct rxe_recv_wqe,
and its flexible-array member, in this case struct rxe_recv_wqe::dma.sge[].
So, `size` bytes are written in qp->resp.srq_wqe, and the reason this works
seems to be because of the pre-allocation of RXE_MAX_SGE number of elements
for flex array struct rxe_recv_wqe::dma.sge[] given by:
struct {
struct rxe_recv_wqe wqe;
struct ib_sge sge[RXE_MAX_SGE];
} srq_wqe;
So, unless I'm missing something, struct ib_sge sge[RXE_MAX_SGE];
should be aligned with struct rxe_recv_wqe wqe::dma.sge[].
The TRAILING_OVERLAP() macro is also designed to ensure alignment in these
cases (and the static_assert() to preserve it). See this thread:
https://lore.kernel.org/linux-hardening/aLiYrQGdGmaDTtLF@kspp/
Thanks
-Gustavo
On Wed, Nov 12, 2025 at 05:49:05PM +0900, Gustavo A. R. Silva wrote:
>
>
> On 11/11/25 23:19, Leon Romanovsky wrote:
> > On Tue, Nov 11, 2025 at 09:14:05PM +0900, Gustavo A. R. Silva wrote:
> > >
> > >
> > > On 11/11/25 20:56, Leon Romanovsky wrote:
> > > > On Tue, Nov 11, 2025 at 12:35:02PM +0900, Gustavo A. R. Silva wrote:
> > > > > -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> > > > > getting ready to enable it, globally.
> > > > >
> > > > > Use the new TRAILING_OVERLAP() helper to fix the following warning:
> > > > >
> > > > > 21 drivers/infiniband/sw/rxe/rxe_verbs.h:271:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> > > > >
> > > > > This helper creates a union between a flexible-array member (FAM) and a
> > > > > set of MEMBERS that would otherwise follow it.
> > > > >
> > > > > This overlays the trailing MEMBER struct ib_sge sge[RXE_MAX_SGE]; onto
> > > > > the FAM struct rxe_recv_wqe::dma.sge, while keeping the FAM and the
> > > > > start of MEMBER aligned.
> > > > >
> > > > > The static_assert() ensures this alignment remains, and it's
> > > > > intentionally placed inmediately after the related structure --no
> > > > > blank line in between.
> > > > >
> > > > > Lastly, move the conflicting declaration struct rxe_resp_info resp;
> > > > > to the end of the corresponding structure.
> > > > >
> > > > > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> > > > > ---
> > > > > drivers/infiniband/sw/rxe/rxe_verbs.h | 18 +++++++++++-------
> > > > > 1 file changed, 11 insertions(+), 7 deletions(-)
> > > > >
> > > > > diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > > > index fd48075810dd..6498d61e8956 100644
> > > > > --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > > > +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > > > @@ -219,12 +219,6 @@ struct rxe_resp_info {
> > > > > u32 rkey;
> > > > > u32 length;
> > > > > - /* SRQ only */
> > > > > - struct {
> > > > > - struct rxe_recv_wqe wqe;
> > > > > - struct ib_sge sge[RXE_MAX_SGE];
> > > > > - } srq_wqe;
> > > > > -
> > > > > /* Responder resources. It's a circular list where the oldest
> > > > > * resource is dropped first.
> > > > > */
> > > > > @@ -232,7 +226,15 @@ struct rxe_resp_info {
> > > > > unsigned int res_head;
> > > > > unsigned int res_tail;
> > > > > struct resp_res *res;
> > > > > +
> > > > > + /* SRQ only */
> > > > > + /* Must be last as it ends in a flexible-array member. */
> > > > > + TRAILING_OVERLAP(struct rxe_recv_wqe, wqe, dma.sge,
> > > > > + struct ib_sge sge[RXE_MAX_SGE];
> > > > > + ) srq_wqe;
> > > >
> > > > Will this change be enough?
> > > >
> > > > diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > > index fd48075810dd..9ab11421a585 100644
> > > > --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > > +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > > @@ -219,12 +219,6 @@ struct rxe_resp_info {
> > > > u32 rkey;
> > > > u32 length;
> > > > - /* SRQ only */
> > > > - struct {
> > > > - struct rxe_recv_wqe wqe;
> > > > - struct ib_sge sge[RXE_MAX_SGE];
> > > > - } srq_wqe;
> > > > -
> > > > /* Responder resources. It's a circular list where the oldest
> > > > * resource is dropped first.
