| Message ID | 20180828093332.20674-4-brgl@bgdev.pl (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | devres: provide and use devm_kstrdup_const() | expand |
On Tue 28 Aug 02:33 PDT 2018, Bartosz Golaszewski wrote: > Provide a resource managed version of kstrdup_const(). This variant > internally calls devm_kstrdup() on pointers that are outside of > .rodata section and returns the string as is otherwise. > > Also provide a corresponding version of devm_kfree(). > > Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Regards, Bjorn > --- > drivers/base/devres.c | 38 ++++++++++++++++++++++++++++++++++++++ > include/linux/device.h | 3 +++ > 2 files changed, 41 insertions(+) > > diff --git a/drivers/base/devres.c b/drivers/base/devres.c > index 438c91a43508..48185d57bc5b 100644 > --- a/drivers/base/devres.c > +++ b/drivers/base/devres.c > @@ -11,6 +11,8 @@ > #include <linux/slab.h> > #include <linux/percpu.h> > > +#include <asm/sections.h> > + > #include "base.h" > > struct devres_node { > @@ -822,6 +824,28 @@ char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) > } > EXPORT_SYMBOL_GPL(devm_kstrdup); > > +/** > + * 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 > + * > + * Strings allocated by devm_kstrdup_const will be automatically freed when > + * the associated device is detached. > + * > + * RETURNS: > + * Source string if it is in .rodata section otherwise it falls back to > + * devm_kstrdup. > + */ > +const 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); > + > /** > * devm_kvasprintf - Allocate resource managed space and format a string > * into that. > @@ -895,6 +919,20 @@ void devm_kfree(struct device *dev, const void *p) > } > EXPORT_SYMBOL_GPL(devm_kfree); > > +/** > + * 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, const void *p) > +{ > + if (!is_kernel_rodata((unsigned long)p)) > + devm_kfree(dev, p); > +} > +EXPORT_SYMBOL(devm_kfree_const); > + > /** > * devm_kmemdup - Resource-managed kmemdup > * @dev: Device this memory belongs to > diff --git a/include/linux/device.h b/include/linux/device.h > index 33f7cb271fbb..79ccc6eb0975 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -693,7 +693,10 @@ 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, const void *p); > +extern void devm_kfree_const(struct device *dev, const void *p); > extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc; > +extern const 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); > > -- > 2.18.0 >
diff --git a/drivers/base/devres.c b/drivers/base/devres.c index 438c91a43508..48185d57bc5b 100644 --- a/drivers/base/devres.c +++ b/drivers/base/devres.c @@ -11,6 +11,8 @@ #include <linux/slab.h> #include <linux/percpu.h> +#include <asm/sections.h> + #include "base.h" struct devres_node { @@ -822,6 +824,28 @@ char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) } EXPORT_SYMBOL_GPL(devm_kstrdup); +/** + * 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 + * + * Strings allocated by devm_kstrdup_const will be automatically freed when + * the associated device is detached. + * + * RETURNS: + * Source string if it is in .rodata section otherwise it falls back to + * devm_kstrdup. + */ +const 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); + /** * devm_kvasprintf - Allocate resource managed space and format a string * into that. @@ -895,6 +919,20 @@ void devm_kfree(struct device *dev, const void *p) } EXPORT_SYMBOL_GPL(devm_kfree); +/** + * 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, const void *p) +{ + if (!is_kernel_rodata((unsigned long)p)) + devm_kfree(dev, p); +} +EXPORT_SYMBOL(devm_kfree_const); + /** * devm_kmemdup - Resource-managed kmemdup * @dev: Device this memory belongs to diff --git a/include/linux/device.h b/include/linux/device.h index 33f7cb271fbb..79ccc6eb0975 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -693,7 +693,10 @@ 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, const void *p); +extern void devm_kfree_const(struct device *dev, const void *p); extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc; +extern const 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);
Provide a resource managed version of kstrdup_const(). This variant internally calls devm_kstrdup() on pointers that are outside of .rodata section and returns the string as is otherwise. Also provide a corresponding version of devm_kfree(). Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl> --- drivers/base/devres.c | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/device.h | 3 +++ 2 files changed, 41 insertions(+)