ionic: Add robust udata support and zero-initialize udata structs

Read the IB_UVERBS_CORE_SUPPORT_ROBUST_UDATA flag from core_support
into ctx->robust_udata during context allocation. This allows the
provider to detect whether the kernel supports forward/backward
compatible udata handling, which is a prerequisite for safely using
extended request structs in future verb extensions.

Also zero-initialize uionic_qp, uionic_qp_resp, and uionic_ah_resp
stack variables to prevent stack garbage from leaking into the kernel
via ioctl buffers.

Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com>

providers/ionic/ionic.c

diff --git a/providers/ionic/ionic.c b/providers/ionic/ionic.c
index 6451aab..17b27c0 100644
--- a/providers/ionic/ionic.c
+++ b/providers/ionic/ionic.c
@@ -78,6 +78,9 @@
 	ctx->sq_expdb = !!(resp.expdb_qtypes & IONIC_EXPDB_SQ);
 	ctx->rq_expdb = !!(resp.expdb_qtypes & IONIC_EXPDB_RQ);
 
+	ctx->robust_udata = !!(verbs_get_device(ibdev)->core_support &
+			       IB_UVERBS_CORE_SUPPORT_ROBUST_UDATA);
+
 	mask = (1u << ctx->pg_shift) - 1;
 	ctx->dbpage_page = ionic_map_device(1u << ctx->pg_shift, cmd_fd,
 					    resp.dbell_offset & ~mask);

providers/ionic/ionic.h

diff --git a/providers/ionic/ionic.h b/providers/ionic/ionic.h
index cb1a8da..e556df3 100644
--- a/providers/ionic/ionic.h
+++ b/providers/ionic/ionic.h
@@ -102,6 +102,7 @@
 	uint8_t			expdb_mask;
 	bool			sq_expdb;
 	bool			rq_expdb;
+	bool			robust_udata;
 
 	void			*dbpage_page;
 	uint64_t		*dbpage;

providers/ionic/ionic_verbs.c

diff --git a/providers/ionic/ionic_verbs.c b/providers/ionic/ionic_verbs.c
index 1aa08f5..1159cec 100644
--- a/providers/ionic/ionic_verbs.c
+++ b/providers/ionic/ionic_verbs.c
@@ -2140,8 +2140,8 @@
 {
 	struct ionic_ctx *ctx = to_ionic_ctx(ibctx);
 	struct ionic_pd *pd = to_ionic_pd(ex->pd);
-	struct uionic_qp_resp resp;
-	struct uionic_qp req;
+	struct uionic_qp_resp resp = {};
+	struct uionic_qp req = {};
 	struct ionic_qp *qp;
 	struct ionic_cq *cq;
 	int rc;
@@ -3386,7 +3386,7 @@
 				      struct ibv_ah_attr *attr)
 {
 	struct ibv_pd *root_ibpd = to_ionic_root_ibpd(ibpd);
-	struct uionic_ah_resp resp;
+	struct uionic_ah_resp resp = {};
 	struct ionic_ah *ah;
 	int rc;