> > > > */
> > > > @@ -232,6 +226,12 @@ struct rxe_resp_info {
> > > > unsigned int res_head;
> > > > unsigned int res_tail;
> > > > struct resp_res *res;
> > > > +
> > > > + /* SRQ only */
> > > > + struct {
> > > > + struct ib_sge sge[RXE_MAX_SGE];
> > > > + struct rxe_recv_wqe wqe;
> > > > + } srq_wqe;
> > > > };
> > >
> > > The question is if this is really what you want?
> > >
> > > sge[RXE_MAX_SGE] is of the following type:
> > >
> > > struct ib_sge {
> > > u64 addr;
> > > u32 length;
> > > u32 lkey;
> > > };
> > >
> > > and struct rxe_recv_wqe::dma.sge[] is of type:
> > >
> > > struct rxe_sge {
> > > __aligned_u64 addr;
> > > __u32 length;
> > > __u32 lkey;
> > > };
> > >
> > > Both types are basically the same, and the original code looks
> > > pretty much like what people do when they want to pre-allocate
> > > a number of elements (of the same element type as the flex array)
> > > for a flexible-array member.
> > >
> > > Based on the above, the change you suggest seems a bit suspicious,
> > > and I'm not sure that's actually what you want?
> >
> > You wrote about this error: "warning: structure containing a flexible array
> > member is not at the end of another structure".
> >
> > My suggestion was simply to move that flex array to be the last element
> > and save us from the need to have some complex, magic macro in RXE.
>
> Yep, but as I commented above, that doesn't seem to be the right change.
>
> Look at the following couple of lines:
>
> drivers/infiniband/sw/rxe/rxe_resp.c-286- size = sizeof(*wqe) + wqe->dma.num_sge*sizeof(struct rxe_sge);
> drivers/infiniband/sw/rxe/rxe_resp.c-287- memcpy(&qp->resp.srq_wqe, wqe, size);
>
> Notice that line 286 is the open-coded arithmetic (struct_size(wqe,
> dma.sge, wqe->dma.num_sge) is preferred) to get the number of bytes
> to allocate for a flexible structure, in this case struct rxe_recv_wqe,
> and its flexible-array member, in this case struct rxe_recv_wqe::dma.sge[].
>
> So, `size` bytes are written in qp->resp.srq_wqe, and the reason this works
> seems to be because of the pre-allocation of RXE_MAX_SGE number of elements
> for flex array struct rxe_recv_wqe::dma.sge[] given by:
>
> struct {
> struct rxe_recv_wqe wqe;
> struct ib_sge sge[RXE_MAX_SGE];
> } srq_wqe;
So you are saying that it works because it is written properly, so what
is the problem? Why do we need to fix properly working and written code
to be less readable?
>
> So, unless I'm missing something, struct ib_sge sge[RXE_MAX_SGE];
> should be aligned with struct rxe_recv_wqe wqe::dma.sge[].
It is and moving to the end of struct will continue to keep it aligned.
>
> The TRAILING_OVERLAP() macro is also designed to ensure alignment in these
> cases (and the static_assert() to preserve it). See this thread:
>
> https://lore.kernel.org/linux-hardening/aLiYrQGdGmaDTtLF@kspp/
>
> Thanks
> -Gustavo
>
>
>
>
On 11/12/25 18:32, Leon Romanovsky wrote:
> On Wed, Nov 12, 2025 at 05:49:05PM +0900, Gustavo A. R. Silva wrote:
>>
>>
>> On 11/11/25 23:19, Leon Romanovsky wrote:
>>> On Tue, Nov 11, 2025 at 09:14:05PM +0900, Gustavo A. R. Silva wrote:
>>>>
>>>>
>>>> On 11/11/25 20:56, Leon Romanovsky wrote:
>>>>> On Tue, Nov 11, 2025 at 12:35:02PM +0900, Gustavo A. R. Silva wrote:
>>>>>> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
>>>>>> getting ready to enable it, globally.
