On Thu, Apr 23, 2015 at 8:58 AM, Ricardo Ribalda Delgado
<ricardo.ribalda@xxxxxxxxx> wrote:
> insert_resource() can fail when the resource added overlaps
> (partially or fully) with another.
>
> Device tree and AMBA devices may contain resources that overlap, so they
> could not call platform_device_add (see 02bbde7849e6 ('Revert "of:
> use platform_device_add"'))"
>
> On the other hand, device trees are released using
> platform_device_unregister(). This function calls platform_device_del(),
> which calls release_resource(), that crashes when the resource has not
> been added with with insert_resource. This was not an issue when the
> device tree could not be modified online, but this is not the case
> anymore.
>
> This patch let the flow continue when there is an insert error, after
> notifying the user with a dev_err(). r->parent is set to NULL, so
> platform_device_del() knows that the resource was not added, and
> therefore it should not be released.
>
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
Acked-by: Rob Herring <robh@xxxxxxxxxx>
> ---
> drivers/base/platform.c | 26 +++++++++++++++-----------
> 1 file changed, 15 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index 6028681..2e7e904 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -332,7 +332,7 @@ int platform_device_add(struct platform_device *pdev)
> */
> ret = ida_simple_get(&platform_devid_ida, 0, 0, GFP_KERNEL);
> if (ret < 0)
> - goto err_out;
> + return ret;
> pdev->id = ret;
> pdev->id_auto = true;
> dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
> @@ -340,7 +340,7 @@ int platform_device_add(struct platform_device *pdev)
> }
>
> for (i = 0; i < pdev->num_resources; i++) {
> - struct resource *p, *r = &pdev->resource[i];
> + struct resource *conflict, *p, *r = &pdev->resource[i];
> unsigned long type = resource_type(r);
>
> if (r->name == NULL)
> @@ -357,11 +357,14 @@ int platform_device_add(struct platform_device *pdev)
> p = &ioport_resource;
> }
>
> - if (insert_resource(p, r)) {
> - dev_err(&pdev->dev, "failed to claim resource %d\n", i);
> - ret = -EBUSY;
> - goto failed;
> - }
> + conflict = insert_resource_conflict(p, r);
> + if (!conflict)
> + continue;
> +
> + dev_err(&pdev->dev,
> + "ignoring resource %pR (conflicts with %s %pR)\n",
> + r, conflict->name, conflict);
> + p->parent = NULL;
> }
>
> pr_debug("Registering platform device '%s'. Parent at %s\n",
> @@ -371,7 +374,7 @@ int platform_device_add(struct platform_device *pdev)
> if (ret == 0)
> return ret;
>
> - failed:
> + /* Failure path */
> if (pdev->id_auto) {
> ida_simple_remove(&platform_devid_ida, pdev->id);
> pdev->id = PLATFORM_DEVID_AUTO;
> @@ -381,11 +384,11 @@ int platform_device_add(struct platform_device *pdev)
> struct resource *r = &pdev->resource[i];
> unsigned long type = resource_type(r);
>
> - if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
> + if ((type == IORESOURCE_MEM || type == IORESOURCE_IO) &&
> + r->parent)
> release_resource(r);
> }
>
> - err_out:
> return ret;
> }
> EXPORT_SYMBOL_GPL(platform_device_add);
> @@ -414,7 +417,8 @@ void platform_device_del(struct platform_device *pdev)
> struct resource *r = &pdev->resource[i];
> unsigned long type = resource_type(r);
>
> - if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
> + if ((type == IORESOURCE_MEM || type == IORESOURCE_IO) &&
> + r->parent)
> release_resource(r);
> }
> }
> --
> 2.1.4
>
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