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

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

[Rafael Mendonca]

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@gmail.com>
Reviewed-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
---
v1 from previous RFC:
- No changes
---
 .../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

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

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 22 Sep 2022 14:51:08 -0300 you wrote:
> 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.
> 
> [...]

Here is the summary with links:
  - [net-next] cxgb4: fix missing unlock on ETHOFLD desc collect fail path
    https://git.kernel.org/netdev/net/c/c635ebe8d911

You are awesome, thank you!
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