>>>>>>
>>>>>> Use the new TRAILING_OVERLAP() helper to fix the following warning:
>>>>>>
>>>>>> 21 drivers/infiniband/sw/rxe/rxe_verbs.h:271:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>>>>>>
>>>>>> This helper creates a union between a flexible-array member (FAM) and a
>>>>>> set of MEMBERS that would otherwise follow it.
>>>>>>
>>>>>> This overlays the trailing MEMBER struct ib_sge sge[RXE_MAX_SGE]; onto
>>>>>> the FAM struct rxe_recv_wqe::dma.sge, while keeping the FAM and the
>>>>>> start of MEMBER aligned.
>>>>>>
>>>>>> The static_assert() ensures this alignment remains, and it's
>>>>>> intentionally placed inmediately after the related structure --no
>>>>>> blank line in between.
>>>>>>
>>>>>> Lastly, move the conflicting declaration struct rxe_resp_info resp;
>>>>>> to the end of the corresponding structure.
>>>>>>
>>>>>> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
>>>>>> ---
>>>>>> drivers/infiniband/sw/rxe/rxe_verbs.h | 18 +++++++++++-------
>>>>>> 1 file changed, 11 insertions(+), 7 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
>>>>>> index fd48075810dd..6498d61e8956 100644
>>>>>> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
>>>>>> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
>>>>>> @@ -219,12 +219,6 @@ struct rxe_resp_info {
>>>>>> u32 rkey;
>>>>>> u32 length;
>>>>>> - /* SRQ only */
>>>>>> - struct {
>>>>>> - struct rxe_recv_wqe wqe;
>>>>>> - struct ib_sge sge[RXE_MAX_SGE];
>>>>>> - } srq_wqe;
>>>>>> -
>>>>>> /* Responder resources. It's a circular list where the oldest
>>>>>> * resource is dropped first.
>>>>>> */
>>>>>> @@ -232,7 +226,15 @@ struct rxe_resp_info {
>>>>>> unsigned int res_head;
>>>>>> unsigned int res_tail;
>>>>>> struct resp_res *res;
>>>>>> +
>>>>>> + /* SRQ only */
>>>>>> + /* Must be last as it ends in a flexible-array member. */
>>>>>> + TRAILING_OVERLAP(struct rxe_recv_wqe, wqe, dma.sge,
>>>>>> + struct ib_sge sge[RXE_MAX_SGE];
>>>>>> + ) srq_wqe;
>>>>>
>>>>> Will this change be enough?
>>>>>
>>>>> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
>>>>> index fd48075810dd..9ab11421a585 100644
>>>>> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
>>>>> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
>>>>> @@ -219,12 +219,6 @@ struct rxe_resp_info {
>>>>> u32 rkey;
>>>>> u32 length;
>>>>> - /* SRQ only */
>>>>> - struct {
>>>>> - struct rxe_recv_wqe wqe;
>>>>> - struct ib_sge sge[RXE_MAX_SGE];
>>>>> - } srq_wqe;
>>>>> -
>>>>> /* Responder resources. It's a circular list where the oldest
>>>>> * resource is dropped first.
>>>>> */
>>>>> @@ -232,6 +226,12 @@ struct rxe_resp_info {
>>>>> unsigned int res_head;
>>>>> unsigned int res_tail;
>>>>> struct resp_res *res;
>>>>> +
>>>>> + /* SRQ only */
>>>>> + struct {
>>>>> + struct ib_sge sge[RXE_MAX_SGE];
>>>>> + struct rxe_recv_wqe wqe;
>>>>> + } srq_wqe;
>>>>> };
>>>>
>>>> The question is if this is really what you want?
>>>>
>>>> sge[RXE_MAX_SGE] is of the following type:
>>>>
>>>> struct ib_sge {
>>>> u64 addr;
>>>> u32 length;
>>>> u32 lkey;
>>>> };
>>>>
>>>> and struct rxe_recv_wqe::dma.sge[] is of type:
>>>>
>>>> struct rxe_sge {
>>>> __aligned_u64 addr;
>>>> __u32 length;
>>>> __u32 lkey;
>>>> };
>>>>
>>>> Both types are basically the same, and the original code looks
>>>> pretty much like what people do when they want to pre-allocate
>>>> a number of elements (of the same element type as the flex array)
>>>> for a flexible-array member.
