[PATCH v3 1/3] dma/idxd: fix memory leak in pci close

[Kevin Laatz]

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")
Cc: sta...@dpdk.org
Cc: bruce.richard...@intel.com

Reported-by: Xingguang He <xingguang...@intel.com>
Signed-off-by: Kevin Laatz <kevin.la...@intel.com>

--
v3: move ref_count increment to pci probe
---
 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;
-- 
2.31.1