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Message-ID: <5e91615b-b2b4-4fe3-4d25-1ae56624976b@arm.com>
Date: Tue, 27 Mar 2018 12:05:15 +0100
From: Robin Murphy <robin.murphy@....com>
To: roy.pledge@....com, devel@...verdev.osuosl.org,
linux-arm-kernel@...ts.infradead.org
Cc: ruxandra.radulescu@....com, arnd@...db.de,
gregkh@...uxfoundation.org, horia.geanta@....com,
linux-kernel@...r.kernel.org, leoyang.li@....com,
stuyoder@...il.com, catalin.marinas@....com,
laurentiu.tudor@....com
Subject: Re: [PATCH v3 2/4] drivers/staging/fsl-mc: Fix DPIO error path issues
Hi Roy,
On 26/03/18 20:05, Roy Pledge wrote:
> The error path in the dpaa2_dpio_probe() function was not properly
> unmapping the QBMan device memory on the error path. This was also
> missing from the dpaa2_dpio_release() function.
>
> Also addresses a memory leak of the device private data structure.
>
> Signed-off-by: Roy Pledge <roy.pledge@....com>
> ---
> drivers/staging/fsl-mc/bus/dpio/dpio-driver.c | 49 +++++++++++++++++++--------
> 1 file changed, 34 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/staging/fsl-mc/bus/dpio/dpio-driver.c b/drivers/staging/fsl-mc/bus/dpio/dpio-driver.c
> index e00f473..e7a0009 100644
> --- a/drivers/staging/fsl-mc/bus/dpio/dpio-driver.c
> +++ b/drivers/staging/fsl-mc/bus/dpio/dpio-driver.c
> @@ -28,6 +28,7 @@ MODULE_DESCRIPTION("DPIO Driver");
>
> struct dpio_priv {
> struct dpaa2_io *io;
> + struct dpaa2_io_desc desc;
> };
>
> static irqreturn_t dpio_irq_handler(int irq_num, void *arg)
> @@ -85,7 +86,6 @@ static int register_dpio_irq_handlers(struct fsl_mc_device *dpio_dev, int cpu)
> static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev)
> {
> struct dpio_attr dpio_attrs;
> - struct dpaa2_io_desc desc;
> struct dpio_priv *priv;
> int err = -ENOMEM;
> struct device *dev = &dpio_dev->dev;
> @@ -117,7 +117,7 @@ static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev)
> dev_err(dev, "dpio_get_attributes() failed %d\n", err);
> goto err_get_attr;
> }
> - desc.qman_version = dpio_attrs.qbman_version;
> + priv->desc.qman_version = dpio_attrs.qbman_version;
>
> err = dpio_enable(dpio_dev->mc_io, 0, dpio_dev->mc_handle);
> if (err) {
> @@ -126,9 +126,9 @@ static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev)
> }
>
> /* initialize DPIO descriptor */
> - desc.receives_notifications = dpio_attrs.num_priorities ? 1 : 0;
> - desc.has_8prio = dpio_attrs.num_priorities == 8 ? 1 : 0;
> - desc.dpio_id = dpio_dev->obj_desc.id;
> + priv->desc.receives_notifications = dpio_attrs.num_priorities ? 1 : 0;
> + priv->desc.has_8prio = dpio_attrs.num_priorities == 8 ? 1 : 0;
> + priv->desc.dpio_id = dpio_dev->obj_desc.id;
>
> /* get the cpu to use for the affinity hint */
> if (next_cpu == -1)
> @@ -139,19 +139,28 @@ static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev)
> if (!cpu_possible(next_cpu)) {
> dev_err(dev, "probe failed. Number of DPIOs exceeds NR_CPUS.\n");
> err = -ERANGE;
> - goto err_allocate_irqs;
> + goto err_too_many_cpu;
> }
> - desc.cpu = next_cpu;
> + priv->desc.cpu = next_cpu;
>
> /*
> * Set the CENA regs to be the cache inhibited area of the portal to
> * avoid coherency issues if a user migrates to another core.
