From 8d87f0c4e2edb38c0bc0f5e447becf124c71ea20 Mon Sep 17 00:00:00 2001
From: Robert Schmidt <robert.schmidt@openairinterface.org>
Date: Tue, 27 Feb 2024 18:54:36 +0100
Subject: [PATCH] get_phy_stats(): full list is non-fatal

Do not assert if the list of phy statistics is full; instead return
NULL.

In most places, this is handled appropriately (we do not store anything
if we can't). In nr_decode_pucch0(), the return value of get_phy_stats()
is used a little bit all over the function, and a constant
  if (uci_stats)
    uci_stats->variable++;
would look ugly, so make uci_stats point to the stack if we cannot store
in the phy_stats.
---
 openair1/PHY/INIT/nr_init.c          |  5 ++++-
 openair1/PHY/NR_TRANSPORT/pucch_rx.c | 11 ++++++++---
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/openair1/PHY/INIT/nr_init.c b/openair1/PHY/INIT/nr_init.c
index c864a0366a..1f918086b2 100644
--- a/openair1/PHY/INIT/nr_init.c
+++ b/openair1/PHY/INIT/nr_init.c
@@ -79,8 +79,11 @@ NR_gNB_PHY_STATS_t *get_phy_stats(PHY_VARS_gNB *gNB, uint16_t rnti)
     else if (!stats->active && first_free == -1)
       first_free = i;
   }
+
+  if (first_free < 0)
+    return NULL;
+
   // new stats
-  AssertFatal(first_free >= 0, "PHY statistics list is full\n");
   stats = &gNB->phy_stats[first_free];
   stats->active = true;
   stats->rnti = rnti;
diff --git a/openair1/PHY/NR_TRANSPORT/pucch_rx.c b/openair1/PHY/NR_TRANSPORT/pucch_rx.c
index 4ef42119bf..8a44e410f9 100644
--- a/openair1/PHY/NR_TRANSPORT/pucch_rx.c
+++ b/openair1/PHY/NR_TRANSPORT/pucch_rx.c
@@ -162,10 +162,15 @@ void nr_decode_pucch0(PHY_VARS_gNB *gNB,
               pucch_pdu->bit_len_harq,
               pucch_pdu->sr_flag);
 
+  /* it might be that the stats list is full: In this case, we will simply
+   * write to some memory on the stack instead of the UE's UCI stats */
+  NR_gNB_UCI_STATS_t stack_uci_stats = {0};
+  NR_gNB_UCI_STATS_t *uci_stats = &stack_uci_stats;
   NR_gNB_PHY_STATS_t *phy_stats = get_phy_stats(gNB, pucch_pdu->rnti);
-  AssertFatal(phy_stats != NULL, "phy_stats shouldn't be NULL\n");
-  phy_stats->frame = frame;
-  NR_gNB_UCI_STATS_t *uci_stats = &phy_stats->uci_stats;
+  if (phy_stats != NULL) {
+    phy_stats->frame = frame;
+    uci_stats = &phy_stats->uci_stats;
+  }
 
   int nr_sequences;
   const uint8_t *mcs;