From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Michael Turquette <mturquette@baylibre.com>,
Stephen Boyd <sboyd@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Arend van Spriel <aspriel@gmail.com>,
Ulf Hansson <ulf.hansson@linaro.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Vivek Gautam <vivek.gautam@codeaurora.org>,
Robin Murphy <robin.murphy@arm.com>,
Joe Perches <joe@perches.com>,
Heikki Krogerus <heikki.krogerus@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
Michal Hocko <mhocko@suse.com>, Al Viro <viro@zeniv.linux.org.uk>,
Jonathan Corbet <corbet@lwn.net>, Roman Gushchin <guro@fb.com>,
Huang Ying <ying.huang@intel.com>,
Kees Cook <keescook@chromium.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, Bartosz Golaszewski <brgl@bgdev.pl>
Subject: [PATCH 1/2] devres: provide devm_kstrdup_const()
Date: Mon, 27 Aug 2018 10:21:00 +0200 [thread overview]
Message-ID: <20180827082101.5036-1-brgl@bgdev.pl> (raw)
Provide a resource managed version of kstrdup_const(). This variant
internally calls devm_kstrdup() on pointers that are outside of
.rodata section. Also provide a corresponding version of devm_kfree().
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
---
include/linux/device.h | 2 ++
mm/util.c | 35 +++++++++++++++++++++++++++++++++++
2 files changed, 37 insertions(+)
diff --git a/include/linux/device.h b/include/linux/device.h
index 8f882549edee..f8f5982d26b2 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -693,7 +693,9 @@ static inline void *devm_kcalloc(struct device *dev,
return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
}
extern void devm_kfree(struct device *dev, void *p);
+extern void devm_kfree_const(struct device *dev, void *p);
extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
+extern char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp);
extern void *devm_kmemdup(struct device *dev, const void *src, size_t len,
gfp_t gfp);
diff --git a/mm/util.c b/mm/util.c
index d2890a407332..6d1f41b5775e 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -39,6 +39,20 @@ void kfree_const(const void *x)
}
EXPORT_SYMBOL(kfree_const);
+/**
+ * devm_kfree_const - Resource managed conditional kfree
+ * @dev: device this memory belongs to
+ * @p: memory to free
+ *
+ * Function calls devm_kfree only if @p is not in .rodata section.
+ */
+void devm_kfree_const(struct device *dev, void *p)
+{
+ if (!is_kernel_rodata((unsigned long)p))
+ devm_kfree(dev, p);
+}
+EXPORT_SYMBOL(devm_kfree_const);
+
/**
* kstrdup - allocate space for and copy an existing string
* @s: the string to duplicate
@@ -78,6 +92,27 @@ const char *kstrdup_const(const char *s, gfp_t gfp)
}
EXPORT_SYMBOL(kstrdup_const);
+/**
+ * devm_kstrdup_const - resource managed conditional string duplication
+ * @dev: device for which to duplicate the string
+ * @s: the string to duplicate
+ * @gfp: the GFP mask used in the kmalloc() call when allocating memory
+ *
+ * Function returns source string if it is in .rodata section otherwise it
+ * fallbacks to devm_kstrdup.
+ *
+ * Strings allocated by devm_kstrdup_const will be automatically freed when
+ * the associated device is detached.
+ */
+char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp)
+{
+ if (is_kernel_rodata((unsigned long)s))
+ return s;
+
+ return devm_kstrdup(dev, s, gfp);
+}
+EXPORT_SYMBOL(devm_kstrdup_const);
+
/**
* kstrndup - allocate space for and copy an existing string
* @s: the string to duplicate
--
2.18.0
next reply other threads:[~2018-08-27 8:21 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-27 8:21 Bartosz Golaszewski [this message]
2018-08-27 8:21 ` [PATCH 2/2] clk: pmc-atom: use devm_kstrdup_const() Bartosz Golaszewski
2018-08-27 10:39 ` Mike Rapoport
2018-08-27 12:28 ` Bartosz Golaszewski
2018-08-27 12:52 ` Mike Rapoport
2018-08-27 12:58 ` Bartosz Golaszewski
2018-08-27 13:04 ` Mike Rapoport
2018-08-27 8:42 ` [PATCH 1/2] devres: provide devm_kstrdup_const() Joe Perches
2018-08-27 9:01 ` Bartosz Golaszewski
2018-08-27 10:33 ` Mike Rapoport
2018-08-27 14:28 ` Bartosz Golaszewski
2018-08-28 6:32 ` Mike Rapoport
2018-08-27 12:47 ` kbuild test robot
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