>>>>
>>>> Based on the above, the change you suggest seems a bit suspicious,
>>>> and I'm not sure that's actually what you want?
>>>
>>> You wrote about this error: "warning: structure containing a flexible array
>>> member is not at the end of another structure".
>>>
>>> My suggestion was simply to move that flex array to be the last element
>>> and save us from the need to have some complex, magic macro in RXE.
>>
>> Yep, but as I commented above, that doesn't seem to be the right change.
>>
>> Look at the following couple of lines:
>>
>> drivers/infiniband/sw/rxe/rxe_resp.c-286- size = sizeof(*wqe) + wqe->dma.num_sge*sizeof(struct rxe_sge);
>> drivers/infiniband/sw/rxe/rxe_resp.c-287- memcpy(&qp->resp.srq_wqe, wqe, size);
>>
>> Notice that line 286 is the open-coded arithmetic (struct_size(wqe,
>> dma.sge, wqe->dma.num_sge) is preferred) to get the number of bytes
>> to allocate for a flexible structure, in this case struct rxe_recv_wqe,
>> and its flexible-array member, in this case struct rxe_recv_wqe::dma.sge[].
>>
>> So, `size` bytes are written in qp->resp.srq_wqe, and the reason this works
>> seems to be because of the pre-allocation of RXE_MAX_SGE number of elements
>> for flex array struct rxe_recv_wqe::dma.sge[] given by:
>>
>> struct {
>> struct rxe_recv_wqe wqe;
>> struct ib_sge sge[RXE_MAX_SGE];
>> } srq_wqe;
>
> So you are saying that it works because it is written properly, so what
> is the problem? Why do we need to fix properly working and written code
> to be less readable?
No one said the original code is not working as expected. The issue here is
that the FAM is not at the end, and this causes a -Wflex-array-member-not-at-end
warning. The change I propose places the FAM at the end, and the functionality
remains exactly the same.
You're probably not aware of the work we've been doing to enable
-Wflex-array-member-not-at-end in mainline. If you're interested, below you
can take a look at other similar changes I (and others) have been doing to
complete this work:
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/log/?qt=grep&q=-Wflex-array-member-not-at-end
>
>>
>> So, unless I'm missing something, struct ib_sge sge[RXE_MAX_SGE];
>> should be aligned with struct rxe_recv_wqe wqe::dma.sge[].
>
> It is and moving to the end of struct will continue to keep it aligned.
I think there is something you are missing here. The following pieces of
code are no equivalent:
struct {
struct rxe_recv_wqe wqe;
struct ib_sge sge[RXE_MAX_SGE];
} srq_wqe;
struct {
struct ib_sge sge[RXE_MAX_SGE];
struct rxe_recv_wqe wqe;
} srq_wqe;
What I'm understanding from your last couple of responses is that you think
the above are equivalent. My previous response tried to explain why that is
not the case.
>
>>
>> The TRAILING_OVERLAP() macro is also designed to ensure alignment in these
>> cases (and the static_assert() to preserve it). See this thread:
>>
>> https://lore.kernel.org/linux-hardening/aLiYrQGdGmaDTtLF@kspp/
>>
Thanks
-Gustavo
On Wed, Nov 12, 2025 at 06:50:16PM +0900, Gustavo A. R. Silva wrote:
>
>
> On 11/12/25 18:32, Leon Romanovsky wrote:
> > On Wed, Nov 12, 2025 at 05:49:05PM +0900, Gustavo A. R. Silva wrote:
> > >
> > >
> > > On 11/11/25 23:19, Leon Romanovsky wrote:
> > > > On Tue, Nov 11, 2025 at 09:14:05PM +0900, Gustavo A. R. Silva wrote:
> > > > >
> > > > >
> > > > > On 11/11/25 20:56, Leon Romanovsky wrote:
> > > > > > On Tue, Nov 11, 2025 at 12:35:02PM +0900, Gustavo A. R. Silva wrote:
> > > > > > > -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> > > > > > > getting ready to enable it, globally.
> > > > > > >
> > > > > > > Use the new TRAILING_OVERLAP() helper to fix the following warning:
> > > > > > >
> > > > > > > 21 drivers/infiniband/sw/rxe/rxe_verbs.h:271:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> > > > > > >
> > > > > > > This helper creates a union between a flexible-array member (FAM) and a
> > > > > > > set of MEMBERS that would otherwise follow it.
