Messages in this thread |  | | From | Bartosz Golaszewski <> | Date | Mon, 27 Aug 2018 11:01:57 +0200 | Subject | Re: [PATCH 1/2] devres: provide devm_kstrdup_const() |
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2018-08-27 10:42 GMT+02:00 Joe Perches <joe@perches.com>: > On Mon, 2018-08-27 at 10:21 +0200, 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. Also provide a corresponding version of devm_kfree(). > [] >> diff --git a/mm/util.c b/mm/util.c > [] >> /** >> * 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); > > Doesn't this lose constness and don't you get > a compiler warning here? >
Yes it does but for some reason gcc 6.3 didn't complain...
> The kstrdup_const function returns a const char *, > why shouldn't this? >
It probably should, I'll fix it for v2.
Bart
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