Commit 0007122a authored by Kevin Hilman's avatar Kevin Hilman Committed by Paul Walmsley

OMAP: omap_device: add omap_device_is_valid()

The omap_device struct contains a 'struct platform_device'.  Normally,
converting a platform_device pointer to an omap_device pointer
consists of simply doing a container_of(), as is done currently by the
to_omap_device() macro.

However, if this is attempted when using platform_device that has not
been created as part of the omap_device creation, the container_of()
will point to a memory location before the platform_device pointer
which will contain random data.

Therefore, we need a way to detect valid omap_device pointers.  This
patch solves this by using the simple magic number approach.
Signed-off-by: default avatarKevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: default avatarPaul Walmsley <paul@pwsan.com>
parent 80c20d54
......@@ -62,6 +62,7 @@
*
*/
struct omap_device {
u32 magic;
struct platform_device pdev;
struct omap_hwmod **hwmods;
struct omap_device_pm_latency *pm_lats;
......@@ -81,6 +82,7 @@ int omap_device_shutdown(struct platform_device *pdev);
/* Core code interface */
bool omap_device_is_valid(struct omap_device *od);
int omap_device_count_resources(struct omap_device *od);
int omap_device_fill_resources(struct omap_device *od, struct resource *res);
......
......@@ -90,6 +90,8 @@
#define IGNORE_WAKEUP_LAT 1
#define OMAP_DEVICE_MAGIC 0xf00dcafe
/* Private functions */
/**
......@@ -403,6 +405,8 @@ struct omap_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
od->pm_lats = pm_lats;
od->pm_lats_cnt = pm_lats_cnt;
od->magic = OMAP_DEVICE_MAGIC;
ret = omap_device_register(od);
if (ret)
goto odbs_exit4;
......@@ -588,6 +592,18 @@ int omap_device_align_pm_lat(struct platform_device *pdev,
return ret;
}
/**
* omap_device_is_valid - Check if pointer is a valid omap_device
* @od: struct omap_device *
*
* Return whether struct omap_device pointer @od points to a valid
* omap_device.
*/
bool omap_device_is_valid(struct omap_device *od)
{
return (od && od->magic == OMAP_DEVICE_MAGIC);
}
/**
* omap_device_get_pwrdm - return the powerdomain * associated with @od
* @od: struct omap_device *
......
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