> > > > > > >
> > > > > > > This overlays the trailing MEMBER struct ib_sge sge[RXE_MAX_SGE]; onto
> > > > > > > the FAM struct rxe_recv_wqe::dma.sge, while keeping the FAM and the
> > > > > > > start of MEMBER aligned.
> > > > > > >
> > > > > > > The static_assert() ensures this alignment remains, and it's
> > > > > > > intentionally placed inmediately after the related structure --no
> > > > > > > blank line in between.
> > > > > > >
> > > > > > > Lastly, move the conflicting declaration struct rxe_resp_info resp;
> > > > > > > to the end of the corresponding structure.
> > > > > > >
> > > > > > > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> > > > > > > ---
> > > > > > > drivers/infiniband/sw/rxe/rxe_verbs.h | 18 +++++++++++-------
> > > > > > > 1 file changed, 11 insertions(+), 7 deletions(-)
> > > > > > >
> > > > > > > diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > > > > > index fd48075810dd..6498d61e8956 100644
> > > > > > > --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > > > > > +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > > > > > @@ -219,12 +219,6 @@ struct rxe_resp_info {
> > > > > > > u32 rkey;
> > > > > > > u32 length;
> > > > > > > - /* SRQ only */
> > > > > > > - struct {
> > > > > > > - struct rxe_recv_wqe wqe;
> > > > > > > - struct ib_sge sge[RXE_MAX_SGE];
> > > > > > > - } srq_wqe;
> > > > > > > -
> > > > > > > /* Responder resources. It's a circular list where the oldest
> > > > > > > * resource is dropped first.
> > > > > > > */
> > > > > > > @@ -232,7 +226,15 @@ struct rxe_resp_info {
> > > > > > > unsigned int res_head;
> > > > > > > unsigned int res_tail;
> > > > > > > struct resp_res *res;
> > > > > > > +
> > > > > > > + /* SRQ only */
> > > > > > > + /* Must be last as it ends in a flexible-array member. */
> > > > > > > + TRAILING_OVERLAP(struct rxe_recv_wqe, wqe, dma.sge,
> > > > > > > + struct ib_sge sge[RXE_MAX_SGE];
> > > > > > > + ) srq_wqe;
> > > > > >
> > > > > > Will this change be enough?
> > > > > >
> > > > > > diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > > > > index fd48075810dd..9ab11421a585 100644
> > > > > > --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > > > > +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
> > > > > > @@ -219,12 +219,6 @@ struct rxe_resp_info {
> > > > > > u32 rkey;
> > > > > > u32 length;
> > > > > > - /* SRQ only */
> > > > > > - struct {
> > > > > > - struct rxe_recv_wqe wqe;
> > > > > > - struct ib_sge sge[RXE_MAX_SGE];
> > > > > > - } srq_wqe;
> > > > > > -
> > > > > > /* Responder resources. It's a circular list where the oldest
> > > > > > * resource is dropped first.
> > > > > > */
> > > > > > @@ -232,6 +226,12 @@ struct rxe_resp_info {
> > > > > > unsigned int res_head;
> > > > > > unsigned int res_tail;
> > > > > > struct resp_res *res;
> > > > > > +
> > > > > > + /* SRQ only */
> > > > > > + struct {
> > > > > > + struct ib_sge sge[RXE_MAX_SGE];
> > > > > > + struct rxe_recv_wqe wqe;
> > > > > > + } srq_wqe;
> > > > > > };
> > > > >
> > > > > The question is if this is really what you want?
> > > > >
> > > > > sge[RXE_MAX_SGE] is of the following type:
> > > > >
> > > > > struct ib_sge {
> > > > > u64 addr;
> > > > > u32 length;
> > > > > u32 lkey;
> > > > > };
> > > > >
> > > > > and struct rxe_recv_wqe::dma.sge[] is of type:
> > > > >
> > > > > struct rxe_sge {
> > > > > __aligned_u64 addr;
> > > > > __u32 length;
> > > > > __u32 lkey;
> > > > > };
> > > > >
> > > > > Both types are basically the same, and the original code looks
> > > > > pretty much like what people do when they want to pre-allocate
> > > > > a number of elements (of the same element type as the flex array)
> > > > > for a flexible-array member.
