git: feeb19201dca - main - tcp: improve consistency of KASSERTs in tcp_sack.c

The branch main has been updated by tuexen:

URL: https://cgit.FreeBSD.org/src/commit/?id=feeb19201dca8364a07b2432161c5cfd8f98b2f5

commit feeb19201dca8364a07b2432161c5cfd8f98b2f5
Author:     Michael Tuexen <tuexen@FreeBSD.org>
AuthorDate: 2025-08-06 10:28:17 +0000
Commit:     Michael Tuexen <tuexen@FreeBSD.org>
CommitDate: 2025-08-06 10:28:17 +0000

    tcp: improve consistency of KASSERTs in tcp_sack.c
    
    When panicing, don't print the condition, which was violated,
    but the condition which holds at the time of the panic.
    
    Reviewed by:            Nick Banks
    MFC after:              1 week
    Sponsored by:           Netflix, Inc.
    Differential Revision:  https://reviews.freebsd.org/D51726
---
 sys/netinet/tcp_sack.c | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/sys/netinet/tcp_sack.c b/sys/netinet/tcp_sack.c
index 4405098a8620..f48e60207cc2 100644
--- a/sys/netinet/tcp_sack.c
+++ b/sys/netinet/tcp_sack.c
@@ -283,7 +283,7 @@ tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_start, tcp_seq rcv_end)
 	INP_WLOCK_ASSERT(tptoinpcb(tp));
 
 	/* Check arguments. */
-	KASSERT(SEQ_LEQ(rcv_start, rcv_end), ("rcv_start <= rcv_end"));
+	KASSERT(SEQ_LEQ(rcv_start, rcv_end), ("SEG_GT(rcv_start, rcv_end)"));
 
 	if ((rcv_start == rcv_end) &&
 	    (tp->rcv_numsacks >= 1) &&
@@ -498,8 +498,8 @@ tcp_sackhole_free(struct tcpcb *tp, struct sackhole *hole)
 	tp->snd_numholes--;
 	atomic_subtract_int(&V_tcp_sack_globalholes, 1);
 
-	KASSERT(tp->snd_numholes >= 0, ("tp->snd_numholes >= 0"));
-	KASSERT(V_tcp_sack_globalholes >= 0, ("tcp_sack_globalholes >= 0"));
+	KASSERT(tp->snd_numholes >= 0, ("tp->snd_numholes < 0"));
+	KASSERT(V_tcp_sack_globalholes >= 0, ("tcp_sack_globalholes < 0"));
 }
 
 /*
@@ -684,7 +684,7 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, tcp_seq th_ack)
 			delivered_data += sblkp->end - sblkp->start;
 			tp->sackhint.hole_bytes += temp->end - temp->start;
 			KASSERT(tp->sackhint.hole_bytes >= 0,
-			    ("sackhint hole bytes >= 0"));
+			    ("sackhint hole bytes < 0"));
 			tp->snd_fack = sblkp->end;
 			sblkp--;
 			sack_changed = SACK_NEWLOSS;
@@ -783,7 +783,7 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, tcp_seq th_ack)
 		tp->sackhint.sack_bytes_rexmit -=
 		    (SEQ_MIN(cur->rxmit, cur->end) - cur->start);
 		KASSERT(tp->sackhint.sack_bytes_rexmit >= 0,
-		    ("sackhint bytes rtx >= 0"));
+		    ("sackhint bytes rtx < 0"));
 		sack_changed = SACK_CHANGE;
 		if (SEQ_LEQ(sblkp->start, cur->start)) {
 			/* Data acks at least the beginning of hole. */
@@ -874,13 +874,13 @@ tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, tcp_seq th_ack)
 
 	if (TAILQ_EMPTY(&tp->snd_holes)) {
 		KASSERT(tp->sackhint.hole_bytes == 0,
-		    ("SACK scoreboard empty, but accounting non-zero\n"));
+		    ("SACK scoreboard empty, but sackhint hole bytes != 0"));
 		tp->sackhint.sack_bytes_rexmit = 0;
 		tp->sackhint.sacked_bytes = 0;
 		tp->sackhint.lost_bytes = 0;
 	} else {
 		KASSERT(tp->sackhint.hole_bytes > 0,
-		    ("SACK scoreboard not empty, but has no bytes\n"));
+		    ("SACK scoreboard not empty, but sackhint hole bytes <= 0"));
 		tp->sackhint.delivered_data = delivered_data;
 		tp->sackhint.sacked_bytes += delivered_data - left_edge_delta;
 		KASSERT((tp->sackhint.sacked_bytes >= 0), ("sacked_bytes < 0"));
@@ -918,9 +918,9 @@ tcp_free_sackholes(struct tcpcb *tp)
 	tp->sackhint.hole_bytes = 0;
 	tp->sackhint.lost_bytes = 0;
 
-	KASSERT(tp->snd_numholes == 0, ("tp->snd_numholes == 0"));
+	KASSERT(tp->snd_numholes == 0, ("tp->snd_numholes != 0"));
 	KASSERT(tp->sackhint.nexthole == NULL,
-		("tp->sackhint.nexthole == NULL"));
+		("tp->sackhint.nexthole != NULL"));
 }
 
 /*
@@ -1061,11 +1061,15 @@ tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt)
 			}
 		}
 	}
-	KASSERT(SEQ_LT(hole->start, hole->end), ("%s: hole.start >= hole.end", __func__));
+	KASSERT(SEQ_LT(hole->start, hole->end),
+	    ("%s: SEQ_GEQ(hole.start, hole.end)", __func__));
 	if (!(V_tcp_do_newsack)) {
-		KASSERT(SEQ_LT(hole->start, tp->snd_fack), ("%s: hole.start >= snd.fack", __func__));
-		KASSERT(SEQ_LT(hole->end, tp->snd_fack), ("%s: hole.end >= snd.fack", __func__));
-		KASSERT(SEQ_LT(hole->rxmit, tp->snd_fack), ("%s: hole.rxmit >= snd.fack", __func__));
+		KASSERT(SEQ_LT(hole->start, tp->snd_fack),
+		    ("%s: SEG_GEQ(hole.start, snd.fack)", __func__));
+		KASSERT(SEQ_LT(hole->end, tp->snd_fack),
+		    ("%s: SEG_GEQ(hole.end, snd.fack)", __func__));
+		KASSERT(SEQ_LT(hole->rxmit, tp->snd_fack),
+		    ("%s: SEQ_GEQ(hole.rxmit, snd.fack)", __func__));
 		if (SEQ_GEQ(hole->start, hole->end) ||
 		    SEQ_GEQ(hole->start, tp->snd_fack) ||
 		    SEQ_GEQ(hole->end, tp->snd_fack) ||