Re: [PATCH 2/3] drivers/base: devres.c: Add block copy func. for managed devices

From: Rob Jones
Date: Wed Jun 18 2014 - 11:52:33 EST



On 18/06/14 14:05, Heiko Stübner wrote:
Am Dienstag, 10. Juni 2014, 15:41:47 schrieb Rob Jones:
Add function devm_kmemdup().
Rationalise with devm_kstrdup() to avoid code duplication.

Reviewed-by: Ian Molton <ian.molton@xxxxxxxxxxxxxxx>
Signed-off-by: Rob Jones <rob.jones@xxxxxxxxxxxxxxx>
---
drivers/base/devres.c | 42 ++++++++++++++++++++++++++++++++++--------
include/linux/device.h | 2 ++
2 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index db4e264..978bbe2 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -791,6 +791,20 @@ void * devm_kmalloc(struct device *dev, size_t size,
gfp_t gfp) EXPORT_SYMBOL_GPL(devm_kmalloc);

/**
+ * static function to avoid code duplication when duplicating buffers
+ */
+static void *devm_kmemdup_nochecks(struct device *dev, const void *s,
+ size_t size, gfp_t gfp)
+{
+ void *buf;
+
+ buf = devm_kmalloc(dev, size, gfp);
+ if (buf)
+ memcpy(buf, s, size);
+ return buf;
+}
+
+/**
* devm_kstrdup - Allocate resource managed space and
* copy an existing string into that.
* @dev: Device to allocate memory for
@@ -802,21 +816,33 @@ EXPORT_SYMBOL_GPL(devm_kmalloc);
*/
char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
{
- size_t size;
- char *buf;
-
if (!s)
return NULL;

- size = strlen(s) + 1;
- buf = devm_kmalloc(dev, size, gfp);
- if (buf)
- memcpy(buf, s, size);
- return buf;
+ return devm_kmemdup_nochecks(dev, s, (strlen(s)+1), gfp);
}
EXPORT_SYMBOL_GPL(devm_kstrdup);
hmm, this looks like an unrelated change to me and may warrant a separate
patch for the devm_kstrdup change.

On reflection, I agree, I'll separate out the change to devm_kstrdup() and resubmit.



/**
+ * devm_kmemdup - Allocate resource managed space and
+ * copy existing data into that.
+ * @dev: Device to allocate memory for
+ * @s: the memory block to duplicate
+ * @gfp: the GFP mask used in the devm_kmalloc() call when
+ * allocating memory
+ * RETURNS:
+ * Pointer to allocated string on success, NULL on failure.
+ */
+void *devm_kmemdup(struct device *dev, const void *s, size_t size, gfp_t
gfp) +{
+ if (!s || (size == 0))
+ return NULL;
+
+ return devm_kmemdup_nochecks(dev, s, size, gfp);
+}
+EXPORT_SYMBOL_GPL(devm_kmemdup);
+
+/**
* devm_kfree - Resource-managed kfree
* @dev: Device this memory belongs to
* @p: Memory to free
diff --git a/include/linux/device.h b/include/linux/device.h
index d1d1c05..7ace116 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -623,6 +623,8 @@ static inline void *devm_kcalloc(struct device *dev,
}
extern void devm_kfree(struct device *dev, void *p);
extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp);
+extern void *devm_kmemdup(struct device *dev,
+ const void *s, size_t size, gfp_t gfp);

void __iomem *devm_ioremap_resource(struct device *dev, struct resource
*res); void __iomem *devm_request_and_ioremap(struct device *dev,



--
Rob Jones
Project Manager
Codethink Ltd
mailto:rob.jones@xxxxxxxxxxxxxxx
tel:+44 161 236 5575

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