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From: paul@pwsan.com (Paul Walmsley)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 01/19] OMAP: omap_device: add omap_device_is_valid()
Date: Mon, 15 Feb 2010 18:24:37 -0700	[thread overview]
Message-ID: <20100216012431.1101.22805.stgit@localhost.localdomain> (raw)
In-Reply-To: <20100216011942.1101.14348.stgit@localhost.localdomain>

From: Kevin Hilman <khilman@deeprootsystems.com>

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: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
---
 arch/arm/plat-omap/include/plat/omap_device.h |    2 ++
 arch/arm/plat-omap/omap_device.c              |   16 ++++++++++++++++
 2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/arch/arm/plat-omap/include/plat/omap_device.h b/arch/arm/plat-omap/include/plat/omap_device.h
index 76d4917..4677ff7 100644
--- a/arch/arm/plat-omap/include/plat/omap_device.h
+++ b/arch/arm/plat-omap/include/plat/omap_device.h
@@ -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);
 
diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
index 5195dbb..40289e0 100644
--- a/arch/arm/plat-omap/omap_device.c
+++ b/arch/arm/plat-omap/omap_device.c
@@ -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;
@@ -589,6 +593,18 @@ int omap_device_align_pm_lat(struct platform_device *pdev,
 }
 
 /**
+ * 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 *
  *

  reply	other threads:[~2010-02-16  1:24 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-16  1:24 [PATCH 00/19] OMAP: more clock/powerdomain/hwmod patches for 2.6.34 Paul Walmsley
2010-02-16  1:24 ` Paul Walmsley [this message]
2010-02-16  1:24 ` [PATCH 02/19] OMAP: omap_device: when 'called from invalid state', print state Paul Walmsley
2010-02-16  1:24 ` [PATCH 03/19] OMAP3: clock: use std _MASK suffix for CM_FCLKEN_IVA2 defines Paul Walmsley
2010-02-16  1:24 ` [PATCH 04/19] OMAP3: Clock: Added IDLEST definitions for SGX Paul Walmsley
2010-02-16  1:24 ` [PATCH 05/19] OMAP2/3 PM: Adding powerdomain APIs for reading the next logic and mem state Paul Walmsley
2010-02-16  1:24 ` [PATCH 06/19] OMAP3 PM: Defining .pwrsts_logic_ret field for core power domain structure Paul Walmsley
2010-02-16  1:24 ` [PATCH 07/19] OMAP3 PM: Adding counters for power domain logic off and mem off during retention Paul Walmsley
2010-02-16  1:24 ` [PATCH 08/19] OMAP2/3 clock: Extend find_idlest() to pass back idle state value Paul Walmsley
2010-02-16  1:24 ` [PATCH 09/19] AM35xx: Add clock support for new modules on AM35xx Paul Walmsley
2010-02-16  1:24 ` [PATCH 10/19] OMAP3 clock: Check return values for clk_get() Paul Walmsley
2010-02-16  1:24 ` [PATCH 11/19] OMAP2/3: PRCM: fix misc. compiler warnings Paul Walmsley
2010-02-16  1:24 ` [PATCH 12/19] OMAP3 clock: Remove FreqSel for 3630 Paul Walmsley
2010-02-16 11:00   ` Sergei Shtylyov
2010-02-16 18:10     ` Paul Walmsley
2010-02-16  1:24 ` [PATCH 13/19] OMAP3: hwmod: support to specify the offset position of various SYSCONFIG register bits Paul Walmsley
2010-02-16  1:24 ` [PATCH 14/19] OMAP: HWMOD: Add support for early device register into omap device layer Paul Walmsley
2010-02-16  1:24 ` [PATCH 15/19] OMAP3630: Clock: Workaround for DPLL HS divider limitation Paul Walmsley
2010-02-16  1:25 ` [PATCH 16/19] ARM: OMAP4 clock domain: Add check for avoiding dependency related update Paul Walmsley
2010-02-16  1:25 ` [PATCH 17/19] OMAP3 clock: introduce DPLL4 Jtype Paul Walmsley
2010-02-16  1:25 ` [PATCH 18/19] OMAP3 clock: Introduce 3630 DPLL4 HSDivider changes Paul Walmsley
2010-02-16  1:25 ` [PATCH 19/19] OMAP3 clock: add support for 192Mhz DPLL4M2 output Paul Walmsley

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