Patchwork [128/150] sfc: Avoid generating over-length MC_CMD_FLUSH_RX_QUEUES request

login
register
mail settings
Submitter Luis Henriques
Date March 26, 2013, 3:20 p.m.
Message ID <1364311249-14454-129-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/231382/
State New
Headers show

Comments

Luis Henriques - March 26, 2013, 3:20 p.m.
3.5.7.9 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ben Hutchings <bhutchings@solarflare.com>

commit 450783747f42dfa3883920acfad4acdd93ce69af upstream.

MCDI supports requests up to 252 bytes long, which is only enough to
pass 63 RX queue IDs to MC_CMD_FLUSH_RX_QUEUES.  However a VF may have
up to 64 RX queues, and if we try to flush them all we will generate
an over-length request and BUG() in efx_mcdi_copyin().  Currently
all VF drivers limit themselves to 32 RX queues, so reducing the
limit to 63 does no harm.

Also add a BUILD_BUG_ON in efx_mcdi_flush_rxqs() so we remember to
deal with the same problem there if EFX_MAX_CHANNELS is increased.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/net/ethernet/sfc/mcdi.c        | 3 +++
 drivers/net/ethernet/sfc/siena_sriov.c | 7 +++++++
 2 files changed, 10 insertions(+)

Patch

diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index b49012d..a423cd3 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -1168,6 +1168,9 @@  int efx_mcdi_flush_rxqs(struct efx_nic *efx)
 	__le32 *qid;
 	int rc, count;
 
+	BUILD_BUG_ON(EFX_MAX_CHANNELS >
+		     MC_CMD_FLUSH_RX_QUEUES_IN_QID_OFST_MAXNUM);
+
 	qid = kmalloc(EFX_MAX_CHANNELS * sizeof(*qid), GFP_KERNEL);
 	if (qid == NULL)
 		return -ENOMEM;
diff --git a/drivers/net/ethernet/sfc/siena_sriov.c b/drivers/net/ethernet/sfc/siena_sriov.c
index 78f5408..4ad8082 100644
--- a/drivers/net/ethernet/sfc/siena_sriov.c
+++ b/drivers/net/ethernet/sfc/siena_sriov.c
@@ -21,6 +21,9 @@ 
 /* Number of longs required to track all the VIs in a VF */
 #define VI_MASK_LENGTH BITS_TO_LONGS(1 << EFX_VI_SCALE_MAX)
 
+/* Maximum number of RX queues supported */
+#define VF_MAX_RX_QUEUES 63
+
 /**
  * enum efx_vf_tx_filter_mode - TX MAC filtering behaviour
  * @VF_TX_FILTER_OFF: Disabled
@@ -578,6 +581,7 @@  static int efx_vfdi_init_rxq(struct efx_vf *vf)
 	efx_oword_t reg;
 
 	if (bad_vf_index(efx, vf_evq) || bad_vf_index(efx, vf_rxq) ||
+	    vf_rxq >= VF_MAX_RX_QUEUES ||
 	    bad_buf_count(buf_count, EFX_MAX_DMAQ_SIZE)) {
 		if (net_ratelimit())
 			netif_err(efx, hw, efx->net_dev,
@@ -683,6 +687,9 @@  static int efx_vfdi_fini_all_queues(struct efx_vf *vf)
 	__le32 *rxqs;
 	int rc;
 
+	BUILD_BUG_ON(VF_MAX_RX_QUEUES >
+		     MC_CMD_FLUSH_RX_QUEUES_IN_QID_OFST_MAXNUM);
+
 	rxqs = kmalloc(count * sizeof(*rxqs), GFP_KERNEL);
 	if (rxqs == NULL)
 		return VFDI_RC_ENOMEM;