> */
> - desc.regs_cena = memremap(dpio_dev->regions[1].start,
> - resource_size(&dpio_dev->regions[1]),
> - MEMREMAP_WC);
> - desc.regs_cinh = ioremap(dpio_dev->regions[1].start,
> - resource_size(&dpio_dev->regions[1]));
> + priv->desc.regs_cena = memremap(dpio_dev->regions[1].start,
> + resource_size(&dpio_dev->regions[1]),
> + MEMREMAP_WC);
Since you already have some devres-managed resources in this driver,
maybe use devm_memremap? (and perhaps convert the existing ioremap too)
> + if (!priv->desc.regs_cena) {
> + dev_err(dev, "memremap failed\n");
> + goto err_too_many_cpu;
> + }
> +
> + priv->desc.regs_cinh = ioremap(dpio_dev->regions[1].start,
> + resource_size(&dpio_dev->regions[1]));
> + if (!priv->desc.regs_cinh) {
> + dev_err(dev, "ioremap failed\n");
> + goto err_ioremap_failed;
> + }
>
> err = fsl_mc_allocate_irqs(dpio_dev);
> if (err) {
> @@ -159,11 +168,11 @@ static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev)
> goto err_allocate_irqs;
> }
>
> - err = register_dpio_irq_handlers(dpio_dev, desc.cpu);
> + err = register_dpio_irq_handlers(dpio_dev, priv->desc.cpu);
> if (err)
> goto err_register_dpio_irq;
>
> - priv->io = dpaa2_io_create(&desc);
> + priv->io = dpaa2_io_create(&priv->desc);
> if (!priv->io) {
> dev_err(dev, "dpaa2_io_create failed\n");
> goto err_dpaa2_io_create;
> @@ -171,7 +180,7 @@ static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev)
>
> dev_info(dev, "probed\n");
> dev_dbg(dev, " receives_notifications = %d\n",
> - desc.receives_notifications);
> + priv->desc.receives_notifications);
> dpio_close(dpio_dev->mc_io, 0, dpio_dev->mc_handle);
> fsl_mc_portal_free(dpio_dev->mc_io);
>
> @@ -182,6 +191,10 @@ static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev)
> err_register_dpio_irq:
> fsl_mc_free_irqs(dpio_dev);
> err_allocate_irqs:
> + iounmap(priv->desc.regs_cinh);
> +err_ioremap_failed:
> + memunmap(priv->desc.regs_cena);
...then you wouldn't need to worry about this.
> +err_too_many_cpu:
> dpio_disable(dpio_dev->mc_io, 0, dpio_dev->mc_handle);
> err_get_attr:
> dpio_close(dpio_dev->mc_io, 0, dpio_dev->mc_handle);
> @@ -189,6 +202,7 @@ static int dpaa2_dpio_probe(struct fsl_mc_device *dpio_dev)
> fsl_mc_portal_free(dpio_dev->mc_io);
> err_mcportal:
> dev_set_drvdata(dev, NULL);
> + devm_kfree(dev, priv);
The whole point of devm_* is that you don't need to do this - the devres
entries are freed automatically by the driver core upon probe failure or
driver detach, i.e. priv was never leaking.
> err_priv_alloc:
> return err;
> }
> @@ -230,8 +244,13 @@ static int dpaa2_dpio_remove(struct fsl_mc_device *dpio_dev)
>
> dpio_close(dpio_dev->mc_io, 0, dpio_dev->mc_handle);
>
> + iounmap(priv->desc.regs_cinh);
> + memunmap(priv->desc.regs_cena);
> +
> fsl_mc_portal_free(dpio_dev->mc_io);
>
> + devm_kfree(dev, priv);
> +
> dev_set_drvdata(dev, NULL);
Note that clearing drvdata is something else the driver core already
does at about the same time as cleaning up devres entries (see
__device_release_driver() and the failure path of really_probe(), in
drivers/base/dd.c), so this has been similarly superfluous all along.
Robin.
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