patch 'dma/idxd: fix memory leak in PCI close' has been queued to stable release 21.11.2

[luca.boccassi@gmail.com]

Hi,

FYI, your patch has been queued to stable release 21.11.2

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 07/08/22. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/1fd4a985e4f5869fa5c04f06d6b22c7d33f046a4

Thanks.

Luca Boccassi

---
From 1fd4a985e4f5869fa5c04f06d6b22c7d33f046a4 Mon Sep 17 00:00:00 2001
From: Kevin Laatz <kevin.laatz@intel.com>
Date: Mon, 4 Jul 2022 16:27:49 +0100
Subject: [PATCH] dma/idxd: fix memory leak in PCI close

[ upstream commit 8a6eb404c4a1e312a13d3a374b0cf3dcdc429ba7 ]

ASAN reports a memory leak for the 'pci' pointer in the 'idxd_dmadev'
struct.

This is fixed by free'ing the struct when the last queue on the PCI
device is being closed.

Fixes: 9449330a8458 ("dma/idxd: create dmadev instances on PCI probe")

Reported-by: Xingguang He <xingguang.he@intel.com>
Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
---
 drivers/dma/idxd/idxd_internal.h |  2 ++
 drivers/dma/idxd/idxd_pci.c      | 35 +++++++++++++++++++++++++-------
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/drivers/dma/idxd/idxd_internal.h b/drivers/dma/idxd/idxd_internal.h
index 3375600217..180a8587c6 100644
--- a/drivers/dma/idxd/idxd_internal.h
+++ b/drivers/dma/idxd/idxd_internal.h
@@ -7,6 +7,7 @@
 
 #include <rte_dmadev_pmd.h>
 #include <rte_spinlock.h>
+#include <rte_atomic.h>
 
 #include "idxd_hw_defs.h"
 
@@ -33,6 +34,7 @@ struct idxd_pci_common {
 	rte_spinlock_t lk;
 
 	uint8_t wq_cfg_sz;
+	rte_atomic16_t ref_count;
 	volatile struct rte_idxd_bar0 *regs;
 	volatile uint32_t *wq_regs_base;
 	volatile struct rte_idxd_grpcfg *grp_regs;
diff --git a/drivers/dma/idxd/idxd_pci.c b/drivers/dma/idxd/idxd_pci.c
index 65c6bbf4c1..fb618d34b6 100644
--- a/drivers/dma/idxd/idxd_pci.c
+++ b/drivers/dma/idxd/idxd_pci.c
@@ -6,6 +6,7 @@
 #include <rte_devargs.h>
 #include <rte_dmadev_pmd.h>
 #include <rte_malloc.h>
+#include <rte_atomic.h>
 
 #include "idxd_internal.h"
 
@@ -115,20 +116,38 @@ idxd_pci_dev_close(struct rte_dma_dev *dev)
 {
 	struct idxd_dmadev *idxd = dev->fp_obj->dev_private;
 	uint8_t err_code;
+	int is_last_wq;
 
-	/* disable the device */
-	err_code = idxd_pci_dev_command(idxd, idxd_disable_dev);
-	if (err_code) {
-		IDXD_PMD_ERR("Error disabling device: code %#x", err_code);
-		return err_code;
+	if (idxd_is_wq_enabled(idxd)) {
+		/* disable the wq */
+		err_code = idxd_pci_dev_command(idxd, idxd_disable_wq);
+		if (err_code) {
+			IDXD_PMD_ERR("Error disabling wq: code %#x", err_code);
+			return err_code;
+		}
+		IDXD_PMD_DEBUG("IDXD WQ disabled OK");
 	}
-	IDXD_PMD_DEBUG("IDXD Device disabled OK");
 
 	/* free device memory */
 	IDXD_PMD_DEBUG("Freeing device driver memory");
 	rte_free(idxd->batch_idx_ring);
 	rte_free(idxd->desc_ring);
 
+	/* if this is the last WQ on the device, disable the device and free
+	 * the PCI struct
+	 */
+	is_last_wq = rte_atomic16_dec_and_test(&idxd->u.pci->ref_count);
+	if (is_last_wq) {
+		/* disable the device */
+		err_code = idxd_pci_dev_command(idxd, idxd_disable_dev);
+		if (err_code) {
+			IDXD_PMD_ERR("Error disabling device: code %#x", err_code);
+			return err_code;
+		}
+		IDXD_PMD_DEBUG("IDXD device disabled OK");
+		rte_free(idxd->u.pci);
+	}
+
 	return 0;
 }
 
@@ -159,12 +178,13 @@ init_pci_device(struct rte_pci_device *dev, struct idxd_dmadev *idxd,
 	uint8_t lg2_max_batch, lg2_max_copy_size;
 	unsigned int i, err_code;
 
-	pci = malloc(sizeof(*pci));
+	pci = rte_malloc(NULL, sizeof(*pci), 0);
 	if (pci == NULL) {
 		IDXD_PMD_ERR("%s: Can't allocate memory", __func__);
 		err_code = -1;
 		goto err;
 	}
+	memset(pci, 0, sizeof(*pci));
 	rte_spinlock_init(&pci->lk);
 
 	/* assign the bar registers, and then configure device */
@@ -330,6 +350,7 @@ idxd_dmadev_probe_pci(struct rte_pci_driver *drv, struct rte_pci_device *dev)
 				free(idxd.u.pci);
 			return ret;
 		}
+		rte_atomic16_inc(&idxd.u.pci->ref_count);
 	}
 
 	return 0;
-- 
2.34.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2022-07-06 21:07:54.462911627 +0100
+++ 0026-dma-idxd-fix-memory-leak-in-PCI-close.patch	2022-07-06 21:07:53.579519398 +0100
@@ -1 +1 @@
-From 8a6eb404c4a1e312a13d3a374b0cf3dcdc429ba7 Mon Sep 17 00:00:00 2001
+From 1fd4a985e4f5869fa5c04f06d6b22c7d33f046a4 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 8a6eb404c4a1e312a13d3a374b0cf3dcdc429ba7 ]
+
@@ -13 +14,0 @@
-Cc: stable@dpdk.org