[RFC PATCH net-next 1/1] cxgb4: fix missing unlock on ETHOFLD desc collect fail path

From: Rafael Mendonca
Date: Thu Sep 22 2022 - 01:33:21 EST


The label passed to the QDESC_GET for the ETHOFLD TXQ, RXQ, and FLQ, is the
'out' one, which skips the 'out_unlock' label, and thus doesn't unlock the
'uld_mutex' before returning. Additionally, since commit 5148e5950c67
("cxgb4: add EOTID tracking and software context dump"), the access to
these ETHOFLD hardware queues should be protected by the 'mqprio_mutex'
instead.

Fixes: 2d0cb84dd973 ("cxgb4: add ETHOFLD hardware queue support")
Fixes: 5148e5950c67 ("cxgb4: add EOTID tracking and software context dump")
Signed-off-by: Rafael Mendonca <rafaelmendsr@xxxxxxxxx>
---
.../net/ethernet/chelsio/cxgb4/cudbg_lib.c | 28 +++++++++++++------
1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cudbg_lib.c b/drivers/net/ethernet/chelsio/cxgb4/cudbg_lib.c
index a7f291c89702..557c591a6ce3 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cudbg_lib.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cudbg_lib.c
@@ -14,6 +14,7 @@
#include "cudbg_entity.h"
#include "cudbg_lib.h"
#include "cudbg_zlib.h"
+#include "cxgb4_tc_mqprio.h"

static const u32 t6_tp_pio_array[][IREG_NUM_ELEM] = {
{0x7e40, 0x7e44, 0x020, 28}, /* t6_tp_pio_regs_20_to_3b */
@@ -3458,7 +3459,7 @@ int cudbg_collect_qdesc(struct cudbg_init *pdbg_init,
for (i = 0; i < utxq->ntxq; i++)
QDESC_GET_TXQ(&utxq->uldtxq[i].q,
cudbg_uld_txq_to_qtype(j),
- out_unlock);
+ out_unlock_uld);
}
}

@@ -3475,7 +3476,7 @@ int cudbg_collect_qdesc(struct cudbg_init *pdbg_init,
for (i = 0; i < urxq->nrxq; i++)
QDESC_GET_RXQ(&urxq->uldrxq[i].rspq,
cudbg_uld_rxq_to_qtype(j),
- out_unlock);
+ out_unlock_uld);
}

/* ULD FLQ */
@@ -3487,7 +3488,7 @@ int cudbg_collect_qdesc(struct cudbg_init *pdbg_init,
for (i = 0; i < urxq->nrxq; i++)
QDESC_GET_FLQ(&urxq->uldrxq[i].fl,
cudbg_uld_flq_to_qtype(j),
- out_unlock);
+ out_unlock_uld);
}

/* ULD CIQ */
@@ -3500,29 +3501,34 @@ int cudbg_collect_qdesc(struct cudbg_init *pdbg_init,
for (i = 0; i < urxq->nciq; i++)
QDESC_GET_RXQ(&urxq->uldrxq[base + i].rspq,
cudbg_uld_ciq_to_qtype(j),
- out_unlock);
+ out_unlock_uld);
}
}
+ mutex_unlock(&uld_mutex);
+
+ if (!padap->tc_mqprio)
+ goto out;

+ mutex_lock(&padap->tc_mqprio->mqprio_mutex);
/* ETHOFLD TXQ */
if (s->eohw_txq)
for (i = 0; i < s->eoqsets; i++)
QDESC_GET_TXQ(&s->eohw_txq[i].q,
- CUDBG_QTYPE_ETHOFLD_TXQ, out);
+ CUDBG_QTYPE_ETHOFLD_TXQ, out_unlock_mqprio);

/* ETHOFLD RXQ and FLQ */
if (s->eohw_rxq) {
for (i = 0; i < s->eoqsets; i++)
QDESC_GET_RXQ(&s->eohw_rxq[i].rspq,
- CUDBG_QTYPE_ETHOFLD_RXQ, out);
+ CUDBG_QTYPE_ETHOFLD_RXQ, out_unlock_mqprio);

for (i = 0; i < s->eoqsets; i++)
QDESC_GET_FLQ(&s->eohw_rxq[i].fl,
- CUDBG_QTYPE_ETHOFLD_FLQ, out);
+ CUDBG_QTYPE_ETHOFLD_FLQ, out_unlock_mqprio);
}

-out_unlock:
- mutex_unlock(&uld_mutex);
+out_unlock_mqprio:
+ mutex_unlock(&padap->tc_mqprio->mqprio_mutex);

out:
qdesc_info->qdesc_entry_size = sizeof(*qdesc_entry);
@@ -3559,6 +3565,10 @@ int cudbg_collect_qdesc(struct cudbg_init *pdbg_init,
#undef QDESC_GET

return rc;
+
+out_unlock_uld:
+ mutex_unlock(&uld_mutex);
+ goto out;
}

int cudbg_collect_flash(struct cudbg_init *pdbg_init,
--
2.34.1