> > > > >
> > > > > Based on the above, the change you suggest seems a bit suspicious,
> > > > > and I'm not sure that's actually what you want?
> > > >
> > > > You wrote about this error: "warning: structure containing a flexible array
> > > > member is not at the end of another structure".
> > > >
> > > > My suggestion was simply to move that flex array to be the last element
> > > > and save us from the need to have some complex, magic macro in RXE.
> > >
> > > Yep, but as I commented above, that doesn't seem to be the right change.
> > >
> > > Look at the following couple of lines:
> > >
> > > drivers/infiniband/sw/rxe/rxe_resp.c-286- size = sizeof(*wqe) + wqe->dma.num_sge*sizeof(struct rxe_sge);
> > > drivers/infiniband/sw/rxe/rxe_resp.c-287- memcpy(&qp->resp.srq_wqe, wqe, size);
> > >
> > > Notice that line 286 is the open-coded arithmetic (struct_size(wqe,
> > > dma.sge, wqe->dma.num_sge) is preferred) to get the number of bytes
> > > to allocate for a flexible structure, in this case struct rxe_recv_wqe,
> > > and its flexible-array member, in this case struct rxe_recv_wqe::dma.sge[].
> > >
> > > So, `size` bytes are written in qp->resp.srq_wqe, and the reason this works
> > > seems to be because of the pre-allocation of RXE_MAX_SGE number of elements
> > > for flex array struct rxe_recv_wqe::dma.sge[] given by:
> > >
> > > struct {
> > > struct rxe_recv_wqe wqe;
> > > struct ib_sge sge[RXE_MAX_SGE];
> > > } srq_wqe;
> >
> > So you are saying that it works because it is written properly, so what
> > is the problem? Why do we need to fix properly working and written code
> > to be less readable?
>
> No one said the original code is not working as expected. The issue here is
> that the FAM is not at the end, and this causes a -Wflex-array-member-not-at-end
> warning. The change I propose places the FAM at the end, and the functionality
> remains exactly the same.
>
> You're probably not aware of the work we've been doing to enable
> -Wflex-array-member-not-at-end in mainline. If you're interested, below you
> can take a look at other similar changes I (and others) have been doing to
> complete this work:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/log/?qt=grep&q=-Wflex-array-member-not-at-end
I'm aware of that work, just trying to find a simplest possible solution
for this specific driver. RXE is a development driver which won't benefit
from this hardening work at all.
>
> >
> > >
> > > So, unless I'm missing something, struct ib_sge sge[RXE_MAX_SGE];
> > > should be aligned with struct rxe_recv_wqe wqe::dma.sge[].
> >
> > It is and moving to the end of struct will continue to keep it aligned.
>
> I think there is something you are missing here. The following pieces of
> code are no equivalent:
>
> struct {
> struct rxe_recv_wqe wqe;
> struct ib_sge sge[RXE_MAX_SGE];
> } srq_wqe;
>
> struct {
> struct ib_sge sge[RXE_MAX_SGE];
> struct rxe_recv_wqe wqe;
> } srq_wqe;
>
> What I'm understanding from your last couple of responses is that you think
> the above are equivalent. My previous response tried to explain why that is
> not the case.
Yes, I already forgot about change in srq_wqe.
Thanks
>
> >
> > >
> > > The TRAILING_OVERLAP() macro is also designed to ensure alignment in these
> > > cases (and the static_assert() to preserve it). See this thread:
> > >
> > > https://lore.kernel.org/linux-hardening/aLiYrQGdGmaDTtLF@kspp/
> > >
>
> Thanks
> -Gustavo
在 2025/11/11 6:19, Leon Romanovsky 写道:
> On Tue, Nov 11, 2025 at 09:14:05PM +0900, Gustavo A. R. Silva wrote:
>>
>> On 11/11/25 20:56, Leon Romanovsky wrote:
>>> On Tue, Nov 11, 2025 at 12:35:02PM +0900, Gustavo A. R. Silva wrote:
>>>> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
>>>> getting ready to enable it, globally.
>>>>
>>>> Use the new TRAILING_OVERLAP() helper to fix the following warning:
>>>>
>>>> 21 drivers/infiniband/sw/rxe/rxe_verbs.h:271:33: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>>>>
>>>> This helper creates a union between a flexible-array member (FAM) and a
>>>> set of MEMBERS that would otherwise follow it.
