From 8d782f3f89e1dcd0c8af1c3c93501d7a06159d66 Mon Sep 17 00:00:00 2001

From: Hyong Youb Kim <hyonkim@cisco.com>

Date: Wed, 7 Mar 2018 18:46:58 -0800

Subject: [PATCH] net/enic: allocate stats DMA buffer upfront during probe

The driver provides a DMA buffer to the firmware when it requests port

stats. The NIC then fills that buffer with latest stats. Currently,

the driver allocates the DMA buffer the first time it requests stats

and saves it for later use. This can lead to crashes when

primary/secondary processes are involved. For example, the following

sequence crashes the secondary process.

1. Start a primary app that does not call rte_eth_stats_get()

2. dpdk-procinfo -- --stats

dpdk-procinfo crashes while trying to allocate the stats DMA buffer

because the alloc function pointer (vdev.alloc_consistent) is valid

only in the primary process, not in the secondary process.

Overwriting the alloc function pointer in the secondary process is not

an option, as it will simply make the pointer invalid in the primary

process. Instead, allocate the DMA buffer during probe so that only

the primary process does both allocate and free. This allows the

secondary process to dump stats as well.

Fixes: 9913fbb91df0 ("enic/base: common code")

Cc: stable@dpdk.org

Signed-off-by: Hyong Youb Kim <hyonkim@cisco.com>

Reviewed-by: John Daley <johndale@cisco.com>

---

 drivers/net/enic/base/vnic_dev.c | 24 ++++++++++++++----------

 drivers/net/enic/base/vnic_dev.h |  1 +

 drivers/net/enic/enic_main.c     |  9 +++++++++

 3 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/net/enic/base/vnic_dev.c b/drivers/net/enic/base/vnic_dev.c

index 05b595eb8..1f8d222fc 100644

--- a/drivers/net/enic/base/vnic_dev.c

+++ b/drivers/net/enic/base/vnic_dev.c

@@ -587,17 +587,9 @@ int vnic_dev_stats_dump(struct vnic_dev *vdev, struct vnic_stats **stats)

 {

 	u64 a0, a1;

 	int wait = 1000;

-	static u32 instance;

-	char name[NAME_MAX];

-	if (!vdev->stats) {

-		snprintf((char *)name, sizeof(name),

-			"vnic_stats-%u", instance++);

-		vdev->stats = vdev->alloc_consistent(vdev->priv,

-			sizeof(struct vnic_stats), &vdev->stats_pa, (u8 *)name);

-		if (!vdev->stats)

-			return -ENOMEM;

-	}

+	if (!vdev->stats)

+		return -ENOMEM;

 	*stats = vdev->stats;

 	a0 = vdev->stats_pa;

@@ -922,6 +914,18 @@ u32 vnic_dev_get_intr_coal_timer_max(struct vnic_dev *vdev)

 	return vdev->intr_coal_timer_info.max_usec;

 }

+int vnic_dev_alloc_stats_mem(struct vnic_dev *vdev)

+{

+	char name[NAME_MAX];

+	static u32 instance;

+

+	snprintf((char *)name, sizeof(name), "vnic_stats-%u", instance++);

+	vdev->stats = vdev->alloc_consistent(vdev->priv,

+					     sizeof(struct vnic_stats),

+					     &vdev->stats_pa, (u8 *)name);

+	return vdev->stats == NULL ? -ENOMEM : 0;

+}

+

 void vnic_dev_unregister(struct vnic_dev *vdev)

 {

 	if (vdev) {

diff --git a/drivers/net/enic/base/vnic_dev.h b/drivers/net/enic/base/vnic_dev.h

index 8c0992063..7e5736b4d 100644

--- a/drivers/net/enic/base/vnic_dev.h

+++ b/drivers/net/enic/base/vnic_dev.h

@@ -165,6 +165,7 @@ struct vnic_dev *vnic_dev_register(struct vnic_dev *vdev,

 	void *priv, struct rte_pci_device *pdev, struct vnic_dev_bar *bar,

 	unsigned int num_bars);

 struct rte_pci_device *vnic_dev_get_pdev(struct vnic_dev *vdev);

+int vnic_dev_alloc_stats_mem(struct vnic_dev *vdev);

 int vnic_dev_cmd_init(struct vnic_dev *vdev, int fallback);

 int vnic_dev_get_size(void);

 int vnic_dev_int13(struct vnic_dev *vdev, u64 arg, u32 op);

diff --git a/drivers/net/enic/enic_main.c b/drivers/net/enic/enic_main.c

index c3796c543..235ef5940 100644

--- a/drivers/net/enic/enic_main.c

+++ b/drivers/net/enic/enic_main.c

@@ -1478,6 +1478,15 @@ int enic_probe(struct enic *enic)

 		enic_alloc_consistent,

 		enic_free_consistent);

+	/*

+	 * Allocate the consistent memory for stats upfront so both primary and

+	 * secondary processes can dump stats.

+	 */

+	err = vnic_dev_alloc_stats_mem(enic->vdev);

+	if (err) {

+		dev_err(enic, "Failed to allocate cmd memory, aborting\n");

+		goto err_out_unregister;

+	}

 	/* Issue device open to get device in known state */

 	err = enic_dev_open(enic);

 	if (err) {

-- 

2.14.3