>>>>
>>>> This overlays the trailing MEMBER struct ib_sge sge[RXE_MAX_SGE]; onto
>>>> the FAM struct rxe_recv_wqe::dma.sge, while keeping the FAM and the
>>>> start of MEMBER aligned.
>>>>
>>>> The static_assert() ensures this alignment remains, and it's
>>>> intentionally placed inmediately after the related structure --no
>>>> blank line in between.
>>>>
>>>> Lastly, move the conflicting declaration struct rxe_resp_info resp;
>>>> to the end of the corresponding structure.
>>>>
>>>> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
>>>> ---
>>>> drivers/infiniband/sw/rxe/rxe_verbs.h | 18 +++++++++++-------
>>>> 1 file changed, 11 insertions(+), 7 deletions(-)
>>>>
>>>> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
>>>> index fd48075810dd..6498d61e8956 100644
>>>> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
>>>> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
>>>> @@ -219,12 +219,6 @@ struct rxe_resp_info {
>>>> u32 rkey;
>>>> u32 length;
>>>> - /* SRQ only */
>>>> - struct {
>>>> - struct rxe_recv_wqe wqe;
>>>> - struct ib_sge sge[RXE_MAX_SGE];
>>>> - } srq_wqe;
>>>> -
>>>> /* Responder resources. It's a circular list where the oldest
>>>> * resource is dropped first.
>>>> */
>>>> @@ -232,7 +226,15 @@ struct rxe_resp_info {
>>>> unsigned int res_head;
>>>> unsigned int res_tail;
>>>> struct resp_res *res;
>>>> +
>>>> + /* SRQ only */
>>>> + /* Must be last as it ends in a flexible-array member. */
>>>> + TRAILING_OVERLAP(struct rxe_recv_wqe, wqe, dma.sge,
>>>> + struct ib_sge sge[RXE_MAX_SGE];
>>>> + ) srq_wqe;
>>> Will this change be enough?
>>>
>>> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
>>> index fd48075810dd..9ab11421a585 100644
>>> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
>>> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
>>> @@ -219,12 +219,6 @@ struct rxe_resp_info {
>>> u32 rkey;
>>> u32 length;
>>> - /* SRQ only */
>>> - struct {
>>> - struct rxe_recv_wqe wqe;
>>> - struct ib_sge sge[RXE_MAX_SGE];
>>> - } srq_wqe;
>>> -
>>> /* Responder resources. It's a circular list where the oldest
>>> * resource is dropped first.
>>> */
>>> @@ -232,6 +226,12 @@ struct rxe_resp_info {
>>> unsigned int res_head;
>>> unsigned int res_tail;
>>> struct resp_res *res;
>>> +
>>> + /* SRQ only */
>>> + struct {
>>> + struct ib_sge sge[RXE_MAX_SGE];
>>> + struct rxe_recv_wqe wqe;
>>> + } srq_wqe;
>>> };
>> The question is if this is really what you want?
>>
>> sge[RXE_MAX_SGE] is of the following type:
>>
>> struct ib_sge {
>> u64 addr;
>> u32 length;
>> u32 lkey;
>> };
>>
>> and struct rxe_recv_wqe::dma.sge[] is of type:
>>
>> struct rxe_sge {
>> __aligned_u64 addr;
>> __u32 length;
>> __u32 lkey;
>> };
>>
>> Both types are basically the same, and the original code looks
>> pretty much like what people do when they want to pre-allocate
>> a number of elements (of the same element type as the flex array)
>> for a flexible-array member.
>>
>> Based on the above, the change you suggest seems a bit suspicious,
>> and I'm not sure that's actually what you want?
> You wrote about this error: "warning: structure containing a flexible array
> member is not at the end of another structure".
>
> My suggestion was simply to move that flex array to be the last element
> and save us from the need to have some complex, magic macro in RXE.
Thanks, I agree with this approach. The macro is rather complicated, and
this solution fixes the problem in a straightforward way.
Yanjun.Zhu
>
> Thanks
>
>> Thanks
>> -Gustavo
>>
>>
>>
>>
>>
--
Best Regards,
Yanjun.Zhu
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